NASA has started the clock ticking on rescue operations for the robotic Opportunity Mars rover. With the Martian skies clearing after a months-long global dust storm, the space agency has started a 45-day operation to send radio signals via the Deep Space Network to the unmanned explorer in hopes of reawakening it.

At present, the condition of Opportunity, which has spent almost 15 years exploring the Red Planet, is unknown. After a giant dust storm engulfed the planet's surface beginning in May 2018, the density of fine particles in the area of Opportunity became so great that it blotted out the Sun. Since Opportunity relies entirely on solar power, this soon caused its batteries to drain and all contact was lost on June 10.

Since that time, mission control has been sending periodic signals to try to re-establish radio contact, but it's believed that the power levels aboard the rover have dropped so low that all of its systems have effectively shut down. However, NASA engineers think that conditions are improving. Data from NASA's Mars Reconnaissance Orbiter's (MRO) Mars Color Imager (MARCI) indicate that the dust has now cleared around Opportunity to the point where its opacity or "tau" is now 1.5 – sufficiently clear to allow the solar panels to begin operating once again.

The plan is now for the Opportunity team at NASA's Jet Propulsion Laboratory in Pasadena, California to increase the number of signals sent. Instead of three times per week, the signals will go to a number of times per day. Meanwhile, the Radio Science Group at JPL will listen for any transmissions from the rover.

This signaling will continue for 45 days. If no reply is heard, this could indicate that the electronics aboard froze during the Martian night, killing the spacecraft, though it's more likely that the panels are simply not getting enough light due to dust settling on them.

"If we do not hear back after 45 days, the team will be forced to conclude that the Sun-blocking dust and the Martian cold have conspired to cause some type of fault from which the rover will more than likely not recover," says John Callas, Opportunity project manager at JPL. "At that point, the team will report to NASA HQ to determine whether to continue with the strategy or adjust it. In the unlikely chance that there is a large amount of dust sitting on the solar arrays that is blocking the Sun's energy, we will continue passive listening efforts for several months."

The hope is that a Martian dust devil or some similar wind will later blow the panels clean, as happened after a dust storm in 2004. But the real fear is that even if the batteries can recharge, the system may have been permanently damaged by the severe drain. In addition, the dust may have caused mechanical damage to the drive systems, the robotic arm, or the instruments aboard. For the moment, NASA sets Opportunity's situation as "critical."

"In a situation like this you hope for the best but plan for all eventualities," says Callas. "We are pulling for our tenacious rover to pull her feet from the fire one more time. And if she does, we will be there to hear her."

Source: NASA

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