Telephoning, navigating, spying: You can't do that without satellites.
There are more and more artificial satellites in space - but who cleans up the space junk?
Munich – Disused upper rocket stages, switched off satellites, astronauts' lost tools.
In orbit, it literally looks like Hempel's under the sofa.
More and more abandoned objects are racing around our planet.
You don't get much of that on Earth.
“The risk of being hit by an object is low.
About 100 parts hit the surface of the earth every year,” says astrophysicist Hauke Fiedler, who researches the disposal of space debris at the German Aerospace Center (DLR) in Oberpfaffenhofen.
The situation in Earth orbit is quite different.
"Due to the high speed, even a ten centimeter particle could destroy the entire ISS," warns Fiedler.
Space junk: DLR and Co. are feverishly researching possible solutions
The ISS is the International Space Station orbiting the earth at an altitude of 400 kilometers.
There was only a garbage alarm in November 2021.
The crew of the ISS, including German astronaut Matthias Maurer, had to retreat to escape pods because of a risk of collision with parts of a disused satellite that Russia shot down while testing an anti-satellite weapon.
The satellite burst into thousands of pieces.
There was no collision, but the ISS has to avoid scrap again and again.
The crew was warned about debris every few weeks, Maurer complained at the time.
"That's because we don't clean up in space."
Astrophysicist Hauke Fiedler is researching solutions: telescope stations for locating space debris, or disposal technology developed at DLR.
Robots are supposed to fish “space debris” out of space.
Fiedler is standing next to a research facility.
“Here you can try to fly to an object in space.
Then you can grab it and bring it back to Earth,” he explains.
The facility in Oberpfaffenhofen is one of the most modern in the world.
Photography is prohibited – trade secret.
There are various approaches worldwide to get the cosmic garbage problem under control: Large nets for fishing, lasers that destroy dangerous parts, or the possibility of lowering objects in space so far that they burn up in the atmosphere.
The European Space Agency ESA lists 36,500 pieces larger than ten centimeters, so-called space debris, in its statistics.
A bigger problem, however, are often smaller parts.
"The ISS normally avoids the large debris," explains Fiedler.
You have to be lucky with the smaller ones – they are unpredictable.
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A lot of space debris has accumulated in orbit.
Numerous satellites cavort in orbit around the earth.
© ESA
Hundreds of millions of pieces of space junk in orbit: There are no binding laws
Scientists estimate that there are about a million pieces of debris in orbit larger than a centimeter.
According to experts, if such a part were to hit a satellite, it would have the destructive power of a hand grenade.
Another 330 million parts are smaller.
The Müller survey, explains Fiedler, takes place using statistical models and individual measurements at different orbit heights.
But it's not just about scrap metal.
Particles of paint, slag from solid fuel engines or golden insulating foil also circle the earth.
"Being hit by such a film can be fatal," says Fiedler.
If you don't clean up space, it will eventually become totally littered.
However, it is not really clear who is responsible for cleaning up.
"What is missing are binding laws," complains Fiedler.
He is a member of the Inter-Agency Space Debris Coordination Committee, IADC for short.
The international forum of 13 space organizations focuses on the garbage problem.
An agreed guideline so far is that everything that is shot into space should be burned up again after 25 years at the latest.
"This time is too long," says Fiedler.
Private companies like billionaire Elon Musk's "Space X" don't have to follow any guidelines at all when launching satellites into space.
"They therefore bear a special responsibility for avoiding space debris," says Fiedler.
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Astrophysicist Hauke Fiedler researches space debris at DLR in Oberpfaffenhofen.
© Marcus sleep
Space debris must be removed - private companies should clean up
The topic is hotly debated.
There are experts who would like to limit the number of satellites or limit their time in space to at least half a year.
The international space treaty of 1967 stipulates, among other things, that the universe belongs to nobody.
In other words, it belongs to everyone.
So who should ban whom and what?
Because good money can be made with waste not only on earth, private companies are also working on solutions.
The ESA uses this for cooperation.
With the Swiss start-up "Clearspace", ESA wants to send a robot into orbit that will remove the scrap with its gripper arms.
"Clearspace-1" is scheduled to start in 2025 for the first clean-up campaign.
ESA is investing more than 100 million euros in the project.
Private investors are also involved.
Holger Krag, Head of the Space Security Program at ESA, doesn't even beat about the bush.
“As with any environmental problem, before you can clean up, you have to prevent litter.
Are we good at preventing?
No!” So a clean-up campaign is needed.
It is planned that the waste will burn up when it enters the earth's atmosphere.
In the future, says Krag,
garbage should be prevented immediately.
"We demand that from 2030 the object must disappear at the end of every mission."
Manuel Metz, astrophysicist at the DLR site in Bonn, also sees a lucrative business model in clean-up missions.
However, robots that fish the garbage out of orbit are not enough; several technologies are needed.
There are various approaches being tested around the world, says Krag.
Some satellites are already equipped with handles so that they can be removed more easily later.
Observation technologies are also important in order to locate the objects precisely.
Garbage in space: Hessian start-up wants to tackle the problem with real-time data
The Hessian start-up "Vyoma" is pursuing such a monitoring strategy.
The company from Darmstadt wants to collect real-time data with its own satellites in order to locate space debris.
There are many satellites in orbit that have to make evasive maneuvers because the data is up to 48 hours old, says co-founder Stefan Frey.
Real-time data would allow satellites to actively stay away from the junk.
But that's expensive.
"For ground-based sensors, the price ranges from $2,500 to $90,000 per month for constant monitoring of one object," says Frey.
The start-up therefore wants to monitor several properties at once in order to reduce the costs per property to a few hundred euros a month.
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The first of two Vyoma satellites is scheduled for launch in 2024.
Commercial and institutional customers already exist, says Frey.
"That will be enough to build up a catalog of objects that are larger than 20 centimeters." Ten more surveillance satellites are to follow.
After the mission, Frey emphasizes, they should burn up in the atmosphere.
"We don't want to fill everything up ourselves."
Rubric list image: © ESA