How To Get Back To the Moon In 4 Years -- This Time To Stay (scientificamerican.com)

Scientific American describes "a way to get to the Moon and to stay there permanently...to begin this process immediately and to achieve moon landings in less than four years." It starts by abandoning NASA's expensive Space Launch System and Orion capsule, and spending the money saved on private-industry efforts like Elon Musk's SpaceX and Robert Bigelow's Bigelow Aerospace. schwit1 quotes their report: Musk's rockets -- the Falcon and the soon-to-be-launched Falcon Heavy -- are built to take off and land. So far their landing capabilities have been used to ease them down on earth. But the same technology, with a few tweaks, gives them the ability to land payloads on the surface of the Moon. Including humans. What's more, SpaceX's upcoming seven-passenger Dragon 2 capsule has already demonstrated its ability to gentle itself down to earth's surface. In other words, with a few modifications and equipment additions, Falcon rockets and Dragon capsules could be made Moon-ready...

Major segments of the space community want every future landing to add to a permanent infrastructure in the sky. And that's within our grasp thanks to Robert Bigelow... Since the spring of 2016, Bigelow, a real estate developer and founder of the Budget Suites of America hotel chain, has had an inflatable habitat acting as a spare room at the International Space Station 220 miles above your head and mine. And Bigelow's been developing something far more ambitious -- an inflatable Moon Base, that would use three of his 330-cubic-meter B330 modules.
The article calls Jeff Bezos's Blue Origin rockets "a wild car" which could also land passengers and cargo on the moon and suggests NASA would be better off funding things like lunar-surface refueling stations, lunar construction equipment, and "devices to turn lunar ice into rocket fuel, drinkable water, and breathable oxygen."

Comments

Rockets are too expensive

[KeithCu]

With rockets it is still $100K - $1M per pound to get to the moon. We need a space elevator.

Re:Rockets are too expensive

[h33t l4x0r]

No we need a space escalator. Much more presidential.

Re:Rockets are too expensive

[Bruce Perens]

And a space elevator, of course, would only cost about a Trillion, and there's this little problem of it hitting something (we'd have to make Earth Orbit absolutely pristine and keep it that way) and there's a problem with the kinetic energy if it falls down. Sort of like having many atom bombs go off.

Maybe someday. But right now making rockets as cheap as they can be is a better idea. It's only $200K to fuel up a Falcon 9. We don't get the whole thing back in working order yet, but that would be a lot easier than making a space elevator.

Re:Rockets are too expensive

[KeithCu]

There are other detailed estimates for a space elevator that are around $10 billion. The people who throw around $1 trillion are trying to pick a number so big it prevents people from considering the feasibility. You definitely won't find any detailed breakdown that leads to something so insane.
Brad Edwards book covers all of the problem scenarios you laid out. He explains why it wouldn't be catastrophic if it did fall apart, and what needs to be done to prevent it. I agree we do need to make space more pristine, but we can clean things up, move the tether around, and repair it. It's all engineering work. This could have started in 1991, when carbon nanotubes were first discovered.

Re:Rockets are too expensive

[HanzoSpam]

First we need the materials to build one. Current materials science isn't quite there yet.

Re:Rockets are too expensive

[KeithCu]

We do need strong carbon nanotube fibers. A number of groups are making them now, but they aren't good enough yet. I think companies like Intel and others could product them of the proper quality if asked and given money.

Once we have some strong fibers, we need to spin them into arbitrarily-long threads like cotton, which we've been doing for centuries.

People aren't making this stuff because there isn't a need. Necessity is the mother of invention. Did you know that we couldn't go to the moon without making better alloys? Kennedy talked about needing improvements to materials sciences in his speeches.

Re: Rockets are too expensive

[KeithCu]

You obviously have done very little reading about the space elevator, AC. It's not a building, it's a tether. How much would it cost to make 50 thousand miles of 3-foot, paper-thin steel? It's not strong enough, but it gives you some idea of costs more than what you are throwing around.

The key to making it cheap is the bootstrapping mechanism that Edwards described in his book. What you do is launch into orbit just a seed string, and the first climbers will be small and actually strengthen the ribbon.

Re: Rockets are too expensive

[backslashdot]

What? What? Check your sources!! He didn't come up with either concept. He may have popularized space elevator though.

Re: Rockets are too expensive

[lgw]

Half the energy to obit at GEO comes from lateral acceleration. A space elevator would be a giant pendulum. And not a nice freshman-physics harmonic oscillator, but a nasty chaotic system with multiple modes of vibration. The energy stored in the system would increase with every payload until it destroyed itself, because there's no way to shed that unwanted energy - minimal friction, trivial air resistance, and so on.

Re: Rockets are too expensive

[drinkypoo]

Sounds like what's needed is a piezoelectric CNT. Lots of people are working on those, and several have been demonstrated...

Re: Rockets are too expensive

[KeithCu]

Definitely these are some interesting problems that people have already written about and studied.

Re: Rockets are too expensive

[khallow]

The energy stored in the system would increase with every payload until it destroyed itself, because there's no way to shed that unwanted energy - minimal friction, trivial air resistance, and so on.

There are a couple of approaches for dealing with that. First,use an extremely efficient propulsion system like electric propulsion to shed said energy and provide the mundane control needed for the system.

Second, you can run payloads down the tether at the same time as your run them up the tether. That would keep the energy balance stable.

Re:Rockets are too expensive

[DrXym]

There are other detailed estimates [spaceelevatorwiki.com] for a space elevator that are around $10 billion. The people who throw around $1 trillion are trying to pick a number so big it prevents people from considering the feasibility. You definitely won't find any detailed breakdown that leads to something so insane.

And people saying $10 billion aren't being serious either. Not even remotely.

Re:Rockets are too expensive

[ShanghaiBill]

And a space elevator, of course, would only cost about a Trillion

Since the material to build it doesn't exist yet, estimates of the cost seem a bit premature.

and there's this little problem of it hitting something

Most designs are for many fibers in parallel. So in an impact you would lose one out of N. Other designs are for a wide ribbon. Nobody is proposing a cylindrical pillar.

there's a problem with the kinetic energy if it falls down.

Since it has a counterweight, why would it "fall down" rather than "float up"?

Sort of like having many atom bombs go off.

Except it is 25,000 miles long, so it wouldn't all go off at once. It would be like a ribbon falling into the atmosphere. It would burn up 60 km up, and unlike a nuke, there would be no radiation or EMP. Chelyabinsk killed zero people, and that happened over land. A space elevator would have its base at sea near the equator.

Re:Rockets are too expensive

[KeithCu]

The numbers come from this book: https://www.amazon.com/Space-E... Their research is more serious than your unsupported opinion.

Re:Rockets are too expensive

[DrXym]

Their research is not serious at all if it comes to such a laughably low figure.

Re:Rockets are too expensive

[KeithCu]

You claim the cost estimate is wrong, but unfortunately you don't have any analysis supporting your comment. I suggest you read the book when you get a chance. It talks a lot about the cost, and other interesting issues.

Re:Rockets are too expensive

[KeithCu]

I wasn't asking you to write a research paper, I was just saying you provided no data or analysis. There is a big difference between a tunnel and a tether. In fact, they are almost opposites of each other aren't they?

Re:Rockets are too expensive

[silentcoder]

Indeed the Lunar Lander as it was built then could not have been done without the (recent) invention of Mylar. And they had to get creative at times - working under extreme limits on weight with an extremely precise set of requirements they had to meet. One of their biggest breakthroughs was tossing out the chairs. Have the crew stand upright - and that meant they could make the observation windows much smaller (since the pilot could stand directly in front of them as opposed to looking through them from a chair) - which cut the weight even more.

There is no doubt that a space elevator - if it's ever done - will require similar bouts of creative ingenuity which are utterly impossible to predict prior to the fact, it will be a case of engineers coming before a seemingly insurmountable conflict of requirements and getting creative to meet them all.

Re: Rockets are too expensive

[joh]

They only need fins because they have to steer a lot due to the inconsistencies of the atmosphere (wind and unknown pressure details). On the moon you need no fins, you can just aim a precise trajectory all the way down to the landing point.

Re: Rockets are too expensive

[Rei]

Are you under the impression that Dragon doesn't have an RCS?

Re:Rockets are too expensive

[Rei]

Quite true. The materials technology required is about two orders of magnitude away from actual materials technology, for starters. And among the countless other problems with space elevators, they're not actually all that efficient. Laser power beaming over those distances works out to single-digit transfer efficiencies, and microwave power beaming even less (microwave power beaming to space can be efficient, but only if the receiving antenna is huge). And no, you can't regularly hang things or run power wires up a space elevator - the mass of the cable has to be vanishingly small.

Active-suspended structures, such as Lofstrom loops, are a much better choice. Power transfer efficiency can be greater than 50% and current materials technology should be sufficient. They can also be designed to shoot payloads into any orbit (unlike space elevators), and work independent of the properties of the body in question, as well as having far greater throughput per unit mass. There's really no reason to choose a space elevator over a Lofstrom loop.

Re:Rockets are too expensive

[Rei]

I have read the book, and it's an absurd degree of wishful thinking. Just ignoring the huge number of things that they just gloss over or omit outright, the materials technology they're talking about is about two orders of magnitude away from what we actually have, and might even be physically impossible. Measurements of individual carbon nanotubes (let alone bundles, let alone bulk fibres) don't approach the strengths being talked about there. Colossal carbon tube does better on an individual tube basis, but again, we're nowhere even close to the materials tech required. And for what? For a massive, very low throughput, tiny safety margin, most-failure-modes-unaccounted-for, low-power-efficiency means of access to space? Colour me unimpressed.

If you want something better, I recommend looking into Lofstrom loops (launch loops). Current materials tech, high efficiency, high throughput per unit mass, no orbit restrictions, and works even on tidally locked bodies.

Re:Rockets are too expensive

[Rei]

Most designs are for many fibers in parallel. So in an impact you would lose one out of N.

Right. Because micrometeoroids/debris never strike edge on, and because only one fiber gets severed per impact, rather than the reality, which is that an impact is basically like a small explosion.

Re: Rockets are too expensive

[TheRaven64]

How much would it cost to make 50 thousand miles of 3-foot, paper-thin steel?

Assuming 'paper-thin' means 1mm thick, then that's around 75,000m^3 of steel, or about 680 Gg. At current steel prices, that's about $250-600m, depending on the kind of steel. The cost of getting that amount of steel to LEO (vastly cheaper than GEO, but assume that most of the mass doesn't have to go up to GEO) at current prices (assuming the cheapest possible launch) is just under $4tn.

The real question is why you care, because steel doesn't have anything like the tensile strength required to be a tether.

Re:Rockets are too expensive

[TheRaven64]

Cotton is strong because the individual threads are imperfect and so the strength comes from the friction between the fibres. Current nanotubes have almost no friction between the fibres, so when you spin them together you end up with something that simply falls apart when you pull on one end. There are research projects to try to improve this, but claiming that it's no different from cotton or wool implies a complete failure to understand the problems.

Re:Rockets are too expensive

[The Real Dr John]

Yeah, let's privatize everything. Nothing could go wrong with that plan. Elon will build a space elevator for very wealthy people to visit the moon for a fancy lunch, and be home by dinner. The rest of us will buy lottery tickets.

Re: Rockets are too expensive

[MachineShedFred]

And how do things get to GSO?

Hint: they don't just shoot them straight up from where they want it "parked."

Every single thing we've put in space gets there the same way: you start straight up in order to clear any launch infrastructure. Usually in less than a minute from liftoff, the rocket will perform a "pitchover maneuver" or "gravity turn" to take advantage of the fact that gravity is always pulling the rocket back down, and use that energy for guidance rather than drag. This results in the vehicle pitching from vertical to horizontal in a natural ascent profile that allows it to continue climbing in altitude, while gaining the horizontal velocity to remain in orbit.

Only once in orbit, does it continue to expend fuel to increase it's orbital altitude to where it's horizontal velocity would be synchronous with a particular point on Earth's surface.

Re:Rockets are too expensive

[MachineShedFred]

The US Government spends $10B on post-it notes. If it only cost $10B to never launch rockets again, don't you think it would have been done by now?

NASA's 2011 budget was $18.4B. If they could have really done this for $10B, they could have done it in like 3 years while maintaining all the science probes and other operations.

Oh wait, the materials to get this done at any price, up to and including the GDP of the entire fucking planet, don't exist. I forgot.

Re:Rockets are too expensive

[MachineShedFred]

Yeah, the difference is that we've been making tunnels for a while now, and they still blow through the budget regularly and leave the taxpayers on the hook for massive overruns.

Budgets are based on guesses that are informed by work that has been done before. Nobody has even remotely come close to a space elevator, so writing a budget for it is an exercise in deep thought comedy, especially since the materials necessary for such a thing only exist in the imagination. You could spend $10B just trying to come up with three feet of a material that could work as the tether, much less making 50,000 miles of it. Or getting it into orbit. Or having the orbital anchor to attach it to already there. Or any of the numerous other issues I can think of without ever reading any book on the subject.

Re:Rockets are too expensive

[halltk1983]

Because he's proven to us that he has absolutely no interest in using the rich early on to finance projects for the masses, which is why the model 3 is only available to the super rich, significantly more expensive than the Model S.

