Pneumatic Proboscis Heat Flow Probe

The heat flow probe directly answers requirements in the topic: S1.11 Lunar Science Instruments and Technology: "Geophysical Measurements: Systems, subsystems, and components for heat flow sensorsÂ?" The primary objective of the Phase I/II is to develop TRL6, robust, low-power and low-mass instrument for geothermal heat flow measurement for small robotic lunar landers. A key challenge is to install thermal sensors to the depths > ~3 m, below the fluctuations of the surface thermal environment, with little thermal disturbance to the regolith. The proposed system is novel in two respects: 1) it utilizes a pneumatic (gas) approach, excavates a hole by lofting the lunar soil out of the hole, and 2) deploys the heat flow probe, which utilizes a coiled up tape with 10 equally spaced RTDs and a cone with thermal needle (for conductivity measurement) to reach >3 meter depth. The system is a game-changer for small lunar landers; it exhibits extremely low mass, volume, and simple deployment. The pneumatic system takes advantage of the Helium gas used for pressurizing lander propellant. In vacuum experiments we found that 1g of gas at 5 psia could loft ~6000g of lunar soil simulant at >10m/s.