That may turn out to be the case, but why try to pick a winning method before anyone has tried anything?
It probably will be easier to mine the moon's pole for volatiles for bases or settlements on the moon. But what about for deep space missions, or LEO or L2 space stations? The moon's gravity well, while much smaller than the earth's, is still much bigger than any asteroid we could capture, so there would be a non-trivial delta-v requirement to get material from the moon's surface to those other outposts.
Asteroids also have some other intriguing possibilities. The NASA study mentioned using just raw asteroid material for radiation shielding. Why not go a step further and just turn an asteroid into a spaceship? It would take a larger body than the one the study considered capturing, but why not, eventually?
For Mars enthusiasts, living, working, and utilizing asteroids would be darn good practice for setting up bases on Phobos and Deimos, which themselves are quite likely captured asteroids. There's a lot of potential in working with asteroids, and I hope that whatever this venture turns out to be fulfills some of that.
They're not going to have the 20% gold problem, anyways. If you had bothered to read the study, you would have known that the asteroids targeted would be C-type, which are full of useful volatiles and organics that can be turned into handy things like water, and hydrogen, and oxygen (which also happen to be pretty good rocket fuels). Any asteroid mining isn't going to be returning stuff to earth. It's going to be using it for other purposes IN ORBIT. That's where the profit comes in: you don't have to launch 500 tons into lunar orbit at today's launch prices.
Plus, that 2.6 billion cost estimate was for a "Prime contractor design, test & build based on NASA-provided specs" with NASA insight/oversight. I'd be willing to bet that a wholly private effort could do a similar mission at a cost quite a bit less than that. (I would also point you to the NASA study that stated the cost difference between SpaceX's Falcon 9 and a NASA developed Falcon 9 was more than half.)
The study wasn't talking about mining the asteroid to return the material to Earth! The asteroid mass would be used to generate water, hydrogen, and oxygen (primarily) for use IN ORBIT, where it is far more valuable than returning x amount of minerals back to earth. It would also be used as a test bed for advancing mining tech, becoming more efficient, and driving down the cost of the next operation.
However, long term, it could very well end up being economical to return materials to earth. If any initial effort at mining of materials that are useful in orbit succeeds, then there will be an existing industrial base for mining asteroids, and the incremental cost of the next one will be less. As mining methods are refined and become more efficient and the industrial capacity in orbit expands, it becomes possible to create more and more of what you need in orbit instead of launching it from earth (which is where much of the expense comes from). Then, when all you have to do is turn the less valuable parts of an asteroid into shipping containers, load it with the more valuable stuff, add an electric propulsion system, then it might be worth returning stuff to earth.
But the bottom line is that mining asteroids is going to be most useful for getting lots of useful material in orbit (be it lunar or Lagrange points or whatnot) without having to go through the process of getting out of earth's gravity well.
Unfortunately this story is now down the page, so this probably won't be read much, but I'm going to correct the false assumption here that seems to have played a major part in this thread.
NASA does not launch military spacecraft. That job, today, falls to the United Launch Alliance (primarily, smaller payloads can go on other US commercial providers), a wholly separate organization from NASA. (ULA does occasionally launch NASA spacecraft, but at that point, NASA is simply a customer who is buying a ride to orbit.) The last time NASA itself launched a military payload was STS-53 in 1992. Since then, all payloads have gone up on unmanned Air-force or commercial launch vehicles. (Why is this? Challenger. The military did not want to be grounded for another two years if another shuttle had an accident.)
So no, we do not need NASA for national security, and have not since 1992.
Back to the point of the main article, I find it interesting that congress appears to be perfectly happy to send hundreds of millions of dollars to Russia for rides to orbit, but have to be dragged kicking a screaming to let NASA pay some American companies to develop the same capability, possibly for even cheaper (i.e. SpaceX's goal of 20-30 million per seat to the ISS)
Though a vehicle may be designed to work in 0.38 earth gravity, that doesn't mean it will collapse or otherwise not work in standard earth conditions. Most often the structural driver for spacecraft, rovers, etc is the launch vehicle environment. Curiosity will be going up on an Atlas V, which will subject the rover to 5-6 G and a strenuous acoustic, shock, and vibration environment. In addition to the launch loads, it also has to survive the sky-crane landing on the surface of Mars. So it really isn't too surprising that it can support its own weight on earth.
Neat. Anyone have an order-of-magnitude idea if this could be used for stationkeeping on sats in Earth orbit or for attitude control in deep space missions? Just wondering if it produces enough torque to control a real spacecraft. IIRC, for most spacecraft fuel for attitude control is the limiting factor on mission duration, and I think in some cases (e.g., Kepler) it's the only expendable.
