As a follow-on to The Planetary Society funded Honeybee Robotics PlanetVac project, a masters' student from Delft University, Siddharth Pandey, is doing a thesis to study how to optimize the lander pad portion of PlanetVac. PlanetVac is a new type of planetary surface sampling system that uses pressurized gas to force regolith (dirt) up lander leg tubes into either sample return capsules or in situ instruments. Honeybee, with Planetary Society support, designed, developed, and tested a prototype PlanetVac system under planetary atmospheric conditions.
Now Siddharth is working on how to further optimize the PlanetVac system. In particular, he is studying both theoretically and experimentally the effects of the orientation of the gas outlets on how much regolith can be obtained for a given amount of gas. He is also studying other effects such as using different gases from air, to nitrogen, to helium. Preliminary results indicate that outlets at an downward angle to the regolith (blowing gas downwards at 45 degree angles) is more efficient than the nearly tangential gas outlets (blowing mostly horizontal) of the original prototype. Even more efficient are gas outlet tubes that not only point down at the regolith, but also impart a swirling effect to the gas, so they are tilted "sideways" to create a "mini-tornado" effect. This seems to be the most efficient at transporting a larger mass of regolith for a given mass of gas. The video shows the "swirl" set up and the resulting lifting of regolith in a tornado like way.
PlanetVac Planetary Regolith (Dirt) Swirly Sampling Test A lab test of a PlanetVac planetary regolith surface sampling option for the gas outlets that would be at the bottom of a planetary lander leg. PlanetVac, a Planetary Society/Honeybee Robotics project, would use gas to force planetary surface materials up tubes to onboard instruments or sample return capsules. This test, by Delft University graduate student Siddharth Pandey, uses gas outlet orientations that create a swirl effect helping to lift planetary regolith in something like a mini-tornado.Video: Siddharth Pandey