Scientists call for space junk treaty

Thanks to the likes of Starlink, the number of satellites is rocketing – but there's little regulation to govern them.

Earlier this month, the International Space Station (ISS) was forced to maneuver to avoid what's believed to be an Earth-observation satellite operated by Argentina.

It was one of more than 30 corrections that the ISS has had to make since its first segment entered Earth’s orbit in 1998, with two carried out last year to avoid debris from a Russian satellite destroyed as part of a weapons test.

This latest near-miss involved a satellite from the Satellogic constellation – only one of several constellations with a number of satellites impinging on the ISS's orbital height range, says Jonathan McDowell, astronomer and astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

And these are just some of an enormous number of objects circling the planet – in May, the Union of Concerned Scientists estimated there were 5,465 satellites currently orbiting Earth. The United Nations Office For Outer Space Affairs (UNOOSA) puts the figure higher, at 8,261 individual satellites in 2022, which it said was an 11.84% increase year over year. And Time magazine cited researchers who believe this number will rise to more than 60,000 by 2030.

"Using space to benefit people and planet is at risk. By comparing how we have treated our seas, we can be proactive before we damage the use of space for future generations."

says Melissa Quinn, head of Spaceport Cornwall.

Accounts vary wildly as to how much human-made debris there is circling the planet. The US Department of Defense reportedly puts the figure at 27,000. But the experts cited by Time say the true figure is far, far higher – a mind-boggling 100 trillion pieces of old satellites circling the planet, all untracked – although its astonishing tally counts anything from a floating fleck of paint as a piece of debris.

One of the biggest sources of satellites is, of course, Elon Musk's communications service Starlink. Right now, this has more than 3,580 satellites in orbit, with more than 12,000 planned for the billionaire’s first-generation artificial constellation.

The company claims its satellites can't contribute to the space junk problem, as their Low Earth Orbit means that they naturally fall towards our planet’s surface and burn up in the atmosphere at the end of their useful life. However, in 2021 active StarLink satellites were reported as estimated to be responsible for around 1,600 close encounters with other spacecraft every week.

And other artificial constellations are being announced all the time, most recently by China, which announced grandiose plans earlier this year to put some 13,000 satellites into space.

Satellites in geostationary orbit, which maintain the same position above the Earth's surface, are licensed by the International Telecommunications Union on a first-come, first-served basis. Those in lower orbits, though, are licensed by individual nations, leading to something of a free-for-all.

Calls for regulation

Guidelines from UNOOSA call for satellites to be removed from orbit within 25 years of completing their missions, either by pushing them up to a 'graveyard orbit' out of harm’s way, or by dropping them into the atmosphere to burn up on re-entry. However, an enormous number are still simply abandoned where they are.

Increasingly, there are calls for regulation, with NASA and other regulatory bodies recently comparing the situation to the problem of plastic pollution in the oceans. They are calling for an international treaty comparable to the mooted Global Plastics Treaty, currently being debated at the UN, that would include measures to make both satellite producers and users responsible for satellites and debris, from the time they launch through to the end of their lives.

There are already signs that some moves are being taken to tighten regulations governing satellites and debris in Earth’s orbit. In September, the Federal Communications Commission (FCC) adopted a new rule that would shorten the deorbiting window from 25 to five years for satellites that terminate their shelf lives at altitudes of 2,000km or lower.

"Satellites are vital to the health of our people, economies, security and Earth itself. However, using space to benefit people and planet is at risk. By comparing how we have treated our seas, we can be proactive before we damage the use of space for future generations," says Melissa Quinn, head of Spaceport Cornwall. "Humanity needs to take responsibility for our behaviors in space now, not later."

Unchecked debris could wreck space travel

Eventually, there's a risk of what's known as Kessler Syndrome, in which the amount of space debris starts to cascade. Collisions break objects up into more and more individual pieces, which in turn collide with others. In the end, the Earth becomes surrounded by a cloud of small pieces of debris, making space flight impossible.

In light of this risk, there are moves to find ways of clearing up space junk, with the European Space Agency (ESA) announcing the ClearSpace-1 mission: dubbed by the ESA as the “first debris removal operation of its kind,” the project aims to remove from orbit in 2025 a portion of the Vega launcher used in the space flight of the same name. It is hoped that this operation will establish basic clear-up techniques, and lay the groundwork for a bigger removal operation.

Meanwhile, the UK Space Agency has awarded funding to two space firms, Astroscale and ClearSpace, to research a mission to remove junk from space, and is collaborating with UNOOSA to examine how best to implement the UN guidelines.

What's lacking, though, is the sort of legally binding international agreement that NASA and other science bodies are calling for. A large part of the reason is the enormous financial interest in allowing launches to continue.

However, as the FCC pointed out while pushing for the new five-year limit on orbital debris, it would be extremely short-sighted to allow things to continue as they are.

"At risk is more than the $279 billion-a-year satellite and launch industries and the jobs that depend on them," it said. "Left unchecked, orbital debris could block all of these benefits and reduce opportunities across nearly every sector of our economy."