You are correct that fuel for attitude control is generally the limiting factor for spacecraft (useable) lifetime. Using solar sails for attitude control would be possible, I think, for spacecraft operating far enough away from a planetary atmosphere. Otherwise, drag from the sail would certainly overwhelm solar pressure. So, though it may be possible, I'm not sure how economical it would be to use for stationkeeping. I would be interested in seeing a trade study between electric propulsion (another low thrust over long duration type system) and solar sails. Solar sails would probably mass more and take up more volume than an equivalent EP system, but would not require nearly as much electrical power, which would reduce solar panel size and save some mass and volume there. Bottom line, though, is that with the state of solar sail tech right now, it'll be a while before anyone tries using solar sails in such a manner. Most solar sail applications I think you'll see is as the main propulsion system getting craft between planets. That's where the greatest benefit of low thrust, but long duration burns that don't require propellant or little to no electric power will be.
Could a spacecraft using this technique have virtually unlimited life? If you're solar powered and don't burn fuel, what limits lifetime-- dust on the solar arrays? Battery degradation?
Aside from propellant, the big limit is degradation of solar panel generation capacity (from atomic oxygen, radiation, etc) and battery capacity that also degrades over time. Moving parts (like momentum or reaction wheels that control spacecraft pointing) can also wear out. Space is hard on lubricants. Then there are things that can ruin your day like computer errors from radiation effects (like the Galaxy 15 spacecraft) and impacts from space debris. So while eliminating the need for attitude control propellant will improve spacecraft life and is a worthwhile endeavor, don't count on getting unlimited spacecraft life any time soon.
One thing I haven't seen discussed is that once this rocket is built, what the hell is going to fly on it? I don't see any mention of funding for building a 75mT payload that will then be ready to fly when the rocket is. Right now, all I see happening is that this giant rocket will be built and then will sit around for years waiting for something large enough to fly on it to be built.
Which raises another question: Do we even need it? What's the point in having a giant rocket without giant payloads to fly? What I would like to see is a study comparing the cost and timescale of doing the following two options:
1) Build this huge rocket, utilizing the expensive legacy shuttle hardware. Then design and build a huge payload as justification for your huge rocket. (Sound familiar, sort of like the ISS-Space shuttle relationship?) Fly this huge rocket a couple times per year, making you unable to amortize fixed costs (launch pads, support personnel, etc) over more launches. If the launcher fails, you've lost 75 mT of payload. Ouch. So you'll also need to spend more money making extra-sure that it'll succeed. Oh, and if you fail, your mission is completely grounded until the vehicle is fixed and re-tested and certified for flight again, because there are no other 75mT capacity launchers in existence.
2) Start designing and building payloads that will fit on existing (or near future) commercial launchers. Start a market for even more launches. Let some economies of scale come into the picture and reduce launch costs for you. Let commercial companies compete and bid for your business. If the launcher fails, you've lost a lot less payload than in option 1. Inconvenient, but not as devastating as losing option one's super-launcher. Also, if one of your commercial launchers does fail, you have some more to choose from to launch things in the meantime while the failed rocket is investigated, fixed, re-tested and re-certified. Your entire program does not have to grind to a halt while the launcher is fixed.
Now, which of those options would result in more activity in space? Personally, I think option 2 would be the way to go. More opportunity for cost saving. No single point of failure to get your stuff into orbit. You can start designing payloads to go up right away, instead of waiting for the funding to become available after your shuttle-derived super launcher is ready.
But, of course, what I wrote above does not matter to congress. All they care about is: Does this program pay back my donors enough for them to keep supporting me?
What trade studies were done that decided a 75mT payload capacity was needed as opposed to a 50 or 60mT? Is there a linear increase in cost vs. payload capacity? Is 75mT some sort of optimum, balancing cost vs. development time vs. existing hardware capabilities?
Or is it a number pulled out of someone's ass?
Arguing requirement vs. design is mostly semantics at this point. What matters is where the number came from and what sort of analysis went into it (if any).
Likely the FCC because the vast majority of commercial spacecraft are communications spacecraft. That means the FCC already regulates power/frequency allocation for ground and inter-spacecraft communication for those spacecraft.
Except that the method of government support in the past is completely different from what the FTC is suggesting here. Your own link talks about how support was given by publishing contracts to print laws, proclamations, etc, as well as reduced mailing costs and tax exemptions. What the FTC is talking about are direct bailouts and artificial restrictions on information (copyrighting facts). Seems to me that this is the antithesis of the spirit in which the early American government promoted the free press.
Proven approaches to what? Orbital fuel depots and refueling, inflatable aero shells, tens of kW electric propulsion for manned missions, and inflatable habitats don't have proven approaches yet. That's the whole point of these kinds of programs. The only way NASA will be able to stay with "proven approaches" is to remain in LEO and build carbon-copy ISSs. Even then, I remain far from convinced that what NASA does today should be considered a "proven approach" to manned spaceflight. While they've done some amazing things, human spaceflight still remains rare and hideously expensive. I would prefer that not be the approach to such matters going into the future.
I'm disappointed in both of the linked articles. Some real substance about the design would have been nice, but as it is, I'm left with a lot of questions:
-70% less fuel? How much of that is aerodynamic savings and how much of that is engine efficiency savings?
-Did they do any wind tunnel testing of their model? How close were their CFD and tunnel test results?
