The number of satellites orbiting our planet has grown massively in the last few years, leading to some concerns that they could start returning to the surface frequently and unpredictably.
Satellites have orbited Earth for almost 70 years, with the Soviet Union launching the first man-made satellite, known as Sputnik 1, into an elliptical low orbit on October 4, 1957.
During its short stint in space, it sent radio signals back to Earth before its batteries became depleted, which allowed for aerodynamic drag to pull it back towards Earth and into the atmosphere on January 4, 1958.
The launch of Sputnik 1 ended up being a major event in the Cold War that triggered the creation of the National Aeronautics and Space Administration, otherwise known as NASA, and the Space Race.
Since then, the number of satellites orbiting Earth has grown.
Associate Professor of Astronomy at Campion College and member of the Department of Physics at the University of Regina, Dr. Samantha Lawler, says the number of satellites orbiting Earth saw a significant increase when SpaceX began to send up their Starlink satellites five years ago.
"Before Starlink, there were a couple thousand satellites in total," explains Dr. Lawler. "Today, there's more than 10,000 and more than 60 per cent of them are Starlink satellites from one company."
Historically, most satellites orbiting Earth were owned primarily by governments around the world, but Dr. Lawler says along with SpaceX and their Starlink satellites, there have been more private companies sending up satellites recently.
"SpaceX made it easier and cheaper to launch all sorts of things, and they launch anything that people will pay them for. So, there are many, many satellites in orbit that are owned by many different countries and many different companies, but the bulk of them are Starlink satellites owned by SpaceX," Lawler said.
Even though there are thousands of satellites in space with many more on the way, Lawler says there isn't really any form of enforcement.
"It's all pretty willy-nilly. There are treaties, in theory, that say that outer space is, I think the language used in the treaties is, 'For All Mankind,'" Lawler says. "But the only entities that are regulating satellites are, really, set up to regulate radio broadcasts, not set up to regulate environmental pollution or orbital safety or any of that."
Lawler adds that if someone wants to broadcast a radio signal to Americans, they have to get permission from the United States Federal Communications Commission (FCC), or the Canadian Radio-television and Telecommunications Commission (CRTC) in Canada.
To launch into space from the United States, permission from the Federal Aviation Administration is required.
"There's just really nothing set up to look at orbital safety and all of these agencies that are not set up to do this are being asked to do this. So, they're not doing a great job of checking for safety, because that's not what they were set up for. That's one big reason that this has gotten so bad so quickly."
With the number of satellites currently orbiting the planet, and with the number of satellites that SpaceX plans on sending up into orbit, Dr. Lawler sees a few potential issues.
"This is big, and these are things that I've given hour-long talks about," chuckles Lawler.
Lawler moved to Saskatchewan in 2019, right when the first Starlink satellites were being launched, and could see them flying overhead.
“I could see them in the sky,” she says. “I suddenly had access to a dark sky at my home for the first time in my life. I could see these satellites and I was, kind of, wondering, ‘How bad is this going to get?’”
When the satellites started to pop up in her data collected from research telescopes, she realized that it was going to get pretty bad.
The satellites reflect sunlight for quite some time after the sun has set, resulting in streaks across the sky and headaches for astronomers.
“It looks like a moving star, basically. And now there are hundreds of them that you can see every night, very easily. So, that was what first got me worrying about this. Then I realized, just the sheer numbers that even just Starlink is planning to launch, there are going to be serious consequences.”
SpaceX is planning on eventually having as many as 42,000 satellites orbiting Earth.
“They have provisional permission from this radio broadcast regulator in the US to launch that. They already have permission. And there are well over 6,000 in orbit now. I haven’t looked at the exact numbers, but they’re launching batches of 60 every few days. So, it’s going up very, very quick.”
Burning questions
Another potential issue with the Starlink satellites is their five-year lifespan.
Given the satellites' short span, SpaceX be launching and de-orbiting 42,000 satellites every five years.
They aren't small either, as they're roughly the size of a standard Ford F-150.
“They are big. There’s a lot of metal,” says Lawler.
Once the satellites are decommissioned, they're ostensibly disposed of by falling back into Earth's atmosphere where they're expected to.
According to Lawler, the disposal process will add tonnes of metal to the atmosphere every day.
“It doesn’t go away, but they’re treating it like it does.”
With there being 42,000 satellites with only a five-year lifespan orbiting the planet and only 43,830 hours in five years, that works out to one satellite de-orbiting and burning up in the atmosphere roughly every 62.4 minutes.
