Yesterday, NASA announced that Spirit had missed a planned transmission.  To date, Spirit (and its twin, Opportunity) have lasted more than 2150 martian days longer than the expected 90.  Not just lasted, but thrived – originally planned to travel a single kilometre, Spirit logged 10 before becoming stuck in soft soil.  After trying and failing to escape for half a year (earth years), NASA decided to give up on mobility and allowed Spirit to perform science.  That was two months ago.  Today, it seems to have shut down to charge its batteries.

These two little rovers have lasted longer, seen more, done more than anybody ever expected, and have survived draining conditions.  Their tenacity has earned them empathy and celebration.  In tribute to Spirit, and in the hope it will revive and continue to contribute to our understanding of Mars, I wanted to offer up my best wishes to the rovers, and to all the people at NASA who keep them going.  Rock on, Spirit!