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NASA Mulling Earth-Moon L2 Point for Mars Staging Station
jamstar7 writes "From the article: 'NASA is reportedly mulling the construction of a floating Moon base that would serve as a launching site for manned missions to Mars and other destinations more distant than any humans have traveled to so far. The Orlando Sentinel reported over the weekend that the proposed outpost, called a "gateway spacecraft," would support "a small astronaut crew and function as a staging area for future missions to the moon and Mars."' This is actually a good idea, using the Moon as a staging base for exploring the cosmos. Once we build manufacturing capability there, why not build spacecraft there? We can build bigger, more spacious craft so as to not lock up future astronauts in a closet for months or years at a time."
Moon base isn't quite accurate: it would be a space station at the Earth-Moon L2 Lagrange point about 60000 km from the surface of the dark side of the moon.
Dark side as in "never receives the light of the Sun"? The Pink Floyd are still casting a dark shadow on astronomy beliefs ;-)
For something to be X miles above the DARK side of the moon, it would have to be orbiting the moon. You want to say FAR side of the moon, and you would probably not get it wrong if you either paid a little attention to your science classes in school or gazed at the moon enough times to think about the lunar phase cycle.
But, no, you should not be editing something like slashdot causing the readers to pull their hair.
Violence is the last refuge of the incompetent. Polar Scope Align for iOS
By the way, the L2 point is not on the dark side of the moon (the dark side of the moon travels around the moon every 28 days), it is on the FAR SIDE of the moon, that is the side facing away from earth.
My question is why L2 and not L1? L2 is going to be exposed to more meteoric traffic, it will have a hard time communicating through the moon to the earth (yeah you can put a comm satellites at L4 or L5 but that's complicating things and adding cost and new failure modes.) That and L1 is closer and easier to get to from Earth and easier to get things to from the moon with the gravitational assist of Earth.
There are plenty of interesting designs, but such a resource would need to be built of lunar material. Because you'd need a structure with walls thick enough to protect from solar storms, cosmic rays and all kinds of meteoric debris hitting the structure. You would probably want to have hydroponics plants on board for food, oxygen, and synthetic meat from Soybeans... or even better synthetic meat from a 3D printer, endless Filet Mignon, sushi grade Yellowtail and Salmon, and Turkey White and Dark meat as long as you have cell cultures and your meat printer. By the way, you could dissolve vital minerals in water and then use that water to build radiation proof walls. About 3 feet ft. would get the job done nicely, 6 ft would be spectacular. You'd want to harvest a reasonable sized asteroid with plenty of water or a number of smaller asteroids and use it/them to build your base. You'd want to use a swarm of assembly bots to build things with only a small human presence, most remote from the ground. Robots that could self replicate from materials in the asteroids would be perfect.
I assume it is L2 specifically because it is a mission staging area. Launches to other planets will be easier and use less fuel if done from L2 because they will not have to navigate around the moon, and because they will be that much closer to the target.
Because LEO is still inside the gravity well. Not that the ISS doesn't need VASIMR for station keeping, but it's not designed to go somewhere else. I'm sure that it would probably take some structural damage from the kind of thrust you need to apply to get up out of LEO, and then it has to go through the Van Allen radiation belts too. You just don't move a fully assmembled multi-segmented space station around like it was an aircraft carrier. Over that kind of scale it should be pretty flimsy.
Besides, there's going to be barely enough power available to use VASIMR just for station keeping. I think it needs to charge for like 20 minutes to get a 5 minute burn or something like that. (too lazy to look up the details)
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
Why not put it in LEO (low earth orbit)? It's a hell of a lot easier to send supplies and astronauts. We have decades of experience with that.
Also, why not use the ISS? It has all you need, I think: astronaut habitat, power, docking ports. Add a few modules, and you're done.
All this talk about either the moon or L1, L2... unless there is a source of fuel (i.e. water, as well as a source of power like sunlight or nuclear), it's utterly pointless to drop yourself into another gravity well, not matter how tiny, if you're gonna have to carry all the fuel there yourself from earth. If the fuel comes from earth, your space station is nothing but an assembly point, and that might just as well be in low earth orbit.
The only reasonable alternative is one of those craters on the moon where they have found some water... but only if a station there can get sufficient power to convert that water to hydrogen and oxygen at conditions (temperature, pressure) that are necessary to be put into a large rocket.
A lot of the "basic research" comes from applied research aimed at a specific goal, the spin-offs from that basic research is what provides the expanded benefit.
