Asteroid Missions May Replace Lunar Base Plans 237
An anonymous reader alerts us to a story about efforts to modify the United States' space exploration plans to focus on asteroid missions rather than a lunar base. Scientists, astronauts, and former NASA division directors will be meeting next month to develop an alternative to the Bush administration's Vision for Space Exploration. We have previously discussed the possibility of a manned asteroid mission. Quoting:
"Numerous planetary managers told Aviation Week & Space Technology they now fear a manned Moon base and even shorter sorties to the Moon will bog down the space program for decades and inhibit, rather than facilitate, manned Mars operations--the ultimate goal of both the Bush and alternative visions. The first lunar sortie would be flown by about 2020 under the Bush plan. If alternative-vision planners have their way, the mission could instead be flown to an asteroid in about 2025."
So... (Score:4, Insightful)
Re:A great idea (Score:3, Insightful)
Re:So it begins (Score:4, Insightful)
Re:A little sad (Score:4, Insightful)
Both missions has their merits (Score:5, Insightful)
The only problem with an unmanned asteroid mission is that it may require some human decision from time to time - but normally there is no problem with time delays there. Not much that's in a hurry on an asteroid unless it's heading for Earth. Just put the robot to sleep for a while and recharge the batteries. Keep in mind that there may have to be different robots there compared to the robots we have on Mars.
The thing that's more interesting with a permanent moon-base is that there is a possibility that a lot of the material found on the moon can be used as construction material. It will require a processing plant - and it can't be used for everything, but it's there. Much of the soil is composed from oxides - which means that you can extract oxygen. Allocation of area for growth is no big problem either. The catch is that all this may have a high cost. But what is the cost when the Chinese decides that it's their turn to go to the moon?
Re:So... (Score:2, Insightful)
Perfection is difficult. But George W Bush is as close to a perfect fool as I want to see in my lifetime in charge of any major country.
In any case, the reason for going to the Asteroids instead of the Moon is that it is a probably a more effective way to spend money. We've been to the moon. What major unanswered questions do we have about the moon? None that I know of. Colonization? We aren't going to build a viable lunar colony with our current technology base any more than the Vikings were going to use their base in Labrador to colonize Malibu Beach The Asteroids surely have a higher payoff scientifically and possibly financially as well.
Signs of intelligent life at NASA after all these decades. Didn't see THAT coming.
Re:A little sad (Score:5, Insightful)
Re:A little sad (Score:4, Insightful)
What's the Goal? (Score:5, Insightful)
I want a Moonbase!
Re:So... (Score:5, Insightful)
The Moon will certainly be useful someday - for mining, for energy collection, for tourism, for pure science...but it isn't a useful stop on the way to Mars, nor has it ever been. We've looked at the Moon in recent years for two reasons, both interrelated: first, the big contractors (Lockheed, Boeing, Raytheon, etc.) figure they can bleed us for the Moon and increase their profits before ever beginning the Mars project. Second, the U.S., and humanity in general, suffers from acute myopia and timidity.
We can go to Mars, and we can start NOW. No need for holes on the Moon into which we pour money...and more importantly, time.
Re:A great idea (Score:3, Insightful)
Slightly greater than 2000 m/sec to land/take-off from lunar orbit. Rather less then 2000 m/sec to enter/leave lunar orbit. Closer to 700 m/sec than to 2000 m/sec.
Velocity change required to rendezvous with an asteroid is rather higher than you seem to think, though. Unless we find an asteroid in very close to the same orbital plane as Earth, with perihelion and aphelion within the range of Mars' and Venus' orbits. Even under ideal conditions, we're talking more than a trip to the moon, and a much longer voyage. Keep in mind also that we prefer free-return trajectories, which take even more delta-V - especially for something like a near-Earth asteroid....
One of the lovely things about doing our learning on the moon is that we're only three days away from Earth in case something goes south. Would be really embarrassing to find that we ran out of vitamin C three months into a 16 month mission, with no way to shorten it (a free return trajectory for a hypothetical asteroid mission will take about 18 months to return to Earth in case the "free return part has to be invoked. At least).
They should go to the asteroids, (Score:3, Insightful)
A number of Earth-crossing asteroids are easier to get to, energetically, than the Moon. (Apollo could certainly have
reached some asteroids, which was pointed out at the time, and a lot more Earth-crossing asteroids are known now.) The trip times tend to be long,
so you need to be prepared for long duration flights (which is not that different from being prepared for long duration lunar visits, and is also
true of any trip to Mars). And, you don't need anything like a lunar module. (With most asteroids, and certainly all of the Earth crossing ones, you will "dock" with
them more than "land" on them, the gravity is that week.) The weight saved from the lunar module can be used for provisions instead.
There is plenty of science to do, and if we are ever going to economically exploit the materials in space, we are much more likely to
do it with asteroids than with either the Moon or Mars.
Re:A great idea (Score:2, Insightful)
That's debatable, but to the extent it is true we should be sending unmanned probes to the asteroids, not expensive manned missions. Besides, manned missions really don't have much to do with science.
The moon is much more like Mars than any little near Earth asteroid. Before we go to Mars we'll need to learn how to live there for several months, and constructing a base on the moon is a great way to gain that knowledge. It's far enough away and a similar enough environment to require similar engineering solutions, but near enough to rescue the mission if something goes awry. Also, landing on and lifting off the Moon is just what we want to be good at for a manned Mars mission. The moon's gravity is about 1/6 earth, Mar's is about 1/4. The main difference is Mar's atmosphere, but we won't learn anything about landing on an atmosphered planet from an asteroid mission.
