Inside Opportunity: ‘Oppy’ fights for its life in massive Martian dust storm

James Rice

Our intrepid Opportunity rover is currently in the midst of riding out a massive global dust storm that began May 30. This storm moved south down the well-known Acidalia storm track into Xanthe Terra. A few days later the storm had stretched from eastern Valles Marineris to northern Arabia Terra. It then moved across the equator and south toward Meridiani Planum where Opportunity is located.

This storm is unusual in that it started so early in the Spring season of the Southern Hemisphere. Dust storms typically start in the Martian Summer. The only other dust event that took place during this season is one that took place back in 2001. In fact this ongoing dust storm is the earliest that has ever been observed.

The last contact we had with our rover was on Sol 5111 (June 10, 2018), we now think that it is likely that Opportunity has experienced a low-power fault and is putting herself to sleep only to wake when the skies eventually clear. We began listening for Opportunity on sol 5112. I was Geology Team Leader for our last meeting before we suspended our science operations. Our rover is perched on the slopes of Perseverance Valley facing south and struggling to survive this dust storm. We decided to leave Opportunity’s robotic arm deployed on the rock target, La Joya.

There has been no signal from Opportunity during any of the potential fault windows up to this point. A formal listening strategy is in development for the next several months. It has now been 21 days since we had our last contact from Opportunity. As of our latest Opportunity status report Saturday (June 30) this storm shows no sign of abating anytime soon. We had a chance to conduct an uplink last night at the potential low-power fault window. We sent a real-time activate of a beep as we have done over the past two weeks. We had a negative detection of the beep at the expected time.

One of the last science measurements that Opportunity collected was what we call a tau, which is a measure of the optical depth, and informs us as to how much dust is in the atmosphere. This tau value was calculated to be 10.8, the highest (worst) ever recorded by a surface Mars mission. The previous record was by Viking at 9. Opportunity survived a pretty severe storm back in June-July of 2007. This recent storm is far more severe and our rover is 11 years older (Opportunity has been on the surface of the Red Planet since January 25, 2004).

We went from generating a healthy 645 watt-hours on June 1 to an unheard of, life-threatening, low just about one week later. Our last power reading on June 10 was only 22 watt hours the lowest we have ever seen. The primary concern is that we will not have enough power to keep us warm enough to prevent any damage to the vehicle’s electronics. However, our thermal experts think that we will stay above those low critical temperatures because we have a Warm Electronics Box (WEB) that is well insulated. So we are not expecting any thermal damage to the batteries or computer systems. Fortunately for us it is also the Martian Spring and the dust, while hindering our solar power in the day, helps keep us warmer at night.

Rumors of Opportunity’s death are very premature at this point and we are far from dead. It’s a grim situation right now, no doubt about it, and we still have a long way to go in this our latest challenge on the Red Planet. However, we have an impressive record of overcoming challenges these past 14-and-a-half years and our team is the best on both worlds.

The preceding update was written by Jim Rice, the Geology Team Leader / Co-Investigator on the Mars Exploration Rover Project’s Science Team. This article reflects his experiences working on the program