There's little hope left for rousing NASA's Opportunity rover, which landed on Mars 15 years ago this month. For the past 6 months, the rover has been silently and NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, is running out of tricks to revive it.
In June 2018, a planet-encircling dust storm blotted out of the sun over Opportunity for several months, weaning it off solar power and draining its batteries. Since then, JPL has sent the golf cart-size rover 600 commands to revive it. Engineers hoped for seasonal winds, running high between November 2018 and the end of January. But that has not happened.
"The end of the windy season could spell the end of the rover," says Steven Squyres, the mission's principal investigator at Cornell University. 15 years into a 90-day mission and taken out of one of the worst martian dust storms in many years. "
John Callas , the misson project manager at JPL, says, "We've got another week. We're running out of time. "
The martian winter, which in 2011 ended the mission of Opportunity's twin rover, Spirit, is months away. Sunlight is waning in the southern hemisphere and temperatures are dropping. Efforts to revive the rover have now as long as the past. JPL is trying a few more long shots, such as commands that would tell Opportunity to switch back to antennas, if it had barely revived and was trying to use a broken antenna. "After that, I do not know what to do next, if anything," Callas says. Before the 5-week U.S. Government shutdown, the plan to do what it takes. NASA science chief Thomas Zurbuchen.
Whenever its mission ends, Opportunity will leave a trail of superlatives. It traversed a path 45 miles long, often driving backward because of an overheating steering control. It explored ever-larger impact craters as it went, with their deposit more and more of the martian interior. Jim Bell, a planetary scientist at Arizona State University at Tempe, says the rover's color camera team. Bell, for one, is not giving up hope. The rover is perched on the rim of Endeavor Crater, he notes, and a wind gust could come still and revive opportunity. "No one has ever won a bet against it. I'm not about to start. "
From its landing in Meridiani Planum in 2004, opportunity quickly revealed the sulfate-rich sandstones it drove on. Raymond Arvidson, a planetary scientist at Washington University in St. Louis, Missouri, and the rover's deputy principal investigator. "There's an ephemeral lake system, going dry, going wet. That's a huge discovery. "
Subsequent craters explored by the rover revealed that periods have been habitable in the deep past, Bell adds, and Opportunity is the first to provide evidence for it of habitability extended far longer in the martian past than once thought. It spotted veins of the mineral gypsum near crater rims, which form thanks to evaporating water. And, in 2013, the first surface observations of 4-billion-year-old clays, from a time on Mars older than the rocks probed by the Curiosity rover, when water could have truly been abundant. The finding, 9 years into its mission, validated observations from orbit, expanding the hunt for such clays, says Alberto Fairén, a planetary scientist at Cornell.
Few expected when they signed up for the Spirit and Opportunity rovers that they would still be working on one 15 years later. In the end, though, Bell adds, "Mars always wins."