Lunar Dust Mitigation: EVA Suit Coverings

Acknowledgements

Project Advisors:

Leslie Light

Sue Anderson

Technical Advisors:

Apollo 17 Astronaut Harrison Schmidt

Dr. Angel Abbud-Madrid

Shuttle Astronaut Dr. James Voss

Donations Made by: Lockheed Martin

Video

Elevator Pitch

We are a senior design team of 5 mechanical engineering students who started in August 2020 and worked eight months to design, develop, and test dust coverings for astronauts during Lunar EVA for the Artemis Moon Landings. The senior design project was inspired by the work of one of the team members during his internship at Lockheed Martin. One of the managers and fellow colleagues took interest and served as the client for the project. This unique design challenge provided students with the opportunity to work closely with a distinguished company to further human exploration of the Moon.

Many aspects of this project were new to the team members, requiring them to explore previous methods used during the Apollo moon landings. Following this research, the students had to learn and develop new design methodologies, testing procedures, networking with other universities, and take on a design-build-test mentality to accomplish the project constraints.  Through this work, the team’s design seeks to improve and prolong EVA time while on the lunar surface. By creating a covering that is disposable and non-intrusive, the protected regions of the spacesuit should see prolonged life and safety.

Design Approach

Design Solution

Through lab testing and trials with the CU xEMU suit, the team settled upon using Velcro as a method to both secure and remove the coverings. These prototypes proved to have easier and faster application to the suit than the alternative solutions. The biggest burden imposed by other designs was the challenge in slipping the boots through the already secured covering. Velcro gave the added flexibility allowing the design to be wrapped around the legs and arms. One-inch overlap in Velcro proved to be effective at preventing dust from being able to penetrate the coverings, while still being removed easily. To hold the coverings snug on the suit, one-inch woven elastic is sewn into the coverings on either end. Through testing with lunar dust simulant, this elastic proved to isolate the covered areas of the suit from dust.

For material, the most important property studied is the permeability of dust through the fabric. The material that showed no penetration while still being light weight and not impeding suit movement is Nomex. Nomex is a material developed by Dupont that has peak thermal and fire protection properties. The material is currently in use as a key protective layer in military and NASA flight suits. To meet the NASA requirements for the optical properties on suit materials, a light color of fabric must be used. The lightest material color that the team was able to source in small quantities was cream. Ideally, this would be the same color as the rest of the arms and legs of the suit: white.

The technical drawings shown below display dimensions that give a snug fit for the coverings onto the arms and legs of the suits. These dimensions are based upon the CU xEMU suit and would require alteration to fit the suit of the exact astronaut wearing the coverings. The coverings for the arms of the suit include one pull tab that the astronaut will be able to insert their thumb into for removal. The leg coverings include two pull tabs as a redundancy to ensure removal despite the increased difficulty when compared to the arms.

Next Steps

In order to achieve an optimized solution, further material testing is required to ensure that the prototype materials meet the specifications set forth by NASA. Additionally, continued development of the dust isolation testing is encouraged. During the limited design scope of the Senior Design process, the team struggled to develop a rigid methodology for isolation testing to achieve quantitative results. Being able to accurately quantify the amount of lunar regolith that penetrates through the material, elastic, and velcro is of the upmost importance.

Following the final testing at CU Boulder, the team recommends a design that involves both the ripwire and velcro. The biggest challenge with the current design is the difficulty in removal of the leg coverings. The leg coverings were easily removed with the ripwire during initial mobility testing. However, difficulty was found in getting them to go over the attached boots of the suit. Combining velcro and ripwire allows for an easy application and removal.

Meet the Team