-Are they using engines based closely off existing ones, or are they projecting fuel savings 25 years into the future (the 2035 time frame from the article)?
-What sort of structural weight-saving advances are they assuming, or projecting from?
-So they made the tail smaller, what makes up for the reduction in control authority there?
-Plus other more detailed questions based on the answers to those questions. Would it have been so hard for MIT to link a design document pdf or something? I guess not being a public university, they don't have to if they don't want to. Too bad.
All that is true. I never said it would be easy, just that it would be the ideal solution (aside from actually repairing the thing and putting it back in service, which is even harder). This whole incident is a good example of just how useful lower launch costs would be. Then it may just be economical to have a rendezvous craft on standby (or ready to go within a week or two) to deal with malfunctioning spacecraft.
In fact, with more reasonable launch costs, you could build a whole series of spacecraft designed to rendezvous and dispose of dead spacecraft. Basically all spacecraft have a ready-made attachment interface (the launch vehicle attach point) to latch onto. I've seen some pretty decent advances in close-in autonomous spacecraft navigation, which would be the largest technical challenge of the project. You wouldn't need to design for a long orbital life, which will ease quite a few other requirements. Solving the technical challenges would be the easy part, really. It's the business case that's hard with high launch costs and whatnot.
Sigh. It's just too bad it's not economical. It'd be a lot of fun to design and build something like that...
as I posted just above, to dispose of a spacecraft from GEO, you put it into a higher orbit above GEO where you won't be in the way of any other operational spacecraft. This is the best compromise between the amount of fuel it takes to dispose of a spacecraft and putting it somewhere where it won't cause harm. Ideally, I suppose, you would want to completely deorbit, but that would take a whole lot of fuel, eating up weight that could be used for payload. You could also send it into an earth escape orbit (put it into orbit around the sun, essentially), but that also takes a lot of fuel.
FYI, I am an aerospace engineer involved in the launch industry. Typically, how a spacecraft gets into GEO is a few stage process. First, a launch vehicle (Delta IV, Atlas V, Ariane 5, etc) puts you into orbit. What almost always happens is that the orbit the launch vehicle deposits the satellite into is a geosynchronous transfer orbit. This orbit is only useful as a, yes, transfer orbit out to actual geosynchronous orbit. From the transfer orbit, the spacecraft's own propulsion system then manuevers the craft into its designated position in GEO. But the launch vehicle itself is long gone. It takes all the delta-v the launch vehicle can deliver just to get the spacecraft into the GEO transfer orbit, so it would not be useful for doing anything else in orbit.
The best way to deal with this rogue satellite would be to send out another one to very gently attach itself to the rogue and then push it into a disposal orbit (which for GEO is typically just a higher orbit outside GEO). Blowing up the rogue would only create a huge amount of debris that would then cause problems for basically everyone in GEO, since it couldn't all be tracked or controlled.
Constellation would have done more to kill NASA than anything in Obama's new plan. Constellation was already over budget and behind schedule. If a fully developed Ares rocket had been dropped in NASA's lap, it wouldn't have been able to afford to operate it. So what do you think the next admin would do with NASA if it had been allowed to continue, accumulating delays and going further and further over budget?
The new plan is the best chance NASA has had in a long time to get back on its feet and stop languishing in LEO. Developing the higher technology needed to go beyond LEO and the moon is what NASA should be concentrating on. Let commercial companies deliver stuff to ISS and LEO.
(One a side note, it seems to me that almost everyone who hates Obama's plan forgets that there would have been just as long, if not longer, gap in US human spaceflight ability WITH constellation. We're not exactly losing a whole lot by giving commercial companies time to produce their human ferrying ability, as opposed to giving NASA time to work on Ares-1)
With NASA buying rides at a few tens of millions each vs. billion+ per launch there will be a lot more money for accomplishing things besides putting stuff into orbit on a rocket with a NASA logo on it.
So I'm all for the new plan. My biggest worry is that congress will screw up the whole thing trying to protect their pork.
While it may be cool to find life on Mars, it would present some additional problems for future colonization (or even just future missions, robotic or otherwise). If we do find life, do we quarantine Mars so that we don't contaminate the native life there? Do we bar ourselves from any terraforming efforts whatsoever so that we don't disrupt possible existing life? You all must realize that that would be the position of at least some people; what percentage of the public that might be, and the influence they would have is another question.
Generally, I think it would be much simpler if we never found life on Mars, and could in fact say with a fair amount of certainty that it is completely dead. That would remove a (possibly significant) reason to oppose human colonization and terraforming.
Why do so many people think that if there isn't a NASA plan to put a couple NASA astronauts on a NASA rocket and launch them to a specific NASA-picked destination by a specific time that we've somehow abandoned human spaceflight? How short-sighted can people be? We already did that 40 years ago, and where did it get us? The huge expense caused the cancellation of any real followup missions and damaged human spaceflight aspirations to this day. We're still seeing the effects, since apparently no one in congress (or much of the public, apparently) can imagine anyone except NASA putting people into space.
