Why we don't know exactly what happened during a near-collision in space
New York(CNN Business) Space traffic experts tracked two pieces of orbital garbage that appeared to be careening toward each other on Thursday night: a defunct Soviet satellite and a discarded Chinese rocket booster. Ultimately, the two objects narrowly missed each other, according to private space-tracking company LeoLabs.
LeoLabs, which uses its own ground-based radars to track spaceborne objects, put the odds of collision at 10% or greater. That's high, but not uncommon, LeoLabs CEO Daniel Ceperley told CNN Business on Thursday.
But the US military, which uses data from the world's largest network of radars and telescopes, said that its space traffic control team detected a "nearly zero percent probability of collision."
In response, LeoLabs's Ceperley said in a statement Friday morning: "We obviously have a great deal of respect for the [US military's] 18th Space Control Squadron and their estimates. Nobody is disputing that these objects came close to one another."
Meanwhile, Moriba Jah, an astrodynamicist at the University of Texas at Austin who has long been trying to raise public awareness about the abundance of junk in Earth's orbit at constant risk of colliding, said the ordeal was only the latest piece of evidence that the world needs an internationally collaborative effort to track space traffic.
His data, an amalgamation of all publicly available real-time space traffic information, show dozens of potential collisions happening at any given moment. Jah suggested the Soviet satellite and discarded rocket booster were expected to come within 72 meters of each other. However, he couldn't say for sure whether a collision was even "likely."
Objects in space are tracked with telescopes and radar operated by governments and private companies. But all those organizations around the globe are hesitant to share their data with each other. So, when there is a chance that two things in space might collide, experts have an extremely difficult time hashing out exactly how high the risks are. LeoLabs does not share its data publicly.
Ceperley told CNN Business Thursday that the company decided to raise public awareness about this particular event because the two objects are both large, and because they're in an area of orbit that's still relatively clean compared to nearby orbits. The company is also trying to raise more general awareness about the debris problem, he said, to encourage the private sector to develop means of cleaning it up.
"Multiple times a week we're seeing dead satellites come within 100 meters of each other, moving at tremendous speeds," Ceperley said.
What happened Thursday
The Soviet satellite, which launched to space in 1989 and was used for navigation, weighs nearly 2,000 pounds and is 55 feet long, according to Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics. The rocket booster, part of a Chinese Long March launch vehicle that likely launched in 2009, is about 20 feet long. Neither of the objects are still in use.
If the rocket and satellite did collide, it would have been the first time in more than a decade that two objects spontaneously collided in space — a situation space traffic experts have hoped desperately to avoid.
The last collision, in 2009, saw a dead Russian military satellite ram into an active communications satellite operated by US-based telecommunications firm Iridium. That event produced a massive cloud of debris, most of which is too small to track from the ground. And the wreckage is still in orbit, posing a constant threat to nearby satellites.
There are also already hundreds of thousands — possibly millions — of objects whirling around in orbit uncontrolled, including tiny pieces of debris, spent rocket boosters, dead satellites and detritus from military anti-satellite missile demonstrations. The junk is heavily concentrated in areas of orbit closest to the Earth's surface. And, though it doesn't pose much of a risk to humans on the ground, it does threaten hoards of active satellites that provide all sorts of services, including tracking the weather, studying the Earth's climate, and providing telecom services. The debris also threatens the International Space Station, where crews of astronauts have lived since 2000, and which has had to adjust its own orbit three times this year due to space debris.
McDowell explained on Twitter that a new collision would be "very bad." The Soviet satellite and Chinese rocket booster could have led to a 10% to 20% increase in the amount of debris in space, and each new piece of debris boosts the odds that more collisions will keep happening.
It could even set off a disastrous chain reaction, leaving space littered with an impenetrable field of garbage that brings new rocket launches and space exploration to a grinding halt.
Part of the problem is that outer space remains largely unregulated. The last widely agreed-upon international treaty guiding the use of outer space hasn't been updated in five decades, which has mostly left the space industry to police itself.
The rise in popularity of megaconstellations — epitomized by the Starlink internet constellation that Elon Musk's SpaceX is building — has sparked a new wave of discussion about the risks of congestion in orbit. Rocket Lab CEO Peter Beck told CNN Business last month that growing congestion in space is already making it more difficult for his company's rockets to find a clear path to orbit to deliver new satellites.