Re:Rockets are too expensive

[Oswald McWeany]

There are other detailed estimates for a space elevator that are around $10 billion.

That silly border wall is going to cost $20billion. I, find it highly unlikely we can build a Space Elevator anywhere near $10billion for several generations at least.

Re:Rockets are too expensive

[Oswald McWeany]

Genetically engineer sheep to grow carbon nanotubes instead of wool.

/ No, I am not being serious.

Re: Rockets are too expensive

[Shatrat]

The Falcon has small thrusters as well, which is what it uses to make final adjustments at low velocity.

Re: Rockets are too expensive

[Type44Q]

The fins clearly provide stability and guidance at higher, atmospheric speeds but their usefulness is likely in proportion to their speed [through atmosphere]... In any case, you make a good point; perhaps the Moon's far-shallower gravity well would make that less of an issue. One thing's for sure, however: Musk's rockets are presumably designed to retrobrake and land nearly empty of fuel and free from top-heavy upper stages containing luna-bound cargo...

Re: Rockets are too expensive

[Type44Q]

...and there's a problem with the kinetic energy if it falls down.

Depending on the location of the break, it might be more likely to fly away.

Re: Rockets are too expensive

[Type44Q]

Clearly this stuff will only begin to realize it's full potential when we figure out how to mass-produce monomolecular lengths of it.. and the only way to achieve that on a large scale will be to grow it as a crystal... perhaps the process can be accelerated with lasers (not a big fan of sharks... but if you've ever read Startide Rising, you already know that dolphins with lasers would be pretty fucking cool).

Re: Rockets are too expensive

[Type44Q]

If you've ever read The Moon is a Harsh Mistress - or visited Australia - you fnd yourself okay with that. ;)

Re: Rockets are too expensive

[vtcodger]

"You have to use small thrusters for control there"

Or steering vanes in the main rocket exhaust. No matter. This is space cadet territory. In SCLand all thing are possible if we can just get the idiots at NASA and its overseas equivalents out of the picture. Just a few minor mods to the technology and we are golden.

Right ...

There's the question of why anyone would think this is a good idea. In the history of manned space flight, there have been three 150B USD (adjusted to 2017 dollars) efforts. Apollo was pretty much a success. The Space Shuttle was pretty much a complete debacle although it is considered to be rude and impolite to mention that. And the ISS is, always has been, and probably always will be, pretty much worthless. A manned lunar colony will probably cost MORE than 150B and we'll end up with a dozen or two people living in a cave at the end of a long, expensive, supply line. There are any number of places here on Earth -- e.g. the deep sea floor -- where we could stuff a handful of people underground many orders of magnitude more cheaply and very likely more profitably.

Tell you what. Why don't we invest maybe 30B-50B USD in a fleet of lunar rovers and orbiting sensors and find out in detail what's on the moon? In a couple of decades we might know if there is any point in people going there permanently. And we probably won't kill anyone in the process.

Re:Rockets are too expensive

[stabiesoft]

Agree totally, when has any big infrastructure project come in under budget and on time? They want to bury I-35 here in austin and keep quoting a stupid low estimate. Adding a lane on loop1 here above ground cost more than their estimate of burying 4, and adding that lane is now a year late and looks like will be at least one more year late. And then there is the flood tunnel they are still trying to finish which went 2 or 3X over budget and is still not done. As you say, this is all stuff we have done before. How badly could something go that has never been done before?

Re:Rockets are too expensive

[OrangeTide]

if the terminal velocity of the materials is low, then it won't impact the Earth with much speed.

Re: Rockets are too expensive

[OrangeTide]

Carbon costs less than steel for the same volume of material, as it is less dense and more abundant in nature.

Now the processing you have to do in order to make carbon into a useful cable is not something we've managed to do at that scale yet. But I suspect it's going to become cheap once we have it figured out.

Re:Rockets are too expensive

[OrangeTide]

Nobody has worked out the details yet.

Re: Rockets are too expensive

[OrangeTide]

Those aren't so great for lifting out of a gravity well. They don't have as much thrust as a chemical rocket. But a nuclear rocket is good for going long distances because you can run it for a very long time. We could get to Mars and back much more quickly with one, and the spacecraft would be lighter as we wouldn't have to carry a bunch of propellant to Mars.

Re: Rockets are too expensive

[stjobe]

There are any number of places here on Earth -- e.g. the deep sea floor -- where we could stuff a handful of people underground many orders of magnitude more cheaply and very likely more profitably.

The average depth of both the Atlantic and the Pacific oceans is roughly 4 km. At that depth, the pressure difference to a 1-atmosphere habitat is about 400 atmospheres. Compare that to the moon, where the difference is merely 1 atmosphere of pressure.

There have been many more people on the moon than have been down on the deep sea floor. Twelve people have walked (and some even drove cars) on the moon, but only three people have ever been down to the bottom of the Marianas trench (and none of those ever exited their vehicle).

In short, exploring and living in the depths of the sea is magnitudes harder (and therefore expensive) than exploring and living on the moon due to pressure differentials alone.

Re: Rockets are too expensive

[religionofpeas]

There have been many more people on the moon than have been down on the deep sea floor.

I'm sure the size of the budget had something to do with that.

In short, exploring and living in the depths of the sea is magnitudes harder

We choose to go to the sea floor in this decade and do the other things, not because they are easy, but because they are hard.

Re:Rockets are too expensive

[KeithCu]

You'd still need rockets for humans. The space elevator is just for cargo.

NASA could have built an elevator if they had tried, but they are a political organization as much as a scientific one.

It's true that the materials don't exist, but at the same time, necessity is the mother of invention. There isn't a lot of research taking place for something which is only needed for the space elevator. Meanwhile, there's been a ton of materials science advancement since the 1960s that has put a workstation into a cellphone.

Re:Rockets are too expensive

[tehcyder]

You claim the cost estimate is wrong, but unfortunately you don't have any analysis supporting your comment. I suggest you read the book when you get a chance. It talks a lot about the cost, and other interesting issues.

I could write a book claiming I could manufacture a fully functional electric car for $49.99 retail. You wouldn't need to read it to know that it was nonsense.

Re:Rockets are too expensive

[tehcyder]

Oh wait, the materials to get this done at any price, up to and including the GDP of the entire fucking planet, don't exist. I forgot.

That's just another engineering problem.

Re:Rockets are too expensive

[tehcyder]

Genetically engineer sheep to grow carbon nanotubes instead of wool.

/ No, I am not being serious.

It sounds a hell of a lot more plausible than the people here saying you could build a space elevator with what's in NASA's petty cash tin.

Re: Rockets are too expensive

[KeithCu]

Thanks for the steel numbers!

Of course it isn't strong enough, however, it can be helpful to have some comparable numbers when people throw around $1 trillion for costs of the space elevator and call it a "building".

Note your launch cost analysis is not useful: the entire ribbon doesn't need to be put into space. The best and cheapest way to build the elevator is with a seed string.

Re:Rockets are too expensive

[KeithCu]

That assumes you are capable of writing a book, and you are comfortable lying, or are extremely incompetent.

However, imagine you saw a book about how someone could get a fully-functional RC helicopter for $12. Would that be nonsense?

It is pretty amazing how many advanced and cheap technologies exist today and yet still many technical people insist carbon nanotubes are totally impossible. Meanwhile, they have workstations packed into a tiny device they carry around in their pocket.

Re: Rockets are too expensive

[Type44Q]

Geez, it'snot going to be about raw materials cost, whether you're talking apples (Fe) or oranges (carbon).

Re: Rockets are too expensive

[Type44Q]

It would burn up 60 km up

Wouldn't it lack the lateral (orbital) velocities needed for that?

Re: Rockets are too expensive

[houstonbofh]

One thing's for sure, however: Musk's rockets are presumably designed to retrobrake and land nearly empty of fuel and free from top-heavy upper stages containing luna-bound cargo...

With 6 times the weight and distance. What you are talking about is simply a math problem.

Re: Rockets are too expensive

[TheRaven64]

Note your launch cost analysis is not useful: the entire ribbon doesn't need to be put into space. The best and cheapest way to build the elevator is with a seed string.

My launch cost numbers were to LEO - GEO is a lot more expensive - and so was only ever intended as a ballpark figure. The seed string itself needs to be lifted and I'd be very surprised if you could do that for under a billion. Sufficient strength of carbon nanotubes to be self supporting (based on theoretical models - we still can't actually build them) would come in above that for launch costs.

Re: Rockets are too expensive

[lgw]

First,use an extremely efficient propulsion system like electric propulsion to shed said energy and provide the mundane control needed for the system.

Adding more energy seems unlikely to help.

Second, you can run payloads down the tether at the same time as your run them up the tether. That would keep the energy balance stable.

Again, not a freshman-physics pendulum. We're not talking spherical cows uniformly radiating milk here. The upwards and downwards payloads would be in different places on the tether (except momentarily) and so would each be doing there own thing to complicate the system.

You might find it entertaining to watch some youtube videos of 2- and 3-section pendulum, elastic pendulums, and so on. They don't work and play well with others.

Re: Rockets are too expensive

[liquid_schwartz]

The tiny little ISS in low orbit cost in excess of 100 billion, and you're telling me you can build a 44 thousand mile tall geosynchronously orbiting building for 10 billion? 1 trillion would be cheap.

Just to be clear, for what's been piddled away since 9/11 we could have had *two* of these at the $1 trillion price tag. It's definitely possible.

Re: Rockets are too expensive

[lgw]

You do realize the context here is "space elevator", right? Or were you emphasizing my point? (If so, sorry, /. is so confrontational these days.)

Re: Rockets are too expensive

[WalksOnDirt]

Umm, maybe. What is RCS?

Re: Rockets are too expensive

[khallow]

Adding more energy seems unlikely to help.

Taking away said energy OTOH is a different matter. That's something that thrusters at the far end of the space tether can do.

Again, not a freshman-physics pendulum. We're not talking spherical cows uniformly radiating milk here. The upwards and downwards payloads would be in different places on the tether (except momentarily) and so would each be doing there own thing to complicate the system.

But in a matter that is significant less worse than your original problem.

You might find it entertaining to watch some youtube videos of 2- and 3-section pendulum, elastic pendulums, and so on. They don't work and play well with others.

So what? We know how to control stuff a lot more complicated than that.

Re: Rockets are too expensive

[OrangeTide]

In the necessary volumes it's a factor. If you consume some significant percentage of annual steel production making cables for your project, that's going to be a problem.

The processing of steel is not likely to change much in cost, a big chunk of the cost is energy (at least it was when I worked in a steel mill). The processing of carbon-based nanomaterials is likely to change dramatically over the new few decades. It's incredibly expensive right now, as to be expected from any nascent technology, but it should scale out very well and have very low energy costs for manufacture. First we need ways to make carbon nanotubes that has a good yield, I believe currently yield is around 1%, which obviously is not going to be practical for producing 36 megameters of cable.

Re:Rockets are too expensive

[rgbatduke]

Sure, one built with imaginary and probably impossible materials, ignoring petty little details such as the non-equivalence of the accelerating inertial reference frames at the ground and top (not to mention all of the way up).

Here's a hint for you (and everybody else that proposes this absurdity):

a) Equatorial speed relative to center of Earth: 460 meters/second or just over 1000 mph. Around 1.35 x the speed of sound.
b) Speed at geosync orbit at R \approx 6 R_e: 6 x 460 = 2.78 km/sec.

Or if you prefer energy:
c) Total mechanical energy of 1 kg object sitting at "rest" at equator: = GMm/R_e + 1/2 m v^2 (using v from a) above): -64 MJ/kg
d) TME of same object sitting at "rest" in geosync orbit \approx -10 MJ/kg

And the worst of them all, angular momentum:
e) Total z-directed angular momentum of 1 kg on equator = mR_e v (from a): 2.9 x 10^9 kg-m^2/sec
f) Ditto at geosync (36x larger): 105 x 10^9 kg-m^2/sec

So, to lift something up from the surface to geosync, one has to:

1) Increase its tangential speed -- tangent to great circles around the axis -- by a factor of 6 as it rises.
2) Increase its mechanical energy by 50 million Joules per kilogram of payload.
3) Increase its angular momentum by well over 100 BILLION kg-m^2/sec. This is done by means of the same torque required to increase its tangential speed.

Now, let's ignore all the picky details, such as how to make a cable that can support its own weight hanging to the ground from geosync orbit -- where if we not unreasonably insist on it having a specific gravity around 1 (same as water) then we need the weight of a cable well over 5 R_e long (at least, if you want to be able to apply tangential force via the same cable) so let's START with 5 R_e -- in round numbers 5 x 6.4 x 10^6 = 32 million meters long (yes, that is million). Figuring the top tension is a bit tricky and involves an integral, but the result of the integral is that the tension at the top is the change in potential energy per kilogram times the density times the cross sectional area: GM_e\rho \Delta A (1/R_e - 1/6R_e) = 50 MJ/kg x 1000 kg/m^3 \Delta A.

