Secondary payload to Asteroid

Has anyone at SSI looked into designing a secondary payload that
could be included in SpaceDev's (http://www.spacedev.com) Near Earth
Asteroid Prospector mission?
The design constraints seem to be pretty severe (2.4kg for the
detachable payloads, not sure about volume), but I was thinking
something along the lines of an inflatable solar concentrator
(parabolic reflector with a secondary mirror that concentrates the
sunlight behind/underneath the primary) and a GC/mass spec. Probably too small for any kind of useful experiments in refinement of space resources, but more science data might be useful. The two broad areas that could be looked at are metals refining and
volatile collection. Lot's of questions about both that I can't
answer:
What temperatures would be needed to purify a usefull metal? What
size solar concentrator would be needed to achieve that temp? Could
separation be done solely on the basis of temperature, or do we need
physical systems as well? I was once chastised by a critic (even though I wasn't actuallyguilty) of naively believing that we will be able to turn space ores into pure metals by shining sunlight on them. The refinement of ores into metals is a very complex chemical process, and the process heating is just one (though a significant) part. Would an asteroid's gravity be enough to
help? I wouldn't count on an asteroid's gravity to be a help anywhere. How deep into the regolith would you need to go to find any usefull
volatiles (water, various carbon based molecules)? I assume anything
'on the surface' would have been baked out. This is the sort of question which will remain unanswerable until we land probes designed for these kinds of investigations. I've been arguing with someone on Usenet who strongly asserts that any asteroidal body closer to the sun than the outermost regions of the Main Belt is going to be worthless for hydrogen extraction due to desiccation. I wouldn't go that far, but agree that more data is needed. It may be significant toward explaining his inclination to this view that this individual is trying to come up with an export for Mars.