Background
The lunar surface-boundary exosphere contains clues to the history of the solar system but is expected to soon be overwhelmed by frequent lunar surface landings and activities. It has been shown that key exospheric species, such as water and argon, spend significant time adsorbed to lunar regolith surfaces. Multiple opportunities for lunar surface payloads have been offered each recent year and are expected to continue in future years. Through this project, we sought to understand and prepare for two hardware capabilities necessary for examining the natural storage of exospheric species adsorbed to the lunar regolith as part of a lunar surface payload, for inclusion in proposals to the ongoing opportunities.
Approach
The project focused on two capabilities: Task 1 was to modify a deployed payload subsystem from the (now TRL 9) SwRI Lunar Magnetotelluric Sounder (LMS) to instead deploy and perturb lunar regolith in a fashion expected to release its trapped gases for measurement by a nearby SwRI mass spectrometer. Task 2 was to perform a trade study of the Space Science Division’s existing vacuum doors and determine the best path to an affordable, leak-free door.
Accomplishments
Task 1 successfully secured buy-in for SwRI to design a modified payload from the vendor that makes the TRL 9 deployment mechanism used on LMS. Key changes to the deployed subsystem included removing sensor and cabling and adding a simple radio, batteries, and rumbler mechanisms. Analysis confirmed the components were compatible and would provide sufficient motion and duration to perturb the regolith multiple times during the nominal lunar surface mission. The design was documented in the final report, including estimated cost and schedule for building a flight-like demonstration model of the surface perturbation hardware.
Task 2 successfully conducted a trade study, collating six existing SwRI vacuum doors/designs of TRL 4 or higher. It was concluded that the best path forward was to modify several aspects of the TRL 8 MASPEX-Europa instrument door by changing the sealing surface technology, simplifying the actuation of the door release, and changing the actuator type. The design was documented in the final report, including estimated cost and schedule for building a flight-like demonstration model of the door.