> The most expensive rare earth element you can currently send to Mars is platinum (...) > All other things you could send either decay quickly (platinum) (...

> The most expensive rare earth element you can currently send to Mars is platinum (...) > All other things you could send either decay quickly (platinum) (...) I don't understand. Did you mean platinum in both places? In that case, I got confused by the "other". Or did you mean something other than platinum in one of the cases? Or am I just failing to comprehend? :)