Satellites continue a lot. As they hurtle across our planet at speeds of up to 17,000 miles per hour, they must deal with the extreme vacuum of space and wild temperature swings as they attempt to accurately point their antennas back at Earth. And that's after launch, where they're shaken like a can of paint and bombarded with deafening noise.
To prepare them for this ordeal, satellites are meticulously tested before shipping, with every loose bolt tightened and all electrical components in excellent condition. This used to require trips to multiple locations for different tests, but in the UK, the recently opened National Satellite Test Facility in Oxfordshire offers a complete satellite health check under one roof.
“Industry said they needed a one-stop shop where they could do all their testing for their big complex satellites in one place,” said Sarah Beardsley, director of the UK government-funded Rutherford Appleton Laboratory Space, which runs the new facility at the Harwell Science and Innovation Campus. “This is the culmination of years of hard work.”
Construction began in late 2018, after the UK government announced it would invest £99 million ($126 million) in the NSTF to develop “a world-class facility” for testing satellites. The project was originally set to become operational in 2020, but has been hit by delays, including Covidwhose official opening has been postponed until May 2024. Several satellites are put through their paces each year, with Airbus expected to be the first customer to use the facility in July for its new Skynet 6A communications satellite.
There are four test areas at the NSTF. The first thing you encounter upon entering—after donning protective gear to keep the facility as clean as possible—is the massive vacuum test chamber that the entire building had to be built around. “There’s no door big enough to fit through,” Beardsley says. Inside the chamber, pumps can reduce pressure to as low as 0.00001 millibars, mimicking the vacuum of space, while a nitrogen cooling system can raise and lower temperatures between -180 and 130 degrees Celsius, the extreme range a satellite can experience as it moves in and out of sunlight during orbit.
At seven metres wide and 12 metres deep, it is the largest vacuum test chamber in the UK. It is so big that the immense door needed to close it, built in Turkey and Italy before arriving in Britain by ship just days before the 2020 lockdown, was the largest size that could fit on a British motorway. Gates at Portsmouth harbour had to be widened to accommodate the door from the ship. “We had the largest peace convoy come through here on the A34,” says Beardsley. Satellites will spend weeks or even months in the test chamber to ensure they can withstand the conditions of space: when WIRED visited, there was a mock-up satellite called The Iron Chicken, a profound nod to the character who lives in a metal nest around the moon in the cult classic British children’s animation The Clangers—took a place of honor at the entrance to the room.
After the vacuum chamber test, the satellites move on to the vibration and acoustic test chamber. Here, they are vigorously shaken—horizontally and vertically—on two pads controlled 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 subjects the satellite to 222 kilonewtons of force, equivalent to four times the bite of a T. Rex. If anything is loose on a satellite, these machines will detect it.
During acoustic tests, a giant wall of 48 speakers will blast satellites with up to 146 decibels of white noise. For a human, this is like standing in a jet engine. “You would suffer serious hearing damage,” says Ian Horsfall, dynamics group leader at RAL Space. The test is designed to simulate both the noise of rocket engines at launch and the unbearable volume at the top of the rocket, where satellites are stored on their way to orbit.
In the antenna test room, 40,000 foam nails on the wall absorb all the noise and electromagnetic waves from satellites, while the room acts as a Faraday cage to block incoming electromagnetic radiation. A satellite’s antenna can then be aimed at a receiver in the room, to check that the beam can be directed back to Earth from orbit, despite being hundreds or thousands of kilometres away and travelling at immense speeds.