It just pisses me off to no end. We need a space program that opens access to space for EVERYONE. Not just the few lucky NASA picked government employees. Do you want to go into space at some point? I certainly do, and constellation had zero chance of ever letting me do that. Maybe you think constellation would have opened access to space and expanded the possibilities for the rest of us, but I think you are wrong. So, so wrong. The current plan for NASA has the best chance of anything NASA has done since its creation of truly opening access to space. New technologies, reducing cost, encouraging multiple options for access to orbit. That's what NASA's goal should be and needs to be. Not a repeat of Apollo. Not another huge expense for flags, footprints, and some neat video that ends up getting 5 minutes on the evening news.
So there's my rant. Take it or leave it.
Constellation was just "Apollo on steroids", as described by Griffin. How does sending a few government employees to the moon help open access to space for everyone? That should be the point, not just going to the moon for the sake of planting flags and making footprints (or "boldly going").
And perhaps the private sector would have gone to the moon, had they been given 150 billion dollars (apollo cost) and a mandate to go there ASAP. But it was NASA that was given the money and the mandate, so they went. And where did it get us, ultimately? There hasn't been a single person past LEO since. Sounds to me like a different approach is needed. Perhaps one that builds and refines basic technologies, opening access to space and making it cheaper and easier to operate there. That way, when we do go back, we go back to stay.
This new program is far better than the old one. It is so very heartening to see in a NASA program a stated goal to reduce the cost of human spaceflight, along with R&D of enabling technologies (orbital refueling, etc). NASA is finally shifting its human spaceflight focus in the right direction. As I've heard said before, it's not NASA's job to put a man on Mars (or the moon). It's NASA's job to make it possible for National Geographic to put a man on Mars.
Now congress just has to not be a bunch of idiots and ruin it (possibly the greatest challenge to human spaceflight yet).
Here's to hoping that this kind of drastic cutting will finally spark some national debate (and perhaps a decision) on what we want our space program (specifically, the human spaceflight program) to do. There are a number of options as I see it:
1) Support earth activities (science/climate/earth observation/etc)
2) Jobs program and political/economic tool
3) Brief exploration for national pride (Apollo moon shots)
4) Enabling permanent, sustained human presence in space (colonization)
Right now, our space program is pretty much just a combination of options 1 and 2. My personal belief is that it should be 4. If humanity is to ultimately survive, or even just take full advantage of the resources and opportunities that space offers, then a permanent human presence in space will be required. Constellation, as it stands now, would likely only lead to options 2 and 3.
The most encouraging part of that article was:
One administration official said the budget will send a message that it's time members of Congress recognize that NASA can't design space programs to create jobs in their districts.
This has been NASA's biggest problem. Congress doesn't want to do anything with NASA that might upset the status quo of job distribution in their districts (along with those stupid cost plus contracts). It's high time that NASA get a cleaning and reorganization around a defined goal that will accomplish something in space. (And there's a whole other side rant about how going to the moon/mars as a goal is useless. Those are destinations/places to operate in fulfillment of the goal of colonization or resource utilization or just "exploration")
I think it's also worth pointing out Elon Musk's rebuttal to the findings of this NASA safety panel. I'm glad to see someone in the private spaceflight industry has the cajones to call BS when he sees it.
You may not be a rocket scientist, but I am, so let me clarify a few things here.
You seem to be confusing ULA and NASA launch efforts here. The Atlas V and Delta IV EELVs are commercial designs. Titan is retired, never to be launched again, and the future (and ultimate feasibility) of Ares I or V remains uncertain. Also, under point 6, Atlas and Atlas-Centaur are the same thing. Atlas refers to the first stage booster and Centaur is the second stage.
Drastically increasing the launch schedule of EELVs would be a tall order, necessitating a great deal of infrastructure development. Where all the money for this, and all these extra payloads you'd like to launch, will come from I have no idea. Right now the gov't is up to its eyeballs in debt, and is rapidly increasing that debt bailing out automakers, banks, and lining congressional districts with cash for votes. I'd love you see the increase in launches just as much as you would (it'd keep me employed), but it's certainly not realistic.
But I have to take issue with the basic premise that seemingly underlies your post here, which is that NASA (or the gov't in general) needs to be the one designing, building, and launching these rockets. Why? Why limit the launch industry to one or two designs with the NASA-approved stamp on them? (Which may or may not be the best vehicles for putting things and/or people into orbit.) Why not promote competition and increase the demand for vehicles in the launch industry by getting NASA out of the launch business altogether. Make NASA a purchaser of rides, not a supplier. The launch industry can then build and fly the designs it wants and let a multitude of designs compete. My dream would be to see another few Space-Xs pop up in the next few years. Thankfully we're actually starting to see a little bit of what I want with the ISS resupply contracts to Space-X and Orbital. I would be even happier, though, if NASA were out of the launch business altogether.
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That may turn out to be the case, but why try to pick a winning method before anyone has tried anything?