Hypothetical goal: L2 staging base
Hypothetical applied research: supporting medical facilities there.
Hypothetical spinoffs: remote surgery, 0 G surgery, remote sensing, microrobotic surgery... and reduced medical costs on earth.
Anyone who thinks this is a good idea to get to Mars needs to read Zubrin's "The Case for Mars" or read up on the "Mars Direct" approach. All this talk about moon bases or staging in orbit or at an Lagrangian point originates in NASA designing the Mars mission via lots of committees, in which various teams and [sub]contractors got to insert dependency on their pet projects. Mars Direct presents a very well thought out and fully vetted approach, nothing but politics at this point is standing in the way - if NASA as an agency was still primarily interested in space exploration instead of pork disbursement and fiefdom preservation, and Congress had to provide slightly longer term budget commitments with less constraints and strings atached, we'd already have a permanent presence on Mars.
Not having a trillion dollars really hasn't stopped our government from spending like they do, so why not?
Space Shuttle was a program that strapped humans to an explosion and tried to stab through the sky with fire and math
I'm surprised that i saw no Iron Sky comments yet.
http://www.ironsky.net/ its a B movie made on a budget with remarkable Hollywood quality. Sequal and prequal are in the works, i've heared.
Relevant because its recent (mid 2012), about the dark side of the moon and an US astronaut.
If you want a good laugh about WW2 germans, watch this.
Hivemind harvest in progress..
Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.
Well we DID have a spare trillion, apparently, but it went to da bankers via stimulus...
Flappinbooger isn't my real name
Yes, why not build spacecraft there? Because we don't have a trillion dollars to spare? That might be it.
Another good reason is because we don't have any metal or fuel or supplies or people or vendors or communication infrastructure or USPS addressing locations or anything other than moon dust and nothingness on the moon.
Yet.
How many times must it be pointed out that back before Columbus sailed to the Americas, there were no Starbucks or Dunkin Donuts or Apple stores in the area now known as the United States? Wasn't a lot of anything except a lot of forest.
Understanding the scope of the problem is the first step on the path to true panic.
http://en.wikipedia.org/wiki/Military_budget_of_the_United_States It seems that it's possible to throw away one trillion dollars every two years.
It's the same force that holds up the moon - centripetal force. The L2 point orbits Earth at the same period (same angular velocity) that the moon does, but further out. That means it moves faster than the moon does.
If the Moon weren't there, a satellite at L2 wouldn't by in a stable orbit: Its centripetal force would be too great.
However, as you said, at that point Earth and Moon pull in the same direction. That means the combined force acts like the gravity of a single more massive body, creating a point further out along the "Earth->Moon->" line where the increased centripetal force is exactly balanced by the increased pull. That sweet spot is L2.
L3 works by the same principle, on the opposite side.
L1, L2 and L3 are pretty easy. The Moon (or whatever secondary body you want, such as the Earth for Earth-Sun Lagrange points) is in some orbit, with some period, about the primary (Earth, in this case). Are there other orbits that have the exact same period ? If the Moon had no mass, the answer would be, no, except for exactly the same mean distance (AKA semi-major axis) from the Earth. With the Moon having a significant mass, things are not quite so simple, but they are not very much harder.
Suppose you are inside the Moon's orbit, on the Earth Moon line. On that line, inside the Moon's orbit, the Moon's gravitational acceleration subtracts from the Earth's, so you feel a little less acceleration towards the Earth, and so your circular orbital period is a little less than it would be in the absence of the Moon. If you go up and down that line, you can find the point where the orbital period (for a circular orbit, with the Moon reducing the Earth's gravity) exactly matches the Moon's original orbital period. That point is the L1 Lagrange point. If you are there, in a circular orbit, you are rotating with the Moon. (It's not stable, but that's another matter.)
Now, suppose you are outside the Moon's orbit on the Earth-Moon line. In that case, the Moon's gravitational acceleration increases the pull of the Earth, so your orbital velocity (for a circular orbit) must be a little faster than it would be without the Moon being present. Again, imagine going up and down the Earth-Moon line until the orbital period (increased by the Moon's gravity) exactly matches that of the Moon. That is the L2 Lagrange point (again, not stable).
L3 is just as easily conceptually - if you are on the opposite side of the Moon, again on the Earth-Moon line, the Moon's gravity again increases the pull of the Earth (by a smidgen, due to its distance), and there is a place on the E-M line, just a smidgen inside the Moon's orbit, where your orbital period is the same as the Moon's. That's the L3 point.
