Humans have gotten pretty good at launching stuff into space—but way less good at getting stuff back down. Up in lower Earth orbit, along with a thousand-plus productive satellites, there are many more slackers: space junk, cosmic trash, garbage of the highest-orbiting order. According to the European Space Agency’s latest statistics, there are about 29,000 pieces of such junk larger than 10 centimeters, 750,000 between 1 and 10 centimeters, and a 166 million between 1 mm and 1 centimeter.
But there’s a lot more smaller stuff where that came from. Previously, NASA studied this diminutive debris by looking at the little craters that it left on the space shuttle like acne scars. But the space shuttle retired in 2011 (RIP). So last month, to take the task back up, NASA installed a new 600-pound
gorilla instrument on the space station: the Space Debris Sensor. This one-meter-square object has one job: to take hits. These, in turn, tell scientists about the trash’s origin and help them make extrapolations about the bigger, more dangerous debris that’s out there.
Stil other projects are already trying to fix the problem, not just measure it—and the world is full of ideas to cut down on astronomical refuse. Ideas like mandating that new satellites deorbit in a reasonable amount of time, harpooning old ones, and catching them in nets or sails.
One company, called D-Orbit, recently tested a new way to take out the trash: a kind of plug-and-play motor that sends any satellite it’s attached to toward a heat death in the atmosphere. They launched a test satellite with the “decommissioning system,” called D3, in June, and finished up this fall—their first attempt at keeping sats from adding to the space junk problem.
The company’s founder, Luca Rossettini, takes space junk seriously. “Space is already full of garbage,” he says. “Let’s be more specific: Not ‘all the space’ but that part of space we humans use for our satellites. That space is limited and very precious and is already a mess.” Rossettini hopes that his customers, someday, will be able to attach D3 kind of like a Lego to their own spacecraft, and then—voila—guarantee that when the satellites reach the end of their useful life, they’ll be terminated.
When D-Orbit wanted to test its flagship system out, the company worked to convince other companies to plop it on their satellites. Although D-Orbit proposed giving it away for free, it was hard to get people on board with unproven technology. And so Rossettini, who had worked in small satellites at NASA’s Ames Research Center with the founders of Earth-imaging company Planet, decided maybe D-Orbit should put up and take down its own satellite.
And so in June, D-Orbit launched D-Sat—a CubeSat with a D3 death device aboard its tiny frame. D-Sat swirled about Earth for around three months, performing a few experiments. And then, at the end of its brief life, D-Orbiters got ready to put D3 into action.
“We knew we were aiming high, especially with a huge motor for such a tiny satellite,” says Rossettini, “but still the D3 should work.” This fall, on the day of reckoning, Rossettini sat in the control room, his finger on the big red button. Before the D3 thrust, the procedure called for them to spin the satellite around, fast, at 700 times per minute, to make it stable. After the revolutions reached that high, Rossettini pressed what is essentially the “go die” button. The D3 came alive. “Everything worked like a charm,” says Rossettini, “but something happened.”
The satellite didn’t end up in its intended death spiral. Although D-Orbit is still finishing the post-flight analysis, Rossettini believes the team has discovered the problem: D3, due to human error, wasn’t quite aligned to the satellite’s center of gravity. Its few millimeters of offness meant that some of D3’s thrust set the satellite spinning, instead of simply pushing it.
“The good news is that the D3 worked as expected,” says Rossettini—even if that work didn’t produce the expected results.
Despite a non-nominal outcome, Rossettini says the company has gotten more requests—from mysterious customers—for snapping D3 onto future satellites. D-Orbit is talking to unnamed potential customers in Europe, the US, and the Middle East. The company also has a contract with the European Commission to make the first decommissioning system for mid-to-big satellites, and another with Airbus. “Airbus is building a platform to test many different passive decommissioning technologies,” says Rossettini, “and our D3 is in charge to remove the platform at the end of the experiments.” Meta!
Rossettini also just returned from a trip to China, where space-farers seemed keen on responsible satellite behavior. In 2007, the country fired a missile at one of its weather satellites. After the missile hit, the FY-1C satellite splintered into tens of thousands of pieces—all trash. It was the largest space-debris birth in history. “They feel the responsibility of the disaster they created,” Rossettini says, and they’re interested in decommissioning with less dynamite.
Right now, D-Orbit is only working to put D3 on as-yet-unlaunched satellites. But in the future, with help of partners, the company hopes to put the propulsion system on already-orbiting satellites, making it a more equal-opportunity killer. Perhaps D3 can keep the space junk problem from getting worse—and help it get better.