It probably will be easier to mine the moon's pole for volatiles for bases or settlements on the moon. But what about for deep space missions, or LEO or L2 space stations? The moon's gravity well, while much smaller than the earth's, is still much bigger than any asteroid we could capture, so there would be a non-trivial delta-v requirement to get material from the moon's surface to those other outposts.
Asteroids also have some other intriguing possibilities. The NASA study mentioned using just raw asteroid material for radiation shielding. Why not go a step further and just turn an asteroid into a spaceship? It would take a larger body than the one the study considered capturing, but why not, eventually?
For Mars enthusiasts, living, working, and utilizing asteroids would be darn good practice for setting up bases on Phobos and Deimos, which themselves are quite likely captured asteroids. There's a lot of potential in working with asteroids, and I hope that whatever this venture turns out to be fulfills some of that.
They're not going to have the 20% gold problem, anyways. If you had bothered to read the study, you would have known that the asteroids targeted would be C-type, which are full of useful volatiles and organics that can be turned into handy things like water, and hydrogen, and oxygen (which also happen to be pretty good rocket fuels). Any asteroid mining isn't going to be returning stuff to earth. It's going to be using it for other purposes IN ORBIT. That's where the profit comes in: you don't have to launch 500 tons into lunar orbit at today's launch prices.
Plus, that 2.6 billion cost estimate was for a "Prime contractor design, test & build based on NASA-provided specs" with NASA insight/oversight. I'd be willing to bet that a wholly private effort could do a similar mission at a cost quite a bit less than that. (I would also point you to the NASA study that stated the cost difference between SpaceX's Falcon 9 and a NASA developed Falcon 9 was more than half.)
The study wasn't talking about mining the asteroid to return the material to Earth! The asteroid mass would be used to generate water, hydrogen, and oxygen (primarily) for use IN ORBIT, where it is far more valuable than returning x amount of minerals back to earth. It would also be used as a test bed for advancing mining tech, becoming more efficient, and driving down the cost of the next operation.
However, long term, it could very well end up being economical to return materials to earth. If any initial effort at mining of materials that are useful in orbit succeeds, then there will be an existing industrial base for mining asteroids, and the incremental cost of the next one will be less. As mining methods are refined and become more efficient and the industrial capacity in orbit expands, it becomes possible to create more and more of what you need in orbit instead of launching it from earth (which is where much of the expense comes from). Then, when all you have to do is turn the less valuable parts of an asteroid into shipping containers, load it with the more valuable stuff, add an electric propulsion system, then it might be worth returning stuff to earth.
But the bottom line is that mining asteroids is going to be most useful for getting lots of useful material in orbit (be it lunar or Lagrange points or whatnot) without having to go through the process of getting out of earth's gravity well.
Unfortunately this story is now down the page, so this probably won't be read much, but I'm going to correct the false assumption here that seems to have played a major part in this thread.
NASA does not launch military spacecraft. That job, today, falls to the United Launch Alliance (primarily, smaller payloads can go on other US commercial providers), a wholly separate organization from NASA. (ULA does occasionally launch NASA spacecraft, but at that point, NASA is simply a customer who is buying a ride to orbit.) The last time NASA itself launched a military payload was STS-53 in 1992. Since then, all payloads have gone up on unmanned Air-force or commercial launch vehicles. (Why is this? Challenger. The military did not want to be grounded for another two years if another shuttle had an accident.)
So no, we do not need NASA for national security, and have not since 1992.
Back to the point of the main article, I find it interesting that congress appears to be perfectly happy to send hundreds of millions of dollars to Russia for rides to orbit, but have to be dragged kicking a screaming to let NASA pay some American companies to develop the same capability, possibly for even cheaper (i.e. SpaceX's goal of 20-30 million per seat to the ISS)
Though a vehicle may be designed to work in 0.38 earth gravity, that doesn't mean it will collapse or otherwise not work in standard earth conditions. Most often the structural driver for spacecraft, rovers, etc is the launch vehicle environment. Curiosity will be going up on an Atlas V, which will subject the rover to 5-6 G and a strenuous acoustic, shock, and vibration environment. In addition to the launch loads, it also has to survive the sky-crane landing on the surface of Mars. So it really isn't too surprising that it can support its own weight on earth.
Neat. Anyone have an order-of-magnitude idea if this could be used for stationkeeping on sats in Earth orbit or for attitude control in deep space missions? Just wondering if it produces enough torque to control a real spacecraft. IIRC, for most spacecraft fuel for attitude control is the limiting factor on mission duration, and I think in some cases (e.g., Kepler) it's the only expendable.
