ESA’s Clean Space initiative performed simulated reentry testing inside a plasma wind tunnel at the DLR German Aerospace Center’s site in Cologne.
The item seen here is a section of a satellite electronics box, measuring 300 x 200 x 150 mm across – the full-sized box being too large to fit inside the 120 mm-diameter plasma wind tunnel. This aluminium-made section of box also contained a backplane connected to four electronics cards made of glass fibre reinforced plastic.
The testing investigated the box’s fragmentation behavior, including how the electronics cards were released from the housing, to verify the predictions of reentry simulation software. Other heavy satellite parts were also subjected to this ‘ablation’ testing, including a ball bearing unit, reaction wheel, magnetotorquer, flywheel unit, battery module and battery cells.
In theory reentering space hardware is vaporised entirely in the course of plunging through the atmosphere. In practice some pieces can make it all the way down to Earth – some of them big enough to do serious damage.
Modern space debris regulations demand that such incidents should not happen. Uncontrolled reentries should have a less than 1 in 10 000 chance of injuring anyone on the ground.
As part of a larger effort called CleanSat, ESA is developing technologies and techniques to ensure future low-orbiting satellites are designed according to the concept of ‘D4D’ – Design for Demise.
See the video of the testing here.