Confession: I have no background in astronomy. I'm not even sure whether this question is apt. So a hypothetical situation goes like this. One of my friends is filthy rich and has one of those richman fantasies. By chance, a space science institution is willing to offer him a trip to planet X. He does whatever it takes, and finally reaches planet X. Unfortunately, the module is no more in the best of its condition, there are lots of technical difficulties to initiate the return trip. The team gives up, soon they all die. Since there is no other living organism on the whole of the planet, as learnt by earlier expeditions, would this team lay dead for eternity(nothing to decompose). If that is so, is it not the best idea to preserve all of Earth's perishable history by just sending all relevant materials to a particular planet?