NASA seeks to rescue Opportunity rover
Having lost contact with the rover in June, engineers are waiting for the Martian skies to clear
NASA scientists have identified key signs which should enable them to touch base with the Mars Opportunity rover months after it became lost to radio silence.
Space agency staff lost contact with Opportunity on 10 June this year when a dust storm encircled the Red Planet and blotted out the Martian skies.
It was the first time the rover had become cut off after trundling across the surface of Mars for close to 14 years and, having landed on the Red Planet in 2004, scientists are hopeful that its batteries – which were in good health prior to the storm – have held up well.
With that in mind a bid to recover the rover is in full swing, with NASA monitoring Opportunity daily. First they are waiting for the skies to clear so that the rover can receive enough sunlight to recharge the batteries. They are doing this by keeping an eye on the wide-angle camera on NASA's Mars Reconnaissance Orbiter in the hope that the planet's surface features will soon become visible.
Once the amount of sunlight reaches a tau of less than 2.0, it should be able to power up. On 10 June, however, the tau measurement was at 10.8; the higher this number reads, the less sunlight is available. Assuming it does end up recharging, NASA will then use the Deep Space Network to ping the rover during ‘wake up’ times before searching for signals in response.
Further to that, engineers will be looking out for the fault mode that Opportunity is likely to have entered on 10 June. This could be a low-power fault which causes the rover to hibernate until there's enough sunlight to recharge it. A bigger problem would be a clock fault, in which case it would be more difficult for it to know when it should communicate, although it can assume the time by detecting sunlight increases. An uploss fault would cause the rover to seek new ways to communicate with ground control since it would indicate the rover's communication equipment has taken a bit of a hit.
Unfortunately, NASA says communication won't be immediate. Engineers will have to understand the state it is in, check its temperature, reset the clock, have it take photos in case of damage and then work out the best time to attempt a full recovery. Even then, there is a chance that the rover will not act in the same way when it wakes because of such prolonged inactivity. This could cause the battery to hold less juice, making future operations more difficult.
“A bid to recover the rover is in full swing”
An artist's concept image of Opportunity, which landed on Mars in 2004