In 1978, NASA scientist Donald Kessler warned of a potential catastrophic, cascading chain reaction in outer space. Today known as “Kessler Syndrome,” the theory posited that space above Earth could one day become so crowded, so polluted with both active satellites and the detritus of space explorations past, that it could render future space endeavors more difficult, if not impossible.
Last week, the CEO of Rocket Lab, a launch startup, said the company is already beginning to experience the effect of growing congestion in outer space.
Rocket Lab CEO Peter Beck said that the sheer number of objects in space right now — a number that is growing quickly thanks in part to SpaceX’s satellite internet constellation, Starlink — is making it more difficult to find a clear path for rockets to launch new satellites.
“This has a massive impact on the launch side,” he told CNN Business. Rockets “have to try and weave their way up in between these [satellite] constellations.”
Part of the problem is that outer space remains largely unregulated. The last widely agreed upon international treaty hasn’t been updated in five decades, and that’s mostly left the commercial space industry to police itself.
Rocket Lab set out to create lightweight rockets — far smaller than SpaceX’s 230-foot-tall Falcon rockets — that can deliver batches of small satellites to space on a monthly or even weekly basis. Since 2018, Rocket Lab has launched 12 successful missions and a total of 55 satellites to space for a variety of research and commercial purposes. Beck said the in-orbit traffic issues took a turn for the worst over the past 12 months.
It was over that time that SpaceX has rapidly built up its Starlink constellation, growing it to include more than 700 internet-beaming satellites. It’s already the largest satellite constellation by far, and the company plans to grow it to include between 12,000 and 40,000 total satellites. That’s five times the total number of satellites humans have launched since the dawn of spaceflight in the late 1950s.
It’s not clear if traffic from its own satellites has also caused frustrations for SpaceX. The company did not respond to a request for comment.
Researchers have warned for decades that congestion in outer space could have devastating consequences. Kessler’s warning said that if space traffic becomes too dense, a single collision between two objects could set off a disastrous chain reaction that effectively turns the space around Earth into an extraterrestrial wasteland. One piece of debris would hit a satellite, and that impact — much like a car crash, except at orbital speeds upwards of 17,000 miles an hour — could generate hundreds, if not thousands, of new pieces of debris in its own right. Those new pieces could hit other objects in orbit, which would hit other objects, and on and on, until low Earth orbit would be saturated with an increasing amount of uncontrollable projectiles.
And any one of them could knock out a satellite, a launching rocket, or even an orbiting space station with humans inside.
Kessler Syndrome was central to the plot of 2013’s “Gravity,” in which satellite shrapnel caused a cascade of disastrous satellite collisions.
The question is whether it will remain fiction. Some experts warn areas of low-Earth orbit have already reached a critical mass of congestion.
SpaceX has said that it is determined to be a responsible steward of outer space. The company says it has equipped its Starlink satellites with the ability to automatically maneuver out of the way of other objects in orbit.
SpaceX’s constellation also orbits at lower altitudes than the most crowded areas, which NASA and international partners estimate is about 400 to 650 miles high. That’s an ideal area for observation satellites that monitor the environment and is also home to swarms of debris.
But Moriba Jah, an astrodynamicist at the University of Texas at Austin and a leading expert in space traffic, said most of Earth’s orbit below about 750 miles is becoming a danger zone.
Jah created a database to help track potential collisions in space, and an online chart uses dots to show how many objects are expected to pass within six miles of each other every 20 minutes. Over the past year, the dots have grown too dense to count.
Jah hopes that more satellite operators and rocket companies, including SpaceX and Rocket Lab, will share real-time location data of their rockets and satellites to make the predictions more precise.
Neither company has done so.
Though there haven’t been any collisions this year, Jah warns, it could be only a matter of time.
Even if SpaceX can manage to keep its area in space clean, there’s a line of other companies waiting to build their own giant constellations. Amazon and UK-based OneWeb plan to build their own telecom ventures also using hundreds of their own satellites. Adding to the problem are swarms of junk currently whizzing through space, including defunct rocket parts, dead satellites and debris from prior collisions and anti-satellite tests.
That junk is practically impossible to clean up on a large scale. And it will take years, if not centuries, for it to naturally fall out of orbit.
The odds of avoiding disaster only become slimmer with each new satellite launch, Jah added. He remains optimistic that we can avoid Kessler Syndrome, even with swarms of satellites in orbit — but only if the SpaceXs and Amazons of the world agree to abide by certain rules and norms of behavior.
“Absent that the answer is no,” he said.
Beck, the Rocket Lab CEO, said he is frustrated that so much of the conversation about space junk revolves around the risk of in-orbit collisions, and there’s not as much conversation about how space traffic is already impacting the launch business. Satellite constellations can be particularly problematic, he said, because the satellites can fly fairly close together, forming a sort of blockade that can prevent rockets from squeezing through.
In Rocket Lab’s early days, Beck said, the company could pick a 30-minute timeframe on a given day and expect to reach orbit safely.
Lately, the company has had to pick “half a dozen separate launch windows because we’ve got to shoot up in between a train of” satellites, Beck said.