This is 50 x 10^9 Newtons times the cross sectional area (in m^2), and is most easily expressed by dividing out the area to get:

Requirement: 50 GPa minimum tensile (yield!) strength

The highest tensile yield strength observed in any material (so far) is less than 5 GPa. Carbon nanotubes have a tensile strength reported as high as 63 GPa, but this is not a yield strength and could not support a sustained load, certainly not safely. So far, then, we are (honestly) well over an order of magnitude short of the required yield tensile strength required for a cable to JUST support its own weight "hanging" from the vicinity of geosync orbit. One cannot force a lower orbit USING such a cable, and higher orbits (with more cable) that are still geosync require more tension and make little sense. But hey, this is science fiction, let's PRETEND that we can make carbon nanotube cables 32 million meters long that have a yield strength of (what the hell) 500 GPa -- our 50 plus a generous margin of safety. Let's not worry about what we are going to wrap our cable around as far as pulleys go at the ends, how we will build bearings etc -- heck, that's just "engineering". Heck, anybody can design a pulley that can support a 64+ million meter long cable (looped, remember! -- oops, there goes a factor of 2 of our ten already!) that has been looped and joined "perfectly" without the slightest defect that might lower the yield strength to (say) 5 GPa and lead to catastrophe! Engineering is just drawing a picture! Why worry about what actual material you might make it out of that the cable won't cut right through (if it is thin) or crush (if it is thick) or wear out in short order as it operates?

Let's just imagine how it might WORK. After all, the whole idea is that you send a payload up on one side of the loop at the same time you send some coun

Re:Rockets are too expensive

[wikdwarlock]

Nanotubes are not yet an engineering material in the sense needed for space elevators. They only allow space elevator tethers if you can have very long tubes, with aspect ratios like a million or billion to one. Right now, nanotubes used in experiments and a few limited production materials are microns or possibly millimeters long. Space elevators need meters or kilometers-long nanotubes to capture the exceptional strength of the molecule. As the length gets shorter, you're relying more on the matrix (material surrounding and binding the nanotubes) for strength, and there's no matrix material that gets close to the nanotube performance.

Re:Rockets are too expensive

[Gavagai80]

There are other detailed estimates [spaceelevatorwiki.com] for a space elevator that are around $10 billion

How can we take an estimate seriously which says that a space elevator will be an order of magnitude cheaper than California's high speed rail?

Re:Rockets are too expensive

[Jeremi]

With rockets it is still $100K - $1M per pound to get to the moon. We need a space elevator.

Nah, what we really need is a transporter. Compared to a space elevator, it's cheaper, faster, safer, and at this point, just as technically feasible to build.

Re: Rockets are too expensive

[hey!]

geosynchronous satellites: when the sun circulates over the north pole and it causes the satellite to exhibit the figure 8 orbit

geostationary : are fixed (fiction) stations , allegedly ground based

That is the most garbled explanation I've ever heard of geosynchronous orbits.

A geosynchronous orbit is one with a period that exactly matches the Earth's rate of rotation.

Geostationary orbits are a special case of geosynchronous orbits where the angle inclination of the orbit to the Earth's equator is zero.

So: a satellite in a geosynchronous orbit that is also geostationary appears to continually hover 22,236 miles above some point on the Earth's equator. If it is in a geosynchronous orbit that is not geostationary, it will appear from the earth to drift north and south of the celestial equator, tracing a figure 8 against the background stars over the course of one Earth rotation.

Of course in both cases the satellite would actually be following an elliptical (in fact almost perfectly circular) path around the Earth. The "stationary" or "figure 8" thing is simply a trick of perspective -- the way car in the next lane traveling at the same speed appears not to be moving.

Yeah, most of you knew all that. But insofar as there's an explanation here, it oughtn't be gibberish.

Re:Rockets are too expensive

[Jeremi]

Seems to me that no serious estimate is possible until you know with some degree of certainty what material you're going to be using.

In the best case, you'd use some magic material with an infinite strength-to-weight ratio, and send the whole thing up inside a a 20-pound cubesat for practically no cost.

In the worst case, it wouldn't matter how much you spend, because the material would never be able to support its own weight no matter how big the ribbon was.

The actual case is somewhere between those two extremes, but without knowing where, you can pick any cost estimate you want, and it won't be any more meaningful than any other cost estimate you might choose.

Re: Rockets are too expensive

[hey!]

I think we were thrown off point by AC, who doesn't seem to grasp that physical systems can be described in alternative reference frames.

I think he is trying to say that there is no such thing as a geostationary orbit, because satellites in that orbit are actually tracing out a circular (or even more pedantically, spiral) path.

I believe the responder was trying to point out, using the example of a rocket ship travelling to geosynchronous orbit, that "stationary" is a kind trick of perspective when viewed from the frame of fixed stars.

Of course in the rotating frame of where we happen to be sitting on the Earth geostationary satellites are indeed actually stationary.

Re:Rockets are too expensive

[Shotgun]

Or get a job on the star liner to serve the wealthy, and see space that way.

The alternative is for the government to do it, and have it locked up for "heroes", and you only have a chance to see it if you are from a "protected class", so that you can be a propaganda piece.

Just think what the airlines would be like if the airlines had not been privatized.

Re: Rockets are too expensive

[Rei]

Reaction Control System.

Re:Rockets are too expensive

[Rei]

1) It's about 7% of what NYC consumes, not 10%. NYC being only a tiny fraction of total US demand, which is in turn just a fraction of world demand. Global electricity production averages around 15 TW.

500MW is a moderate sized power plant. Not even a large one. It's nothing that impressive. Cost of such a plant is 500M-$1,5B, which is nothing by rocketry standards.

2) That's not 500MW to stand idle; that's 500MW to launch 175 tonnes per day. That's 68.5kWh per kilogram. $7 of electricity per kilogram. Oooh, what a terrible waste of power.

3) If that's too much, the larger version uses significantly less per kilogram.

Is there some reason to get so much mass out of this gravity well

Do you seriously have to ask what sort of market there would be for ~$800 tickets to orbit? I'm sorry, but we're not talking "for the wealthy", we're talking for everyone at those prices.

Re:Rockets are too expensive

[The Real Dr John]

Oh, so then it is better to send rich folk than heroes? Got it. I would never have come up with that myself. Government bad, capitalist good. Got it. That sounds like a really great idea. And it had been working out so well for us regular folk.

Re:Rockets are too expensive

[KeithCu]

It's amazing how many people think nanotubes are impossible yet carry workstations in their pocket. If only they knew all the materials sciences work needed to make that happen.

Re: Rockets are too expensive

[RiscIt]

And if they ever break down we can have space stairs. How convenient is that?

Re: Rockets are too expensive

[hey!]

You are confusing two different coordinate systems. Both can be true at the same time -- corkscrews and figure 8 -- but not in the same coordinate system.

Looked at from the outside, in the so-called "Galilean frame", you would see the satellite making corkscrews. Another observer on the surface of the earth would see the satellite tracing a figure 8, in his coordinate system.

Since your two coordinate systems are rotating with respect to each other, the parametric equation of motion looks very different. A fixed point in one necessarily traces some kind of spiral in the other.

Re: Rockets are too expensive

[lgw]

Ah, sure, non-inertial reference frames are tricky.

Re: Rockets are too expensive

[Type44Q]

What you are talking about is simply a math problem.

Far be it for me to point out the obvious but a math problem, not so simply, could very well mean an engineering problem... and an engineering problem could require a different design.

Re: Rockets are too expensive

[Shirley Marquez]

Nuclear thermal rockets are inadequate for lifting out of a gravity well. Nuclear pulse rockets (Project Orion: https://en.wikipedia.org/wiki/... ) are another matter, but they have this little problem of nuclear fallout that make them unsuitable for planetary liftoff.

Re:Rockets are too expensive

[Shirley Marquez]

Just sending rich people and just sending heroes is about equally bad. But NASA didn't only send heroes to space; it sent up a lot of scientists, though mostly that was later in the Space Shuttle and ISS era. The question is how to get to the point of sending up more ordinary people, and it's not clear to me whether we will get them more effectively with a government program or with private launches.

The early phases of space exploration would have been harder to accomplish without government involvement. They were about national pride, long term scientific research, and national defense - all things that either pay off with event horizons that are too far off for most private investors (the long term research) or don't pay at all. There is plenty of money to be made by taking government defense contracts, but it's hard to figure out how you could make money as a private business with no government involvement, anarcho-capitalist fantasies notwithstanding.

The Apollo program spent $20 billion in dollars of the time ($122.5 billion in 2017 dollars) to launch 33 people, for a total cost of $3.7 billion per astronaut in current money. Not even the super-rich would pay that much to go to space. Even if you absorbed a lot of that as an R&D expense and charged a mere $1 billion I don't think there would be any takers.

But we have now reached the point where private launch companies are feasible. There is plenty of business for the routine work of launching satellites, and costs are now low enough that a few people can afford space tourism. It might be feasible to finance a moon shot with a combination of corporate sponsors (presumably in exchange for advertising), crowdfunding from space enthusiasts, and selling a couple of seats on the mission. (You can't sell all of them because you need a pilot/mission commander and you certainly want to send a couple of scientists.)

Re:Rockets are too expensive

[Shirley Marquez]

False equivalence. We're about an order of magnitude away from having good enough materials to build a space elevator, but huge amounts of progress have been made in materials science over the years and we know of materials that might be able to fill the need with further development. I think it's more like 70 years off than 7, but at least we an imagine a path to get there from here. A transporter, on the other hand, requires one of three things:

Path #1 is to invent some new physical principle that lets you open mini-wormholes to get people and things from point A to point B.

Path #2 is to develop a different new physical principle that lets you take people apart into component molecules, move those molecules to another location in a particle beam, and then put the people back together at the other end. The visual evidence suggests that the Star Trek transporter works by this method.

Way #3: somehow completely encode the entire molecular structure of a person at one end (which would require orders of magnitude more computing power than the entire planet currently possesses), send the encoded information to the other end (which might involve sending many terabytes of data... or it might be possible to do much more efficiently, we don't know), and assemble a new copy of the person at the other end (which would require large amounts of energy to rearrange atoms). This method would require a receiver at the other end, so it couldn't be used to transport people to empty planets and the needed raw materials must be available at the receiving end. The energy consumption would be substantial. It also assumes that fully encoding the physical structure of the human body is sufficient; if it turns out that there is some kind of intangible soul after all, all the plans are out the window. And finally, there are ethical questions, because this method would make it possible to COPY people as well as move them.

Only the third is even close to being an extrapolation of current science rather than requiring the discovery of new principles that may not even be possible to accomplish in this universe, and the third one requires singularity-level computer science as well as advanced nanoconstructors. Basically, we don't even know enough about any of those possibilities to venture a guess about how long it will take for one of them to happen.

Re:Rockets are too expensive

[The Real Dr John]

Whenever private, for profit companies get involved in anything, the problems increase; the pollution, the industrial accidents, and the corruption. I am not saying the government does things better, sometimes it does, sometimes it doesn't. I am just saying that the entire privatization movement, which is being driven by the wealthy, not the working people, is an attempt to reign in democracy, and facilitate oligarchy. There is currently no money to be made in space, so any private effort is going to rely on gimmicks including offering very rich people an orbit or two. That is not space exploration, that is not building a sustainable infrastructure for space travel, and it isn't doing the public any good.

With all their faults, I am sticking with the NASA model until they can actually mine asteroids, moons and planets. Otherwise, it is just shooting stars to the stars for profit.

Re: Rockets are too expensive

[suutar]

Any given portion of it has the same lateral velocity as a satellite with a 24 hour period; the center of gravity will be 23k miles (from the surface; 27k miles from the center of Earth), and doing about 3km/sec (mach 9). That's three times as fast as the SR-71, and that got hot enough to deform (in an expected fashion; the fuel tanks leak until friction heat causes the panels to expand). The sources I found said that friction got it up to 232+ Celsius; the cockpit was at 338C. Carbon fiber ignites about 300C, so let's say that SR-71 speed is enough to cause burning in atmosphere to elevator materials. That's achieved at 9k miles from earth's center or 5k miles up.

So if the elevator breaks up, the lowest levels won't be moving fast and will fall into the ocean (assuming they did the sane thing and based it in an ocean). The higher levels will be doing a good clip, and by the time they get down to hit atmosphere will be doing more, and should burn up nicely. The stuff below 5k miles but above say 100 miles is where it gets interesting. Something at 5k miles altitude doing 24 hour orbits is doing about 1km/sec. Since it was staying up before, assume it starts with 0 up/down velocity. Ignoring lateral effects it'll fall to the surface in 1260 seconds. Lateral velocity would tend to carry it 1260km east, but the earth's rotation will eat up about 580km of that, so really it'll only go about 700km east of the base, less than 500 miles.

Re: Rockets are too expensive

[khallow]

The tiny little ISS in low orbit cost in excess of 100 billion, and you're telling me you can build a 44 thousand mile tall geosynchronously orbiting building for 10 billion?

The ISS was put with the Space Shuttle. That alone added tens of billions of dollars to the cost. Meanwhile most of the launch cost of the tether (which would be using a much cheaper launch vehicle from the future rather than one of the most expensive vehicles of the past) would be the initial tether, with future tethers riding off of the cheap launch costs of the first tether.

Second, the ISS is comprised of a bunch of really expensive, custom-made, one-off pieces. Meanwhile most of the tether is a cable which only differs along its length in width. That allows you to apply substantial economies of scale since you're making 44k miles of the thing.

