Mars dust storm clears, raising hope for stalled NASA rover

One of the biggest Martian dust storms on record is clearing up after nearly three months, raising hope that NASA’s stranded, solar-powered robotic vehicle, Opportunity, will soon come back to life.

Read more at: https://phys.org/news/2018-08-mars-storm-stalled-nasa-rover.html#jCp

NASA Just Gave the Opportunity Rover a Survival Deadline on Mars—Here’s What That Means

Tau.Neutrino said:

Mars dust storm clears, raising hope for stalled NASA rover

One of the biggest Martian dust storms on record is clearing up after nearly three months, raising hope that NASA’s stranded, solar-powered robotic vehicle, Opportunity, will soon come back to life.

NASA Just Gave the Opportunity Rover a Survival Deadline on Mars—Here’s What That Means

I was reading a slightly different article about this topic yesterday or the day before. I’ll see if I can find it. No, can’t find it. But this is similar, from 30 Aug.

https://www.jpl.nasa.gov/news/news.php?feature=7227

A planet-encircling dust storm on Mars, which was first detected May 30 and halted operations for the Opportunity rover, continues to abate.

With clearing skies over Opportunity’s resting spot in Mars’ Perseverance Valley, engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, believe the nearly 15-year-old, solar-powered rover will soon receive enough sunlight to automatically initiate recovery procedures — if the rover is able to do so. To prepare, the Opportunity mission team has developed a two-step plan to provide the highest probability of successfully communicating with the rover and bringing it back online.

The rover’s last communication with Earth was received June 10. … 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.

This is also similar, from August 12.
https://www.jpl.nasa.gov/news/news.php?feature=7215

JPL engineers predict that Opportunity will need a tau of less than 2.0 before the solar-powered rover will be able to recharge its batteries. JPL’s radio science group uses special equipment on DSN antennas that can detect a wider range of frequencies. Each day, they record any radio signal from Mars over most of the rover’s daylight hours, then search the recordings for Opportunity’s voice.

When Opportunity experiences a problem, it can go into so-called “fault modes” where it automatically takes action to maintain its health. Engineers are preparing for three key fault modes if they do hear back from Opportunity.

• Low-power fault: engineers assume the rover went into low-power fault shortly after it stopped communicating on June 10. This mode causes the rover to hibernate, assuming that it will wake up at a time when there’s more sunlight to let it recharge.

• Clock fault: critical to operating while in hibernation is the rover’s onboard clock. If the rover doesn’t know what time it is, it doesn’t know when it should be attempting to communicate. The rover can use environmental clues, like an increase in sunlight, to make assumptions about the time.

• Uploss fault: when the rover hasn’t heard from Earth in a long time, it can go into “uploss” fault — a warning that its communication equipment may not be functioning. When it experiences this, it begins to check the equipment and tries different ways to communicate with Earth.