On Wednesday, after seven months during which NASA was unable to establish contact with the machine, its 15-year mission was declared complete.
The solar-powered craft’s last communication was received on June 10 as a massive dust storm was enveloping the planet. On Tuesday night, after more than 600 electronic pings aimed at Opportunity since last summer, engineers at NASA’s Jet Propulsion Laboratory sent their final commands to the rover, hoping to spark a response.
Opportunity was one of two Mars Exploration Rovers (MERS) sent to the planet 16 years ago, arriving in January 2004. Its twin, Spirit, was lost in March 2010. Both of the 384-pound rovers were designed for 90-day service spans, with NASA reaping years of data from each beyond the original mission schedules.
Among its many scientific achievements, Opportunity found evidence in 2004 that salty water once flowed on the surface of Mars. It followed that early discovery with years of additional rock and sediment examinations across an array of landscapes.
Beyond the deeper geologic understanding of Mars’ history, the rovers “significantly improved our knowledge about how to navigate on other planets—something that will help future robotic and human exploration of Mars,” Thomas Zurbuchen, NASA’s associate administrator, wrote in a blog post. The rovers’ photography and journeys also made the planet less foreign to both scientists and the public at large.
After the rover failed to respond on Tuesday, scientists at JPL’s California offices wept, according to Tanya Harrison, a former member of the Mars Exploration Rover team.
The program’s end was emotionally difficult for many at the facility, from which rover operations are conducted. “You develop a special bond. They become your children,” said John Callas, project manager for JPL’s rover program. “Even though it’s a machine and we’re saying goodbye, it’s very hard and very poignant.”
Some in the Martian exploration community criticized NASA for its plan to rouse the rover. The initial 45-day plan was too brief, according to detractors, given the dust storm’s severity. Mars experiences regional dust storms each year, but only occasionally do they expand to engulf the entire planet. The last such major storm occurred in 2007, which sent NASA’s rovers into a “hunker down” mode for several weeks before the skies cleared.
“To have a 90-day mission last for 15 years, and then end as a consequence of one of the most ferocious dust storms to hit Mars in a very long time, we can walk away with our heads held high,” Steve Squyres, a Cornell professor and principal investigator on the mission, told Gizmodo. “The mission exceeded far beyond what I could have expected.”
NASA retains a presence on Mars. The larger, nuclear-powered Curiosity rover has been roaming the planet since August 2012. In November, a stationary robot called Mars InSight arrived to begin exploring the planet’s interior. The next large rover, Mars 2020, is scheduled to launch next summer. The 2,300-pound craft will also carry a drill to collect rock samples. DM
