NASA is trying one last time to contact its Mars mobile registration opportunity, before calling it, before leaving it.

The rover has been silent for eight months, suffering from one of the most intense dust storms in decades. A thick dust clouded the sky last summer and, for months, blocked sunlight from the solar panels of the probe.

NASA announced Tuesday that it would send a final round of recovery orders, in addition to the 1,000 already sent. If there is no response by Wednesday – which NASA suspects to be the case – Opportunity will be declared dead, 15 years after its arrival on the Red Planet.

Team members have already looked at Opportunity's achievements, particularly on confirmation water once sunk on Mars. The opportunity was by far the most enduring lander on Mars. In addition to endurance, the six-wheeled rover has set a record 45 kilometers of roaming.

His identical twin, Spirit, was declared dead in 2011, a year after being caught in the sand and communication interrupted.

Both survived and exceeded expectations on either side of Mars. The rovers the size of a golf cart were designed to function as geologists for just three months, after bouncing on our planetary neighbor in airbags in January 2004. They exploded from Cape Canaveral to a interval in 2003.

It's not easier to say goodbye now to Opportunity than to Spirit, said project manager John Callas.

"It's like a missing loved one, and you keep hoping that they will show up and that they'll be healthy," he said. "But each passing day goes down, and at some point you have to say" enough "and move on in your life."

The project's assistant scientist, Abigail Fraeman, was a 16-year-old high school student when Opportunity landed on Mars. she was inside the control center as part of an awareness program. Inspired, Fraeman later became a global scientist, joined NASA's reaction propulsion laboratory in Pasadena, California, and was appointed deputy project scientist for Opportunity.

"It gives you an idea of ​​the duration of this mission," she said. "Opportunity is just a workaholic … it's really a testament, in my opinion, about the quality of the design of the mission and the care taken by the team in driving the vehicle. "

Instead of considering the dust storm as bad luck, Callas considers it "very lucky that we have survived as many storms as possible over the years." Global dust storms are triggered from time to time , and "we had had it for a long time without. "Unlike NASA's nuclear-powered Curiosity rover, which is still on Mars, Opportunity and Spirit have never been designed to withstand such harsh weather conditions.

Steve Squyres of Cornell University, Senior Scientist at Opportunity and Spirit, believes that succumbing to a fierce storm is an "honorable way" to end the mission.

"You could have lost a lot of money over the years by betting against Opportunity," said Squyres on Tuesday.

The best gift of the rovers, according to Squyres, was to provide a geological record at two separate places where water once flowed on Mars and describe the conditions that could have supported a possible old life.

The last time NASA heard of Opportunity on June 10th. The flight controllers tried to wake up the rover, to design and send, command after command, month after month. The Martian sky was finally clear enough for the sunlight to reach the solar panels of the vehicle, but nothing was done. It is now colder and darker on Mars, further reducing prospects.

Engineers believe that the internal clock of the mobile could become scrambled during the prolonged failure, disrupting the sleep cycle of the mobile and draining the onboard batteries. It's particularly frustrating, according to Callas, not to know precisely why Opportunity – or Spirit – has failed.

Now it's up to Curiosity and the new InSight lander to perpetuate the legacy, he added, as well as a spacecraft in orbit around Mars.

As for Opportunity, "It gave us a bigger world," Callas said. "Mars is now part of our neighborhood."