When you send something to space, it’s good to have redundancy. Sometimes you want to send two whole duplicate spacecraft just in case — as was the case with Voyager — but sometimes it’s good enough to have two of critical components. Mars Rover Curiosity is no exception, and it is now in the process of switching from one main “brain” to the other so it can do digital surgery on the first.
Got some spare time this weekend? Why not build yourself a working rover from plans provided by NASA? The spaceniks at the Jet Propulsion Laboratory have all the plans, code, and materials for you to peruse and use — just make sure you’ve got $2,500 and a bit of engineering know-how. This thing isn’t made out of Lincoln Logs.