NASA has put a key component of its Orion deep-space probe through its paces, conducting a static firing of the spacecraft's service module's main engine at the space agency's White Sands Test Facility near Las Cruces in New Mexico. The purpose of the 12-minute test of the qualification version of the propulsion system was to demonstrate its ability to return the manned capsule safely to Earth in an emergency.

Built by ESA and derived from its Automated Transfer Vehicle, the service module for the next Orion flight is designed to provide power and propulsion to the Orion capsule. At its heart is a recycled AJ10-190 maneuvering rocket engine from the Space Shuttle program that has already flown 19 missions and carried out 89 burns.

Fueled by liquid hydrogen and oxygen, the main engine can generate 6,000 lb of thrust. Its function is similar to that of the Apollo Service Module, which is to provide propulsion to place Orion into lunar orbit and to return it to Earth. However, the August 5, 2019 test was designed to demonstrate how well the Orion service module can handle a major emergency.

The test was a major milestone in the run up to the unmanned Artemis 1 mission that is scheduled to fly in June of next year. But to ensure its success as well as the safety of later manned missions, the main engine needs to be able to handle what NASA calls alternative mission scenarios.

In less benign words, the test was based on an abort-to-orbit emergency, which is the failure of the Space Launch System's (SLS) second stage, also called the Interim Cryogenic Propulsion Stage (ICPS). If this were to happen, the Orion spacecraft might fail to reach translunar orbit or even Earth orbit, so the service module would need to make an emergency burn to achieve a safe, temporary orbit.

According to NASA, once Orion is in such an orbit, the astronauts and mission control would have time to inspect the spacecraft and either switch to some alternative mission trajectory or execute a reentry maneuver for return to Earth. To simulate this scenario, NASA engineers not only fired the main engine, but also eight of the spacecraft's auxiliary engines, in a series of bursts similar to what would be needed to control Orion's attitude.

"This was our most demanding test for the pressurization system, including our propellant tanks, valves and other components," says Josh Freeh, deputy manager, Orion's Service Module, at NASA's Glenn Research Center. "The combined international team has been working towards this test for many months."

The engine used for the tests is an engineering version specifically built for ground tests and will not fly on Artemis 1, which has already had its crew capsule and service module joined and will be shipped to the Kennedy Space Center in Florida. After extensive testing, the completed spacecraft will be stacked atop the SLS.

"The tests at White Sands have been very helpful to better understand and operate our service module propulsion system," says Jim Withrow, project manager for the test engine. "This firing was one of a series of tests performed to date and in the coming months to simulate contingency modes and other stressful flight conditions."

The video below shows the static fire test.

Source: NASA

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