+ Visit NASA.gov + Contact NASA   + Home Collection > NASA  Author > Daniels, C.  Author > deGroh, Henry C., III  Author > Dunlap, P.  Author > Steinetz, B.  NASA Center > Glenn Research Center  Publication Year > 2001-2010 > 2007  Subject > S-U > Space Transportation And Safety  Availability Options > Order From CASI > CD-ROM, DVD, Print  Item/Media Type > Conference Paper  Note: Start a new navigation search by selecting a link above     Previous Record | Next Record + Back to Results   + Printer Friendly Title: Assessing MMOD Impacts on Seal Performance Author(s): deGroh, Henry C., III; Daniels, C.; Dunlap, P.; Steinetz, B. Abstract: The elastomer seal needed to seal in cabin air when NASA s Crew Exploration Vehicle is docked is exposed to space prior to docking. While open to space, the seal might be hit by orbital debris or meteoroids. The likelihood of damage of this type depends on the size of the particle. Our campaign is designed to find the smallest particle that will cause seal failure resulting in loss of mission. We will then be able to estimate environmental risks to the seal. Preliminary tests indicate seals can withstand a surprising amount of damage and still function. Collaborations with internal and external partners are in place and include seal leak testing, modeling of the space environment using a computer code known as BUMPER, and hypervelocity impact (HVI) studies at Caltech. Preliminary work at White Sands Test Facility showed a 0.5 mm diameter HVI damaged areas about 7 times that diameter, boring deep (5 mm) into elastomer specimens. BUMPER simulations indicate there is a 1 in 1440 chance of getting hit by a particle of diameter 0.08 cm for current Lunar missions; and 0.27 cm for a 10 year ISS LIDS seal area exposure. NASA Center: Glenn Research Center Publication Date: November 13, 2007 Document Source: CASI No Digital Version Available: Go to Tips On Ordering Document ID: 20080012734 Publication Information: Number of Pages = 24 Contract-Grant-Task Number: WBS 644423.06.31.04.01.03.22 Price Code: A03 Meeting Information: 2007 NASA Seal/Secondary Air Systems Workshop, 13-14 Nov. 2007, Cleveland, OH, United States Keywords: LEAKAGE; ELASTOMERS; SEALS (STOPPERS); CREW EXPLORATION VEHICLE; SPACE DEBRIS; HYPERVELOCITY IMPACT; FAILURE; EXPOSURE; RISK; SIMULATION; METEOROIDS; Accessibility: Unclassified; Copyright; Unlimited; Publicly available; Updated/Added to NTRS: 2008-04-01 + Back to Top + Sponsored by the NASA Scientific and Technical    Information Program + 2004 Vision for Space Exploration + Freedom of Information Act + NASA Web Privacy Policy and Important Notices + NASA Disclaimers, Copyright Notice,    and Terms and Conditions of Use NASA Official: Calvin Mackey Page Curator: NASA Center for AeroSpace Information (help@sti.nasa.gov) Last Updated: July 5, 2007