1) Money isn't actually used up when we build things. The money goes into the hands of the people who build them, the people who create the materials in them, etc. None of the money will actually leave the planet.
2) I'd rather spend a trillion dollars doing this than spend a trillion dollars fighting wars we don't need to fight.
"Wasn't a lot of anything except a lot of forest."
So only...
Old growth trees (extremenly valuable at the time for shipbuilding).
Vast tracts of untilled arable land.
"Easily displaced" indiginents.
Not to mention the coal and oil deposits discovered later.
We know a lot more about what's on the moon than Columbus (or the Spaniards) did about North America, but what we know is that it's not all that.
The moon, sadly, is kind of crappy resource-wise. It is, on the other hand, really handy for causing tides, which helped a lot of life proliferate down here, so go moon! (but don't necessarily go TO the moon)
Also, instead of wikipedia we could link to an actual source. E.g. Phil Plait's excellent blog: http://www.badastronomy.com/bad/misc/dark_side.html
Violence is the last refuge of the incompetent. Polar Scope Align for iOS
I read all the other answers and they are accurate but not complete. L2 and L3 are not points of stability in the sense that you can put an object there and it will stay there -- they are metastable in that the forces on the object are balanced, but balanced in the sense of balancing on a knife edge. A small perturbation inward or outward from L2 or L3 will be amplified and the object leaves position. That said, there are stable trajectories of the object such that it can "orbit" L2 or L3 such that it stays nearby. Thus there is an regular motion of the object where it trades potential energy for kinetic in a repeatable pattern, sort of how an object in an elliptical orbit around the earth does the same. Sorry, I don't know the details and don't have time to go deeper -- I had to do a quick review on Wikipedia to get this far.
Herschel and Planck are at Earth-Sun L2 (solar orbit), not Earth-Moon L2 (earth orbit)
Forgive me if this has already been covered, but does this mean that if we sent up materials for it that it might be possible to build ships with nuclear-powered engines, since firing them won't be on earth?
This could be awesome news in terms of getting fuel up there.
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Not to mention the coal and oil deposits discovered later.
Columbus didn't know about that stuff, and no one found out about or made use of those things until hundreds of years later.
We know a lot more about what's on the moon than Columbus (or the Spaniards) did about North America, but what we know is that it's not all that.
The moon, sadly, is kind of crappy resource-wise.
You don't know that. It's not like we've done any drilling there; all we've done is collect a few rock samples on the surface. There's probably lots of valuable minerals there, just like we've found many in the earth's crust. Most of our minerals on Earth came from meteorite bombardment; well, take a look at the moon. What do you think all those round things are? And without an atmosphere, the minerals won't be dispersed so much on the Moon, they'll be concentrated at the impact sites. There's probably lots of resources on the Moon we don't know about yet, because we haven't looked. We only recently discovered that there's water ice there; sending up a few astronauts in a half-hearted rock-gathering mission totally missed that important detail.
No, there's many other improvements too; any ship you build on Earth would have to withstand severe stresses in being launched out of the atmosphere. With a ship assembled in space, you don't have this problem; only the smaller assemblies need to withstand such stress, and that's much easier and cheaper. You don't have to build the ship to be as robust in this case.
The other big improvement is that if you have some space-based or lunar-based infrastructure, you can mine the moon or asteroids for materials to build your ships, instead of mining it on earth's surface in someone's backyard, and then lifting it out of the gravity well. Yes, developing that infrastructure is by no means trivial, but once it's in place, it'll pay for itself over time.
To turn regolith and rock into simple building supplies suitable for micro-g and airless environ, you need...considerably more.
Exactly. You need a whole infrastructure to support all that stuff and to support itself.
See, this is my minor gripe. Everybody's all about exploring. "We need to put astronauts on Mars! They'll accomplish more in a year than 50 years of Mars probes!" But, to me, this is just more of a circus.
I'd rather see us return to the Moon to stay. That means figuring out how to stay there without getting supplies every month. There's water which we can drink. There's water which we can turn into oxygen. Not sure about the nitrogen part. What will be needed to create a habitat? Above ground? Below ground? Inflatable? Solid? Some combination of the four? How will we handle electricity? Solar? Nuclear? Some combination of the two?
