Contact: Barron Beneski, (703) 406-5000,

Orbital and NASA Postpone Launch of DART Spacecraft

(Dulles, VA 26 October 2004) - Orbital Sciences Corporation (NYSE: ORB) and
the National Aeronautics and Space Administration (NASA) have postponed the
launch of the Demonstration of Autonomous Rendezvous Technology (DART)
spacecraft for at least 48 hours. The mission's target satellite, the
Multiple Paths, Beyond-Line-of-Sight Communications spacecraft, had a
temporary loss of Global Positioning System (GPS) data reception that might
have impacted the navigation accuracy for the on-orbit rendezvous sequence
of events.

While the GPS dropout has been corrected, the launch team wanted additional
time to verify the data. In addition, the high probability of adverse
weather at the scheduled launch time also contributed to the decision to
postpone the launch for at least 48-hours, pending the availability of
certain range assets.

DART is a flight demonstrator that provides a key step in establishing
autonomous rendezvous capabilities for the U.S. space program and the Vision
for Space Exploration. While previous rendezvous and docking efforts have
been piloted by astronauts, the unmanned DART spacecraft will have only
computers and sensors to perform all of its rendezvous functions.

Future applications of technologies developed by the DART project will
benefit the nation in future space systems development requiring in-space
assembly, services, or other autonomous rendezvous operations.

About Orbital
Orbital is one of the world's leading developers and manufacturers of
affordable space systems for commercial, civil government and military
customers. The company's primary products are satellites and launch
vehicles, including geostationary and low-orbit spacecraft for
communications, remote sensing and scientific missions; ground- and
air-launched rockets that deliver satellites into orbit; and missile defense
boosters that are used as interceptor and target vehicles. Orbital also
offers space-related technical services to government agencies and develops
and builds satellite-based transportation management systems for public
transit agencies and private vehicle fleet operators.


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Jacques :-)

www.spacepatches.info