Denali’s Near Miss and the Growing Problem of Space Debris
On January 27th, 2019, early Sunday morning, we were notified of a potential collision probability with another satellite traveling towards our pathfinder craft, Denali.
We had received alerts in the past but all were for “close-approaches” from other nearby objects traveling at relatively low speeds of no more than 3 meters per second, with a distance of at least 200 meters. This particular alert was for a head-on impact at a relative speed of nearly 15 kilometers per second (33500 mph) — a velocity that would obliterate Denali, resulting in a massive amount of debris. And a massive debris field in an increasingly crowded Low-Earth Orbit, is a big problem and a growing source of risk for governments and businesses.
This got our full attention. Impact was imminent, we had to act fast. By Tuesday morning we dispatched four maneuvers to raise our orbital altitude. The maneuvers were successful, but the orbital trajectory of Denali and this other small satellite remained still too close for comfort. As the approach neared, we waited nervously for a safe pass by. At 12:22:40 p.m. on January 29, the two satellites would either collide, sending a field of debris hurtling through space, or pass each other by at a close distance. At 12:58 p.m. as Denali came over the hill we established communication, a spark ran through our office, we were able to verify: we had dodged a bullet.
Although talking about space conjures images of great, empty expanses between stars, space is getting crowded. A growing cloud of space debris has been circling the Earth since the Soviet Union launched Sputnik in 1957. According to the European Space Agency, more than 29,000 large pieces are orbiting our planet, everything from 4-inch hunks of metal to whole defunct satellites and spent fuel canisters. Add in an estimated 670,000 pieces of metal detritus between 1 centimeter and 10 centimeters in size, an estimated 170 million flecks and particles of paint, and untold billions of frozen droplets of coolant and bits of dust smaller than a centimeter, and the operating space of low-Earth appears is less empty expanse and more minefield of debris.
This is not a new problem, but it is a growing one. The threat space debris poses to scientific research, telecommunications and military intelligence has been around for decades. NASA was the first space agency to issue mitigation guidelines and the U.N. put it on its agenda in the early 90s. Plans to improve monitoring of current debris and reduce on-orbit collision were included in President Trump’s initial proposal of a Space Force, and many experts and companies have proposed solutions to this problem—including deploying a space harpoon—but there’s no easy answer.
Space is an emerging frontier for commerce, with the potential to advance our knowledge and communication capabilities on Earth by leaps and bounds. A company like Capella would not have a smallsat on-orbit , let alone a feasible path toward a 12-plane, high-revisit constellation, if not for the enterprise and imagination of smart companies, with big aspirations. And with more rockets lifting off and more satellites taking flight, the risk for hitting space debris—and creating more in the process—also rises.
The sea change in space innovation has been driving down size, which in turn enables scale and new possibilities and applications in how we use space infrastructure to explore and monitor conditions on Earth. Instead of the behemoth satellites of the past which were often the size of a school bus, new models embed more power into smaller, capital-light packages. We can now get into space faster and at lower cost, opening up tremendous opportunities for monitoring our planet, but also greater risks of collision. With increasing activity, the time is ripe to rethink our approach to designing, deploying, and managing assets on-orbit, and form a more collaborative approach to de-risking an increasingly crowded low-Earth orbit.
Let’s make space systems smarter and more maneuverable
Most small satellites that are launched these days lack any propulsion system and capability to actively and swiftly maneuver around a potential collision. In fact the satellite that was traveling toward Denali last week had no active means to maneuver and avoid a collision. If Denali were a passive satellite with no capability to maneuver itself out of harm, this past week could have easily turned into a major catastrophe in space with consequences far beyond Denali impacting other satellites in orbit.
There is currently no law that requires any satellite to have any maneuverability capability or collision avoidance systems. The only space debris related guideline is to bring down a satellite (either through deflection into space or burn into the atmosphere) within 25 years. This guideline helps for not adding more space junk, but does not help with the problem already at hand. This lack of regulation might have worked okay for the last few decades, but in the 21st century, where space is open for business, we need to re-think our policies and regulations.
Let’s improve multi-lateral coordination and communication
Just as airplanes globally operate within the safety and flight regulations outlined by the United Nations-sprung International Civil Aviation Organization, we as a worldwide community of space pioneers and stewards, could adopt a collective vision and policy structure for safe and prosperous low-Earth orbit. To fly harmoniously, we all need to play by the same rules–and we need to make sure those rules are legible and enforced, regardless of the flags we operate under, or the location of our launch pads.
Let’s plan for obsolescence
The crafts of yesterday aren’t the sole source of the space junk problem. Current and future missions have a real potential to equal or surpass past debris. Practicing space stewardship means better life-cycle management, pro-active collision avoidance, and de-orbiting plans–in other words, before something goes up, we need to have a plan for how it’s going to come down and how it would maneuver around a potential collision.
There’s no magic bullet to solve the space debris problem, but these three improvements together can come close. We’re living in the dawn of a golden age of satellite use and research. To realize our potential, we need to clean up the orbit and leave it better than we found it for future generations. But we can do it, if we work together.