Just about two years ago, This article was posted on Space.com, outlining the selection process for the twin NASA rovers Spirit and Opportunity. Take a look at the last paragraph:
Once they reach their landing sites, each rover*s prime mission will last at least 90 Martian days (92 Earth days). The rovers are solar-powered, and in approximately 90 days, dust slowly accumulating on their solar arrays likely will decrease rover power, bringing to a close each robot’s sojourn.
Well, it*s now been over a year since the first lander, Spirit, touched down at Gusev crater, and 51 weeks since Opportunity also landed on the Red Planet. Both of them have experienced system problems, notably a rather serious software problem that had scientists fearing that they would lose the ability to communicate with one of the rovers. Happily enough, NASA engineers were able to repair the software (from another freaking PLANET, mind you. Someone explain why I can*t get Service Pack 2 of XP installed right, dammit) and now both probes have exceeded their expected shelf life by, oh, a factor of 4 so far.
The mission to Mars was designed to find out whether, and where, water may have existed (or still exists) on the planet*s surface. Perhaps most fascinating to me is that after three years of discussion regarding 155 possible landing sites and a painstaking process to finally select Gusev Crater and the Meridiani Planum, it turns out that only one of them had ready evidence of hydrological activity. Years of work, analysis and collaboration between rocket scientists, and they still only batted .500. This is not an exact science. Or, rather, it is, but we do not have enough data to do better than a 50/50 shot (and even that*s pretty damn amazing).
There are days when I am proud to be a member of a race of explorers.
