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The Orion spacecraft passed the Moon on Monday, flying 130km above that world’s surface as it was en route to return to Earth this weekend.
By making this “powered flyby burn” to fly away from the Moon, the Orion service module performed the longest main engine burn to date, lasting 3 minutes and 27 seconds. After successfully completing the maneuver, NASA’s mission management team gave the go-ahead to send recovery teams into the Pacific Ocean, where Orion is expected to crash-land on Sunday, during the middle of the day.
Entering an orbit around the Moon and back out of it during its deep space mission, Orion has now completed four main thruster firings. This completes a major test of the spacecraft and its propulsion service module, which was built by the European Space Agency. Although a repeating version of the Orion made a flight in 2014, it did so without a service module.
As part of this Artemis I mission, NASA is now three weeks into a 25.5-day test flight of the Orion spacecraft. The goal is to validate the spacecraft’s capabilities ahead of a human flight of the vehicle in about two years’ time, the Artemis II mission.
Orion has accomplished most of its primary objectives to date, with only entry, descent, and splashdown as part of its mission ahead. The spacecraft’s heat shield must demonstrate its ability to survive re-entry at a speed of 24,000 mph. This big test will come on Sunday during a fiery reentry into Earth’s atmosphere.
A minor power issue
So far, the Orion test flight has gone very well. Usually with new spacecraft, there are issues with thrusters, navigation, onboard avionics, and more. However, Orion hasn’t had any major problems. The only real troubleshooting involved an issue with the vehicle’s power systems.
The problem has occurred with four “stall current limiters” that help route power to the propulsion and heating systems on Orion. For some reason, the automated controllers on Orion ordered all four current limiters to “open” when no such command was supposed to be sent. “We’re not exactly sure of the root of the problem, but the teams are doing tests on the ground,” Debbie Korth, deputy manager for the Orion Program, said during a briefing Monday night at the Johnson Space Center in Houston.
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This system is sort of like a breaker box in a house and for some reason four of the breakers tripped when they weren’t supposed to. This did not pose a threat to Orion, as there are backup power systems. If there had been a crew on board, a minor procedure would have been required to fix the problem.
In an interview after the press conference, Korth said he did not believe the failure would affect the service module that will be used for the Artemis II mission. This hardware is already built and is being tested in the United States.
“I think it’s probably too early to say for sure, but ideally we don’t want to disturb the Artemis II service module,” he said. “It’s quite possible that this is something we can handle with software.”
