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Extended Life Testing of Duplex Ball BearingsSierra Nevada Corporation’s Space Systems performed bearing life testing for the Scan Mirror Motor/Encoder Assembly (SMMA), part of the Scan Mirror Assembly on-board the Aerosol Polarimetry Sensor (APS) on the NASA Glory Spacecraft. The baseline bearing life test duration extended beyond the launch date for the Glory Spacecraft; a risk that the program was willing to undertake with the understanding that if any anomalies or failures occurred before the required life was achieved, then the mission objectives or operating profile could be modified on orbit to take those results into account. Even though the Glory Spacecraft failed to reach orbit during its launch in March of 2011, the bearing life testing was continued through a mutual understanding of value between Sierra Nevada Corporation and our customer; with a revised goal of testing to failure rather than completing a required number of life cycles. Life testing thus far has not only exceeded the original mission required life, but has also exceeded the published test data for Cumulative Degradation Factor (CDF) from NASA/CR-2009-215681. Many lessons were learned along the way regarding long life testing. The bearing life test has been temporarily suspended due to test support equipment issues.
Document ID
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Mobley, Jeffrey
(Sierra Nevada Corp. Durhan, NC, United States)
Robertson, Michael
(Sierra Nevada Corp. Durhan, NC, United States)
Hodges, Charles
(Sierra Nevada Corp. Durhan, NC, United States)
Date Acquired
June 30, 2016
Publication Date
May 4, 2016
Publication Information
Publication: 43rd Aerospace Mechanisms Symposium
Subject Category
Mechanical Engineering
Meeting Information
Meeting: Aerospace Mechanisms Symposium
Location: Santa Clara, CA
Country: United States
Start Date: May 4, 2016
End Date: May 6, 2016
Sponsors: NASA Ames Research Center, Lockheed Martin Space Systems Co., Mechanisms Education Association
Distribution Limits
Public Use Permitted.
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