A Pegasus XL Expendable Launch Vehicle, built by the Orbital Sciences
Corp., Dulles, Va., arrived at the Cape Canaveral Air Force Station (CCAFS),
Fla., Skid Strip on Dec. 17. The vehicle was ferried non-stop from
Vandenberg Air Force Base (VAFB), Calif., using the Orbital Sciences L-1011
aircraft.

The Pegasus vehicle will be transported to the Multi-Payload Processing
Facility (MPPF) in the Industrial Area at Kennedy Space Center later today.
The vehicle will be towed into the highbay to undergo testing, verification
and three flight simulations prior to its scheduled launch in late January
2003.

The Pegasus XL vehicle will carry NASA’s Solar Radiation and Climate
Experiment (SORCE) into orbit. The SORCE satellite includes four instruments
to study and measure solar irradiance as a source of energy in the Earth’s
atmosphere.

SORCE was built by Orbital Sciences Space Systems Group. The SORCE
project is managed by NASA’s Goddard Space Flight Center, Greenbelt, Md. The
instruments were built by the Laboratory for Atmospheric and Space Physics
(LASP) for the University of Colorado.

Tammy Harrington, mission integration manager for the SORCE mission
said, “The arrival of the Pegasus XL launch vehicle marks a significant
milestone in the launch preparations for the SORCE mission. This mission
will demonstrate the unique capability where the Pegasus vehicle and the
SORCE spacecraft are co-processed and integrated entirely at KSC.” SORCE
will be the third Pegasus launched from CCAFS, but the first Pegasus
“campaign mission” operation at NASA KSC.

The SORCE spacecraft has undergone spacecraft testing and processing
activities since its arrival in October 2002. SORCE will be mated to the
Pegasus rocket inside the MPPF and additional testing will be performed
concurrent with the Pegasus XL launch vehicle. This event will mark the
first time that both a launch vehicle and a payload have been processed,
tested and integrated in parallel inside the same facility at KSC prior to
being transported to the launch site. It will also be the first time that
the Pegasus vehicle receives final launch processing at KSC rather than
VAFB.

The spacecraft-to-launch vehicle mate is currently planned for Jan. 5,
2003. Fairing installation will occur on Jan. 20, leading to transport back
to the CCAFS Skid Strip for final launch preparations on Jan. 22.

The MPPF at KSC will also be used for NASA’s GALEX (Galaxy Evolution
Explorer) mission in the first quarter of 2003. GALEX was developed and is
managed by NASA’s Jet Propulsion Laboratory, Pasadena, Calif.

Launch of the Pegasus vehicle, carrying SORCE into a low-Earth orbit,
is scheduled for Jan. 25, 2003. NASA’s Kennedy Space Center is responsible
for government oversight of launch vehicle engineering, spacecraft
integration and launch countdown management.