UPDATE (May 2): NASA has regained full control over the Opportunity rover after uploading a new set of commands on May 1.
Opportunity’s operators discovered the rover faulted to standby mode on April 27 as Mars emerged from solar conjunction.
For the last month, Opportunity has been operating on its own. As Mars approached solar conjunction last month, degrading radio contact between Earth and its Martian spacecraft fleet, scientists sent Opportunity a list of commands to execute in the month operators would be out of contact. At some point during the radio blackout, Opportunity stopped executing those commands and reverted to what mission operators call automode.
John Callas, the mission’s project manager, explains: “Our current suspicion is that Opportunity rebooted its flight software, possibly while the cameras on the mast were imaging the sun. We found the rover in a standby state called automode, in which it maintains power balance and communication schedules, but waits for instructions from the ground. We crafted our solar conjunction plan to be resilient to this kind of rover reset, if it were to occur.”
NASA’s current sequence of events place the shutdown at some point during the day of April 22. Since then, Opportunity has done nothing but ensure that its power levels remain stable and attempt to communicate with its handlers. New commands were sent to the rover on April 29, but were not successful in bringing the rover out of automode. They plan to try again over the coming days.
The original plan for Opportunity after solar conjunction ended was to resume exploration around the rim of Endeavor Crater, a 22-km wide crater in Meridiani Planum. The rover arrived at Endeavor in 2011, and has been performing science operations along the crater’s rim. Before solar conjunction, the rover was finishing up work at Cape York, a layer of basalt that was peeled up by the impact. If mission operators regain control of the rover, the plan is for the rover to continue south towards a ridge named Solander Point, where Opportunity is expected to spend its next winter. Along the way, it will sample hydrated sediments exposed in a low area named Botany Bay.
In other Mars rover news, Curiosity is resuming operations. Curiosity is in fine health, and will be resuming operations within the next week. JPL scientists plan to update Curiosity’s software. Once that task is complete, the rover will wrap up its fieldwork at Yellowknife Bay. The rover found rocks deposited in extremely mild conditions in March, and scientists want to make sure that the area is well-sampled before they move on. Current plans are to drill at least one (and possibly several) more rocks in the area.