Re: Rockets are too expensive

[khallow]

Something like NASA's asteroid capture would be adequate to get a counterweight of the necessary size on that other end.

Re: Rockets are too expensive

[LifesABeach]

Oooooooh, is Moderator desperately hoping it can lick Trump's ass? Kiss kisssss, LOL

Re: Rockets are too expensive

[eric_harris_76]

It's been quite a while since I've watched CNN, but that sounds about right.

Re:Rockets are too expensive

[Coren22]

https://www.google.com/aclk?sa...

What is such a big deal about that?

Not Happening Anytime Soon

[Anonymous Coward]

The cost of a manned moon base was and is astronomical. Moreover, there remain substantial unsolved problems, particularly with regard to moon dust which is razor sharp, microscopic and gets into everything, quickly degrading gaskets, lenses and other dust sensitive surfaces. Finally, there's nothing there valuable enough to justify the expense at this time.

Re:Not Happening Anytime Soon

[Rei]

That's the biggest concern I have. People tire of ongoing expenses. ISS seemed neat at first; now everyone hates it. Why would a moon base fare differently?

Long-term presences in space need to very quickly cut ties with earth, on order of greatest resource dependencies down to smallest resource dependencies. Aka, first things like oxygen, propellant, etc, then to industrial chemicals, of increasingly smaller quantities, with increasingly diversified manufacturing facilities, with very complex/low volume chemical feedstocks and manufacturing processes coming last. Cutting all ties is a process that would take centuries. But you can start with the low hanging fruit, bit by bit, and keep stockpiles of everything needed for maintenance that you can't produce locally.

Unfortunately, running counter to this is expansion. Because if you double the size of your operations, you also double your resource demands. So you need to improve resource independence at a faster rate than you grow.

Part of the problem with the moon is that it's just not a great place for ISRU. Volatiles are rare. We've never even sampled any moon that aren't depleted in volatiles, although there's some data to suggest that various volatiles might be scattered in permanently shaded areas (all of them, in the same place? That's a good question). Surface mineral diversity is limited - primarily light, non-volatile elements. Oxygen is at least widely abundant, but locked up tightly. And while the moon offers short transit times, it's surprisingly not that advantageous concerning delta-V. You can't aerocapture there, landing is fully powered (no parachute deceleration), and to get there you have to already be on such a high apogee orbit that it's not much more energy to go into a Mars transfer. Gravity is less and night is two days long. There are a couple "maybe" peaks of eternal light, but that doesn't mean that they're colocated with volatiles; the last I looked into it it looked like the closest suggested find of water was dozens of kilometers away from the nearest such peak, which would be quite the commute (and thus low throughput / high wear).

The moon is certainly the "cautious" option; emergency returns / resupplies are easy there, and communication fast. Its main value appears to be a testing ground for systems while minimizing risk. But it's not a very appealing place from a settlement perspective.

Of course, I prefer Venus to Mars, but that's neither here nor there ;) I'd like to see a parallel program for both, as the same sort of booster and transfer stage can be used for both, so it's only habitat / ascent stage development costs that are doubled. And once you get past the differences in feedstock sources, production industrial processes converge (Venus advantaged by the higher power availability and easier ability to get rid of heat - excepting in the case of cryogenics, where Mars holds the advantage)

Re:Not Happening Anytime Soon

[Fire_Wraith]

Not at this time, perhaps - but it's worth noting that Bigelow aerospace is owned by a hotel magnate, because he's interested in hotels in space.

And why would you want to stay at a hotel on the moon? Well, besides the view and bragging rights, the swimming pool would be awesome: https://what-if.xkcd.com/124/

Re: Not Happening Anytime Soon

[Type44Q]

Electrostatic seals/rings on all locks/hatches/ports of entry...

Re: Not Happening Anytime Soon

[Type44Q]

Perhaps a couple metal-rich asteroids could be nudged into orbit around the moon. I wonder, is there a particular orbit around the moon that guarantees [nearly] constant sunlight... if so, that might be the perfect place to slap a zero-g smelting/refining/manufacturing facility.

Re: Not Happening Anytime Soon

[religionofpeas]

Apart from the energy required to move the asteroids in the first place, there's also a lack of stable lunar orbits. You don't want the asteroid to escape, and get smashed into the Earth at some point in time.

Re:Not Happening Anytime Soon

[Anonymous Coward]

The cost of a manned moon base was and is astronomical.

I see what you did there, it's out of this world.

Re: Not Happening Anytime Soon

[Type44Q]

Slap some solar sails/ion thrusters/em drives on them and bide your time? Perhaps Lagrange Points would make more sense.

Re: Not Happening Anytime Soon

[Geoffrey.landis]

Lunar distant retrograde orbit (DRO) turns out to be pretty stable. It's the close orbits that are unstable.
http://ccar.colorado.edu/asen5...
http://www.sciencedirect.com/s...
Another virtue of lunar DRO is that when they do decay, they tend to drop into the moon or to escape, not down to the Earth

Re:Not Happening Anytime Soon

[Trogre]

ISS seemed neat at first; now everyone hates it.

Who does?

No Dragon 2 Soft Landing Yet

[Bruce Perens]

Dragon 2 isn't built yet. The escape test was a boilerplate capsule more like a Dragon 1 than 2. Dragon 2 has not demonstrated a soft landing, because it's not built yet. That was the Falcon 9 first stage.

Also, you can't get Dragon 2 down to the Moon and back up on it's own. Not enough delta-V. You would need to have Dragon ride on top of something that can hold enough fuel. Like a larger version of the Apollo Service Module.

The Command/Service module was originally intended to land on the moon and return without the LEM, before NASA bought the LEM concept, and was overpowered for the mission it got. Dragon is larger and heavier, but a lunar landing one would probably look a lot like an Apollo Command and Service module, and legs.

And yeah, Orion: I'm Not on Board. Big expensive obsolete rocket with no mission that makes sense.

But good luck getting Elon Musk to focus on the practical and eminently desirable target of the Moon. He isn't interested. It's only Mars for Elon.

I try not to watch all of the Mars Colonial Transport speculation. Falcon 9 and Dragon are great, and they're here, and we could do so much with them.

Re:No Dragon 2 Soft Landing Yet

[religionofpeas]

But good luck getting Elon Musk to focus on the practical and eminently desirable target of the Moon. He isn't interested. It's only Mars for Elon.

There's nothing practical about the Moon. It's a dead dusty rock in a vacuum.

Re:No Dragon 2 Soft Landing Yet

[religionofpeas]

You could build a ground based weapon on the far side of the moon that always faces away from Earth

That's not very useful when all our enemies are here on Earth.

Re: No Dragon 2 Soft Landing Yet

[WindBourne]

Wrong about musk. In order to get BFR costs down, he has to launch monthly and he knows it. Mars will have multiple launches and then a 20 month wait. He will be happy to throw up 300 tonnes monthly for the moon

Re: No Dragon 2 Soft Landing Yet

[Bruce Perens]

Do you think Mars is the land of milk and honey?

Re: No Dragon 2 Soft Landing Yet

[religionofpeas]

Not at all, but it's Elon's plan and he's using his own rockets, so more power to him.

Re: No Dragon 2 Soft Landing Yet

[lgw]

Venus is the only target that makes sense. Much easier in the long run than Mars or Luna, but the initial stake is high, as you have to get a fairly sizeable dirigible there to start things off. Once you do, though: proper gravity, proper pressure, reasonable temps, plenty of atmospheric rad shielding, plenty of oxygen, trace elements there for the scavenging so you don't need a "perfect" sealed colony that would never work. It's a great idea, really.

Re: No Dragon 2 Soft Landing Yet

[religionofpeas]

What, exactly, is the purpose of hanging in the clouds of Venus ? You might as well live in a cave here on Earth and paint the walls white. Or in a big submarine in the ocean. I'm not exactly seeing volunteers for that.

Re:No Dragon 2 Soft Landing Yet

[BarryHaworth]

But good luck getting Elon Musk to focus on the practical and eminently desirable target of the Moon. He isn't interested. It's only Mars for Elon.

The SpaceX launch manifest begs to differ. Elon Musk may have Mars as his ultimate goal and be developing the hardware to do it, but in the mean time he is busy launching communication satellites, Iridium satellites, space station resupply, military payloads - anything and everything that people will pay him to launch. If NASA were to foot the bill, he'd be more than happy to land on the Moon.

Or to put it another way, you don't need luck, just money.

Re:No Dragon 2 Soft Landing Yet

[khallow]

But good luck getting Elon Musk to focus on the practical and eminently desirable target of the Moon. He isn't interested. It's only Mars for Elon.

He's interested in paying customers. Maybe someone who is interested in lunar development should buy some Falcon 9 or Heavy launches and just make it happen?

Re:No Dragon 2 Soft Landing Yet

[Anonymous Coward]

And yeah, Orion: I'm Not on Board. Big expensive obsolete rocket with no mission that makes sense.

Orion isn't a rocket. SLS is the big expensive rocket you're thinking of with no sensible plan. Orion is just the capsule they're going to put on the top of SLS. Of all the parts of system that NASA is building, Orion is probably the most worthwhile. That's not to say it's perfect, but a sufficiently good design that it's worth building. SLS isn't worth building, but if they were to stick Orion on top of another rocket, it would be good.

But good luck getting Elon Musk to focus on the practical and eminently desirable target of the Moon. He isn't interested. It's only Mars for Elon.

He has laid a out very good case for his reasoning behind that. His main point to counter your argument above would be that the Moon isn't actually as practical as you'd think compared with Mars. I happen to agree with him on that reasoning, although I don't see why it should be a case of either-or. We should be aiming to explore and colonise both of them.

I try not to watch all of the Mars Colonial Transport speculation. Falcon 9 and Dragon are great, and they're here, and we could do so much with them.

Yeah, MCT should be considered vaporware until they start to produce hardware. I'm rooting for them to do it, but it isn't going to happen any time soon. There's a lot of R&D still to be done, and right now SpaceX needs to concentrate on the short term -- avoid any more accidents, start re-using some rockets, and get Falcon Heavy flying.

Re: No Dragon 2 Soft Landing Yet

[Rei]

He's first going to have to learn how to launch that fast. That's one area where SpaceX hasn't had much success - getting its launch turnaround times down. Hopefully they will in the future. Also, since an explosion takes them out for half a year or more (regardless of turnaround times), they better up their reliability by an order of magnitude or more, since each increase in launch rate means more possible rockets that can fail. And of course they want the ITS booster to have a service life of 1000x launches, which means an immensely high reliability.

Anyway, SpaceX's big goal is to have their satellite service give them a nearly unlimited demand for launches in the coming decade, as well as a correspondingly huge income from global sales of satellite net / communications services - and to funnel those profits into ITS. Time will tell... but there's certainly no shortage of ambition.

Re:No Dragon 2 Soft Landing Yet

[Rei]

Well, they did produce that huge carbon fiber tank. Which appears to have failed during one of their pressure tanks. Really, building such a huge rocket out of composites is crazy ambitious (if not just crazy), but my hat goes off to them if they can succeed.

They've also made a mini-Raptor that they've started putting through tests. The fact that they've apparently managed those chamber pressures without corrosion problems so far is very impressive.

It occurred to me the other day that they have an interesting potential "halfway" route to ITS, which is that since they clearly plan to have different variants of the spaceship (cargo, crew, tanker), they could start off with the cargo variant and instead of a cargo fairing, have an interstage and use that to boost an elongated Falcon 9 (like the Falcon Heavy central core). So the spaceship would function as a first stage until it got its own booster so that it could function as a second stage. It'd be a perfect testbed for their new technologies (same construction style and engines as the booster, just smaller), while at the same time boosting SpaceX's launch capabilities into the super-heavy range. They'd want to use more atmosphere-optimized nozzles, but apart from that... it's already designed to handle much greater heat loads as well as full propulsive landings.

Re: No Dragon 2 Soft Landing Yet

[Oswald McWeany]

People live in Kansas.

Yeah, and they fantasize about escaping Kansas and living in a land filled with flying monkeys, witches, and cities ran by con-men.

Re: No Dragon 2 Soft Landing Yet

[religionofpeas]

His own rockes, paid by the people who give money to the US government - the tax payers and the foreign lenders.

The US government is only paying for rocket launches they need themselves, and would have paid someone else if SpaceX didn't exist. They aren't paying his Mars adventures.

Re: No Dragon 2 Soft Landing Yet

[Rei]

What, exactly, is the purpose of hanging in the clouds of Venus ?

What, exactly is the purpose of hanging out in the near-vacuum of Mars?
What, exactly, is the purpose of life?

If you don't agree with the merits of the human race becoming a starfaring civilization centuries from now based on investments made today in getting the ball rolling today, I'm not going to debate that with you. But if you agree with that, then the whole point in expanding offworld is to develop into a multiplanetary species, where demand drives down launch costs and we learn, step by step, to make everything that we need in offworld environments and to become adept at the multi-month journeys between planets. At first, it's a sunk cost. With time, it's increasingly supported by trade. And after long periods of time, it brings the immense resources beyond our planet into our grasp.

If you want to talk about economics on Venus, here's a few for you.

* Power is immensely abundant. Many technologies that we employ are basically energy costs - to pick an example, isotope enrichment. So once the higher marginal capital cost for doing things on Venus becomes overtaken by the greater energy availability, Venus becomes the logical place to conduct such activities.

