Discovery Awaits Final Authorization For Launch

The next major review of launch readiness is two days before launch, when the Mission Management Team meets to give the final authorization for launch.

At Launch Pad 39B, final preparations for launch are under way. Loading of hypergolic propellants should be completed this weekend.

This process includes loading the propellants monomethyl hydrazine and nitrogen tetroxide into the Orbiter Maneuvering System and Forward Reaction Control System.

The flight crew visited the pad yesterday to perform an inspection for sharp edges in the Orbiter. After the crew inspection was completed, a payload contamination walk down was performed, closeout photos were taken and the payload bay doors closed for flight.

All four Extravehicular Mobility Units (EMU) have been installed in the Orbiter. The crew will wear the EMU suits during the three spacewalks scheduled during the mission.

Atlantis (OV-104)

Technicians continue processing Atlantis for its mission to the Space Station. Orbiter modal testing was completed last week.

This test involved using devices called "shakers," which send vibrations throughout the Orbiter.

Measuring instruments called accelerometers are positioned all over the vehicle to read the effects of the vibrations to check the structural health of the vehicle.

Early Tuesday morning, the Mobile Launch Platform carrying the STS-121 External Tank (ET-120) and twin Solid Rocket Boosters was moved from High Bay 1 in the Vehicle Assembly Building to High Bay 3.

The move was made so modification work could take place in High Bay 1.

Endeavour (OV-105)

Endeavour is in its Orbiter Major Modification period, which began in December 2003.

Copyright 2005 by Space Daily, Distributed by United Press International