Zacny, Kris - PlanetVac: Pneumatic Sample Acquisition and Delivery System for Asteroids

Abstract: 
One of the hardest things to do in planetary exploration, but one of the most valuable, is to sample a planetary surface – gather planetary regolith – and then transfer it to a science instrument or sample return capsule.  Current ways to do that, such as robotic arms, are costly and complex with lots of moving parts. 
PlanetVac, which stands for Planetary Vacuum, is a concept that effectively blows material up tubes using compressed gas provided from the pressurant tanks or dedicated tanks. The PlanetVac sampling devices is built into the lander legs to eliminate costly deployment from the lander deck to the ground.  This technique can be used to feed regolith, including small rocks, to science instruments and/or feed it into sample return rockets on landers on Mars, asteroids, or the Moon.  Because of the low pressures on all those bodies, the technique is extremely efficient; the efficiency is related to the ratio of the exit gas pressure to the ambient pressure (or vacuum). 
To demonstrate this approach, PlanetVac lander with four legs and two sampling tubes has been designed, built, and tested. Testing has been performed in vacuum chamber and with two planetary simulants: Mars Mojave Simulant (MMS) and lunar regolith simulant JSC-1A. One sampling system was connected to an earth return rocket while the second sampling system was connected to a deck mounted instrument inlet port (clear box for easy viewing). Demonstrations included a drop from a height of ~50 cm onto the bed of regolith, deployment of sampling tubes, acquisition of regolith into an instrument (sample container) and the rocket, and the launch of the rocket. In all tests, approximately 20 grams of sample has been delivered to the regolith box and approximately 5 grams of regolith has been delivered into a rocket. The gas efficiency was calculated to be approximately 1000:1; that is 1 gram of gas lofted 1000 grams of regolith.

PlanetVac video can be watched here:  https://www.youtube.com/watch?v=DjJXvtQk6no