Engineers have captured some spectacular images of one of the denser parts of a satellite being fried in steam inside an ultra-hot plasma wind tunnel. They destroyed it in the name of science, of course.
Researchers at the European Space Agency (ESA) wanted to better understand how satellites burn in Earth's atmosphere when they fall out of orbit. Using this knowledge could help protect all of us from huge pieces of burning metal crashing to the ground.
While many space debris are totally burned into the atmosphere at re-entry, some of them do not, and from time to time the objects that survive are large enough to cause serious damage to people, wildlife and properties.
The object destroyed in this experiment was a 4 cm x 10 cm (1.6 in x 3.9 in) magnetotorquer, an instrument that interacts with Earth's magnetic field to keep its satellite steady and correctly oriented.
There is not much of a chance in the DLR's plasma wind tunnel German Aerospace Center in Cologne – as the name suggests, it's a wind tunnel that uses an electromagnetic field to heat a gas to the point of turning into plasma. case to simulate the journey of a device through the upper atmosphere of the Earth.
With temperatures inside the tunnel reaching several thousand degrees Celsius, the experiment gave the scientists some useful data to refer to their earlier models and studies.
"We observed the behavior of the equipment in different heat flow configurations for the plasma wind tunnel in order to obtain more information about material properties and demability," says ESA Clean Space engineer Tiago Soares.
"The magnetotorquer has reached a complete end in the high heat flow level. We have observed some similarities, but also some discrepancies with the forecast models."
The test is part of the largest Clean Space Initiative, which aims to reduce the level of orbiting debris and ensure that if it falls from the sky, it does not pose a threat.
Regulations in place today are designed to ensure that uncontrolled reentry of space objects have less than 1 in 10,000 chances of injuring someone in the ground – but there is still a chance, and that risk will increase as the number of orbiting objects increases. (See Elon Musk's SpaceX Starlink Initiative.)
Magnetotorquers, optical instruments, thrust and pressure tanks, and trigger mechanisms are the most likely satellite bits to survive a voyage through Earth's atmosphere. As the parts fragment and break, there is a greater chance of hurting someone.
Whether in orbit or falling on Earth, space junk is a growing problem of what agencies around the world are trying to cope with. With private companies also entering space travel, the need to find a solution is becoming more urgent.
Aside from spectacularly burned things, the work done by ESA engineers and elsewhere means that we are in the case – and if clean space research can involve such cooler experiments, then that's all the better.