NASA is finally saying goodbye to its Opportunity rover on Mars after spending nearly a year trying to reestablish communication with the silent robot. A team of engineers at NASA’s Jet Propulsion Laboratory (JPL) sent one final radio command to the rover last night but did not receive a response. Now, NASA will stop trying to communicate with Opportunity, effectively bringing the rover’s 15-year mission on Mars to an end.
Opportunity has been radio silent since June 2018 when a massive dust storm overwhelmed the skies of Mars and blotted out the Sun. The storm, one of the thickest NASA has ever seen, made it impossible for Opportunity’s solar panels to stay powered. As a result, the rover’s internal battery drained, and Opportunity went into hibernation mode.
After the storm passed, the mission team for Opportunity was hopeful that they might be able to wake the rover up again. They figured that once light hit Opportunity’s solar panels again, it could get enough power to turn on and establish a radio link with Earth. But it’s been total silence since June 10th when the rover sent back its last message that indicated the environment on Mars was incredibly dark and that the bot’s battery was nearly depleted.
The team has tried every possible method of getting Opportunity to phone home again using NASA’s Deep Space Network, an array of massive radio telescopes here on Earth that are used to communicate with spacecraft deep in the Solar System. But they’ve had no luck. One theory is that the dust storm that engulfed Opportunity was so obtrusive that it left a layer of dust on the rover’s solar panels, further preventing it from receiving sunlight. NASA was still hopeful, though, as November through January was considered a particularly windy time on Mars. Engineers hoped that a powerful gust might be able to blow off whatever was blocking the panels.
Now, Opportunity’s demise is all but certain, as the rover is about to enter Martian winter. Opportunity needs to stay above negative 40 degrees Fahrenheit (negative 40 degrees Celsius), and when it’s working, it has many ways to keep warm. These include eight small plutonium heating units that give off a small amount of warmth, as well as electrical heaters. Moving around on the planet produces heat for the robot’s battery and components, but with the rover sitting still all this time and drained of power, it hasn’t been able to warm itself up through movement or its electrical heaters.
This wasn’t as much of a concern during the storm, which occurred in the summertime; temperatures were well above what Opportunity could handle. But now nighttime temperatures could plunge to negative 157 degrees Fahrenheit (negative 105 degrees Celsius). That means many of Opportunity’s components could grow brittle and break.
For those that have worked on Opportunity, it’s a heartbreaking time. Many at NASA JPL said their goodbyes to the rover last night, while the final message was sent to Mars. Numerous NASA scientists revealed that Opportunity didn’t send anything back. Today, NASA will make the final determination of the rover’s fate during a press conference at 2PM ET, but it’s clear that the mission is over.
The end is also bittersweet. Opportunity lasted far longer on the Martin surface than anyone expected. NASA launched Opportunity and an identical twin rover called Spirit in the summer of 2003. The two successfully landed on Mars in January 2004 with the goal of each lasting for at least 90 days. Both went well beyond that. Spirit lasted for six years, before getting stuck in a sand trap and losing energy. Opportunity boasts a 15-year lifespan, making it the longest-running rover that NASA has ever had.
During its time on Mars, Opportunity did some incredible work. It traversed more than 28 miles (45 kilometers) of Martian terrain — the farthest of any surface robot — exploring multiple craters on the planet. It even survived another dust storm in 2007, though that one was much less intense than the one in June. Both Opportunity and Spirit have helped uncover clues about what Mars’ climate used to be like billions of years ago, revealing that the Red Planet once hosted oceans of liquid water on its surface. This ancient wet climate may have made it possible for alien life, like tiny microbes, to survive on Mars long ago.
Opportunity is leaving a great legacy behind. Still, NASA scientists at JPL will spend this week mourning a spacecraft that some have spent over a decade operating. Many have already started to move on to other missions, such as operating the Curiosity rover on Mars or planning for the next Martian rover launching in 2020, but they’ll bring their experience with Opportunity with them. Maybe we’ll see other rovers lasting beyond 15 years on the Red Planet.