Thermal-vacuum testing at Plum Brook finished

Since December 26 the first Orion spacecraft to fly around the Moon on the Artemis-1 mission has been under test in the world’s largest vacuum chamber at NASA’s Plum Brook Station in Ohio, USA. Far from sitting idly the spacecraft was subjected to environmental temperatures varying from -175°C to 75°C with all the air pumped out of its surrounding to give the spacecraft its first taste of space.

The spacecraft was switched on and under power as tests are run on the avionics and hardware. Obviously, no humans could survive these conditions (except inside the crew module or in a spacewalk suit) so cameras record the movement of hardware such as the main OMS-E engine that can swivel on gimbals to direct thrust and the Solar Array Drive Mechanisms that move the two solar wings over two axes to keep the electricity-generating solar panels in sunlight – or away from the OMS-E exhaust.

The solar arrays are not installed so Orion was fed power through the Solar Array Wings Front End Electronics (SAW-FEE).

It takes days to cycle through the hot and cold passes, during which the large spacecraft regulates its temperature, enclosed in a cage, or Thermal Enclosure Structure (TES), which radiates infrared heat or pumps cold liquid through tubes to cool down.

ESA and Airbus personnel are on hand with NASA and Lockheed Martin colleagues at all times – 24 hours a day – working in shifts on console to monitor the behaviour of the equipment and report on progress.

ESA’s Pierre Boisvert reports that “we finished ahead of schedule and encountered very few issues, the tests progressed remarkably smoothly.”

Working at all hours over the Christmas period far from home came with the job, with great support from all teams, but the winter was mild in Ohio, and a nice addition to the commute to Plum Brook includes frequent sightings of deer that thrive in the large site, that is practically a nature reserve.

The thermal-vacuum test finished on February 9. The spacecraft and test setup will now be reconfigured for electromagnetic testing, planned to start in the last week of February.