A number of the last posts have looked at mission priorities for primitive bodies being formulated for the U.S. Decadal Survey. This post will close out that series by looking at a series of presentations from last May at an ESA sponsored meeting.
Sample returns from comets and asteroids rank high in priorities for missions to primitive bodies in the priorities being set by the scientific community. ESA and Japan (JAXA) are both considering missions to return samples from a near Earth asteroid. For ESA, this mission is a candidate for selection as the next medium class science mission, but the proposed Marco Polo mission doesn't fit within the ESA budget. For JAXA, this would be a follow on mission to the troubled HAYABUSA mission. The two agencies are investigating options for combining these missions.
ESA held a conference last May on near Earth asteroid sample return. Quite a large number of presentations are posted on the meeting website (http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=43784). I won't try to summarize all the presentations, but will instead provide highlights.
The ESA defined mission appears to still be in definition, with a several spacecraft configurations under consideration from true landers to touch-and-go sampling.
Samples would be returned to Earth in the mid-2020s after a year and a half remotely studying the asteroid and collecting samples.
Less information is available on the website for the JAXA mission. In fact, the overview presentations for both the ESA and JAXA missions were not posted. However, some ideas for the potential science compliment of a JAXA mission can be found at http://sci.esa.int/science-e/www/object/doc.cfm?fobjectid=45164.
Two presentations were made for possible NASA New Frontiers near Earth sample return missions. Neither gave out many details on the missions -- this is a competitive field. However, the OSIRIS-REx presentation shows the dedication needed to win selection. The team prepared proposals for three sequential Discovery (~$450M) mission competitions. In the last competition, the team was a semifinalist, but wasn't selected because the review board felt that the mission was too risky for the mission budget. The team planned to submit a New Frontiers (~$650M) mission proposal for the competition in progress.
A summary presentation laid out the key technical risk and political challenges facing the Marco Polo mission. Based on what I've read, the technical problem highlighted applies to sample return from any asteroid or comet -- we know too little about the surface properties to be sure what technique(s) might work. (But this issue is being worked on; see Small Body Sampling Techniques being Developed at JHU/APL.)