19-2- S4.04-3349

 80NSSC19C0517

 Extreme Environments Technology

 Extreme Environment Tribological Characterization of Advanced Bearing Materials

Estimated Technology Readiness Level (TRL) :
Begin: 3
End: 5

Technical Abstract (Limit 2000 characters, approximately 200 words)

This proposal addresses subtopic S4.04 Extreme Environments Technology and specifically interest in long life bearings, tribological surfaces, and lubricants. NASA is expanding its ability to explore deep atmosphere and surface of gas giants, moon surfaces, asteroids, and comets through use of long-lived balloons and landers. Dragonfly will launch in 2026 and arrive in 2034 on Titan. Future Mars missions will return samples from the surface of Mars to Earth. The Artemis program will land humans on the Moon by 2024. Conceptual landing probes for Europa and Venus have been proposed. These missions will experience extreme temperatures ranging from -220°C on Europa to 462°C on Venus, and environmental pressures ranging from vacuum on the Moon to 9.3 MPa on Venus. At these extreme atmospheric conditions, traditional oil lubricants and greases are infeasible, resulting in dry sliding conditions with detrimental effects on component performance. Tribological experiments are therefore necessary to simulate relevant environments so as to mitigate mission risk. This proposal offers unique solutions for these extreme conditions:

1. We will develop a compact high temperature (HT) stage for an existing high pressure (HP) tribometer - providing a unique capacity to simulate wear and friction on Venus (462°C and 9.3MPa gas pressure)
2. ATSP coating vs. ATSP coating has low coefficient of friction (COF) and “zero wear” from -196°C to 300°C. This excellent tribological performance leads us to introduce ATSP-based coatings for Lunar and Mars’ abrasive conditions and wide thermal demands. We further propose use of this coating to resolve wear issues for a cam-follower tribo-pair in the rotary-percussion drill for the Titan Dragonfly mission.
3. For hard coatings in Phase II, tribo-pairs for Venus conditions will be identified by doing tribological study for tribo-pairs, including PS400 vs. Inconel and PS400 vs. DLC, under Venus simulating conditions: 462°C and 9.3MPa 96.5%CO₂ + 3.5%N₂

Potential NASA Applications (Limit 1500 characters, approximately 150 words)

1. The high temperature and high pressure testing capability will be invaluable in evaluating tribo-pairs of mechanical devices on Venus probes.
2. ATSP-based tribological products have wide temperature range (-196 to 300°C) with low wear and friction and have  applicability for devices used in future missions to Titan, the Moon, and Mars.  
3. Best-performing tribo-pairs will be identified for Venus missions, for Moon and Mars’ dusty conditions, and for a cam-follower tribo-pair in the rotary-percussion drill for Titan Dragonfly mission.

Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words)

1. The high temperature/high pressure (HTHP) tribological testing capability allows study of nuclear reactors’ HTHP helium cooling system bearings and gas valves.
2. ATSP-based tribological products applicable for Aerospace, Automotive, Space Exploration, and Energy. The tribo-pair concept developed in Phase I offers world-leading reduction in friction and wear across a very broad range of temperatures.

Duration: 24