You are correct that fuel for attitude control is generally the limiting factor for spacecraft (useable) lifetime. Using solar sails for attitude control would be possible, I think, for spacecraft operating far enough away from a planetary atmosphere. Otherwise, drag from the sail would certainly overwhelm solar pressure. So, though it may be possible, I'm not sure how economical it would be to use for stationkeeping. I would be interested in seeing a trade study between electric propulsion (another low thrust over long duration type system) and solar sails. Solar sails would probably mass more and take up more volume than an equivalent EP system, but would not require nearly as much electrical power, which would reduce solar panel size and save some mass and volume there. Bottom line, though, is that with the state of solar sail tech right now, it'll be a while before anyone tries using solar sails in such a manner. Most solar sail applications I think you'll see is as the main propulsion system getting craft between planets. That's where the greatest benefit of low thrust, but long duration burns that don't require propellant or little to no electric power will be.
Could a spacecraft using this technique have virtually unlimited life? If you're solar powered and don't burn fuel, what limits lifetime-- dust on the solar arrays? Battery degradation?
Aside from propellant, the big limit is degradation of solar panel generation capacity (from atomic oxygen, radiation, etc) and battery capacity that also degrades over time. Moving parts (like momentum or reaction wheels that control spacecraft pointing) can also wear out. Space is hard on lubricants. Then there are things that can ruin your day like computer errors from radiation effects (like the Galaxy 15 spacecraft) and impacts from space debris. So while eliminating the need for attitude control propellant will improve spacecraft life and is a worthwhile endeavor, don't count on getting unlimited spacecraft life any time soon.
One thing I haven't seen discussed is that once this rocket is built, what the hell is going to fly on it? I don't see any mention of funding for building a 75mT payload that will then be ready to fly when the rocket is. Right now, all I see happening is that this giant rocket will be built and then will sit around for years waiting for something large enough to fly on it to be built.
Which raises another question: Do we even need it? What's the point in having a giant rocket without giant payloads to fly? What I would like to see is a study comparing the cost and timescale of doing the following two options:
1) Build this huge rocket, utilizing the expensive legacy shuttle hardware. Then design and build a huge payload as justification for your huge rocket. (Sound familiar, sort of like the ISS-Space shuttle relationship?) Fly this huge rocket a couple times per year, making you unable to amortize fixed costs (launch pads, support personnel, etc) over more launches. If the launcher fails, you've lost 75 mT of payload. Ouch. So you'll also need to spend more money making extra-sure that it'll succeed. Oh, and if you fail, your mission is completely grounded until the vehicle is fixed and re-tested and certified for flight again, because there are no other 75mT capacity launchers in existence.
2) Start designing and building payloads that will fit on existing (or near future) commercial launchers. Start a market for even more launches. Let some economies of scale come into the picture and reduce launch costs for you. Let commercial companies compete and bid for your business. If the launcher fails, you've lost a lot less payload than in option 1. Inconvenient, but not as devastating as losing option one's super-launcher. Also, if one of your commercial launchers does fail, you have some more to choose from to launch things in the meantime while the failed rocket is investigated, fixed, re-tested and re-certified. Your entire program does not have to grind to a halt while the launcher is fixed.
Now, which of those options would result in more activity in space? Personally, I think option 2 would be the way to go. More opportunity for cost saving. No single point of failure to get your stuff into orbit. You can start designing payloads to go up right away, instead of waiting for the funding to become available after your shuttle-derived super launcher is ready.
But, of course, what I wrote above does not matter to congress. All they care about is: Does this program pay back my donors enough for them to keep supporting me?
What trade studies were done that decided a 75mT payload capacity was needed as opposed to a 50 or 60mT? Is there a linear increase in cost vs. payload capacity? Is 75mT some sort of optimum, balancing cost vs. development time vs. existing hardware capabilities?
Or is it a number pulled out of someone's ass?
Arguing requirement vs. design is mostly semantics at this point. What matters is where the number came from and what sort of analysis went into it (if any).
Likely the FCC because the vast majority of commercial spacecraft are communications spacecraft. That means the FCC already regulates power/frequency allocation for ground and inter-spacecraft communication for those spacecraft.
The FCC calls for all US-registered spacecraft to be disposed of at the end of its useful life. This means either decay into the atmosphere within a specific amount of time (25 years, I think) or placement into a "disposal" orbit. For geosynchronous spacecraft, that disposal orbit is one slightly higher, getting it out of the way of operational spacecraft.
Except that the method of government support in the past is completely different from what the FTC is suggesting here. Your own link talks about how support was given by publishing contracts to print laws, proclamations, etc, as well as reduced mailing costs and tax exemptions. What the FTC is talking about are direct bailouts and artificial restrictions on information (copyrighting facts). Seems to me that this is the antithesis of the spirit in which the early American government promoted the free press.
Proven approaches to what? Orbital fuel depots and refueling, inflatable aero shells, tens of kW electric propulsion for manned missions, and inflatable habitats don't have proven approaches yet. That's the whole point of these kinds of programs. The only way NASA will be able to stay with "proven approaches" is to remain in LEO and build carbon-copy ISSs. Even then, I remain far from convinced that what NASA does today should be considered a "proven approach" to manned spaceflight. While they've done some amazing things, human spaceflight still remains rare and hideously expensive. I would prefer that not be the approach to such matters going into the future.
