By Mary O’KEEFE

Scientists and engineers at Jet Propulsion Laboratory are listening every day for a signal from Opportunity, the “little rover that could.” The Martian rover has powered down as a fierce storm covers the Red Planet.

“We got notice on Friday, June 1, of the storm,” said Bill Nelson, engineer manager for the project.

At that point the storm was about six miles west of Opportunity; by the next day engineers began to see the effects of the storm on the rover.

“We hunkered down by cutting out [its] activity,” Nelson added.

The last contact with the rover was on June 10. The storm was intense and by June 12 had covered more than 14 million square miles of Martian surface, a quarter of the planet. The storm has blocked out a lot of the sunlight, which is not a good thing for the solar arrays on the rover. The rover shut itself down for the storm’s duration to reserve power, but it is difficult to tell how long the storm will last.

“My personal opinion, just a wild-eyed guess, is it will last for three or four weeks, maybe longer. Some have lasted two to three months,” Nelson said.

Opportunity has gone into sleep mode, reserving its power except for the onboard clock. Those on the rover mission continued to listen for Opportunity in case it comes out of sleep mode during its fault window, the period of time when it attempts communication, according to a JPL release.

But Opportunity not sending a signal is a concern. Nelson is optimistic that the dust is high in the atmosphere and does not lie heavily on the solar arrays. Light may break through the dust clouds to help the rover and the wind may blow some of the sand off the arrays, yet blot out the life-powering sun.

“Mars giveth and Mars taketh away,” he joked.

He does have some concerns about the extreme temperatures on the Martian surface though. After an analysis, it appears Opportunity’s electronics and batteries can stay warm enough to function. The dust could also act as a blanket.

“When you have overcast skies [on Earth], the cold temperatures are not as cold,” he said meaning that the surface stays warmer. The same might be happening on Mars. Those same dust clouds could help trap the heat on the surface of Mars, helping Opportunity stay warm. It is a favorable time of year with the atmosphere and ground warming up naturally.

Thermal is not as much of a concern as Opportunity’s batteries.

“As energy declines … the response is to turn everything off and hunker down,” he said.

The concern is that the energy reserves could get so low that it will be difficult to power up and not even the mission clock will be powered. That is the internal clock that tells engineers what time of day it is and guides them on where to point the antennas. If the storm continues to block out the light, the clock may not work properly. It could continue to function but only for a short while. Nelson uses an example of a flashlight in which the battery is almost drained but will still produce a low light. However, it will continue to drain the power.

With all of the concerns regarding the storm, there is still the Opportunity record to be taken into consideration. The little rover keeps on going after about 15 years of service and a broken robotic arm. In 2015, Opportunity had completed a “marathon” of 26.219 miles across the Martian surface with a time of just over 11 years – quite an impressive feat for a mission that was originally set for only 90 days.

“We are cautiously optimistic and are in it for the long haul,” Nelson said.

He is somewhat surprised about the international interest regarding Opportunity.

“The outpouring of interest under these immediate circumstances has been heartwarming,” he added.

Despite the storm, JPL will continue to listen for Opportunity to phone home.

  Mary Okeefe