No one had expected that an announcement about the end of a rover’s mission on Mars would be so moving. But it was.
The Opportunity rover – Oppy, for short – was only supposed to work for 90 days. It lasted 15 years. It was only supposed to travel 1,000 yards. It covered over 28 miles. Along the way, Opportunity found evidence that liquid water existed on the surface of Mars at some point in the past, and lasted long enough that microbial life could possibly have developed. But that’s not why people were so moved by the Feb. 13 news.
It was the final message sent by Oppy, as a planet-wide dust storm – one of the strongest in a decade – enveloped the rover, that got to people: “My battery is low and it’s getting dark.”
Writer Jocelyn Rish tweeted, “I never imagined I’d be sitting at my computer crying over a last message from a robot on Mars, but here I sit wiping away tears.” George Takei, Star Trek’s Sulu, added: “Perhaps one day we shall find you again, friend, when humans finally set foot on Mars.”
We could all imagine this little robot that had overcome so much and lasted so long, all alone, far from help, the storm blocking out the Sun, slowly losing power as dust kept its solar panels from recharging its battery. Oppy’s seeming self-awareness of its impending end affected many of us, including myself. It stunning images, amazing science, and perseverance captured our imagination and our hearts.
It turns out, however, that Opportunity didn’t really “say” that. The rover never “talked” using words. Instead, it communicated by sending bursts of data that included the status of its systems and results from its instruments. The final data burst included an update on its battery level and a note that no sunlight was getting to the solar panels. In a Twitter thread that quickly went viral, science reporter Jacob Margolis offered a poetic interpretation of that information, tweeting: “The last message they received was basically, ‘My battery is low and it’s getting dark.’”
Opportunity did have an amazing life. The rover landed on Mars in 2004, cradled in a cocoon of air bags, bouncing 26 times before finally coming to rest. Its twin, Spirit, had landed a few weeks earlier on the opposite side of the Red Planet. Seven years later, Spirit got stuck in soft soil, and, a few months later, stopped communicating with Earth entirely.
But Opportunity kept going. It wasn’t always easy, but every time it got into trouble, engineers on Earth were able to figure out how to fix the problem. At one point, Opportunity found itself also stuck in a bank of sand. The rover spent several weeks at the aptly named Purgatory Dune, until engineers, working with a duplicate rover in a sand box in Pasadena, finally figured out how to teach it to shimmy its way to freedom.
Last summer, as Opportunity was traveling through Perseverance Valley, a huge dust storm hit Mars. The plucky rover had survived similar storms. But it was older now, and not quite as hardy. A fault in one of its memory banks had affected its long-term memory. Problems with its wheels and robotic arm affected its movement, almost like arthritis. Engineers worried the rover might not survive a prolonged loss of power.
The dust storm lasted over three months and, when the skies finally cleared, the little rover didn’t wake back up. Engineers tried to re-establish communication with it over 1,000 times, but never got a response.
Last Tuesday, engineers tried one last time to talk to the rover. They sent Oppy a wake-up song – Billie Holliday’s “I’ll Be Seeing You.” Silence. Engineers waited. Silence. They asked to listen for just a few minutes more. Silence. Finally the project manager told the radio operators to stop.
The mission of Opportunity, the rover that exceeded so many expectations and taught us so much about Mars, had ended.
“My battery is low and it’s getting dark.”
Sally Stephens is an animal, park and neighborhood activist who lives in the West of Twin Peaks area. She is a guest columnist.