JPL engineers sent the final official transmission to the rover last night, but communications back to NASA ended last June, according to NASA. The reason for the loss of communication is due to a massive dust storm that blotted out the sky. Opportunity runs on solar power, so this was as good as a death sentence for the little rover. This storm in particular was one of the thickest NASA has ever seen. Once the storm had passed, engineers were hopeful that the sun would wake Opportunity up again. It had gone into hibernation mode as the internal battery slowly drained away. However, the sun appears to have not breathed new life into the rover, as radio silence continues.
One theory for the rover not powering up again was that the dust storm left a layer of dirt and silt on Opportunity’s solar panels. The windy months are now behind us, and there’s still no sign of life, leading NASA to the situation it’s in now. Opportunity is going to enter Martian winter soon, which could bring temperatures down to -157 degrees Fahrenheit. NASA says that without power for the internal heaters, this could cause components to become brittle and break.
Opportunity went far beyond what anyone thought it would be able to withstand. NASA wanted this rover and its identical twin named Spirit to last 90 days. After 15 years and over 28 miles of martial terrain traveled, Opportunity is the most traveled and longest lasting rover ever launched to another planet. Spirit got stuck in a sand trap and went dark in 2009, still far beyond its intended expiration date.
NASA held a press conference chronicling its life and going into even further detail on why Opportunity is officially being let go. You can watch the stream below.