More and more satellites, more and more space junk. International scientists have called for a legally binding treaty that will ensure Earth’s orbit is not polluted beyond repair.
Exact numbers vary by source, but the order of magnitude is clear. According to the European Space Agency Esa, there are currently more than 7,000 active satellites in various orbits, other sources even speak of 9,000. And by 2030, according to manufacturers’ current plans, there will probably be more than 60,000.
Image copyright: AstriaGraph / University of Texas
Although the universe is (probably) infinitely large, the space around the earth at a reasonable satellite distance is not at all. Just take the so-called Low Earth Orbit (LEO) at an altitude of 200 to 2,000 kilometers. Most of the satellites are buzzing around here, several thousand. Then there are the satellites that have already given up the ghost, i.e. have ceased operations, which are at least several hundred, probably a few thousand.
Active satellites can be specifically positioned and thus controlled. It is different with the inactive ones and with space debris, for example rocket leftovers or debris. This rubbish or scrap flies uncontrolled through space and is constantly multiplying. Because every time two parts collide, several new ones are created, which, however, do not lose any of their speed due to weightlessness, which increases the probability of new collisions with the same effects. Although the debris in collisions becomes smaller, at a flight speed of up to 56,000 kilometers per hour, even small parts can cause considerable damage. This vicious circle in space collisions is called the Kessler effect.
Legally binding contract required
Many scientists who have joined forces to speak with a stronger voice and thus perhaps be heard by decision-makers are now demanding that all of this has to be improved. They refer to the agreement to protect the world’s oceans, which was recently signed after a long struggle.
Oceans and space, how does that fit together? The analogy is best explained by Professor Richard Thompson of the University of Plymouth, England. He was one of the first to warn about the plastic pollution of the world’s oceans 20 years ago and does not want to have to wait so long again on the subject of space debris until something legally binding to protect the area is signed. “We were aware of the problem of plastic pollution a decade ago, and if we had acted then, the amount of plastic in our oceans might have been half what it is today,” says Thompson. “In the future we need to take a much more proactive attitude to secure the future of our planet. We can learn a lot from the mistakes we have made in our oceans, which also has relevance for the accumulation of garbage in space.”
million parts
Image copyright: AstriaGraph / University of Texas
Known and cataloged as space debris are currently Esa sea about 32,000 parts in space. That sounds like a lot, but it is almost nothing compared to the estimated numbers that result from scientific model calculations. According to them, there are 36,500 scrap parts that are larger than ten centimeters, as well as a million small parts between one and ten centimeters and then a whopping 130 million tiny parts under one centimeter, which of course still cause damage because of their high speed. In addition, the number of satellites does not increase linearly, but rather exponentially.
There should be 60,000 by 2030, and each individual has a purpose, mostly one that is of use to humanity. The scientists therefore consider it all the more important not only to ensure order in space at some point, but now. They recognize that a number of corporations and countries have already begun to consider satellite sustainability. But that must apply now and in the future to all countries and companies that want to use Earth orbit.
Incentives to take responsibility
Written agreements must state that satellite manufacturers and users bear full responsibility for their devices and any debris from the moment of launch. One could create incentives for this with money, for example.
“Humanity must take responsibility for our behavior in space now, not later,” said Melissa Quinn, director of the Cornwall Spaceport. “I urge all leaders to take note of this next step and recognize its importance.”
The article with the scientists’ demands is in the journal Science appeared.
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