Orbital Sciences Corporation
announced today that the National Aeronautics and Space
Administration (NASA) has decided to postpone the launch of its High Energy
Spectroscopic Imaging (HESSI) satellite aboard the company’s Pegasus XL space
launch vehicle.
NASA has elected to delay the HESSI mission in order to allow
time for review of the analysis being performed by the X-43A Mishap Review

As a result of the delay in the launch schedule, Orbital will ferry the
air-launched Pegasus rocket from Florida back to the company’s facility at
Vandenberg Air Force Base in California.
This is necessary to permit
replacement of the rocket’s flight termination batteries that will exceed
their approved life cycle as a result of the delay.
Orbital will maintain
overall flight readiness for HESSI in order to preserve the ability to launch
on short notice.

Orbital is one of the world’s leading manufacturers of low-cost space
systems, including satellites, launch vehicles and sensors and electronics
Orbital is also involved with satellite-based networks that provide
wireless data communications and high-resolution Earth imagery to customers
all around the world.

More information about Orbital can be found at http://www.orbital.com .

Media: Barron Beneski, 703-406-5528, or
beneski.barron@orbital.com; or Investors: Timothy Perrott, 703-406-5997, or
perrott.tim@orbital.com, both of Orbital Sciences Corporation