PlanetVac: A Two-Step Regolith Sampling System
A revolutionary pneumatic actuator-free regolith sample return system
Why Create PlanetVac
Before we send humans to Mars, we need to bring Martian samples back to Earth for thorough scientific analysis. Bringing even a small sample back from Mars will be more beneficial than doing any type of in-situ analysis. In-situ investigations rely on instruments which, although highly capable within the mass and power constraints of spaceflight, cannot compare with a fully outfitted analytical laboratory on Earth. Other alternative, reliable sampling systems could also be important for sampling material for in situ instrument study, whether it be on Mars, the Moon, or on asteroids.
Our hope is to steward the creation of a new way to gather regolith (the top layer of material overlying bedrock on a planetary surface) on another planet, on the Moon, or on an asteroid. On Mars, the Viking landers used scoops to gather samples of regolith, while Spirit and Opportunity used instruments mounted on articulated arms to study regolith up close. These marvels of design and testing contained many moving parts, making them vulnerable. A failure of just one joint or actuator could endanger the whole sampling system.
Elegant In Its Simplicity
PlanetVac, developed by Honeybee Robotics, is a simple system with no moving parts that gathers regolith into hollow sample tubes placed underneath the lander footpads. A puff of gas directed at the tube’s rim and up the tube can effectively move a plug of regolith through the connecting hose and into a sample return container (or into analytical instruments for in-situ analysis). Redundancy is provided by integrating sampling tubes below each lander footpad, so two tubes could fail and the system could still successfully gather samples. PlanetVac could be used to for quick, reliable sampling for sample return, or to on-board instruments, whether it be on Mars, the Moon, or an asteroid.
How It Works
1. Compressed gas cylinder releases a pulse of gas
2. Gas travels down lander leg strut
3. Gas is expelled through the lander leg pad nozzle into the regolith
4. Regolith is pushed up the second leg strut towards the lander deck
5. Regolith reaches sample intake manifold where it combines with two other sample sources
6. Regolith from all three lander pads is pushed up into the sample canister (or alternatively in to in situ instruments).
Learn about the Planetary Society’s newest project: PlanetVac, with Honeybee Robotics, aims to prototype and test in a huge vacuum chamber a new way to sample planetary surfaces that could be used for sample return or for in situ instruments.
Our PlanetVac development partner, Honeybee Robotics is no stranger to planetary exploration. They built the rock abrasion tool (RAT) for the Mars Exploration Rovers, the scoop for the Phoenix lander, and the brush and portions of the sampling system for MSL Curiosity. Their expertise makes them world leaders in sample manipulation, on Mars in particular, and we think they’ve come up with a worthy idea in PlanetVac.
Honeybee’s initial tests, conducted on reduced gravity flights and in vacuum chambers, demonstrated amazing sampling efficiency. However, no one has performed an end-to-end test under analog conditions. That is what Honeybee, with The Planetary Society, plan to do, building a prototype of PlanetVac by constructing the base of a landing vehicle with a PlanetVac system. Then, the prototype will be tested in Honeybee's 3.5m vacuum chamber using drop testing under Mars atmospheric conditions and lunar/asteroid vacuum conditions.
PlanetVac’s end-to-end sample acquisition and transfer system could provide a new solution to one of the most difficult problems in planetary exploration: the sampling and transferring of a sample to an instrument.