In two or three years, NASA’s Artemis program may return humans to the Moon. This time, heavier landing modules will be used than in the Apollo program. Therefore, the previously accumulated experience of interaction between the modules’ engines and the lunar surface must be adapted to the new conditions. The lunar regolith, which flies away uncontrollably under the action of jet streams, is dangerous, and this must be taken into account.
Image source: NASA
NASA will test the regolith simulant’s behavior under the jet streams from the experimental engine in a vacuum chamber — specifically, an 18-meter chamber at NASA’s Langley Research Center in Hampton, Virginia. Before being shipped to Virginia, the engine was assembled and tested more than 30 times in a vacuum and twice at atmospheric pressure at another NASA facility, the Marshall Space Flight Center in Huntsville, Alabama.
The engine itself was designed and built at Utah State University. It has an interesting design: it is a hybrid rocket engine that runs on a combination of solid fuel and gaseous oxygen. It is largely made using 3D printing. The design was created specifically for testing the impact of a jet stream on a simulated lunar surface.
«”The firing of a hybrid rocket engine to impact a lunar regolith simulator in a vacuum chamber has not been done for decades,” NASA experts explain. It appears that the last time this happened was during the development of the Apollo program.
«NASA will be able to use the data from the tests and scale it to flight conditions to better understand the physics of the process, refine our models, and ultimately make the lunar landing safer for Artemis astronauts,” the agency added.
Lunar regolith, under the influence of the landing module’s jet streams, can sag, fly apart and, ultimately, form irregularities on the lunar surface. This will lead to unstable operation of the landing module’s engines and increase the likelihood of an accident. Also, flying regolith can damage the module itself, the payload or infrastructure elements on the Moon. All these risks must be foreseen and prepared for, which is what NASA will do in the coming months.