Environmental Chamber Testing of a Rock Sampling Drill for Venus Exploration  Fredrik Rehnmark*, Evan Cloninger*, Cody Hyman*, Jameil Bailey*, Nick Traeden*, Kris Zacny*,  Kristopher Kriechbaum**, Joseph Melko**, Brian Wilcox**, Jeffery Hall** and Kristopher Sherrill** Abstract  Honeybee Robotics has developed a rotary-percussive rock sampling drill and high temperature (HT)  electromagnetic actuator for a proposed mission to Venus known as VISAGE (Venus In Situ Atmospheric  and Geochemical Explorer). The drill is powered by two brushless DC motors that have been characterized  in dynamometer tests run at both room temperature and Venus surface temperature of ~462°C.  Dynamometer test results are compared with performance estimates obtained using ANSYS Maxwell  analysis software, demonstrating that losses at high temperature can be predicted with reasonable  accuracy. Drilling trials conducted in JPL’s Venus Material Test Facility (VMTF) have demonstrated the  feasibility of sampling threshold strength Venus analog material within a time window compatible with the  proposed VISAGE mission concept of operations.  Introduction  The surface of Venus presents a harsh environment for robotic exploration. Many of the critical subsystems  comprising a Venus lander would be housed inside an insulated pressure vessel protecting them from the  extremely hot and dense atmosphere (95% CO 2 at 462°C and >90 bar pressure). Under these conditions,  conventional thermal management methods can provide only a few hours of mission life before the lander  interior overheats. The surface sampling subsystem, on the other hand, must be mounted externally to  interact directly with rocks and soil at the landing site. Environmentally “hardened” robotic mechanisms and  high temperature (HT) sensors and actuators are needed to deploy to the ground, drill into rock and  transport samples into the lander.  A logical first step in designing a mechanism for an extreme and unfamiliar environment like Venus is to  build and test a high-fidelity prototype. In order to survive Venus conditions and yield useful performance  data in a realistic test, albeit a very short one, the prototype should be built using high TRL (i.e., flight-like)  materials, components and fabrication techniques. Per the proposed VISAGE (Venus In Situ Atmospheric  and Geochemical Explorer) mission concept, the rock sampling drill breaks up surface rock into fine powder  that can be pneumatically transported via an airlock into the cool interior of a lander, where science  instruments can analyze the sample to determine elemental composition and other properties. Due to the  short mission life, the drill should nominally penetrate to a 5-cm depth in threshold strength Venus analog  material (Saddleback Basalt ~130 MPa) in 10 minutes. This desired penetration rate drives the drilling  power which, in turn, drives the actuator sizing.  Honeybee Robotics has developed a rotary-percussive rock sampling drill and high temperature (HT)  electromagnetic actuator (motor, sensor and gearbox) for Venus [1]. The motors have been characterized  in dynamometer tests and simulations to study the effects of the high temperature environment. Drilling  trials have been conducted in a CO 2 gas atmosphere at full Venus temperature and pressure (VTP) in JPL’s  Venus Materials Test Facility (VMTF). These tests have demonstrated the feasibility of collecting surface  samples in threshold strength Venus analog material within the time window allocated for sampling. The  paper will present a comparison of predicted and measured motor performance at room temperature and  *Honeybee Robotics, Pasadena, CA ** Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA Proceedings of the 44th Aerospace Mechanisms Symposium, NASA Glenn Research Center, May 16-18, 2018  NASA/CP—2018-219887 41