And that’s just accounting for Starlink satellites, let alone all the other satellites in orbit.
“One Ford F-150 burning up in earth’s atmosphere every hour. Like, that’s crazy.”
Lawler says there have been some recent papers published that have shown this will help to deplete the ozone layer, change the chemistry of the upper atmosphere, and it could accelerate climate change.
“We don’t actually know what it’s going to do, and nobody is studying it. So, it’s really quite scary.”
While SpaceX has claimed that these satellites will burn up completely in the atmosphere, Lawler described a recent incident where a piece of a SpaceX satellite fell into a farmer’s field not far from her home in Saskatchewan.
“This was in Ituna, Saskatchewan. I wrote a Scientific American article about it recently, and the whole process. It was such a weird mix of emotions, too. It was like, ‘Oh my gosh! I’m standing next to things that were in orbit! That’s so cool!’ But, oh my God! This could have killed people. And this is, like, fine.”
It's led Lawler to question if these satellites will burn up in the atmosphere, or if there will be pieces of metal falling from the sky every hour.
Lawler says there are no safety regulations involved, and no one seems to be checking to see if the equipment is actually going to burn completely before making through the atmosphere.
“Nobody’s checking to see what chemicals are going to be added to the atmosphere when they burn up. The US federal agency that regulates this doesn’t consider space to be an environment. They have categorically excluded satellites from environmental reviews. So, they’re not. They’re not looking at this at all.”
Lawler left to discuss this exact issue at the UN a few days after she spoke with us.
Kessler Syndrome
Another issue known as Kessler Syndrome could eventually arise once there are enough objects orbiting Earth.
In the 1970s, NASA scientist Donald Kessler realized that as spent rockets, satellites, and other space debris accumulate in orbit, a chain reaction of collisions may occur.
As each collision creates more debris, that debris can cause more collisions, resulting in more debris, and so on.
Once the amount of debris hits critical mass in one particular orbit, collision cascading begins, regardless if anything else gets sent up into orbit.
After collision cascading has begun, the risk to spacecraft and satellites increases to the point where they are no longer able to maintain orbit.
Back when Kessler Syndrome was initially proposed, Donald Kessler estimated that it would take roughly 30 to 40 years to reach the threshold.
According to the NASA website, experts believe we are already at critical mass in low-planet orbit, which is between 900 and 1,000 km above the surface.
“Starlink is operating in the densest part of orbit that has ever existed,” Lawler explains. “And they want to launch tens of thousands more satellites into that same orbit. So, they’re making it more and more likely, that if there is a collision in orbit, we will enter Kessler Syndrome.”
If we were to enter Kessler Syndrome, the risk posed by sending anything into orbit could remain incredibly high for potentially centuries. Lawler says it would be like trying to launch a space shuttle through a field of bullets.
Additionally, the night sky would likely be filled with flashes of light, as the debris reflects the sunlight back to Earth.
“And again, nobody is checking this. It’s just crazy, to me, that nobody is worried about this.”
Lawler adds that with different organizations and companies owning the satellites, they all must work together to help make sure they don’t collide, and she isn’t fully convinced they will.
When companies or organizations send objects into orbit, they must identify what orbit they plan to use, but Lawler says it isn’t regulated and there's no equivalent to shipping lanes in space.
“It very much worries me how little regulations there are right now, and it doesn’t have to be that way. There are treaties that could be enforced, but nobody is enforcing them, so private companies are just sort of doing whatever they want to right now.”
Even if someone wanted to enforce the treaties, Lawler says that the best option is to fine the companies that don’t play along.
As an example, Lawler says the FCC in the United States has recently fined a company for not removing its satellite from an orbit the company said it would remove it from once the satellite reached its end of life.
That satellite was in a geosynchronous orbit, which means that it is in an Earth-centered orbit that matches the planet’s rotation on its axis. This means, when observed from Earth’s surface, that satellite would appear as though it is standing still in the sky.
Lawler says these geosynchronous orbits are at a higher altitude and are better regulated, but there isn’t much real estate in that orbit.
While these companies can be fined, Lawler says there is a concern the company will pack up and stop doing business with that country.
“Given the example of what if the Canadian government starts fining Starlink for, effectively, making taxpayer-funded astronomy research less effective. They’re basically taking money away from astronomy research because we have to use telescopes for longer to get the same results. Because we lose so much data to their satellites now,” Lawler explains. “So, if Canada started fining Starlink for that, then Starlink can just say, ‘Eh, we don’t need to broadcast to Canadians, you’re a small market anyways.’”
