The space agency will now attempt to contact Opportunity for the final time on Wednesday.
Opportunity has not been riled since last June when it was the victim of one of the most intense dust storms in decades.
NASA last heard from Opportunity on June 10. Flight controllers tried to awaken the rover, devising and sending command after command, month after month.
Opportunity was the fifth of eight spacecraft to successfully land on Mars so far, all belonging to NASA.
Project manager John Callas said, "It's just like a loved one who's gone missing, and you keep holding out hope that they will show up and that they're healthy ..." It was 2004, and Fraeman was visiting NASA's Jet Propulsion Laboratory in Pasadena as part of an outreach event.
The experience inspired her to pursue a career at JPL; Fraeman is now a deputy project scientist on the Mars exploration rover project, and works with Opportunity nearly daily.
NASA's nuclear-powered Curiosity rover was created to endure severe weather but Opportunity and Spirit were not so the mere fact they lasted so long is testament of the durability of the models.More news: Manchester United steward unintentionally crowd surfs during PSG win at Old Trafford
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"Opportunity's just been a workhorse ... it's really a testament, I think, to how well the mission was designed and how careful the team was in operating the vehicle".
Scientists consider this the end of an era, now that Opportunity and Spirit are both gone.
Since last summer, NASA has sent over 1,000 commands to the rover, and have received no response.
"You could have lost a lot of money over the years betting against Opportunity", Professor Squyres said.
Opportunity's mission has led to many discoveries about the Red Planet, but perhaps the most exciting was when Opportunity found evidence that Mars once had water and supported conditions for sustaining microbial life. It's especially frustrating, according to Callas, not knowing precisely why Opportunity-or Spirit-failed.
As for Opportunity, "It has given us a larger world", Callas said.
"Mars is now part of our neighbourhood", he added.
In November 2018 NASA announced that it has selected the location where its Mars 2020 rover will land on the Red Planet.