Mercury Landers Options

[gndonald]

While the likelyhood of a Mercury Lander mission is very low, I was wondering if any planning/studies have been done on such a project?

[edstrick]

Two or three years ago, there was some reporting on an odd meteorite that had distinctive isotope patterns and chemistry. There was some speculation it was Mercury ejecta, but that interpretation didn't seem strongly favored. I don't recall it's name/designation. I've heard no further discussion of it, and have wondered what the status on it is. Meteoritical Society meeting abstracts may have contained something but I haven't broused them extensively.

[JRehling]

I can't find the reference to the Mercury smash-and-grab sample return either, although I had found it on the web a couple of years ago. It was a real "outsider" proposal, conceived from someone not really working in space exploration, IIRC, and I don't know if it was an official Discovery proposal or not -- yet it is a solid idea. Certainly this kind of sample return is not as useful scientifically as having a rover move around and delicately select a geologist's wishlist, but what this kind of mission lacks in benefit, it makes up for in cost savings.

NWA 011 is the name of the meteorite that was speculated upon as being mercurean in origin. Here are some discussions of the item's origin, however, that don't even mention the word "Mercury", FWIW:

http://web.utk.edu/~lataylor/pub-list/Floss-1153.pdf
http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1094.pdf
http://aaa.wustl.edu/Work/pub_files/northwestafrica011.html

There can only be so many rocky parent bodies in our solar system's past/present that were large enough to exhibit major radiogenic heating, and Mercury is one of them. Perhaps we'll end up with an exhaustive list one day and identify the Mercury meteorites by elimination. But we're not close to that day...

A smash-and-grab sample return would not only have its own value, but would also possibly clinch the identification of Mercury meteorites in our possession. In terms of delta-v, we more or less need a solar orbit that has aphelion at 1 AU and perihelion at 0.48 AU -- that is more delta-v than a Venus/Mars lander, but then the craft would essentially be an Earth lander without instruments. It would be highly desirable to perform remote sensing of the impact site, a la Deep Impact -- the instruments should perhaps be mainly contained on the impactor, since instruments on the return craft wouldn't have any use after the impact while flying back to Earth.