Mars Sample Return Options

[Rakhir]

Next phase reached in definition of Mars Sample Return mission

http://www.esa.int/esaCP/SEMJAGNFGLE_index_0.html

[Explorer1]

An important aspect, however, is that the caching method allows finding the most scientifically interesting samples to be gathered, rather than whatever is in range of a fixed lander's scoop or robotic arm. China's sample return will just rely on chance to gather whatever happens to be at the landing site. If an interesting rock is a just few cm out of reach, it has to stay there. There's always a tradeoff.

In hindsight, perhaps a much lighter 'Pathfinder' MAV, which just gathered whatever soil/rock was in reach (and perhaps atmosphere samples), would have been a good test of the most critical failure point. But, of course, predicting budgets so far ahead of time is impossible.

[StargazeInWonder]

This very thread presents an interesting sample of the discussion going back to 2006; it suddenly jumps at one point from 2009 to 2015 in the space of only two posts. I guess the pivotal decision was putting (1) the caching and (2) the return into concrete enough of a plan where the knowledge of whether or not the sampling rover would be usable for the retrieval was unknown. That was not part of anyone's original plan and seems like a sort of operational blackmail a la the sunk cost fallacy.

Reading between the lines of the Washington Post article (or any other coverage) there are people rightly pointing out that risk is inevitable and now someone at the top saying that the things one might trade off to mitigate risk are intolerable. So something has to give. Whether it's a risky but lucky success, years of thumb-twiddling, or Perseverance's samples lost in space remains to be seen.