Satellites pass through A lot. As they circle our planet at up to 27,000 kilometres per hour, they must cope with the extreme vacuum of space and huge temperature swings, all while trying to precisely orient their antennas back to Earth. And that’s after launch, where they’ll be shaken around like a can of paint and bombarded with deafening noise.
To prepare them for this tough test, all satellites are thoroughly tested before they are shipped, making sure every loose screw is tightened and all electrical components are in perfect working order. Previously, this would have required trips to several locations to carry out different tests, but in the UK, the newly opened National Satellite Test Facility in Oxfordshire offers complete monitoring of satellite health under one roof.
“Industry said they needed a single place where they could do all the testing for their large, complex satellites in one place,” said Sarah Beardsley, director of the UK government-funded Rutherford Appleton Space Laboratory, which runs the new facility on the Harwell Science and Innovation Campus. “This is the result of years of hard work.”
Construction began in late 2018, after the UK government announced it would invest £99m ($126m) in the NSTF to develop “a world-class facility” for testing satellites. Originally planned to begin operations in 2020, the project was hit by delays, including Covid, that saw its grand opening pushed back to May 2024. Multiple satellites will be tested each year, and Airbus will be the first customer to use the facility for its new Skynet 6A communications satellite in July.
Inside NSTF are four test areas. The first one you encounter upon entering (after donning protective clothing to keep the facility as clean as possible) is the massive vacuum test chamber around which the entire facility had to be built. “There’s no door big enough to fit it,” Beardsley says. Inside this chamber, pumps can reduce the pressure to just 0.00001 millibars, mimicking the vacuum of space, while a nitrogen cooling system can raise and lower the temperature between -180 and 130 degrees Celsius, the extreme range a satellite can experience as it enters and leaves sunlight during orbit.
At seven metres wide and 12 metres deep, this is the UK’s largest vacuum test chamber. It’s so big that the immense door needed to close the chamber – built in Turkey and Italy before arriving in Britain by ship just days before lockdown in 2020 – was at the size limit of what would fit on a UK motorway. The dock gates at Portsmouth had to be widened to get the door out of the ship. “We had the largest peacetime convoy come up the A34 to get here,” says Beardsley. Satellites will spend weeks or even months inside the test chamber to make sure they can cope with the conditions of outer space: when WIRED visited, a simulated satellite called The Iron Chicken – a deep cut to the character who lives in a metal nest orbiting the moon in the cult classic British children’s animated film – was sitting on a rock in the middle of the night. The Clangers—It occupied a place of honor at the entrance to the chamber.
After testing in the vacuum chamber, the satellites will head to the acoustic and vibration test room, where they will be shaken violently (horizontally and vertically) on two platforms driven by a pair of electromagnetic motors (nicknamed Wallace and Gromit after the beloved stop-motion characters) that simulate the extreme conditions of a launch. The shaking will expose the satellite to 222 kilonewtons of force—equivalent to four times the bite of a T. Rex. If anything is slightly loose on a satellite, these machines will find out.
During the acoustic tests, a giant wall of 48 speakers will blast the satellites with white noise of up to 146 decibels. For a human, this would be like being inside a jet engine of an airplane. “I would have severe hearing damage,” says Ian Horsfall, head of RAL Space’s dynamics group. This test is designed to mimic both the noise of rocket engines during takeoff and the unbearable volume at the top of the rocket, where the satellites are stored on their way to orbit.
In the antenna test room, 40,000 foam spikes on the wall absorb all noise and electromagnetic waves from the satellites, while the room acts as a Faraday cage to block incoming electromagnetic radiation. A satellite’s antenna can then be trained on a receiver in the room, to test that its beam can be directed from orbit back to Earth, despite being hundreds or thousands of miles away and travelling at immense speeds.