Personally I think going to Mars is going to be a hell of a tough prospect, much harder than most people think. I can imagine a future where the first successful two-year mission barely survives the ordeal and the bleakness and suffering of the explorers turns everyone off the whole idea. Probably what we need is a faster, better, cheaper propulsion system to get us there in a month or less.
Re:So... (Score:3, Insightful)
Re:So... (Score:5, Insightful)
George W Bush is many things. But he is not a fool.
I agree with you, I don't think he's a fool, or that he's stupid. I've also defended his verbal gaffs, similar to the way you do -- I don't care about speechmaking, I care about results.
So, speaking as a Republican, what the hell *is* wrong with him? Is it arrogance? Hubris? I really can't defend much of what he's done. He's allowed spending like a drunken sailor. The war has been so totally mismanaged I literally can't believe it ("Wait, you mean we weren't keeping people there after we cleared out the town ALL ALONG?? WTF?") The idiotic waffling on what torture is or isn't. That supreme court nomination that even Rush Limbaugh couldn't stomach. The arrogant dismissals of Europe.
Again, I don't think he's a fool -- that's media created. But based on results, you can't conclude that he's anything but stunningly incompetent, and I don't understand where it all went so wrong. He had such grand opportunities at the start of his presidency, and it was all pissed away.
Re:A great idea (Score:2, Insightful)
Cheers,
Ian
doable; cold war (Score:4, Insightful)
One big advantage of a crewed mission to a near-earth asteroid over a crewed mission to Mars is that we simply don't have the technology to get to Mars. A transfer orbit to Mars takes 1.4 years (total round-trip time). (This is simply the period of a body in a Keplerian orbit that's tangent to the Earth's orbit at perihelion and tangent to Mars's orbit at aphelion. A spaceship isn't like a car, which takes less time to get there if you drive faster. A spaceship only thrusts with its engines in order to change its orbit.) The big unsolved scientific and engineering problem is how to keep a crew of human beings from getting exposed to unacceptable doses of radiation when they're in Earth-Mars orbital space for that long. The radiation intensity from galactic cosmic rays [wikipedia.org] is much, much higher out there than it is in Earth orbit. Feasible amounts of shielding actually make the problem worse rather than better, because of secondary radiation. According to this article [space.com], the duration of a mission to a near-earth asteroid could be 60-90 days, so it avoids this very tough, unsolved problem. There are many other aspects of a near-earth asteroid mission that are also a heck of a lot easier than a Mars mission. You don't have to land in a deep gravity well and then take off again, for one thing. If you look at the history of uncrewed Mars missions, it's pretty damn scary -- the success rate is very low, and that's for missions that don't have to take off and return to Earth, and don't have to provide life support.
The big question in my mind is what is the rational justification for government-funded crewed spaceflight at this point. There's no scientific justification; uncrewed probes give more bang for the buck. The shuttle's only mission is to go to the ISS, and the ISS's only mission is to give the shuttle somewhere to go. Thirty or forty years ago, this was all basically cold war propaganda stuff. It seems to me that the U.S. is having a hard time dealing with an unanticipated outbreak of peace. The rational thing to do would have been to continue harvesting the peace dividend, start ramping down our foreign military commitments, and let both crewed and uncrewed space exploration make the transition to the private sector. Instead we've been blundering around like idiots with our ridiculously large military, and in terms of space exploration we've been choking the scientifically productive uncrewed program by diverting the available money into extremely expensive projects like the ISS that have no rational justification.
The End of Spirit (Score:3, Insightful)
Now that fact that so many posters think this is a good idea, is terribly disheartening. If these posts are for real (and not more b.s. from the propaganda machines that now dominate our media), then it means America has lost it's Spirit. We no longer have a can-do attitude. We no longer care about going beyond ourself and pushing frontiers. We no longer see our ourselves as capable of achieving great things. In short we no longer Dream. And that...more than anything else will be our doom.
Re:A great idea (Score:3, Insightful)
V is for Vision (Score:4, Insightful)
What exactly is the vision? The founding document [nasa.gov] [large PDF warning] for the "VSE" lists goals and strategies, but no vision of what the goals and strategies are meant to accomplish. A vision involving the Moon could be "create a new civilization on the Moon that might do for the U.S. what the New World colonies did for the Old World." (you can snicker but that is an example).
"Go to the Moon and Mars" is not a vision. It's an strategy.
"Build launchers and spacecraft based on current infrastructure & technology" is an implementation of that strategy.
Again... what is the vision?
What we need the Moon for (Score:2, Insightful)
Re:So... (Score:3, Insightful)
This has nothing to do with intelligence and everything to with knowing about your limits - and caring about them. He has, despite knowing better, done a large number of things that he shouldn't have; I refuse to believe that he didn't know that he was lying about Iraq, that he didn't know that he alienated all America's allies etc.
The only hypothesis I can offer for his stupidity is "blind faith": the kind of religious faith that says "close your eyes and ears to reality, only your religion matters". He is stupid because he has made conscious choice to be so, for religious reasons. Not that the Bible (or the Qur'an for that matter) dictates this, but fundamentalists wants to be better than God's word - and that is truly hubris.