* Deuterium levels are ~240 times higher than on Earth. So depending on the level of enrichment you need and the means by which you return it, if you can return goods for somewhere in the "couple thousand to several tens of thousands of dollars per kilogram" range, it's profitable. Deuterium recovery can be rendered an inherent part of nighttime fuel cell power storage, since electrolysis has an excellent enrichment factor.

* Venus's lavas appear to be highly differentiated, and there's a great degree of chemical weathering and atmospheric processing, which can be another resource enrichment process. So concentrations of high value ores far greater than are found on Earth are not unrealistic. There are a couple dozen elements whose values are worth exporting at realistic launch costs several decades from now.

* Even simple rocks from offworld have great value (collectors, luxury goods, etc). It's not theoretical - people really do pay huge sums for offworld items. Their value will of course depend first the abundance of their export (if you export 100kg per year, you can sell for 10x more per kg than if you export 10000kg per year, which you can sell for 10x more per kg than if you export 1000000kg per year...). If you're selling in small quantities, the value could be in the millions of dollars per kilogram. Venus's surface atmosphere is dense enough that you can outright dredge loose rocks.

* The size of the market and sensitivity to export quantity also depends on their aesthetics (aka, moving more from the collectors market into the larger luxury goods market). This means minerals that are durable and aesthetically pleasing. What we've sampled so far of Venus's surface fits that bill - gabbro (sold as "black granite" - large crystalled, dark, hard rock, forms excellent slabs), anorthosite (rare on Earth, often associated with labradorite, which is an iridescent bluish-purple semiprecious to precious mineral), troctolite (rare, olivine (peridot)-rich relative of anorthosite and gabbro - looks like this when cut and polished), etc. It's one thing for your typical sheikh or dotcom millionaire to say "my yacht's countertop is made from the finest tuscan marble." It's another to say "my yacht's countertop is from freaking Venus." You're looking at a very large market in the 4 figure/kg range, a reasonable market in the 5 figure/kg range, and a small but decent market in the 6 figure/kg range.

* Venus's apparently high levels of repeated differentiation, in conditions very different from Earth, likely mean that some minerals, including gemstones, that are rare or no

Re: No Dragon 2 Soft Landing Yet

[religionofpeas]

What, exactly, is the purpose of life?

None, but we're kinda stuck doing it, because the alternative is unpleasant.

If you don't agree with the merits of the human race becoming a starfaring civilization centuries from now

Either progress will continue for the next couple of centuries, or civilization will collapse. In the first case, they will be in a much better position to explore space with much superior technology. In the second case, it's pointless anyway.

Re: No Dragon 2 Soft Landing Yet

[Type44Q]

You must get some real detail through that narrow field of view...

Re: No Dragon 2 Soft Landing Yet

[lgw]

Any "colony" this century is going to be higher dependent on Earth for resources, don't kid yourself. The nice thing about Venus is you don't have to solve the serious problems of humans living in a low-g, high-rad environment. People could actually come back from Venus.

Re: No Dragon 2 Soft Landing Yet

[MattskEE]

Actually the US Govt through NASA did pay for specific design and development work that was specific to the NASA resupply mission, though SpaceX did the core launch vehicle entirely on their own I believe.

But this is the way NASA structured the program and put it out to bid. If NASA had wanted to purchase resupply flights but provide no development money then SpaceX could have bid on that but it would be a very different program, and they would have had to end up charging more overall to cover up-front development, risk, and financing costs.

Re: No Dragon 2 Soft Landing Yet

[Jeremi]

It's all fun and games until the dirigible's envelope gets a hole punched in it. I suggest deploying only unmanned dirigibles at first, until the necessary redundancies and materials have been thoroughly proven under real Venutian conditions!

Re: No Dragon 2 Soft Landing Yet

[david_thornley]

Thing about Venus is that, while it might be reasonable to create a floating habitat high in the atmosphere, it gets really hellish at ground level. Conducting enough operations on it to be worthwhile is going to be really, really expensive. Not to mention that shipping things like gems and construction materials between planets is not going to be economically feasible.

Re:No Dragon 2 Soft Landing Yet

[slashdot_commentator]

and it could be self sustaining.

Self sustaining, in what sense? You'd still have to ship organic chemicals (dry form, of course) to act as nutrient agent for the plants you'd be growing to consume. Is there actually enough moon/space material that's readily collectable to keep producing a synthesized atmosphere and water indefinitely? And what would you be doing on the Moon that would result in interest to indefinitely fund all the materials and operations necessary to support a moonbase doing very little?

Mars on the other hand, is big and materially diverse enough to provide for the chemical agents to actually be self-sustaining. People could travel, produce & raise kids, and live their entire life on Mars, once there's a sustainable engineering model. The Moon, on the other hand, would still need regular shipments of organic chemicals to keep its hydroponics sustained. Once Earth stops paying for that, or that massive rock ends all civilization on Earth, forget about the Moon having a self-sustaining colony.

Re:No Dragon 2 Soft Landing Yet

[slashdot_commentator]

Maybe someone who is interested in lunar development should buy some Falcon 9 or Heavy launches and just make it happen?

People brighter than Perens with more money realize that the Moon is just a big homogenous, inert rock orbiting the Earth, currently with no significant, self-sustaining, financial enterprise to exploit. A permanent moon base would merely be a giant, useless suck of money until the rich guy/nation stops paying to sustain it. Then it would be a lifeless, inert moon base.

It doesn't take much more rocket propelled energy to go to Mars, rather the Moon. At least Mars has a better potential to self-sustain a colony there (more material to work with). Its just a matter of working out the engineering, which isn't cheaper if its done on the Moon first.

I hate to say it...

[VAXcat]

...but this ain't gonna happen. America lacks the will to colonize the moon. Heck. America lacks the will to even visit the moon again.

Re:I hate to say it...

[Oswald McWeany]

...but this ain't gonna happen. America lacks the will to colonize the moon. Heck. America lacks the will to even visit the moon again.

There's a good reason for that. There is nothing worthwhile going to the moon for. There are other bodies in the solar system that have things worth going to, and they're not that much harder to get to. They're just further away and so too far for a quick rescue mission when things go wrong.

If we weren't a human risk-averse society we would never even bring the moon up in conversation as a place to place a base- we would be setting our eyes elsewhere further afield.

Re:I hate to say it...

[slashdot_commentator]

Guess why I think Space Nutters are misanthropic, maladjusted, religious nutcases?

Because you're a moron.

Directed space nuttery can result in new scientific and engineering knowledge that can be applied to desirable outcomes, whether its a self-sustaining colony on Mars, or abundant energy collected from satellites and microwaved to an Earth based collector, or harvestable H3 on the Moon to power a fusion power plant, or whatever.

Universal healthcare just extends the life of organic beings that has to die anyway. UBI may not even be economically sustainable or "desirable" in a capitalist society, and basically rewards people that can't do anything useful for existing. I'm not sure if a leisure society could have significantly desirable economic or cultural results. I'll withhold my condescension on that.

What can SpaceX do with their hardware?

[Michael Woodhams]

I have considered before that the hardware SpaceX have or are building come quite close to supporting moon landing, and wondered how much of a gap there is and what it would take to bridge it. Unfortunately the article here is very light on detail and does not address my questions.

The Saturn V could put 140 tonnes into LEO. The Falcon Heavy will be able to put 55 tonnes into LEO. If you can split the Apollo hardware into three approximately equal bits, three FH launches could put them into orbit, then they rendezvous and head to the moon. You could probably use the existing second stage as a third stage to take the stuff from LEO to lunar orbit. (I couldn't quickly find the mass of a fuelled Falcon second stage, nor how much mass it could deliver to low lunar orbit.) You could use a Dragon in place of the Apollo command module. Whether you could use a second Dragon as the lunar lander is less clear.

Wikipedia (https://en.wikipedia.org/wiki/Delta-v_budget) says lunar surface to low lunar orbit requires 1.9km/s delta-v. If you wanted to land and takeoff with the same vehicle, that would be 3.8km/s. SpaceX are planning a 'Red Dragon' mission to land a Dragon capsule on Mars. Low Mars orbit to surface is 4.1km/s (assuming no aerobraking/parachuting) so Red Dragon should be able to land on the moon and return to orbit. However, Red Dragon is unmanned - I don't know whether you have space and mass budget to stuff some people and life support in there also.

The manned Dragon capsule has rockets allowing it to propulsively land - taking from terminal velocity falling through the atmosphere to zero velocity on a landing pad. I don't know how much delta-v this requires, but I expect much less than 3.8km/s.

(Falcon Heavy and manned Dragon capsule have been under development for some time and should fly this year. I don't know how advanced Red Dragon is, but they want to launch in 2020.)

Re: What can SpaceX do with their hardware?

[Bruce Perens]

Dragon 2 uses a heat shield to shed most of its orbital velocity. To do a planetary or lunar mission, it needs to ride atop something like an Apollo Service Module.

Re: What can SpaceX do with their hardware?

[Michael Woodhams]

All you need do is dock the bits

Re: What can SpaceX do with their hardware?

[religionofpeas]

That requires the design of bits that are dockable, which greatly restricts your design freedom, as well as add extra mass for the docking ports.

Re:What can SpaceX do with their hardware?

[khallow]

It's easier to make a bigger rocket than to assemble stuff in LEO.

Then why is the US the only one to have ever made this "bigger rocket" (Saturn V and Shuttle). And currently doesn't make it?

Meanwhile we have a fair number of countries who have assembled things in orbit (US, Russia, China, all separately and the ISS group).

The problem here is that there's no rocket so big that you don't need to assemble things in orbit. You need to learn how to assemble things no matter how big your rocket is.

Meanwhile once you've learned how to assemble things in orbit, you don't need that expensive big launcher. You can put all your stuff up on the cheapest, high launch frequency launcher instead, greatly reducing the cost of such missions.

Re:What can SpaceX do with their hardware?

[religionofpeas]

Then why is the US the only one to have ever made this "bigger rocket" (Saturn V and Shuttle). And currently doesn't make it?

Because there's not much need for lifting giant payloads right now. But *if* we wanted to go back to the Moon, it would make sense to build another one.

Meanwhile we have a fair number of countries who have assembled things in orbit (US, Russia, China, all separately and the ISS group).

I never said you couldn't build stuff in orbit. it just adds extra complexities and cost.

Re:What can SpaceX do with their hardware?

[khallow]

Because there's not much need for lifting giant payloads right now. But *if* we wanted to go back to the Moon, it would make sense to build another one.

*If* we wanted to go back to the Moon, we could have done it right after halting the Saturn V with one of the many 20-25 ton launchers that has been kicking around for the past 50 years. What's ignored here is that you can buy a lot of lunar presence on existing rockets with the funds that have been spent on big rockets from the Shuttle up to the SLS.

I never said you couldn't build stuff in orbit. it just adds extra complexities and cost.

Big rockets might be a little less complex, but they are more expensive due to the terrible launch frequency.

Re:What can SpaceX do with their hardware?

[religionofpeas]

Big rockets might be a little less complex, but they are more expensive due to the terrible launch frequency

Presumably, we'd launch more of them, *if* we wanted to go back to the Moon.

Re: What can SpaceX do with their hardware?

[joh]

That requires the design of bits that are dockable, which greatly restricts your design freedom, as well as add extra mass for the docking ports.

Not only the docking ports. Every piece would need to be a fully independent spacecraft to rendezvous with the other bits, with propulsion, RCS, avionics, communication, antennas, power and thermal management, RADAR or LIDAR...

Re: What can SpaceX do with their hardware?

[Michael Woodhams]

Only one of the two craft docking needs all that. The other only needs to not rotate and be locatable. In this case two of our three bits (command module and lunar lander) need to be independent spacecraft anyway, even if launched all together like Apollo.

Re: What can SpaceX do with their hardware?

[WindBourne]

Actually, you want an assembly approach. For spending time in space, you want multiple redundant systems so that if micro meteoroids take out 1, u have others. For lunar base, you need sections to go down at a time.

Re:What can SpaceX do with their hardware?

[khallow]

Presumably, we'd launch more of them, *if* we wanted to go back to the Moon.

Hasn't been the case in practice. Saturn V, Shuttle, Constellation, and now SLS have all sucked oxygen out of the room for actual exploration and development of the Moon and elsewhere. They've never achieved the launch frequency, reliability, or cost savings to justify their use. And aside from the Saturn V era, we've never had the need for the capabilities (particularly, the large payload and fairing size) these rockets bring,

For example, this blog post discusses an alternate past where the Shuttle wasn't built and NASA instead continued on with the Saturn 1B and a small reusable manned vehicle (say 3 people plus cargo, a bit better than the Apollo capsule in payload).

They could have still flown everything that the Shuttle flew for 30 years and have a demonstration of a reusable vehicle at a small fraction of the cost of the Shuttle.

Another alternate past. Consider that we knew after the Challenger accident that the Space Shuttle would never achieve a launch frequency that would be economical. Discontinue the Shuttle in 1990. From that point on, there was only one thing that ever required the features of the Shuttle, the Hubble Telescope repair missions which simply weren't valuable. Instead, hustle the development of the EELV (Evolved Expendable Launch Vehicle) program (which built the Delta IV and AtlasV rockets) so that it was developed a decade earlier in the early 1990s instead of the early 2000s.

