California-based Masten Space Systems is developing a method for protecting lunar landers from the clouds of lunar dust thrown up by their own engines on descent, a press statement reveals. The innovative approach would see landers inject alumina ceramic particles into the rocket engine plume in order to glue lunar dust together, creating a makeshift landing pad on the surface of the moon, moments before landing.
Lunar dust, or regolith, poses a surprisingly serious problem for future space missions — so much so that NASA announced an award program last year for students who could think up new innovative methods for dealing with the issue. The materials' small sharp particles can cause damage to spacecraft machinery, spacesuits, and equipment, and could even cause damage to astronauts' lungs in future space habitats.
Lunar lander engines propel sharp regolith particles at 3,000 meters per second
The problem of wear from lunar regolith was an issue with Apollo-era landers, which weighed approximately 10 metric tons. Now, with NASA's upcoming Artemis moon missions, it aims to send much heavier landers to the moon, weighing approximately 20 to 60 metric tons. Masten explains that these landers will send sharp regolith particles dangerously hurtling outwards at speeds in excess of 3,000 meters per second.
The firm, which recently unveiled the design for a lunar rover that uses controlled blasts to collect lunar ice and provide water and oxygen for future moon missions, hopes that its new solution will help to mitigate the threat of this potentially silent killer. Their method, called the in-Flight Alumina Spray Technique (FAST), injects alumina ceramic particles into the lander's rocket plume as it descends towards the moon's surface.
FAST's alumina ceramic particles coat the area directly below the lander before allowing it to quickly cool and harden to form a landing pad with greater thermal and ablation resistance. In only 10 seconds, the FAST system can drop 186 kg (410 lb) of particles over a circular area with a 6-m (20-ft) diameter, Masten says. The lander would then need to hover for only 2.5 seconds while the pad cools down before touching down.
Masten completed a year-long preliminary study of its new FAST method in collaboration with Honeybee Robotics, Texas A&M University, and the University of Central Florida under a Phase 1 NASA Innovative Advanced Concepts award. The companies estimate the cost of a mission building a landing pad on the moon for following lunar landings would be approximately $120 million, which led them to devise a more cost-effective approach.
Makeshift landing pads could enable human exploration like never before
In tests, Masten and its partners determined the best particle deposit rate, landing pad thickness, and how the ceramic particles will stick together to form a landing pad on the moon, and how effective that pad would be for preventing dust scattering. They say that the concept is feasible, even for the largest of the proposed Artemis landers, and that the size and temperature of the engine plume can be adjusted depending on the size of the landing pad required.
Next, Masten is literally shooting for the moon as it would like to test its method on the moon. Other similar approaches have been proposed, such as the student-designed 'Lunar PAD', which is 3D printed and features a series of petal-like channels that send exhaust upward and outward at the same time as trapping lunar dust. However, Masten's new proposal has the potential to allow landers to safely touch down with minimal materials required, potentially helping to embolden human exploration like few other concepts.