Instead of blowing money on re-inventing the wheel, except much more expensively... *cough* Ares-1
I'm disappointed in both of the linked articles. Some real substance about the design would have been nice, but as it is, I'm left with a lot of questions:
-70% less fuel? How much of that is aerodynamic savings and how much of that is engine efficiency savings?
-Did they do any wind tunnel testing of their model? How close were their CFD and tunnel test results?
-Are they using engines based closely off existing ones, or are they projecting fuel savings 25 years into the future (the 2035 time frame from the article)?
-What sort of structural weight-saving advances are they assuming, or projecting from?
-So they made the tail smaller, what makes up for the reduction in control authority there?
-Plus other more detailed questions based on the answers to those questions. Would it have been so hard for MIT to link a design document pdf or something? I guess not being a public university, they don't have to if they don't want to. Too bad.
All that is true. I never said it would be easy, just that it would be the ideal solution (aside from actually repairing the thing and putting it back in service, which is even harder). This whole incident is a good example of just how useful lower launch costs would be. Then it may just be economical to have a rendezvous craft on standby (or ready to go within a week or two) to deal with malfunctioning spacecraft.
In fact, with more reasonable launch costs, you could build a whole series of spacecraft designed to rendezvous and dispose of dead spacecraft. Basically all spacecraft have a ready-made attachment interface (the launch vehicle attach point) to latch onto. I've seen some pretty decent advances in close-in autonomous spacecraft navigation, which would be the largest technical challenge of the project. You wouldn't need to design for a long orbital life, which will ease quite a few other requirements. Solving the technical challenges would be the easy part, really. It's the business case that's hard with high launch costs and whatnot.
Sigh. It's just too bad it's not economical. It'd be a lot of fun to design and build something like that...
as I posted just above, to dispose of a spacecraft from GEO, you put it into a higher orbit above GEO where you won't be in the way of any other operational spacecraft. This is the best compromise between the amount of fuel it takes to dispose of a spacecraft and putting it somewhere where it won't cause harm. Ideally, I suppose, you would want to completely deorbit, but that would take a whole lot of fuel, eating up weight that could be used for payload. You could also send it into an earth escape orbit (put it into orbit around the sun, essentially), but that also takes a lot of fuel.
FYI, I am an aerospace engineer involved in the launch industry. Typically, how a spacecraft gets into GEO is a few stage process. First, a launch vehicle (Delta IV, Atlas V, Ariane 5, etc) puts you into orbit. What almost always happens is that the orbit the launch vehicle deposits the satellite into is a geosynchronous transfer orbit. This orbit is only useful as a, yes, transfer orbit out to actual geosynchronous orbit. From the transfer orbit, the spacecraft's own propulsion system then manuevers the craft into its designated position in GEO. But the launch vehicle itself is long gone. It takes all the delta-v the launch vehicle can deliver just to get the spacecraft into the GEO transfer orbit, so it would not be useful for doing anything else in orbit.
The best way to deal with this rogue satellite would be to send out another one to very gently attach itself to the rogue and then push it into a disposal orbit (which for GEO is typically just a higher orbit outside GEO). Blowing up the rogue would only create a huge amount of debris that would then cause problems for basically everyone in GEO, since it couldn't all be tracked or controlled.
Constellation would have done more to kill NASA than anything in Obama's new plan. Constellation was already over budget and behind schedule. If a fully developed Ares rocket had been dropped in NASA's lap, it wouldn't have been able to afford to operate it. So what do you think the next admin would do with NASA if it had been allowed to continue, accumulating delays and going further and further over budget?
The new plan is the best chance NASA has had in a long time to get back on its feet and stop languishing in LEO. Developing the higher technology needed to go beyond LEO and the moon is what NASA should be concentrating on. Let commercial companies deliver stuff to ISS and LEO.
(One a side note, it seems to me that almost everyone who hates Obama's plan forgets that there would have been just as long, if not longer, gap in US human spaceflight ability WITH constellation. We're not exactly losing a whole lot by giving commercial companies time to produce their human ferrying ability, as opposed to giving NASA time to work on Ares-1)
With NASA buying rides at a few tens of millions each vs. billion+ per launch there will be a lot more money for accomplishing things besides putting stuff into orbit on a rocket with a NASA logo on it.
So I'm all for the new plan. My biggest worry is that congress will screw up the whole thing trying to protect their pork.
While it may be cool to find life on Mars, it would present some additional problems for future colonization (or even just future missions, robotic or otherwise). If we do find life, do we quarantine Mars so that we don't contaminate the native life there? Do we bar ourselves from any terraforming efforts whatsoever so that we don't disrupt possible existing life? You all must realize that that would be the position of at least some people; what percentage of the public that might be, and the influence they would have is another question.
Generally, I think it would be much simpler if we never found life on Mars, and could in fact say with a fair amount of certainty that it is completely dead. That would remove a (possibly significant) reason to oppose human colonization and terraforming.
