Madrid, 15 years (European Press)

(Human Landing System) HLS-Starship will be used during the Artemis III and Artemis IV missions to land American astronauts near the lunar south pole.

The Starship HLS will be powered by two different types of the company’s Raptor engines: one optimized to operate at sea-level atmospheric pressure and another optimized to operate in space or a vacuum, where there is no atmosphere.

Last month, SpaceX demonstrated the vacuum-optimized performance of its Raptor engine with a test that successfully confirmed that the engine could start in the extremely cold conditions resulting from spending extended time in space.

A challenge that distinguishes Artemis missions from those in low Earth orbit is that landers can remain in space without engines for a long period of time, causing the temperature of the instruments to drop to a lower level than would be experienced on a much shorter mission. In Earth’s orbit, according to NASA.

One of the first testing milestones SpaceX completed under the Artemis III contract in November 2021 was also engine testing, demonstrating the Raptor’s ability to perform a critical landing phase on the Moon.

In a 281-second test launch, Raptor demonstrated the robotic landing portion of the mission, when the HLS spacecraft leaves its orbit above the lunar surface and begins its descent toward the lunar surface for landing. The test had two goals: to demonstrate the Raptor’s ability to change the engine’s power level over time, known as the acceleration profile, and to operate the engine throughout the instrument landing phase.

SpaceX’s Raptor engines will be tested during the second integrated flight test of Elon Musk’s Starship and Super Heavy vehicles.