The worst case Starlink scenario? We could be 'right on the edge' of Kessler syndrome

SpaceX's Starlink mega-constellation is growing at rocket speed.

SpaceX CEO Elon Musk recently announced that the private space company expects "over 4,200 Starlink satellites in operation within 18 months", constituting two-thirds of all active satellites. Roughly 2,300 Starlink satellites are currently in orbit, and SpaceX has approval for 30,000 more. 

Musk has often stated that his ultimate goal for SpaceX is to expand human consciousness by making humanity a spacefaring civilization — and that the profits of Starlink will go towards developing its Mars-bound Starship rocket.

While that suggests SpaceX's interests should be strongly aligned with those of the astronomical community, their actions over the last few years have shown this not to be the case, according to Dr. Samantha Lawler, an astronomer at the University of Regina in Canada.

"We're going to be able to do less science with the same amount of time, and our time is all taxpayer-funded," Lawler, who led a recent investigation into the impact of Starlink on astronomical observations, told IE over a video call. "So it's a higher cost to taxpayers for the same amount of science because of the actions of a private company."

And all of this could be magnified to catastrophic effect in the increasingly likely event of a threat from an approaching asteroid.

Stargazing through a grid of moving Starlink satellites

Lawler and her colleagues' study shows that future satellite constellations, including SpaceX's Starlink and others like Amazon's in-development Project Kuiper constellation, will be most visible during summer nights at latitudes of roughly 50 degrees south and 50 degrees north. This is where many European and Canadian astronomical facilities train their equipment and conduct their investigations.

"From a naked eye, stargazer perspective, I calculate that one in 15 [bright objects] in the sky will be satellites," Lawler explained on a video call. "The stars will still be there of course, but you'll be looking at them through this grid of moving satellites."

These satellite constellations are already inescapably visible from almost anywhere on Earth, and it's a problem that will only get worse in the coming years. "If I just stare at one little spot in the sky — even in a dark sky site — a satellite will pass through that I can see with my eyes within about 30 seconds," she said. "It's crazy how many satellites there are. And so, with a telescope, you can see 1000s of satellites that are reflecting sunlight. Every single image that we take will have a streak through it, and it will change the way that we have to do science."

When Lawler moved for a faculty job to Saskatchewan, Canada, in 2019, she had no idea how extensive the plans were for Starlink. She and her family found a farmhouse with very dark skies from which she could observe the cosmos. "I could see the Milky Way from my back door for the first time, and I noticed the number of satellites increasing with my eyes," Lawler said. Then she started noticing a massive increase in satellites in her data.

The astronomical community's reaction to Starlink draws climate change comparison

The issue came to a head when Lawler was looking for new Kuiper Belt objects — "small icy bodies beyond Neptune to try to prove or disprove [the existence of] Planet Nine". To do this, Lawler and her colleagues used wide-field telescope imaging, which involves training a telescope on a spot in the sky for three to five minutes and looking for anything that moves between successive images.

"I saw streaks of satellites that are millions of times brighter than the small Kuiper Belt objects that I'm looking for," she said. "And it's quite noticeable how many more streaks there are now in my data than there were two years ago." 

Next, Lawler will start an extensive program on the Canada France Hawaii Telescope, looking for even more distant Kuiper Belt objects, which she claims will be "severely affected" by satellite constellations — "it's going to be really horrible to watch over the course of two years," she explained.

"I saw streaks of satellites that are millions of times brighter than the small Kuiper Belt objects that I'm looking for."

Though Starlink has yet to make any of her observations completely unusable, Lawler says it's only a matter of time, given the rate at which SpaceX is sending satellites into orbit. This, despite the fact that Musk claimed, in 2020, that Starlink would have no impact on the astronomical community. According to a report by Nature, the private space firm has halted attempts to add sun-blocking technology to its satellites. 

When it comes to the global response of the astronomical community to these issues, Lawler leveled a savage indictment at others in her field: "It's very similar to the reactions to climate change," she said. "I've given talks at many different universities, and usually people just ignore it at the end. It's just like, 'this is too big, I can't deal with it.'"

"So there are a few people who are very involved in fighting against this. And there are a lot of people who are just kind of pretending it doesn't exist — many people are in denial. Ultimately, it feels more solvable [than climate change], but people are reacting the same way."

Worst-case Starlink scenarios involve Kessler syndrome and failed asteroid detection

Though SpaceX and Starlink have accrued a great deal of goodwill for their work helping civilians remain connected in Ukraine using donated Starlink terminals, even their biggest partner, NASA, warns of the potential dangers Starlink poses. In a statement, the space agency explained that SpaceX's mega-constellation could decrease "our planet's ability to detect and possibly redirect a potentially catastrophic impact."

This, as well as the potential for Kessler Syndrome, are the possible worst-case scenarios, according to Lawler. Kessler syndrome — in which space debris increases exponentially by continuously crashing into other space debris and creating ever smaller pieces — would be disastrous for the astronomical community.

"I think one of the worst-case scenarios is if we go into Kessler syndrome," she said. "For Starlink, their strategy is to put many, many, many satellites into these very dense orbital shells. Obviously, they have a lot of vested interest in not letting the satellites crash into each other. But if they make a mistake, two Starlinks crash into each other, or a Starlink satellite crashes into a piece of space junk, and that makes a whole bunch more debris."

"Other satellites have avoidance algorithms, but how can they possibly avoid debris when everything is moving at a few kilometers per second? If we go into this runaway collisional cascade, which I think we're right on the edge of already, then there will just be tumbling space junk in the sky everywhere."

"The sky will just be full of little glimmers of light," she continued. "Like being inside a snow globe within a couple hours of sunrise or sunset."

Though several startups say they are building technologies for space debris collection, Lawler compares this to "collecting bullets", as these pieces of space shrapnel will be moving at a few kilometers per second. There's also "no money in that right now, so it's not going to happen with a startup," she said.

In theory, Starlink could also prevent important discoveries from taking place. "Most of those really amazing discoveries are right on the edge of what we can do with a survey, right? So if you just add in just a little bit more noise, you're not going to make those amazing discoveries."

As for what can be done to improve the situation, Lawler explained that she's focused on getting her message out there. While she said she's not calling for people to boycott Starlink, she believes people should consider other options if they have them. 

"If consumers tell SpaceX to prioritize protecting the night sky, maybe they'll listen," she explained. "They have incredible engineers on their team, and the situation can definitely still be improved with better engineering."