Why do so many people think that if there isn't a NASA plan to put a couple NASA astronauts on a NASA rocket and launch them to a specific NASA-picked destination by a specific time that we've somehow abandoned human spaceflight? How short-sighted can people be? We already did that 40 years ago, and where did it get us? The huge expense caused the cancellation of any real followup missions and damaged human spaceflight aspirations to this day. We're still seeing the effects, since apparently no one in congress (or much of the public, apparently) can imagine anyone except NASA putting people into space.
It just pisses me off to no end. We need a space program that opens access to space for EVERYONE. Not just the few lucky NASA picked government employees. Do you want to go into space at some point? I certainly do, and constellation had zero chance of ever letting me do that. Maybe you think constellation would have opened access to space and expanded the possibilities for the rest of us, but I think you are wrong. So, so wrong. The current plan for NASA has the best chance of anything NASA has done since its creation of truly opening access to space. New technologies, reducing cost, encouraging multiple options for access to orbit. That's what NASA's goal should be and needs to be. Not a repeat of Apollo. Not another huge expense for flags, footprints, and some neat video that ends up getting 5 minutes on the evening news. So there's my rant. Take it or leave it.
Constellation was just "Apollo on steroids", as described by Griffin. How does sending a few government employees to the moon help open access to space for everyone? That should be the point, not just going to the moon for the sake of planting flags and making footprints (or "boldly going").
And perhaps the private sector would have gone to the moon, had they been given 150 billion dollars (apollo cost) and a mandate to go there ASAP. But it was NASA that was given the money and the mandate, so they went. And where did it get us, ultimately? There hasn't been a single person past LEO since. Sounds to me like a different approach is needed. Perhaps one that builds and refines basic technologies, opening access to space and making it cheaper and easier to operate there. That way, when we do go back, we go back to stay.
This new program is far better than the old one. It is so very heartening to see in a NASA program a stated goal to reduce the cost of human spaceflight, along with R&D of enabling technologies (orbital refueling, etc). NASA is finally shifting its human spaceflight focus in the right direction. As I've heard said before, it's not NASA's job to put a man on Mars (or the moon). It's NASA's job to make it possible for National Geographic to put a man on Mars.
Now congress just has to not be a bunch of idiots and ruin it (possibly the greatest challenge to human spaceflight yet).
1) Support earth activities (science/climate/earth observation/etc)
2) Jobs program and political/economic tool
3) Brief exploration for national pride (Apollo moon shots)
4) Enabling permanent, sustained human presence in space (colonization)
Right now, our space program is pretty much just a combination of options 1 and 2. My personal belief is that it should be 4. If humanity is to ultimately survive, or even just take full advantage of the resources and opportunities that space offers, then a permanent human presence in space will be required. Constellation, as it stands now, would likely only lead to options 2 and 3.
The most encouraging part of that article was:
One administration official said the budget will send a message that it's time members of Congress recognize that NASA can't design space programs to create jobs in their districts.
This has been NASA's biggest problem. Congress doesn't want to do anything with NASA that might upset the status quo of job distribution in their districts (along with those stupid cost plus contracts). It's high time that NASA get a cleaning and reorganization around a defined goal that will accomplish something in space. (And there's a whole other side rant about how going to the moon/mars as a goal is useless. Those are destinations/places to operate in fulfillment of the goal of colonization or resource utilization or just "exploration")
I think it's also worth pointing out Elon Musk's rebuttal to the findings of this NASA safety panel. I'm glad to see someone in the private spaceflight industry has the cajones to call BS when he sees it.
You may not be a rocket scientist, but I am, so let me clarify a few things here.
You seem to be confusing ULA and NASA launch efforts here. The Atlas V and Delta IV EELVs are commercial designs. Titan is retired, never to be launched again, and the future (and ultimate feasibility) of Ares I or V remains uncertain. Also, under point 6, Atlas and Atlas-Centaur are the same thing. Atlas refers to the first stage booster and Centaur is the second stage.
Drastically increasing the launch schedule of EELVs would be a tall order, necessitating a great deal of infrastructure development. Where all the money for this, and all these extra payloads you'd like to launch, will come from I have no idea. Right now the gov't is up to its eyeballs in debt, and is rapidly increasing that debt bailing out automakers, banks, and lining congressional districts with cash for votes. I'd love you see the increase in launches just as much as you would (it'd keep me employed), but it's certainly not realistic.
But I have to take issue with the basic premise that seemingly underlies your post here, which is that NASA (or the gov't in general) needs to be the one designing, building, and launching these rockets. Why? Why limit the launch industry to one or two designs with the NASA-approved stamp on them? (Which may or may not be the best vehicles for putting things and/or people into orbit.) Why not promote competition and increase the demand for vehicles in the launch industry by getting NASA out of the launch business altogether. Make NASA a purchaser of rides, not a supplier. The launch industry can then build and fly the designs it wants and let a multitude of designs compete. My dream would be to see another few Space-Xs pop up in the next few years. Thankfully we're actually starting to see a little bit of what I want with the ISS resupply contracts to Space-X and Orbital. I would be even happier, though, if NASA were out of the launch business altogether.