Commissioning and Testing of Dusty Thermal Vacuum Chamber Designed for Lunar Environment Simulation

A new generation of landers, mobility systems, and science instruments are in development for the return to the Moon as part of the Artemis program. Many proposed payloads and systems are at a low Technology Readiness Level (TRL) due to novel design and activities. Raising the TRL of Lunar surface missions poses a challenge for many research and development groups due to unique testing facility requirements. Testing the interaction of surface exploration systems with a simulated lunar surface is required to increase TRL. Lunar regolith has unique properties that are represented in the lunar simulant to recreate the unique challenges posed when interacted with it. Regolith mixed with water-ice, depending on concentration, has strength in a range from loose granular material to similar to cemented sandstone [1], while lunar soil built up by ejecta in Permanently Shadowed Regions (PSRs) will not undergo thermal cycling and may be very loose [2]. Both species of regolith are likely to be encountered within PSRs. No surface vehicle has entered a lunar PSR; facilities that account for thermal, vacuum, and surface-based environmental factors found within a PSR are scarce but also a requirement to raise the TRL of any mission traveling to the Moon to an acceptable level. The newly founded Planetary Surface Technology Development Lab (PSTDL) at Michigan Technological University (MTU) is a new 1100 square feet lab and environmental facility whose goal is to perform rapid testing of lunar surface systems and equipment. The baseline performance of the PSTDL facilities will be explored and compared against similar systems in the United States and the world. An operational test of the PSTDL facility will be conducted using a prototype lunar robotic system focused on Permanently Shadowed Region (PSR) exploration during the fall/winter of 2020. Prototype rover testing will continue initially in an atmospheric facility colloquially referred to as the “sandbox”. This 1.8mx4.2m enclosed space holds 30 cm deep, up to 3800kg of MTU-LHS-1A lunar regolith simulant produced in-house. A gravity-offloading device capable of supporting rovers up to 50kg, runs the length of the sandbox, moving with vehicles under test in 2 axes via IR tracking. After validation testing in the sandbox, vehicle or system testing is then be continued in the PSTDL Dusty Thermal Vacuum Chamber (DTVAC). This vacuum chamber consists of an internal usable volume of 50x50x70in, removable regolith beds, and a rectangular layout to maximize testing area within the thermal shroud and pressure vessel. The encompassing thermal shroud operates from -196°C up to 200°C to simulate temperature ranges and cycles found in most illuminated and shaded areas of the Moon. Combined utilization of the DTVAC and Sandbox will provide an effective means to rapidly develop, test and raise the TRL of new technologies and lunar hardware.