The emails all start the same way: “The United States 18th Space Control Squadron has identified a close approach between” your satellite and another. The messages also note the projected odds of a collision, anywhere from 1 in 10,000 to 1 in 1,000.
The next email could give odds that are drastically — and dangerously — different.
For scores of operators around the globe, these emails may be the only warning signs that disaster lies ahead for their satellites. But with so many variables to consider, deciding when, how, and if to maneuver a satellite to safety can be a game of high-stakes chicken.
With projected odds of 1 in 50,000, doing nothing is always an option. But what if the chances creep up to 1 in 10,000, or 1 in 3,000? Is it time to move orbits? Should the oncoming satellite move instead? What if it’s a piece of space garbage, like an old rocket booster or defunct satellite?
“It’s like all of us are driving on a highway in a dense fog,” said Moriba Jah, an astrodynamicist at the University of Texas at Austin. “And I have no idea if I’m about to hit something in front of me, and so maybe I decide to change lanes, but do I know what’s beside me?”
There’s growing urgency to improve traffic management. As space travel gets cheaper, the number of satellites in orbit is expected to grow exponentially, boosting the odds of disastrous collisions. Collisions don’t only destroy satellites, they could render areas of orbit unusable for generations.
Flying through fog
In 2009, a satellite operated by US-based telecom firm Iridium slammed into an inactive Russian communications spacecraft.
According to a report about the accident by the Secure World Foundation, the US military had been providing daily warnings to Iridium of potential collisions between its satellites and other objects. But the data was often inaccurate, and at some point the warnings stopped prior to the collision.
The fallout from the collision was massive. About 2,000 detectable pieces of debris spewed into nearby orbits, along with thousands more too small to track. Much of the shrapnel will remain there for decades, until Earth’s gravity drags it out of orbit.
The incident brought new urgency to space traffic management concerns.
Iridium, for its part, still operates a constellation of satellites in the same area of orbit, and the company now receives thousands of potential collision notices daily. As often as once a week, the company deems one of the warnings serious enough to maneuver a satellite out of harm’s way.
Satellite assembly lines
Soon, however, Earth’s orbit will become far more crowded. The satellite industry is undergoing a Model-T moment: Gone are the bespoke devices with 9-figure price points. Small, cheap satellites — costing less than $1 million each— are now rolling off assembly lines.
The global space industry plans to deploy as many as 20,000 new satellites in the next decade, a 10-fold increase from the number of active satellites flying today.
Such an influx could easily overload the current space traffic management system. Experts say that with so many devices flying around, it’s inconceivable that operators can continue to monitor potential collisions as they do today.
What’s wrong with the data?
The US Air Force is the world’s de facto space traffic cop, operating the most extensive network of telescopes to track debris and inactive satellites. The USAF system was designed to track missiles and other threats to national security, and only started issuing warnings about potential collisions because no one else was.
“For most objects in space, there’s nobody controlling it,” said Roger Thompson, a space debris expert at the Aerospace Corporation, a nonprofit that advises the US government on space-related issues. “There’s somewhere between 22,000 and 24,000 pieces of debris being tracked by [the US military], but it doesn’t see all of them, and it doesn’t see all of them all the time.”
Business as usual won’t work very well in the future, he added.
The Air Force’s database doesn’t always have the most accurate data about active satellites, which typically have GPS trackers – a more precise way to determine an object’s exact location. Individual satellite operators get to decide whether and how much data to share with the public or the USAF.
Additionally, the Air Force doesn’t have the resources to store moment-to-moment location data for thousands of objects, and constantly estimate different collision courses.
Jah, the UT astrodynamicist, has proposed a solution. He wants commercial operators to agree to hand over their GPS data to a single, independent database. The Air Force could focus on providing location data for orbital debris, and junk-tracking telescopes operated by other organizations could add their information as well.
The database, which he calls AstriaGraph, could be a single location for tracking debris, satellites and calculating the odds of collisions.
A key part, Jah says, is that he’s got the computing power needed to crunch those numbers in real time.
“One of the reasons I chose [to work at] UT Austin is because it’s home to one of the most advanced computing centers in the world.” Jah said. “It’s home to the fifth fastest supercomputing facility on the planet.”
Experts from the European Space Agency and several US institutions told CNN Business that such a database could help operators avoid a crash course with greater confidence.
The hard part is convincing satellite operators to get on board.
Foreign governments aren’t likely to share information about national security satellites, which can be involved in secret surveillance activities. And commercial satellite companies might not want to make their data public.
Earlier this year, SpaceX, Elon Musk’s space exploration company, launched the first 60 of what is planned to be thousands of satellites into Earth’s orbit for a megaconstellation called Starlink, which is designed to beam cheap internet all over the globe. SpaceX shares its location data with the Air Force, but doesn’t make the information public.
There are no guarantees that Jah’s idea will gain broad support. But he’s hopeful that stakeholders will recognize the benefit of having more precise collision data .
He and other space traffic experts see a need for a new international body that would help coordinate satellite tracking globally.
No international body has the authority to police space. But if the global space community agrees to better coordinate traffic management, Earth’s orbit will be safer.