Then everything that was done with the Shuttle could then be done with EELVs, such as building the ISS or launching space telescope replacements for Hubble, with the use of EELVs, saving tens of billions of dollars over the 20 year period through 2010 and boosting commercial space flight in the process. And when Falcon 9 was developed, it would easily slide into this NASA strategy where everything is launched on rockets of that size.

Re: What can SpaceX do with their hardware?

[WindBourne]

Once we leave LEO, we need SHLVs. Absolutely NO DOUBT ABOUT IT. And Ideally, it would be big enough with volume to take up things like a nuclear reactors (cold, not hot).

Re:newsflash

[Aighearach]

My advice is to check in a dictionary before you try to correct somebody. Or else just read a fucking book now and then, asshole.

EM drive?

[Anonymous Coward]

Supposedly will be a way to maneuver spacecraft, at least those in space, in the future.

http://arc.aiaa.org/doi/10.2514/1.B36120

Too soon to say

[Eloking]

As much as I love Elon and his accomplishments, let's not forget that SpaceX reusable launch system's costs to refurbish and relaunch are not demonstrated...yet. Have they forgotten the the Space Shuttle Program already?

Re:Too soon to say

[thinkwaitfast]

At the very least we've forgotten the ISS and all of its promise and promises.

Re: Too soon to say

[WindBourne]

Actually, it is known to them and where issues are. Remember grasshopper?

Good grief

[Anonymous Coward]

Abandon Ares. Abandon SLS...

SLS is up to 2.5 times the LEO capacity of a Falcon Heavy, which SpaceX has never actually launched. SLS is in a different class. SpaceX might launch a Heavy in 2017, but I personally doubt it; SpaceX has never hesitated to push back dates and they've done exactly that with each new development phase. That's not a knock; they've done well and should continue their pattern. But SLS goes up in 2018 and even that first launch will achieve greater lift capacity than anything SpaceX or its competitors are actually building, never mind the SLS scale out to 130,000kg.

A least Trump doesn't appear to want to kill off SLS. If anything he seems to want to accelerate the program into a manned phase. And I'm pretty sure he doesn't give a warm piss what Scientific American has to say about it, so it looks like this heavy lift system will finally survive US politics.

Re:Good grief

[khallow]

SLS is up to 2.5 times the LEO capacity of a Falcon Heavy, which SpaceX has never actually launched. SLS is in a different class. SpaceX might launch a Heavy in 2017, but I personally doubt it; SpaceX has never hesitated to push back dates and they've done exactly that with each new development phase. That's not a knock; they've done well and should continue their pattern. But SLS goes up in 2018 and even that first launch will achieve greater lift capacity than anything SpaceX or its competitors are actually building, never mind the SLS scale out to 130,000kg.

In other words, NASA might launch an SLS variant this decade, but they probably won't. Funny how your personal doubt fails to extend to NASA which is even more notorious than SpaceX for delaying launches and failing to deliver on a launch vehicle.

Re:Good grief

[Kjella]

SLS is up to 2.5 times the LEO capacity of a Falcon Heavy, which SpaceX has never actually launched. SLS is in a different class.

The block 2 version that's at least a decade away, yes. The one they plan to launch late next year is in pretty much the same class (70 vs 54 tons), by the time the 130 ton version is ready SpaceX should have a Raptor-based competitor to match. Maybe not ITS-size, that's a bit megalomania (300 ton reusable, 550 ton expendable) but even a "Raptor 9" would give NASA a run for the money. But yeah... I want to see the Falcon Heavy fly now too, it's been pushed back quite a few times.

Re:Good grief

[khallow]

And I say that it's your party's fault too. Year after year of republitard cuts killed NASA.

You do realize that SLS exists in the first place only because of republitard senators? My view is that SLS will probably fail utterly, not because of the republitards, but because SLS is based on really stupid economics. Even if it successfully launches some point in the future, it'll be many times more expensive than commercial alternatives.

Not to be a wet blanket...

[Radical Moderate]

...but what's the point of colonizing the moon? What's there that's of any use to us? We already have ISS for zero-G experiments, and it's far easier and cheaper to get to. Going to the moon was an impressive "because it's there" achievement. But colonizing? I can't see any ROI.

Re:Not to be a wet blanket...

[crispytwo]

a moon base is uniquely suited to warehousing and building for bigger craft that head out further than earth's orbit.

examples:
1) going to Mars from the moon would be simpler, and cheaper.
2) mining on asteroids would be cheaper

Think of it as a lower cost half-way house. Doing the same thing from a space station is much more costly and complicated process. The moon has some raw materials that can be used to construct things like habitats, etc. A space station has nothing.

A habitat on the moon would be relatively cheap to build, and launching from it would be many times less than from earth, I think 36 times less. Ideally, you would only have to transport people to the moon, and everything else could be built and launched from the moon.

Re:Not to be a wet blanket...

[religionofpeas]

Ideally, you would only have to transport people to the moon, and everything else could be built and launched from the moon.

You're proposing an entire industrial base to be build on the moon, starting empty handed ? And you think this would be "relatively cheap" ?

Re:Not to be a wet blanket...

[ColdWetDog]

If all you are doing is waving your hands and drawing cool pictures, yeah it's cheap.

Actually building the thing ... not so much.

Re:Not to be a wet blanket...

[Anonymous Coward]

Baby steps. Get a running habitat up there first, drawing water from craters with ice to make a working enclosed biosphere. Expand upon that over time. In thirty generations our descendants will be thanking us for our foresight.

Re:Not to be a wet blanket...

[khallow]

You're proposing an entire industrial base to be build on the moon, starting empty handed ?

Presumably, it'd start with a seed factory and build out from there. The cheapness oft he project depends on what inputs are required from Earth.

Re:Not to be a wet blanket...

[DrXym]

I don't really buy the argument that it would be cheaper to go to Mars from the Moon. Any manned Mars mission would likely to be assembled in stages in orbit of the Earth. Much cheaper and less risk than sending those same stages to the moon and assembling them there.

Re:Not to be a wet blanket...

[religionofpeas]

It doesn't really make sense to start with a factory on the Moon to produce things that we don't need yet. Let's start at the other end, and actually demonstrate a need for stuff in space. We can launch everything from Earth, until we need such large quantities that it becomes cost effective to produce them on the Moon. I expect we'll never reach that point.

Re:Not to be a wet blanket...

[joh]

Going to Mars from the moon would NOT be simpler and cheaper. To go to the Moon you have to land things there, which is very expensive in terms of delta-V since there is no atmosphere to brake. Then you have to launch out of this gravity well again. And in the meantime you have to have everything you need on the Moon launched from Earth and land on the Moon.

Re:Not to be a wet blanket...

[4im]

I guess you misunderstood... it is not at all about sending stages to the Moon, to be assembled there, then launched. The point is to not have to launch great masses from Earth in the first place, but to build them on the Moon, from Moon materials, to fuel straight from there, and then launch. Or if it's not the Moon, then it will be asteroids.

Of course, this requires bootstrapping an industrial base from as small an invest as doable, i.e. sending robotic craft to start bringing in raw materials, and getting stuff done with them.

The trick is of course to figure out the details. Many ideas were already written up by Gerard K O'Neill back in 1976 - read "The High Frontier". Technology has since advanced, and there have been many proposals since. Private companies are digging into the problem, there are government invests.

The goal also is not to get to Mars, but to get mankind into Space, not just on a few short excursions, but for good. Moving heavy industry up there might also solve some problems down here (think energy, pollution).

Re:Not to be a wet blanket...

[religionofpeas]

The goal also is not to get to Mars, but to get mankind into Space, not just on a few short excursions, but for good.

Let's start with a few short excursions, and maybe then people will realize it's a waste of time. That would save a lot of effort compared to building a moon base.

Re:Not to be a wet blanket...

[wisnoskij]

You don't build rockets on planets, you build them in orbit like next to the ISS for example. 90% of the energy to move rocket parts from LEO to the moon is lost, and has to be respent to when you launch the rocket towards for example Mars. So you are launching like a 1/6 more fuel (with loads more fuel to lift this fuel) just so you can build the rocket on the Moon. Then you have to somehow construct a giant clean room over your entire rocket manufacturing base (instead of just using the natural clean room of space). Then you need cranes and shit, because now we have gravity to overcome. Basically, building a rocket on the moon would likely take twice as much money as building one next to the ISS.

Re:Not to be a wet blanket...

[Oswald McWeany]

It's cheaper and easier to get the materials we need on Earth rather than setting up expensive mining, refining, and assembly structures on the moon.

Not until or unless we are expecting heavy space traffic and exploration would it make sense to set up entire industries on the moon just to produce space craft. (and doubtless, we would need to send a great deal of material from Earth to the moon anyway)

Re:Not to be a wet blanket...

[guacamole]

What's the point of sending humans to Mars when all conceivable tasks and benefits can be accomplished by robots at a fraction of cost?

Re:Not to be a wet blanket...

[Rei]

Yes, wake me up when you've recreated Earth's vast diversity of industrial infrastructure on the moon.

Spacecraft are incredibly complex thing, and you're proposing to build them on a place where you're starting with absolutely nothing. And why? To save launch costs? Yes, launch costs are expensive relative to peoples' everyday experience, but they're only a (ever-diminishing) fraction of the cost of a whole mission.

If you're planning to wait until you can outright build entire spacecraft on the moon, you're planning on pushing Mars missions off by many generations. Even the concept that simple raw, bulk sheet metal of even comparable quality (and thus mass) to that available on Earth will be produced on the moon after two decades of high budget dedicated effort straddles the line between "crazy ambitious" and "crazy". Let alone being able to build it into something of relevance with sufficient reliability, and let alone being able to produce it at a rate that, after factoring in consumables that you have to ship from Earth to keep workers alive and all industrial processes running (consumable feedstocks, maintenance, etc) isn't vastly higher than on Earth.

There is absolutely nothing "cost saving" about operating on the moon; it is a huge money sink, and will continue to be so for generations. The same with Mars. You don't go there to save money, you go there as a very long-term investment in the future.

Re:Not to be a wet blanket...

[ElizabethGreene]

Then you have to launch out of this gravity well again and do an extremely expensive plane change maneuver to line up with Mars.

I want to see colonies of thousands or millions living and working off-world within my lifetime and am excited about revisiting the moon. That said, I fear the moon is a distracting diversion from the long term goal of colonizing space. It is logistically impossible to build a self-sustaining colony on a body that does not contain significant quantities of carbon, nitrogen, hydrogen, and oxygen. We shouldn't try to live there until we locate and prove those resources exist.

Re:Not to be a wet blanket...

[jeff4747]

You don't build rockets on planets, you build them in orbit like next to the ISS for example.

What do you make the rocket out of? There isn't anything next to the ISS from which to build a rocket.

The point of doing this from a moon base is you build the rocket on the moon from materials mined on the moon. That way you are not launching tons of rocket parts out of Earth's gravity well. Instead, you're only launching the people who will man the mission.

Re:Not to be a wet blanket...

[religionofpeas]

That way you are not launching tons of rocket parts out of Earth's gravity well

Instead, you'll be launching millions of tons of factory parts out of Earth's gravity well to land them on the Moon.

Re:Not to be a wet blanket...

[khallow]

It doesn't really make sense to start with a factory on the Moon to produce things that we don't need yet.

Depends on the lead time and the need. There already is some need for propellant in space at costs less than a few thousand dollars per kg.

We can launch everything from Earth, until we need such large quantities that it becomes cost effective to produce them on the Moon. I expect we'll never reach that point.

Depends on what inputs are needed for activity on the Moon. If everything coming from the Moon has to come from Earth first, it'll never make sense. If it just takes a few tens of millions of dollars initial input, plus a few hundred thousand dollars per year in telepresence work to deliver hundreds of tons of liquid oxygen propellant to low Earth orbit, then it'll pay for itself fast.

Re:Not to be a wet blanket...

[argee]

But I bet you voted Clinton too.

Re:Not to be a wet blanket...

[jeff4747]

Instead, you'll be launching millions of tons of factory parts out of Earth's gravity well to land them on the Moon.

No, again you build that out of materials mined on the moon.

You use a relatively small launch to send something to the moon that can start building the necessary mining and manufacturing equipment on the moon. First to build more mining and manufacturing equipment, and later rocket parts.

Re:Not to be a wet blanket...

[hamburger lady]

smarter move would be to put a station in orbit around L2. less of a gravity well to fuck with, parts can be spun up to simulate earth gravity so peoples' bodies don't fuck up.

Re:Not to be a wet blanket...

[slashdot_commentator]

1) going to Mars from the moon would be simpler, and cheaper.

No, it would not! Based on what rationale? You'd still have to build and rocket most of those Mars station components on Earth. The Moon doesn't have known deposits of iron or aluminum to smelt and manufacture into useful devices by robots on the Moon. Even if there was enough harvestable water on the Moon, done by robot, you could still send an automated robot to Mars to do the same chore.

2) mining on asteroids would be cheaper

Again, in what sense? The only way it would be cheaper would be to process the ore on the Moon, and ship it to Earth, but it would still be even cheaper to process the ore from a space station located a a Lagrange point.

