-- Company's First Spacecraft of 2009 Is Performing As Expected Early In Its Mission --

DULLES, Va.Feb. 13, 2009-- Orbital Sciences Corporation (NYSE:ORB), the world’s leading manufacturer of smaller-sized geosynchronous (GEO) communications satellites, announced today that the NSS-9 satellite, which is based on the company’s STAR-2 platform, was successfully launched into orbit during a mission that took place on Thursday, February 12, 2009. Orbital designed, built, integrated and tested the NSS-9 spacecraft for SES NEW SKIES of the Netherlands. The satellite was delivered into its initial orbit by an Ariane 5 rocket launched from the European space launch complex located near the Equator in French Guiana. Results from early tests of the satellite indicate that it is operating as planned for this phase of its mission.

The NSS-9 spacecraft will provide C-band telecommunications services using three interconnected beams, enabling global, Eastern and Western hemisphere coverage. The satellite weighed approximately 2,200 kilograms at launch and will generate approximately 2.3 kilowatts of payload power to service 28 active transponders. The NSS-9 satellite will be positioned at 183 degrees East longitude upon successful completion of its testing.

“The early mission results show that the NSS-9 satellite is off to a very good start. The initial tests we ran overnight were successful and we anticipate a smooth in-orbit check-out sequence over the next several weeks,” stated Mr. Christopher Richmond, Senior Vice President and head of Orbital’s GEO satellite programs division. “We would also like to congratulate and thank Arianespace for another excellent launch campaign, resulting in the accurate deployment of the NSS-9 satellite.”

During the next several days, the NSS-9 satellite will perform a series of orbit-raising burns using its onboard rocket engines to achieve a circular orbit approximately 22,300 miles above the Earth. For several weeks thereafter, the SES and Orbital mission engineering team will conduct a comprehensive series of tests to ensure the spacecraft is ready for final hand-over to the customer.

Over the past five years, Orbital has established itself as the world leader in the market for smaller-sized GEO communications satellites. Orbital currently has 10 additional GEO spacecraft in various stages of design, production and testing at its Dulles, VA satellite manufacturing facility for marquee customers such as SES Global, Intelsat and several regional satellite service operators around the world.

The company’s commercial communications satellite business is in addition to Orbital’s long-established presence in the market for civil government space- and Earth-science satellites and its rapidly growing position in the national security space systems market. To accommodate the rapid growth of these satellite businesses, Orbital completed an expansion of its manufacturing plant and has added approximately 500 people to its satellite design, manufacturing and testing operations at its Dulles, VA campus in the past two years.

About Orbital

Orbital develops and manufactures small- and medium-class rockets and space systems for commercial, military and civil government customers. The company’s primary products are satellites and launch vehicles, including low-Earth orbit, geosynchronous-Earth orbit and planetary spacecraft for communications, remote sensing, scientific and defense missions; human-rated space systems for Earth-orbit, lunar and other missions; ground- and air-launched rockets that deliver satellites into orbit; and missile defense systems that are used as interceptor and target vehicles. Orbital also provides satellite subsystems and space-related technical services to government agencies and laboratories. More information about Orbital can be found at http://www.orbital.com

Note to Editor: High-resolution images of the NSS-9 satellite are available on Orbital’s web site at: http://www.orbital.com/NewsInfo/Images/GEO/index.html

Source: Orbital Sciences Corporation

Orbital Sciences Corporation
Public and Investor Relations
Barron Beneski, 703-406-5528