A stationary Spirit or Opportunity is far from dead. Instead, the rover becomes like the Phoenix lander, which, after touching down in the Martian far north in May 2008, detected snowfall and clear evidence of water ice, and made it to early November, well past its 90-day projection, before waning sunlight caused a loss of contact. Or it becomes like the two Viking landers launched in themid-1970s, which studied the chemistry, meteorology, seismology, and magnetism of their Martian environments while searching for signs of microbial life, and lasted almost 10 years combined. Phoenix and Viking never budged from their landing spots. Spirit could be very valuable, say, as a climate station for months to come. “There’s a whole list of geodynamic measurements that we can use that you need a stationary vehicle [for], to track the radio signals to explore the geodynamics of Mars,” says JPL rover project manager John Callas. “And we also have an ability to do a crude seismometry with the rover. So those are both long-term objectives, new things that the rover can do.” Bottom line: It’s unthinkable that NASA would abandon a half-billion-dollar rover with almost all systems working just because it can’t rove.
So while Spirit continues to worry the team, Opportunity has a good chance of surviving another Martian winter as it rolls south toward Endeavour Crater, its biggest crater yet. It will need more than one Earth year to get there. When the fateful day comes and the Mars rovers cease to transmit, perhaps the JPL folks will be emotionally prepared, and will focus on Earthly companions: cars, pets.
“I have two cats,” says Sharon Laubach. “Our rovers follow orders better than cats do.”
Michael Klesius is an Air & Space/Smithsonian associate editor.