It blows my mind how people here claim to understand basic science and a layman level of engineering, but can't comprehend the basics of orbital mechanics. (It doesn't take much more energy to go to Mars rather than the Moon. They're about equal in difficulty to do at this point in space science/engineering.), or how projects require money to be developed (there's no money saved testing a sustainable hab module on the Moon, rather than testing it on Mars.) Why are people so convinced that Spain needed a colony on the Azores before they could send Columbus to the "New World"?

Re:Not to be a wet blanket...

[slashdot_commentator]

But you can't plan to go to Mars with that plan. You have to spend decades first developing the robotics to do sophisticated manufacture in space/Moon. Then you're sending that factory to the Moon, rather than Mars. Oh yeah, there's no (known) iron or aluminum, or anything useful, other than sand (silica) to mine on the Moon. Then somehow you have to be able to mine an asteroid, when most asteroids are in an orbit farther than Mars but before Jupiter. Which means you'll probably be doing that with an automated robot as well. Unless you want to spend money developing a habitat module that can sustain human life in space/Moon without a radiation shield for about a year. And that's assuming there are asteroids with useful materials to mine within rocket distance of the Earth that is less than the distance to Mars. And where will be the savings in rocket launches or Earth materials for this scenario?

Re:Not to be a wet blanket...

[slashdot_commentator]

...when all that effort could be saved by building an automated space fabrication facility and sending that to a Lagrange point, thus totally avoiding the kinetic expense landing and launching out of the Moon's gravity well.

Re:Not to be a wet blanket...

[slashdot_commentator]

1) Eventually a self-sustaining human colony on Mars. Which then ensures humanity or civilization won't be wiped out by a space rock every 300K(?) years.
2) Having the self-sustaining colony on Mars also means more living area to populate with humans. Not prime real estate (unless you're dystopian), but possibly better than living in your toilet on Earth.
3) Once man can sustain themselves indefinitely outside of Earth, it may become lucrative to collect useful materials outside of Earth, process it in space, manufacture something useful in space, and then send that to Earth. Yeah, automated robots could do that too, but it may be too difficult to manage/repair those devices the further out you go for materials away from Earth.

"A wild car"

[Anonymous Coward]

I wonder what that could be?

A Jaguar? A Beetle? A Plymouth Barracuda?

Re:"A wild car"

[Fire_Wraith]

It certainly couldn't be a typo in the summary. This is Slashdot, after all - that never happens here. ;)

No Idea on how valid the alternates are

[Crashmarik]

But it's hard to do worse than NASA's SLS

http://www.thespacereview.com/...

It has been estimated at a per launch cost of 5 billion a shot, and a cost per pound that makes the shuttle look like Amazon Prime.

Re: Before we go back to the moon

[backslashdot]

What comedy it is for a racist to accuse another race of tribalism. LOL!

Hydrogen is really useful for going places

[Anonymous Coward]

SpaceX's kerosene is a good decision for putting stuff into low earth orbit compared to hydrogen. When you go farther away than that, the hydrogen advantage kicks in. For Low Lunar Orbit and Mars transfer orbit, hydrogen is very useful. Also, the Falcon heavy will need an extra stage to go much beyond geosynchronous orbit. The SLS solid boosters seem ready now. The big SLS first stage will probably be ready in 2 years. An upper stage for the SLS seems to be in early work right now. It's not the SLS that seems to be the problem. It's Orion, and the lack of payloads for the SLS, which are the problem.

Re: Hydrogen is really useful for going places

[WindBourne]

No. The problem with any part of SLS is economics. Simple as that. It is too expensive to fly.

Re:Hydrogen is really useful for going places

[Rei]

SpaceX's kerosene is a good decision for putting stuff into low earth orbit compared to hydrogen. When you go farther away than that, the hydrogen advantage kicks in. For Low Lunar Orbit and Mars transfer orbit, hydrogen is very useful.

The problem with going further away on hydrogen is that hydrogen is not generally considered a "storable" propellant; it's very hard to manage boiloff. Mild cryogenics like methane (SpaceX's plan) are easier. It allows you to use the same stage for transfer, entry, and launch burns.

Also, the Falcon heavy will need an extra stage to go much beyond geosynchronous orbit

Why? It's a 3-stager (or if you'd rather not count boosters as full stages, 2 1/2). Designed specifically with Mars missions in mind. 3 stages is a good number for kerolox missions to MTO if the stages have a low mass fraction (like SpaceX's do). You could even do it with 2, although it'd cut your payload.

The SLS solid boosters seem ready now.

They're not. You're confusing test firing with completion.

The big SLS first stage will probably be ready in 2 years.

In your dreams. The smallest variant isn't scheduled to fly for 1 1/2 years, and that's assuming that the schedule doesn't slip. That's Block 1, 70 tonnes. Block 1B (again, assuming no schedule slips) isn't scheduled until 2021 - and that's only 105 tonnes. There's three scheduled launches of Block 1B, the last in 2026. The latter being asteroid redirect, which, well, don't hold your breath ;) There are no scheduled launches of Block 2 (130 tonnes).

You have this weird conception of how far along SLS is. They only even finished the test stand for the tank last month.

"a wild car" ?! EDITORS !

[Anonymous Coward]

Slashdot Editors ? Edit Slashdot !
FFS

and fairy dust and unicorns too!

[Anonymous Coward]

Space elevators are not gonna happen in the next five or six centuries.

First, there is no actual workable scheme to build one or deploy one. Yeah, there are all sorts of wildly imaginative concepts - but rockets are PROVEN. We know how to build and launch rockets. We, as a species, do not know how to build and deploy a space elevator, and quite frankly we're not good enough at rockets yet to launch large enough ones and in such quick succession to be able to place the required hardware into space to build a space elevator. For example, while people thing Musk could use Falcons to assemble a Mars mission, HE knows full-well he cannot fly Falcons one-after-another rapidly enough to do it and is instead planning a super-rocket to do Mars missions in only two launches. If rocketry advances enough to be able to lift all the elements for such an elevator and in a timely-enough manner to enable deplyment, then we'll be so good at rockets that the elevator will be unneeded.

Second and no-less important, however, are all the bureaucratic reasons. How are you gonna get the environmental and geopolitical approvals for a space elevator? we're talking about something that needs to be an extremely durable thin structure tethered to something in space and on the ground. What happens if it breaks free from its ground tether point? It becomes a massive whip like a big weed-wacker cord that (to be tough enough hey thin enough to work in the first place) would rip to shreds anything on Earth that it whipped into as it ripped across countrysides, through cities, across international borders, through international airspace etc. When we plan for things like nuke plants, disasters must be planned for (and experience shows we're not too great at assessing those risks and plans). Your space elevator would need far more planning and approvals since it has the potential to cause direct destruction (not just indirect effects) to many nations.

Re:and fairy dust and unicorns too!

[silentcoder]

You underestimate engineers. We went from "first flight" to the moon in less than 70 years. We went from "First rocket" that flew 30 feet to the moon landing in about 4 decades.It's JUST AS LIKELY that we'll go from "material with enough tensile strength invented" to "space elevator" in a few decades too.

Re:and fairy dust and unicorns too!

[Anonymous Coward]

You underestimate engineers. We went from "first flight" to the moon in less than 70 years. We went from "First rocket" that flew 30 feet to the moon landing in about 4 decades.It's JUST AS LIKELY that we'll go from "material with enough tensile strength invented" to "space elevator" in a few decades too.

This is what I like to call the "extrapolation fallacy". People assume that if something is possible, anything is possible.

There are limits in the universe that put upper bounds on what's achievable. At the moment, we're not even sure that it's theoretically possible to create that "material with enough tensile strength". If it turns out it's not, then no amount of engineering will make it reality (disclaimer: I'm an engineer).

It's the same fallacy that people make when they imagine advanced alien races coming up with physics-breaking technologies (FTL, Dyson spheres, ring worlds, teleportation), or when they imagine life inside of stars (it's just too extreme inside there for stable systems to exist, let alone evolve).

Re:and fairy dust and unicorns too!

[david_thornley]

And you extrapolate wildly from one example.

Come on, everybody does that. I mean, silentcoder does, so....

Re:and fairy dust and unicorns too!

[khallow]

I have a quibble here:

coming up with physics-breaking technologies [...] Dyson spheres

Aren't physically impossible. When Dyson first proposed the Dyson sphere he was talking about what is now termed Dyson swarms, clouds of satellites absorbing the light of a star. That is physically possible though a difficult relativistic traffic routing/fluid flow problem.

Lots of bits coming together

[Anonymous Coward]

SpaceX to Earth orbit.

Ion/plasma/m-drive for cargo from Earth orbit to lunar orbit. Reaction engines for people moving.

Materials strength may be enough for a lunar space elevator. Practice there first.

Tele-operated lunar construction robots, AI'ed by autonomous vehicle software for when there too few local operators.

High-power communications link, driven by lunar power source -- lunar manufactured solar arrays, nuclear reactors.

Oxygen cooked out of the lunar regolith, other materials from the poles. Test out automated production machinery before a Zubrin-like Mars attempt.

Re:if it were possible to go the moon we'd have go

[Anonymous Coward]

And there can be no proof because there is none that you'll accept. Pictures can be faked. We could even send you to the moon and set you down next to a LEM base and the whole experience will be drug induced brain washing, memories implanted while hypnotized.

See how that works?

You gotta whip it out.

[argee]

You got to whip it out and take a piss on it before you can claim to having been there. All we've ever done is to leave some
footprints and tire tracks. We need to go there and set up a base. Reusable rockets launched from orbit, and shuttle to the
moon over the years. Just gas them up in orbit - earth or moon orbit. And how can you guys claim "there is nothing up there."
We know for a fact a monolith was found in 2001, there could be lots up there. Diamonds, Gold, Helium-3. Lets put the
golden arches up there! Better than wasting money enriching insurance companies with Obamacare.
--
Late term abortion should be legal until age 8

The problem - taking off again

[Chrisq]

Sure they can take off and land. But the the "landing" is of a separated dragon capsule and the two stages of the falcon 9, and there will be a full check and refuel before take off again. Whereas it is possible that the dragon capsule could land on the moon with enough fuel to take off again, being guaranteed to be able to stop and re-ignite will probably be more than a minor tweak.

Also, the current dragon capsule has an emergency parachute system will be retained as both a redundant backup and for water landings. They would have to be confident enough to work without this backup.

Re: The problem - taking off again

[Michael Woodhams]

I think normal landing will be rockets only, and if they fail it will be too late to parachute, so they are already trusting the landing rockets in a safety critical role. The chutes are there for emergency escape during launch. In this case, the landing rocket fuel has been expended getting away from the exploding launcher.

STS has a problem

[joh]

It's not reusable and much too expensive to be flown more often than a few times. It never was anything than a gift to the companies that built the shuttle, so they could continue to supply tanks and solid boosters and hideously expensive engines. The point of it never was getting anything into space, but to keep the same old rivers of money flowing.

Re:Younger astronauts

[Rei]

One, there would be howls of protest. Two, you're not taking that argument to its logical end. You should only send pygmy women by that logic.

Women do consume less resources (by a good margin on average) and take up less space, but if I recall correctly are more vulnerable to radiation-related disease. So it's a tossup depending on what factors are constraining your mission architecture.

Easy

[jocarren]

Grab the schematics, build a Saturn V rocket, an Apollo capsule and a Lunar Lander.

Re: Who gives a fuck?

[WindBourne]

Wrong. We have been learning how to survive in space.

STS is not a problem

[WindBourne]

STS, otherwise known as the space shuttle, was retired 6 years ago. So not a problem. OTOH, the SLS is an economic problem

Re:STS is not a problem

[joh]

Fuck. Replace STS with SLS in what I wrote. I'm acronym challenged sometimes.

Re: STS is not a problem

[WindBourne]

woosh.

Its Not If We Could get to the Moon, Its Why?

[wisnoskij]

We already have a space station, the difference between LEO and the moon is small, and would probably take about the same amount of fuel as it burned up in one second during launch.

But the environment on the moon is hazardous to machines. It takes more to build a station on the moon than floating in space, and it is not really any closer to exploring the rest of the system than LEO.

Their are really only downsides to stationing men on the moon vs on a space station.

Re:Its Not If We Could get to the Moon, Its Why?

[wisnoskij]

Distance in space is measured in Delta-V.

Re:Its Not If We Could get to the Moon, Its Why?

[Baron_Yam]

Delta-V and time, because within the limits of your propulsion system you can trade energy for time or visa versa.

And if you want to get really nit-picky... also timing, because the delta-v requirements change as your origin and destination endpoint's relative positions change.

Wait. How about just 'timing, time, distance, energy, mass, hazards and Isp'?

Err... I want to change my answer to "it's really, really complicated"!

Re:Its Not If We Could get to the Moon, Its Why?

[wisnoskij]

Not really.

Yes, in empty space, going anywhere is a tradeoff between dV and time. But since in reality we are moving between gravity wells, it is heavily weighted towards dV.
Your orbital distance is synonymous with your orbital velocity. It is a 1:1 relationship. So to get further from the Earth, you simply add velocity. To ever get to the moon, your dV has to be so big that their is minimal time savings to putting in more. A bigger issue is thrust, how long it takes to speed up, but that is mostly only true for the Moon. Everything else is so far away that it does not matter that much how long it takes to speed up.
Mass is part of dV, space craft usually are not dodging asteroids, so the only hazard is not manufacturing faulty parts to begin with. And again ISP is factored into dV. Getting a better ISP can mean increasing your dV or reducing the weight of your ship, therefor making it cheaper. And yes timing is important, but it has nothing to do with distance.