Can we add water to lunar soil and grow stuff in it? How will various tasty earth animals react to 1/6th G. Hell, how will human beings react to 1/6 G? Will we have more/less/the same problems we have with zero G? How can we turn lunar ores into useful metal which we could then use to build stuff?
These are all answerable questions. There's no unobtainium necessary to do any of this stuff. You build up the infrastructure on the Moon. It may take 50 years. But, in 50 years, I'd rather look up at the Moon and see a community. I think that would be much better than some flag sitting among a pile of junk on Mars.
Most of the Space Station was built in one crappy old NASA building - 4708 at MSFC, in Huntsville, AL (I used to work there). One side was the factory floor where the module and truss structure were fabricated, the other side was the clean room where the equipment was installed. No way that would cost a $ Trillion. We didn't even have robotics, it was almost all manual assembly. With modern robotics, and "seed factory" machine tools you can start with even less stuff. Seed machines take metallic asteroid metals and turn it into parts. Then robots and remote control and a few live humans assemble those into a wider range of finished machines. Eventually you can process most asteroid materials into fuel, water, oxygen, and whatever else you need.
The advantage, of course, is that Near Earth Asteroid orbits take about 100 times less energy to reach from the Earth-Moon L-2 point than the Earth itself. So it is way easier in the long run to get your supplies from the asteroids. That includes fuel to land on the Moon or go to Mars. EML2 is only 60% of the velocity to reach as the Moon's surface. It's on the way, so you may as well build a "Space Truck Stop" there.
One downside is it is outside the Earth's magnetic field, so humans would be exposed to radiation/solar flares. You will want to do most of the work by remote control until you haul back your first big load of asteroid rock, and can use that for shielding.
Most of what we consider "high tech" actually came out of WWII and the Space Race. We're in the last stages now of ideas and technologies that were originated to solve those goals. Now we need new goals.
Basic research is of course needed, but if there is no place to focus it, mankind will get bored of it. It's like making national parks but not allowing people to go to them by either telling us we're not allowed to sully their pristine nature or just plain pricing the costs to visit them too high for the average person . Eventually people will forget about the flora and fauna there and not give a shit if some toad or owl goes extinct. Out of sight, out of mind. (Sorry, no car metaphor.)
The same applies for basic research (for the most part). If people can't see it being applied somewhere eventually, they won't give a rat's ass whether funding is cut for it or not. That is what is happening now. To combat this we NEED some place to apply at least some of what we learn in a spectacular way. Then people, average people, the ones who actually pay for most of the research, can actually see some of what they are getting for the money, and how cool that stuff is; and how it is worth it. Even if only a small part is used in a new space race, it will be enough to help pull funding through for all the less glamorous areas of research.
Stop thinking rationally if you want others to pay for your stuff. They'll only do it if they get something out of it. Directly. In the U.S., national pride is huge. The more you can help fuel that, the more money people will give you. Build a space station. A real space station, not just some "let's stick our toe in the water and do a bit of research" space station. Less of a lab, and more of a one that gives meaning to the word 'station', much like train station, and begins to make space travel routine. Use the research to create that in turn to create whole new technological ecosystems (much like the Apollo series did), and help keep people interested in science so they'll pay for more. The economic benefit (if it isn't offshored by some cynical self serving idiot) is that America will have technology to sell to the rest of the world that it doesn't yet have. This in turn fuels a healthy economy which can then afford to finance basic research. But only if the economic benefits STAY in the country.
Cool sells. Space stations are cool. A nerd in some back lab is cool to many technology lovers, but even then, not all. And certainly not to most of the rest of society. Proof? People pay billions for spoiled sports stars to make millions entertaining them. This gives society a place to vent its anxieties and aggressions (even vicariously). And it is labelled cool and spectacular because it allows those human emotions in full force. Face it, some guy writing equations at a desk, or dolling out solutions from a pipette is pretty dull and boring in comparison. The science that excites is big rocket ships, robots, and risk. Give the crowds what they want, give them Orange Flavoured Tang and Space Opera and they will love you. Give them the spectator sport of science. Then you can pay for basic research. There is a grain of truth even in satire. In this case it is more like a boulder.
-- I ignore anonymous replies to my comments and postings.
The costs and resources to achieve this so far outweigh the benefits that I don't believe any rational analysis can justify it. There are many important projects on Earth that could be pursued for a thousandth of the cost and increase US national pride if that's important to you (I'm not American). Irrigating the Sahara? Cleaning up the Pacific Garbage Patch? Or just getting rid of some dictators (Mugabe?).