Ivan Kosenkov, the head project manager in space technologies at the Skolkovo Foundation, recently spoke to Gazeta.ru regarding the ongoing issue of artificial "space junk" in Earth's orbit, which poses a threat to satellites underpinning our telecommunications infrastructure.
Space debris. Image source: https://www.gazeta.ru/business/2021/05/19/13599368.shtml.
The space industry has been around for over sixty years. In that time, the amount of debris from disused satellites and other defunct artificial objects has accumulated to such a degree that it could pose a genuine problem in the future. According to the European Space Agency (ESA), the amount of debris in Earth’s orbit numbers 34,000 objects greater than 10 cm, 900,000 objects greater than 1 cm to 10 cm, and 128 million objects from 1 mm to 1 cm in size. While most debris comprises small pieces of junk, things move at very high velocities in space – up to around 29,000 kilometers per hour, almost seven times faster than a bullet. If an object ten centimeters across were to hit the International Space Station (ISS) at such a velocity, it could cause massive damage. To give an extreme example of the effects of velocity, the UK’s Natural History Museum states on its website that the Chicxulub asteroid is estimated to have been around 10-15km wide; however, its velocity is what caused the damage that rendered 75% of Earth’s species extinct, including the dinosaurs. Picture a piece of space debris and a large telecommunication satellite as scaled-down versions of the Chicxulub asteroid and Earth, and there you have it.
But where does all this small debris come from? As of April 15, 2021, the ESA states that approximately 11370 satellites have been launched into orbit since the dawn of the space age; around 6900 are still orbiting Earth, and around 4000 are still functioning. Over time, the defunct objects collide and create smaller bits of space debris – stuff that’s nearly impossible to track – and as this has accumulated, the world’s space industry is increasingly unable to ignore it. Needless to say, cleaning up space debris is no small task, nor is it a cheap one, but the cost of doing nothing might outweigh the cost of taking the problem head-on, given how much our globalized world relies on telecommunications to function.
In a recently published Gazeta.ru article, Russia’s State Space Corporation Roscosmos and Ivan Kosenkov, the head project manager in space technologies at the Skolkovo Foundation, discussed the issue and what could be done to combat it.
Roscosmos, like other space agencies around the world, is looking into ways to remove space debris, and according to the Gazeta.ru article, the agency recorded (from the ISS alone) over 200 near misses with various spacecraft and debris, and warnings come in almost weekly regarding defunct satellites that are high risk. It also noted that most of the space debris that poses a threat is in low Earth orbit (LEO).
With the amount of space debris increasing every year, we draw nearer to a key point. There is actually a term for this: Kessler syndrome, a.k.a. the Kessler effect. This is when the amount of space debris in LEO passes a certain critical mass. The total amount keeps increasing, and collisions give rise to more debris, leading to even more collisions and eventually rendering LEO more or less inaccessible for many years.
Roscosmos’s Central Institute for Machine Building is looking into several cleanup robots, while the ESA, NASA, as well as NEO-01 (China), Astroscale (a Japanese startup), ClearSpace SA (Switzerland) are also working on creating solutions.
Aside from the large quantities of debris that have to be removed, there is also the issue of who will pay for it, not to mention the genuine prospect that such space debris removal technologies could potentially be weaponized and used to remove functioning satellites.
Ivan Kosenkov told Gazeta.ru that they “could be used both as a means of removing space junk from orbit, but also as a means of removing functioning satellites belonging to other countries. That is, it takes on the form of a space weapon. Based on this, the issue with developing such spacecraft is that it is a dual-technology that can be used for removing objects from orbit and for docking with them.”
Roscosmos also recognizes this and stated that we need new international agreements, concrete legal mechanisms, mutual information exchange, and strong regulations to conduct such operations successfully.
As mentioned above, one of the main issues facing space organizations and private entities looking to clean up near-Earth space is investment because the cost of sending a robot into space to conduct a cleanup is high, and there aren’t any immediate financial returns. How does a financier get a return on an investment into a project that removes space junk from orbit?
“Docking to a defunct object in outer space is still a difficult task,” said Mr. Kosenkov. “Most likely after the space interceptor docks with a piece of space junk, it has performed its task and should also be brought back from orbit. In practice, that is a costly single-use solution.” He went on to add that “it is a big problem from the legal point of view and is a classic ‘tragedy of the commons’: a shared resource that everybody uses and all suffer from pollution. Those who control themselves in using this resource lose out in the end; it’s not profitable because if you compel your own space industry to do so, your competitors will thank you.”
Yet according to Bloomberg, “the US Space Force’s chief of space operations, General David Thompson, said that if it were possible to remove debris from orbit, the US would be willing to ‘pay by the ton.’”
Mr. Kosenkov remains skeptical, however, and said that “it is challenging to make an economically viable model where somebody would be able to make money from cleaning up space debris simply because people don’t have the same attitudes towards collisions in space. ‘Well, so what? Someone bumped into someone, it’s a pity, but we keep going.’”