When a rocket lands on the airless Moon, the spray of dust, sand, gravel, and rocks can be far-reaching and extremely damaging to surrounding hardware. Research has unraveled some of the basic physics of this event, revealing several competing cratering mechanisms may occur. However, much of the physics needed to quantify these events has not been adequately solved to support development of perfectly adequate physics-based simulations. Therefore, approximation methods need to be used, but it is not yet clear what approximations will give adequate results, and the existing datasets are inadequate. Experiments have been performed on the Earth in vacuum chambers, in reduced gravity flights, and in complex geologically-relevant field sites, but it is impossible to combine all the environmental features into one test, so more data is needed from actual lunar landings. This talk will overview what we know and do not know about the physics and will discuss several technologies that are already in development to try to mitigate lunar landing blast effects, including sintering lunar soil, infusing it with polymer, creating rock filtration systems, and creating interlocking pavers for landing pads.
Dr. Philip Metzger is a planetary physicist who recently retired from NASA’s Kennedy Space Center, where he co-founded the KSC Swamp Works. He now is now at the University of Central Florida — but still a part of the Swamp Works team — performing research related to solar system exploration: predicting how rocket exhaust interacts with extraterrestrial soil, investigating the mechanics of soil, characterizing lunar and martian soil simulants, modeling the migration of volatiles on airless bodies, etc. While at NASA he led the Agency’s work in rocket blast effects for human-class missions. He participated in architecture studies for the Lunar Architecture Team, the Mars Architecture Team and the Lunar Exploration Analysis Group, and he helped develop NASA’s technology roadmap for planetary surface technologies. He has also led projects to develop extraterrestrial excavators, regolith conveyance technologies, dust-tolerant quick disconnects, lunar/martian landing pads, and other surface systems technology. He co-founded NASA’s biannual Workshop on Granular Materials in Lunar and Martian Exploration and is a founding member of the ASCE Technical Committee for Regolith Operations, Mobility and Robotics. He received the astronaut’s Silver Snoopy award in 2010 and was selected as the Kennedy Space Center’s NASA Scientist/Engineer of the Year for 2011.