Re:Its Not If We Could get to the Moon, Its Why?

[Rei]

Not exactly. Minimum energy trajectories are really undesirable for humans. Fine for cargo, but you get a lot of time cut off the trip with just a relatively small amount of extra delta-V. Seriously, I recommend running out the numbers for fast Hohmann transfers to Mars - assuming aerocapture, it's a major improvement at little cost.

SpaceX, for one, wants fast transits with ITS. And I don't blame them.

Simple. Change the gravitational constant

[Thud457]

phhht, just let them throw away the money building the wall, then when he's out of office, just turn it up on its end. Presto, space elemavator!

Not really private

[jdavidb]

It starts by abandoning NASA's expensive Space Launch System and Orion capsule, and spending the money saved on private-industry efforts like Elon Musk's SpaceX and Robert Bigelow's Bigelow Aerospace

I'm sure suddenly throwing a bunch more government money at private space efforts won't change those projects in the least or make them more expensive or anything like that.

Interest in the Moon? I'm amazed.

[k6mfw]

Let's see how far this goes, everybody loves to talk about Mars (which a human mission to that planet will always be 20 years into the future). I'd like to see these new space people think about the Moon, unlike old guys who seem to carry a lot of baggage, that is, any reference to the Moon, then it is always Apollo methods and design. Apollo may have been a great adventure but it was a one-off stunt designed specifically to beat the Reds. Because of its unique purpose it could not be fiscally sustained or readily adapted to other missions. And definitely not scalable to routine use. Which I wonder if systems of SpaceX and Blue Origins, is it scalable to economically routinely use like airlines and cargo ships?

Re:Interest in the Moon? I'm amazed.

[argee]

Never mind the X-prize. Lets do the P-Prize. $100 million to the first person to piss on the moon.

Clarke wrote about it in SF

[Geoffrey.landis]

As noted, Clarke did not invent the concept of the space elevator, although he was one of the first two writers to highlight it in science fiction (with Charles Sheffield the other). The concept of the space elevator was invented independently several times, the first time Artsutanov (who only published in Russian), then by Isaacs et al, and then by Pearson.

http://www.isec.org/index.php/10-resources/18-the-history-of-the-space-elevator

Clarke didn't invent the concept of a geosynchronous satellite, either, although he was the first to point out that geosynchronous orbit was an excellent orbit for communications.

Nanotubes aren't as good as predicted

[Geoffrey.landis]

The numbers come from this book: https://www.amazon.com/Space-E...

Their research is more serious than your unsupported opinion.

Most of the space elevator research assumes that the problems of making long, perfect carbon nanotubes can be solved, that they be made in volume at very low cost, and that they will have an ultimate tensile strength equal to that calculated from theory of perfect carbon, and not one that is the actual measured tensile strength of nanotubes in the real world.

Unfortunately, carbon nanotubes not only have never been made with this theoretical strength, newer work makes it look like they cannot reach this theoretical strength. The pentagons of perfect nanotubes spontaneously convert into pentagons and heptagons under strain, which reduces the breaking stress.
https://www.newscientist.com/a...

Right now, the materials needed to make a low cost space elevator are still in the future. Later materials science may make us revise that estimate, but right now: it's still hard.

Re:Nanotubes aren't as good as predicted

[KeithCu]

Actually, from my reading, the theoretical strength of carbon nanotubes is far more than what is needed for an earth-based elevator.

The reason the materials sciences advances are still in the future is because there aren't many people working on it. (You should be amazed by the materials sciences technology that goes into your cellphone.) Kennedy said that we couldn't go to the moon without inventing better alloys. Necessity is the mother of invention. Many things are hard if you don't try.

The good news about the nanotubes is that you don't need them until the launch date, after the climbers and everything else are also made.

obHeinlein

[rcharbon]

Where is Delos D. Harriman when you need him?

Moon- not perfect, but has possibilities

[Geoffrey.landis]

Part of the problem with the moon is that it's just not a great place for ISRU. Volatiles are rare.

That was the old, Apollo-era thinking. The newer thinking is that once you get away from the equatorial regions, volatiles aren't so rare. In the high latitudes, you have hydrated minerals (seen by Chadrayaan), and in the actual polar craters, ice (as seen by Lunar Prospector, LCROSS, etc.).

We've never even sampled any moon that aren't depleted in volatiles, although there's some data to suggest that various volatiles might be scattered in permanently shaded areas

Exactly. The problem with Apollo era sampling was that they never got more than about 20 degrees from the equator.

...

Of course, I prefer Venus to Mars, but that's neither here nor there ;) I'd like to see a parallel program for both, as the same sort of booster and transfer stage can be used for both, so it's only habitat / ascent stage development costs that are doubled. And once you get past the differences in feedstock sources, production industrial processes converge (Venus advantaged by the higher power availability and easier ability to get rid of heat - excepting in the case of cryogenics, where Mars holds the advantage)

Hey, we're thinking along parallel lines!!

  https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20030022668.pdf

Re:Moon- not perfect, but has possibilities

[Rei]

I mentioned that. The discoveries on lunar water are in consistent (for example, non-detection by Kaguya, disputed detection by Deep impact, criticism of Chandrayaan's detection as not being consistent with solid ice (at best small ice particles), etc. But I do agree that on the balance the evidence is pretty compelling that there are places where ice could be recovered/produced. Even if you take the optimistic view on volatiles (not just water), they're clearly not evenly spread, and generally seem to be (as expected) at significant driving distances from lit regions. Workable? Probably. Ideal? Not really. But hey, it's certainly a better outlook than it was a couple decades ago :) I'll be a lot happier though when we have some ground truth on the subject showing CHONPS all in the same general area ;)

Hey, we're thinking along parallel lines!!

I'm part of a group called Venus Labs that's actually developing the concept further, doing more detailed studies on each component of the concept that Landis presented. :)

wild car

[CresCoJeff]

Doesn't anybody proof, even a little? Obviously the cited article refers to Bezos' rockets as a wild card, not a wild car... typos and misspellings are one thing, but when you go from one word to a totally different (and in this context hilarious/insane) one, the problem becomes functional rather than aesthetic.

Re: newsflash

[Type44Q]

Or else just read a fucking book now and then, asshole.

Seems like i hit a raw nerve (which i very much expected). Well, this might sound counterintuitive to a mind like yours but the very reason I don't have to resort to making up words is because I may have done just a wee bit more of that than youth - and likely anyone you know - considering i read Revolution in 2100 at the age of seven.

Do try to carry a proper firearm to a gunfight?! ;)

Re: newsflash

[Aighearach]

No, whining and saying something insulting isn't the same as reading a book, moron.

Flat earth

[argee]

This reminds me of little games I like to play with the local schoolteachers.

I say: "The earth is flat. I want YOU to prove me otherwise!"
Teacher: "Easy, I can take you out to earth orbit and you can see the earth is round."
Me: "Ok, lets go!"

Hard. You wont get it past OSHA

[argee]

Or the greenies, the do gooders, the democrats, the pro-welfare state. To go space exploring will take BALLS, and there will be setbacks, loss of life, etc.
Today with modern materials, computers, Bigelows and the like, we can make the whole lander/capsule etc at a fraction of the weight, and if we use the
same safety standards we did in 1968, probably a fraction of the price as well. And there are LOTS of volunteers with "the right stuff."

Re:The question is why, Why? WHY?

[argee]

Because, sir, a robot cannot piss on the moon or Mars. Only people can do that.

Its like my friend's dog. It is a life support system for a stomach.
Similarly, the Lunar vehicles etc are just a system for getting a toilet to the Moon.
Or, if you are a low tech Luddite, a pissing stick. See how high you can "mark" it.

Re:newsflash

[Aighearach]

I'm one of those annoying people who considers English to be English, not one of those people who cries that it won't gift changes to mollify personal hangups.

Re:newsflash

[Aighearach]

Right, dictionaries should only be listing known published uses of words, not mere utterances. Those might have some place in the phrontistery, but the dictionary is not that place.

Onward to Venus [Re:Moon- not perfect, but has...]

[Geoffrey.landis]

Hey, we're thinking along parallel lines!!

I'm part of a group called Venus Labs that's actually developing the concept further, doing more detailed studies on each component of the concept that Landis presented. :)

http://venuslabs.org/a?

Wow, nice graphic! I'll be fascinated to see what you come up with!

Re:newsflash

[hamburger lady]

verbing weirds language.

Re:The question is why, Why? WHY?

[Gavagai80]

We could launch a toilet and a wide assortment of urine samples to the moon for a fraction of the cost of a manned mission.

busted

[epine]

to gentle itself down to earth's surface

That's about all we need to know concerning the narrative spinneret powering Space Odyssey #10,017.

We like the moon!

[macdaddy357]

Cuz it is close to us! http://www.rathergood.com/moon...

What a difference 18 hours makes. Sofia Vergara

[raymorris]

> good luck getting Elon Musk to focus on the practical and eminently desirable target of the Moon. He isn't interested. It's only Mars for Elon.

And 18 hours later:
https://science.slashdot.org/s... :)

Bruce, would you please post whether you think Sofia Vergara will show up in my bedroom? I'd sure appreciate it.

Details already worked out

[neoRUR]

Look they already did this in:
Space 1999
2001: A Space Odyssey
Independence Day: Resurgence
Moon
The First Men in The Moon
A Trip to the Moon
Transformers 3: The Dark of the Moon

So what more proof do you need?

Re:Onward to Venus [Re:Moon- not perfect, but has.

[Rei]

That's an old graphic, but yes, we have an excellent artist aboard. Of course, they mostly want to go for what looks the most aesthetically pleasing, while I'm always niggling on the technical details ;) The conversations usually go like,

"But.... you can't have people living there, the ballonets are going to expand into that when they launch the ascent stage... either the ballonets are going to dramatically expand or the habitat is going to dramatically collapse, take your pick. And if you store the ascent stage that close, it's going to destroy the whole habitat if there's a mishap while it's fueled. And how can I possibly fit all of that floor area into the fairing? Plus I don't see any scrubber for ISRU... it's going to need to be big, I'm struggling to get the absorption figures to work for sufficient resource collection with a 4.2 meter prop....." ;) But really, so long as their final graphics don't end up with a giant pirate flag or anything like that, I'm sure we can deal with a bit of "artistic license" :)...

Oh wait a minute, I just noticed your username. Geoffrey.landis? As in, the Geoffrey Landis? Oh wow, hey, we should chat some time. ;) (bare minimum, I at least need to ask for permission to reproduce some figures from a few of your papers). If you get a chance, definitely drop me a line at mQeme@eaQku.neQt (remove Qs to despammify). I actually just dropped by Slashdot as a break in the middle of working on some graphics illustrating non-Hohmann transfer times vs. delta-V between Earth, Mars and Venus, demonstrating the advantage Venus has due to the Oberth effect ;)

Don't believe it.

[theendlessnow]

Don't believe anything you read until they send Commander John Koenig up there to take charge (err... wait a minute....)

Re:Onward to Venus [Re:Moon- not perfect, but has.

[Geoffrey.landis]

That's an old graphic, but yes, we have an excellent artist aboard. Of course, they mostly want to go for what looks the most aesthetically pleasing, while I'm always niggling on the technical details ;) The conversations usually go like,

"But.... you can't have people living there, the ballonets are going to expand into that when they launch the ascent stage... either the ballonets are going to dramatically expand or the habitat is going to dramatically collapse, take your pick. And if you store the ascent stage that close, it's going to destroy the whole habitat if there's a mishap while it's fueled. And how can I possibly fit all of that floor area into the fairing? Plus I don't see any scrubber for ISRU... it's going to need to be big, I'm struggling to get the absorption figures to work for sufficient resource collection with a 4.2 meter prop....." ;) But really, so long as their final graphics don't end up with a giant pirate flag or anything like that, I'm sure we can deal with a bit of "artistic license" :)...

Oh wait a minute, I just noticed your username. Geoffrey.landis? As in, the Geoffrey Landis? Oh wow, hey, we should chat some time. ;) (bare minimum, I at least need to ask for permission to reproduce some figures from a few of your papers). If you get a chance, definitely drop me a line at mQeme@eaQku.neQt (remove Qs to despammify). I actually just dropped by Slashdot as a break in the middle of working on some graphics illustrating non-Hohmann transfer times vs. delta-V between Earth, Mars and Venus, demonstrating the advantage Venus has due to the Oberth effect ;)

Sure, I should do that; see what you're doing.

Re:newsflash

[Zontar The Mindless]

Uh, what? That wasn't even a thing until just the last few years.

Re:newsflash

[Aighearach]

You might want to double-check your etymology there. It is the same as above, don't spend time correcting me when you didn't know and didn't even look it up. Word uses you recently discovered might not be new, after all.

Re:Nonsense

[khallow]

The earlier poster meant SLS, but it applies to the Shuttle as well. It was always about making sure considerable public funds makes it way to the right campaign donors and the right congressional districts.