Safely setting down a vehicle on a celestial body is one of the most crucial parts of any space mission seeking to explore places far from Earth. The most recent effort by NASA saw its Perseverance rover successfully touch down on Mars in February 2021, a tricky maneuver that was captured in dramatic footage shared by the space agency.
One of the challenges is to ensure that the lander will be able to handle the plume of dust and small rocks — known as regolith — kicked up by the lander’s thrusters when they deploy to slow it down on its approach. NASA points out that while rocks and sand on Earth feature rounded edges due to weathering, particles on the moon are irregularly shaped with many sharp angles that make the material extremely abrasive.
In a worst-case scenario, the regolith could destabilize the lander and cause it to crash. It could also damage onboard instruments, potentially leading to serious problems if the lander needs to lift off again.
With its Artemis program aimed at putting the first woman and next man on the moon before the end of the decade, NASA is keen to ensure that its lander will be up to the job of safely deploying its astronauts to the lunar surface.
To carry out tests prior to launch, the space agency is using 16 tons of a regolith simulant called Black Point-1 (BP-1), a commercial by-product of particular mining operations. BP-1 comes from the Black Point lava flow in northern Arizona, and is available in large quantities, making it an ideal material for lander testing.
Rob Mueller, senior technologist and principal investigator of the Exploration Research and Technology programs at the Kennedy Space Center in Florida, said NASA compared BP-1 with regolith recovered from lunar missions and several other regolith simulants and concluded that “the physical properties of BP-1 were similar to both.”
NASA is using BP-1 in various experiments aimed at studying the behavior and effects of rocket exhaust plumes during a lunar landing. The results of these experiments, many of which are carried out in vacuum chambers, will help engineers to refine the design of the lunar lander. BP-1 is also used for testing machines such as robotic rovers at an enclosure at the Granular Mechanics and Regolith Operations laboratory at Kennedy.
In April NASA selected SpaceX to provide the hardware to land the next humans on the moon, a feat that will be performed by the company’s Starship spacecraft. The astronauts will launch from Earth aboard an Orion spacecraft atop NASA’s powerful SLS rocket. When it enters lunar orbit, the Orion crew will transfer to SpaceX’s Starship spacecraft for the relatively short though challenging journey to the lunar surface. Starship will also return the astronauts to Orion to bring the astronauts home.
The mission is currently slated for 2024, though delays and other issues mean the date is likely to slip.