For Release: July 10, 1995

June Malone
Office of Media Services
(205) 544-0034
june.malone@msfc.nasa.gov

RELEASE: 95-44P

SUPER DURABLE "GLASS" BEARINGS IMPROVE SHUTTLE ENGINE RELIABILITY

A new super-tough ceramic bearing material is increasing the reliability of an improved Space Shuttle Main Engine scheduled to fly for the first time this month on mission STS-70. The new bearings incorporate balls made of silicon nitride, a ceramic material that is 30 percent harder and 40 percent lighter than steel. The balls have an ultra-smooth finish, thus producing less friction during engine operation, and are expected to last significantly longer than their steel counterparts currently flown on the Shuttle’s engines. The redesigned bearings have been incorporated into the new Pratt & Whitney High-Pressure Oxidizer Turbopump on the Shuttle engine. This is the first known application of ceramic bearings in a cryogenic rocket engine. The new bearing design was developed and tested at NASA’s Marshall Space Flight Center where the Space Shuttle Main Engine project is managed. (NASA photo by Dennis Keim)