The little "engines" that could!
Update from SpaceflightNow.com :
TUESDAY, AUGUST 9, 2005
1855 GMT (2:55 p.m. EDT)
Engineers are working to determine if there are any problems with a pair of Redundant Rate Gyro Units (RRGUs) aboard the Atlas 5 rocket that will launch the Mars Reconnaissance Orbiter. The units are part of the vehicle's flight control system.
The concern stems from an RRGU that failed factory testing while being readied for a future launch.
If the issue can be resolved promptly, liftoff will proceed on Thursday morning.