Lawler adds that these satellites do provide a service, but she doesn’t see the need for 42,000 orbiting overhead.
According to Lawler, Starlink satellites are mass-produced and leak radiation.
They leak so much radiation, Lawler says, that even the classified Starlink satellites doing military operations are getting picked up on radio telescopes.
Radio observatories try to do their best to keep their surrounding area as free from radio emissions as possible, often going as far as creating radio quiet zones that don’t even allow cell phones, let alone microwave ovens.
“And then all of a sudden, these satellites start flying over, blasting radio waves down on this radio-quiet site,” Lawler says. “It’s a really big problem for radio astronomy.”
Additionally, Lawler says that with an increased number of satellites comes increased difficulty in identifying and tracking asteroids, because they need to be observed near twilight, which is when satellites tend to be at their brightest.
Due to that, they lose lots of data, and it makes it harder to track the asteroid’s orbit.
Quality over quantity
Dr. Jeroen Stil, Associate Professor of Astronomy at the University of Calgary, says it's hard to picture life as we know it without satellites.
He says that satellites help to provide us with valuable information, such as tracking hurricanes, and facilitate much of our communication abilities.
"Satellites are part of modern life. And not all satellites are the same," Still says. "There has been an explosion in the number of satellites since about 2019. And these are relatively low-orbit satellites for phone communication and internet anywhere on earth."
This number of low-orbit communication satellites will exceed the total number of satellites for every other use combined.
Stil adds that there is a good side to that, but it does affect astronomy in several ways.
According to Stil, roughly one-third of the astronomical images they take will be affected by satellites flying through them.
"Imagine those big telescopes. They cost thousands of dollars per hour to operate. They're tuned, they're very precise, high-sensitivity cameras that are made to detect very faint light from deep into the universe. And then this bright satellite comes through, and it is very bright," Stil explains.
When a satellite passes through a camera's field of view, they are unable to remove it from the image.
"What astronomical observatories are doing now, is trying to mitigate the effect, strategize to minimize the loss of data, given the circumstances."
One of the ways they do that is by taking photographs with a shorter exposure to help minimize the chance of having a satellite fly through the image, but by doing so, they are losing valuable data due to the background noise that will get picked up in the image.
"You can adjust, but only up to a point. If you have to discard a larger and larger section of your data, then your scientific output is going down. And certain observations may be very difficult to do, if not impossible," Stil says.
He adds that sometimes the telescope needs to have an exposure in the magnitude of in the tens of hours.
"Even though SpaceX is currently the primary company putting up all of these satellites, Stil pointed out that this is free enterprise and asked, "Do you think SpaceX will be the only company that runs these? I'm not familiar with all the companies, but this is a system that only works if it launches thousands and thousands of satellites. So, every competitor is going to do that."
As a radio astronomer, Stil points out that his work is impacted by these satellites.
"The satellites communicate by radio signals and those radio signals are allocated specific frequency bands. Those we can deal with and live with, because astronomers know that there are other uses of space and that society needs to use space, as communication and everything that is also very important. Astronomers are one user, but a recognized user of space and of radio bands."
The challenge that satellites pose for Stil's work is the unintended radio emissions that seep out of the allocated frequencies they are supposed to use.
While the amount of radio emissions seeping out of the satellites may not hinder everything, Stil says these radio emissions can be a thousand times brighter than the natural radio emissions that radio astronomers study with radio telescopes.
In fact, back in 2013, radio astronomers observed Starlink satellites emitting radio emissions that were far outside the radio band that the satellites use to communicate.
Stil adds that these satellites act as a type of mirror that also reflects radio waves back to Earth.
"There's a lot of unintended consequences of these satellites being launched. And I don't want to single out SpaceX with their Starlink network, but they are the biggest and they're leading the way," Stil says.
With that, Stil alluded to unintended consequences with impeded growth in the past, pointing to the amount of plastic waste floating in the oceans and the issues we are dealing with around greenhouse gases.
Stil says that the legal process to create new space laws is a slow one, and regulators have a difficult time keeping up.
While space may seem like it is never-ending, satellites need to be in specific orbits in order for them to do their jobs, and if there is no more room in that orbit, then there is no room to add any more, and the chances of initiating the Kessler Syndrome grows.