NASA and SpaceX are collaborating to develop a Starship crewed landing system for lunar missions. After successful engine testing under extreme conditions, the next step will be comprehensive flight testing of Starship and Super Heavy.
NASA is working with SpaceX to develop the Starship Human Landing System (HLS), which will be used on the Artemis III and Artemis IV missions to land American astronauts near the moon's south pole. The Starship Crew Landing System will be powered by two variants of the company's Raptor engines - one optimized to operate at sea level atmospheric pressure and one optimized to operate in space or a vacuum (without an atmosphere) environment.
Cryotesting of Raptor vacuum engines to simulate conditions after long-duration flights in space. Image source: SpaceX
Last month, SpaceX demonstrated the performance of its vacuum-optimized Raptor engine through a test, successfully demonstrating that the engine can start in the extremely cold conditions created after long periods of operation in space. One challenge that makes Artemis missions different from low-Earth orbit missions is that the lander may not fire for long periods of time in space, causing hardware temperatures to drop below those on shorter low-Earth orbit missions.
The 281-second throttle test proved the engine's ability to meet the requirements for descent and combustion to the lunar surface. Image source: SpaceX
In November 2021, one of the first test milestones completed by SpaceX under its Artemis III contract was also an engine test that demonstrated the Raptor's ability to perform the critical phase of a lunar landing. During the 281-second test launch, the Raptor demonstrated the powered descent portion of the mission, in which Starship HLS left orbit on the lunar surface and began its descent to the lunar surface for landing. The test had two goals: to demonstrate the Raptor's ability to change the engine's power level (i.e., the throttle curve) over time, and to demonstrate the engine's ability to burn throughout the power reduction phase. The success of the test gave NASA early confidence in the company's engine development work.
Testing key technologies and hardware under simulated and actual flight conditions is key to developing the Artemis lunar lander. These tests provide early and similar mission validation of the systems needed to carry astronauts to and from the lunar surface. Review of data following these tests gives NASA growing confidence that U.S. industry is ready for the mission. Next, SpaceX's Raptor engines will be put to the test in the company's second combined Starship and Super Heavy flight test.