World Space Week: How to Keep Astronomy Alive in the Age of Satellite Megaconstellations

At the start of 2022, there were 4,852 operational satellites in orbit above Earth, and the number is steadily increasing. The night sky is a resource that we all have access to, but it is quickly becoming a 'tragedy of the commons scenario. Thousands of satellites in the night sky not only detract from the beauty of the stars but also impede astronomers and constitute a severe space debris concern. As this year's World Space Week focuses on the concept of space sustainability, it is vital to ask: Are we nearing a point where the amount of satellites in the night sky is becoming unsustainable?

Starlink broadband satellite constellations from SpaceX currently number over 2,300 spacecraft, with potentially thousands more on the way. Other internet service companies have plans to deploy hundreds or thousands of satellites as well. In the most recent development, AST SpaceMobile's BlueWalker 3 communications satellite launched on September 10, 2022, with a highly reflecting 693-square-foot (64.4-square-meter) antenna that might shine brighter than Venus, the moon, and the sun. More BlueWalker launches with bigger antenna arrays are planned in the future. Meanwhile, SpaceX plans to launch 30,000 Starlink Generation 2 satellites. Various firms from across the world have proposed launching 400,000 satellites in the near future.

According to Andy Lawrence, Regius Professor of Astronomy at the University of Edinburgh, "we're at a critical branching point."

Lawrence has fought against the unregulated spread of satellite constellations, publishing a book titled Losing the Sky on the subject.

Furthermore, he testified as an expert witness in a court dispute brought by a US business, ViaSat, against the Federal Communications Commission (FCC) for exempting Starlink and other satellite constellations from environmental reviews. Although ViaSat lost on technical grounds, a court has yet to rule on whether or not satellite constellations are immune from environmental review. This is significant since the FCC is presently examining SpaceX's Gen 2 constellation plan.

Lawrence stated that Starlink Gen 2 has requested 30,000 satellites, which are 10 times larger [than generation 1 satellites]. So this is a critical aspect. The FCC is the ultimate decision-maker on whether or not to proceed with this.

Satellite mega constellations are terrible news for all types of astronomers. The streaks of satellites traveling through the field of view distort long, deep exposures of the night sky. The work of Chile's Vera C. Rubin Observatory, with its 26.2-foot (eight-meter) survey telescope slated to commence science operations later this decade, is jeopardized by the expansion of satellite constellations. Satellite tracks are increasingly being discovered by asteroid hunters, rather than the fainter streaks of potentially hazardous near-Earth asteroids. Astrophotographers have their hard work ruined by invading satellites, while radio astronomers are at risk of being drowned out by satellite babble.

While there are workarounds, such as building software to eliminate satellite trails from photographs or delaying exposures if a satellite passes overhead, it ultimately results in more effort that costs more money, according to Lawrence.

Lawrence stated that it is a percentage game since it will not make any one form of astronomy suddenly impossible, but it does imply that we will miss certain things and that everything will become more difficult. We're working on software to remove satellite streaks, which will work to some extent but not totally depending on how bright they are. We may simply have to accept that a certain percentage of photographs will be damaged.

Lawrence and his colleagues aren't ready to call it quits just yet. He is also quick to stress out that they are not luddites. Satellite internet definitely has extremely vital applications, as seen by Starlink's recent provision of emergency internet service to areas of Florida severely damaged by Hurricane Ian, or by giving internet access to Ukraine during the continuing Russian invasion.

Those of us who are worried just want to say, "Whoa, slow down." Lawrence added, "Let's do some independent environmental assessments; they may take a couple of years, which may be uncomfortable for SpaceX, but they're so far ahead of the competition that they should be able to live with that."

It would be unjust not to add that engineers from SpaceX and OneWeb, one of its rival satellite businesses, are collaborating with astronomers to attempt to solve these challenges. They do speak to astronomers, according to Lawrence, and there are portions of their organizations that are really serious about it. They want to contribute because they enjoy astronomy. For example, SpaceX engineers are working hard on projects like VisorSat and new dark coatings [to make the satellites less reflective], but it's all about reducing the difficulties, and the only way to truly minimize them is to launch just 3,000 satellites rather than 30,000. There's also the issue of space junk.

The more satellites in orbit, the more likely it is that they may collide, distributing debris over Earth's orbit. These collisions can increase the likelihood of subsequent hits, resulting in even more debris in a runaway effect that, in the worst-case scenario, might render launching new spacecraft extremely unsafe due to too much junk circling the Earth. It's known as the Kessler syndrome, and it's becoming a major issue for some in the satellite business. According to Lawrence, the debris situation is really concerning. It could be terrible, and the entire business might wind up shooting itself in the foot. Some in the business are apprehensive, but it's almost as if if it's going to be awful, we'd better get in there quickly before it becomes impossible to launch a new satellite without it being destroyed by shrapnel.

That is the exact definition of unsustainable, but Lawrence is quick to point out that we haven't reached that stage yet. Much will be determined by the FCC's judgment on Starlink Gen 2 and, in general, environmental evaluations for satellite constellations. There have been discussions in the United Kingdom about having the equivalent of a 'Kitemark' (a certification that a product has been safety tested in the United Kingdom), where investors and insurers could buy into satellite internet, for example, knowing that it has been environmentally assessed and is mitigating its impact. In the United States, Moriba Jah, an aerospace engineering professor at the University of Texas in Austin, is leading the Space Sustainability Rating effort, which is linked to the World Economic Forum and encourages responsible conduct by satellite providers.

You, too, can get engaged by taking part in a letter-writing campaign to the FCC in advance of their vote on Starlink Gen 2. Anyone, according to Lawrence, may submit a letter to the FCC and express their opinions. "With my friends at ViaSat, I've put together instructions on how to write a letter to the FCC, and that appears to be slowly working with a number of people having written letters."

Lawrence advises keeping letters brief and emphasizing how satellite constellations may interfere with your own view of the night sky, as well as how they are terrible for science and the long-term viability of commercial activity in Earth orbit.

So, what is a reasonable amount of satellites? Lawrence acknowledges that he is unsure. My gut feeling is that we haven't yet reached that threshold, but we will if we end up with 400,000 satellites. But I believe this is a struggle that, while I loathe to say 'win,' since we are not attempting to defeat anyone, we can hopefully resolve.