Joe Pally
Headquarters, Washington
(202) 358-7239

Jessica Rye
Kennedy Space Center, Fla.
(321) 867-2468



NASA’s space shuttle fleet is housed and processed at Kennedy Space
Center, Fla.

Mission: STS-121 - 18th International Space Station Flight (ULF1.1) -
Multi-Purpose Logistics Module
Vehicle: Discovery (OV-103)
Location: Orbiter Processing Facility Bay 3
Launch Date: Launch Processing Window July 1-19, 2006
Launch Pad: 39B
Crew: Lindsey, Kelly, Sellers, Fossum, Nowak, Wilson and Reiter
Inclination/Orbit Altitude: 51.6 degrees/122 nautical miles

Technicians continue final preparations on Discovery prior to its move
to the Vehicle Assembly Building. The move is scheduled for May 12.
Shuttle program managers will discuss readiness for the move and any
final technical details during the Orbiter Rollover Review on May 8.

As a precautionary measure to provide protection from the tin
whiskering phenomenon, a reaction jet driver was replaced in an
avionics bay and successfully retested early this week. Whiskering is
a phenomenon identified decades ago whereby certain metals, primarily
tin, zinc and cadmium, develop pure metallic crystalline extrusions.

During retesting of the reaction jet driver replacement, an unrelated
problem was discovered in the load control assembly in a line
replacement unit box in the forward avionics bay. The remotely
controlled assembly provides power to the reaction jet driver.
Technicians have replaced the assembly and will retest the equipment
over the weekend.

Mission: STS-115 - 19th International Space Station Flight (12A) -
P3/P4 Solar Arrays
Vehicle: Atlantis (OV-104)
Location: Orbiter Processing Facility Bay 1
Launch Date: No earlier than Aug. 28, 2006
Launch Pad: 39B
Crew: Jett, Ferguson, Tanner, Burbank, MacLean and Stefanyshyn-Piper
Inclination/Orbit Altitude: 51.6 degrees/122 nautical miles

Technicians are carrying out powered-up system testing on Atlantis for
its mission to the station. Workers continue to perform water coolant
loop samples.

The remote manipulator system, or shuttle robotic arm, is scheduled to
be installed early next week. The shuttle arm maneuvers a payload
from the payload bay of the orbiter to its deployment position and
then releases it. The arm can also grapple a free-flying payload,
maneuver it to the payload bay of the orbiter and berth it in the

Endeavour (OV-105)

Powered-up system testing continues on Endeavour in Orbiter Processing
Facility Bay 2 following an extensive modification period.
Technicians continue completing system leak and functional checks on
the liquid oxygen side of the main propulsion system.

Heater checks for the multi-purpose logistics module are complete. The
logistics module will be added to the payload bay at the launch pad
and will carry supplies and equipment to the station.

External Tank

Following detailed discussions Thursday, Space Shuttle Program
management decided that a tanking test of the external fuel tank will
not be needed prior to Discovery’s STS-121 mission. Managers decided
the proposed objectives of the test could be achieved during the
actual launch attempt.

Technicians continue to perform final closeouts on the external tank
and solid rocket boosters in the Vehicle Assembly Building in
preparation for Discovery to be attached to the tank and boosters, or
as it’s also known, the stack.

For previous space shuttle processing status reports on the Web,