© Screenshot, YouTube
– The animation of the first space debris removal mission assigned to a private company.
A day after the world discussed the risks of human activity to Earth at a climate conference in Glasgow, another disaster, also related to humans, took place far above their heads, in space.
Space debris has been talked about again on a geopolitical issue when Russia blew up an old Soviet satellite to test a weapon this week, splitting it into hundreds of thousands of pieces. Of these, no more than 1,500 can be detected from Earth.
All these pieces revolve in orbit around the planet. Even one of them could pose a risk to the International Space Station, and when it flew nearby, its occupants were forced to prepare for an emergency takeoff.
And there are hundreds of thousands of debris in space – 9,600 tons of man-made waste that are already threatening the nascent space industry (estimated at $ 3 trillion in the coming decades). Ships will have to maneuver to avoid large and small pieces of garbage, which will only increase as the number of new missions multiplies each year.
Who will clear all this?
A lump of salt can kill a person in space
Behind the term “space debris” are usually hidden parts of satellites, rocket components, the remains of other devices. Self-propelled spacecraft can usually go out of orbit on their own, but the need to set aside fuel for this process limits the payload that the spacecraft can carry.
Depending on how big the piece of garbage is, it poses a different type of risk to space. The data of OUR a report published in January 2011 states that:
– 26 thousand pieces are at least as big as a tennis ball (or much bigger)
– over 500 thousand are at least as small as a colorful ball to play with;
– over 100 million are at least as much as a lump of salt.
The “tennis ball” can destroy a satellite in the event of a collision with it. The “game ball” will damage it or damage a spaceship. A “lump of salt” can pierce a spacesuit or burst a manned window.
This means that an object the size of a lump of salt has the potential to kill a person in space. The explanation is in the enormous speed they develop, orbiting the Earth. For comparison, the height of the International Space Station orbital speed reaches 27,500 km / h.
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Problems on the ground
Comparisons with earth objects used in the classification are by NASA. Its estimates are conservative compared to those of the European Space Agency (THIS): according to her, the smallest fragments (between 1 mm and 1 cm in size) are already over 330 million
It also follows from the comparisons and data that while orbiting, the pieces may collide and the “balls” and “lumps of salt” may increase. At the same time, some of the debris is far above the described dimensions. The risks this poses to the future of the space industry – filled with ships, stations, satellites and most of all people, according to current visionaries, from the “big three” in space to the “mere mortal” space entrepreneurs with modest startups – are difficult to calculate.
© NASA/Goddard Space Flight Center
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The good news is that some of the space debris in low-Earth orbit eventually enters the atmosphere and burns; this will be a lot of debris from the destroyed Soviet satellite “Cosmos-1408”, if you believe a specialized company Leolabs. The bad thing is that the balances of the European Space Agency and NASA do not show a reduction in waste, as most of them are not in such an orbit.
A small piece is enough to hit a satellite used in telecommunications, meteorology, GPS services to create a problem for life on Earth. OrbitGuardians, one of the companies in the niche for space garbage, lists the areas that may be affected by space garbage: Internet, finance, communications, transport, electricity, science, Earth observation (for agricultural, environmental, security and other purposes) .
There are currently 6,542 satellites in orbit. Of these, writes the specialized Indian edition ZME Science, only half “do something”. The others are space junk (According to the ESA, there are 4,700 active ones) And in 2020 alone, a record 1,200 satellites were launched and their number is expected to increase. By 2010, an average of only 100 were fired per year.
Only in the communication project “Starlink” of billionaire Elon Musk can fly around 40 thousand satellite.
“Imagine that one day the Earth’s orbit becomes overcrowded and two large satellites collide. Both will shatter into small pieces that will collide with other satellites and trigger a series of uncontrollable collisions. It has already happened.”
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ZME Science
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However, the situation described above is not a hypothesis, but a reality – in March it was a Chinese satellite struck from the wreckage of a Russian rocket fired in 1996 and split in the collision. There was also discrepancies That close “,” almost. So far, they are exceptions. Satellites can be set up to avoid such a collision, but this will become increasingly difficult in the future.
The article, which talks about space garbage, also mentions the so-called Kessler’s syndrome – the hypothesis of unusability of the Earth’s orbit due to huge amounts of garbage. This does not seem to be a problem now, but with the speed of “absorption” of the Earth’s orbit, its effect may not be far off.
“Dirty work”
In other words, humanity is faced with the question: how to clean space garbage?
The task is difficult – at least because collecting debris one by one is expensive. They move fast and can constantly change their position and rotate. Detection in the same orbit is a challenge. Both the capture and the captured device in most technologies are destroyed in the atmosphere. Over time, various ideas have been explored, both by private companies and by universities, institutes and national agencies – for example, with special satellites, which are connected with certain debris and dragged to the Earth (in whose atmosphere the two burn together).
The private sector is increasingly important in this endeavor. In recent years, companies whose main mission is related to space garbage are gradually increasing. For two months now, the attention in the technology sector has unexpectedly turned to him by another billionaire who entered the space race – Apple co-founder Steve Wozniak. He create your own startup, whose goal turned out to be mapping space debris before it was too late. Privateer announced a few days ago that it will use various tools, including hundreds of its own satellites, to create an idea of the dimensions of the problem. “I think we’re talking about a few hundred satellites,” Moriba Ja, the company’s chief scientific adviser, told the paper. Space.com. “We will not let them all together; we will increase them slowly.”
At the same time, Wozniak’s work is only the initial stage. Japan’s Astroscale launched the ELSA-D satellite this year, using magnetic technology to capture small inactive satellites in orbit. The first successful test was on August 25, 2021 and showed that it is possible for an object such as an inactive satellite to be captured or to be docked with it (capture can be done with a magnet, retention with a mechanical locking system).
Last year THIS signature the first contract for “non-demonstration” collection of space debris, which should happen in 2025 and for which the Swiss startup ClearSpace receives 86 million euros. By the same year, the company, along with Astroscale, should do study about the possibility of two British spacecraft being taken out of low Earth orbit.
It is also possible supply of satellites with a special “sail” or membrane to be deployed at the end of the operational life of the satellite or rocket and designed to help attract the object from the Earth’s atmosphere. Such technology would ensure that any object fired by a person will be able to “go home” on its own.
This technology is already tested in real time, but the possibility of its widespread use remains to be explored. Meanwhile, if the first actual mission to clear space debris is in four years, then the debris from human devices will only multiply. This is why space entrepreneurs, gradually filling this niche, are warning: let’s start with the measures now, before it’s too late.
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