NASA has not heard from the long-lived Opportunity rover since June 10, when a growing global dust storm eclipsed the red planet's sky so that the spacecraft's solar cells could not recharge its batteries.
managers at the Jet Propulsion Laboratory in Pasadena, California, say the storm seems to have subsided at last, and engineers remain hopeful that the rover will try to call home when the air is sufficiently clear to keep the sun on its energy system. load.
A detailed analysis of telemetry of the robber before it fell silent showed that his batteries were healthy and in a relatively good condition. Although not convincing, the data indicate that the power packs would endure the storm without any significant degradation.
Nature also offered a little help. Dust storms tend to heat the atmosphere and as it developed at Opportunity's location at the beginning of the summer, temperatures remained above the level that could cause widespread disturbances.
Yet, engineers do not know what they will discover when – and if – Opportunity eventually calls home. They take steps to deal with three possible "error modes" that the robber may have experienced.
In case of a weak current error, the most likely scenario, the rover would have gone into a kind of electronic hibernation, so that virtually all of its systems only keep an internal clock running with programming that would wake the flight computer as soon as the batteries had enough charge reached.
A clock error would add an extra layer of complication, preventing the rover from knowing the time and trying to call the earth. In that case the Opportunity flight computer would try to use ecological clues, such as an increase in sunlight, to find out in general what time it could be and to the home radio.
After a long period without contact with the earth, the on-board computer of the robber could assume an "uploss error" in which he believes that his communication device is not working properly. In that case it tries different communication methods.
Engineers are attempting to contact Opportunity several times a week using the NASA's Deep Space Network, pinging the rover during "wake-up" times programmed on the spacecraft's computer. They also listen to a larger than normal frequency range during the day, looking for a signal that can come at other times due to a malfunction in clock or uploss.
Until they receive telemetry, engineers will not know whether Opportunity will fully recover or if its capabilities will diminish due to storm-related battery degradation. The analysis will take some time, and a rapid resumption of normal scientific observations and roving, assuming Opportunity has survived, is not expected.
Launch of Cape Canaveral on 7 July 2003, Opportunity ended up on Mars the following January, three weeks after a twin Rover, Spirit, landed on the other side of the planet. Both landers had a design life of just 90 days, but both proved exceptionally long.
Spirit finally fell silent on March 22, 2010, stuck in deep sand and unable to orient itself, so that the solar panels could keep their batteries charged. But Opportunity remained in relatively good health, marking the 5,000th March day, or sol, last February.