Question regarding Near Earth Asteroids and the VSE

[darkenfast]

This is in regard to a question I've been asking over on the Missions forum about a possible mission to an NEA for NASA's proposed new manned spacecraft (the CEV), as an intermediate step between lunar missions and the vastly more difficult Mars mission. Briefly, I was proposing the use of a modified lander, with the ascent stage being a Hab and Logistics module, and the descent stage (minus landing gear) being an asteroid arrival/partial earth return stage (the CEV service module finishing the job). The actual landing on the asteroid would be with Maneuvering Units as were briefly used on the Shuttle, or with an open platform lander. The mission would give experience in long-duration deep-space flight while the Mars hardware was stilll being built. My questions for this board are: would there be any scientific value in a manned visit to an asteroid, as opposed to a robotic probe? Are there any candidates that stand out as possible targets? The crew would be four astronauts, two of which could be scientists. I'm assuming at least two actual descents to the surface by teams of two at a time. Time-frame 2020-25 (-ish). This is "just for fun" speculation. Given the lack of vision in Washington DC, the whole CEV thing may never happen, no matter how good Dr. Griffen is. <br />Thanks.

 

[Philotas]

Well, if I`m not mistaken, all NEOs or NEAs are too small for visits by humans being possible, or at least they`ll have big trouble keeping themselves on the surface of the asteroid. <br />Someone please correct me if I`m wrong. <div class="Discussion_UserSignature"> </div>

 

[darkenfast]

I doubt if they would walk around. It would be more like a spacewalk. Perhaps amble about on hands and knees. This is why I thought the actual landing could be done in suits and manuevering units.

 

[robnissen]

I have also thought about this. It seems to me, the ideal mission would be to the small asteroid scheduled to pass a few tens of thousands of miles from earth in 2028. This mission could be done very cheaply with very little fuel. Merely land on the asteroid when it is a little ways from earth (1 M miles?). Collect samples and do other science, then "step-off" the asteroid as it approaches within a few 10k miles of earth, and take the short ride back home. Now obviously, this would not be as simple as I am making it out to be, the timing, especially for the return, would have to be very exact, but it seems well within our technological capabilites we have now, let alone 20 years from now. The beauty of this is 1) the trip is done with half the fuel (I know it would actually be much more than half, because most is spent escaping the gravity well that is earth) , and 2) most importantly, most of the time is spent doing science rather than getting to and from the destination. This seems like a 'no-brainer' to me, but I have not heard any discussion about this. Am I missing something?

 

[darkenfast]

I get the impression that going from Earth's orbit to a NEA's orbit is not as simple as it might seem. Unless one of the astronomers here knows of a really good candidate, I think a NEA mission will be at least a year long, if not more. The advantage is that it doesn't need a lot of new hardware (like a Mars lander). The key would be the modified LSAM (if it could carry the consumables), and things like water re-cycling. It would be a tough mission. Again, is there a scientific reason to do it? Anyone?