NASA is building a system to send astronauts to the Moon for Artemis missions, and that includes tests to make sure the Orion spacecraft is prepared to safely carry crew on an alternate mission profile in the face of unexpected problems. That capability was most recently demonstrated with a successful, continuous 12-minute firing of Orion's propulsion system that simulated a possible alternate mission scenario.
“Inserting Orion into lunar orbit and returning the crew on a trajectory back home to Earth requires extreme precision in both plotting the course and firing the engines to execute that plan,” said Mark Kirasich, program manager for Orion at NASA’s Johnson Space Center in Houston. “With each testing campaign we conduct like this one, we’re getting closer to accomplishing our missions to the Moon and beyond.”
The Aug. 5 test was conducted using a qualification version of the propulsion system at NASA’s White Sands Test Facility near Las Cruces, New Mexico. While the system never left the ground, it simulated one of the most taxing situations the spacecraft’s engines could encounter after launch.
This test simulated what is referred to as an abort-to-orbit scenario. In the event the interim cryogenic propulsion stage (ICPS) was unable to set the spacecraft on its path to the Moon, Orion would deliberately separate early from the ICPS and the ESA (European Space Agency)-provided service module’s engines would fire to boost the spacecraft into a safe, temporary orbit. That would allow time to evaluate the crew and spacecraft before a decision is made to either continue with an alternate mission profile, or return to Earth. Under an alternate mission profile, Orion and its crew may still be able to accomplish some of the mission objectives even if the trajectory and the primary mission objective has changed.
During the successful test, engineers simulated the abort-to-orbit scenario by firing the Orion main engine on the service module, in addition to all eight of its auxiliary engines simultaneously. Each of the reaction control thrusters were also periodically fired throughout the test to simulate attitude control and overall propulsion system capacity.
“This was our most demanding test for the pressurization system, including our propellant tanks, valves and other components,” said 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 qualification version of the service module’s propulsion system serves as a testbed to verify the performance of the multiple types of engines, propellant systems and other propulsion-related subsystems.
“The tests at White Sands have been very helpful to better understand and operate our service module propulsion system,” said Jim Withrow, project manager for the test article. “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.”
As the powerhouse of the Orion spacecraft, the service module provides in-space maneuvering, power and other astronaut life support systems, including consumables like water, oxygen and nitrogen. Engineers at NASA’s Kennedy Space Center are joining the completed Artemis 1 crew module and service module together, before sending the spacecraft to NASA’s Plum Brook Station in Sandusky, Ohio, later this fall for simulated in-space environmental testing. Once testing is complete in Ohio, the spacecraft will return to Kennedy for final processing and integration with the Space Launch System (SLS) rocket.
Artemis 1 will be the first, full test flight of the SLS and Orion as it is sent around the Moon. The uncrewed test will precede Artemis 2, the first flight with astronauts aboard, and both will pave the way for the first woman and the next man to land on the Moon by 2024, while preparing for future missions to Mars.
Engineers perform work at NASA’s White Sand Test Facility ahead of testing of the Orion propulsion system.