-- Intelsat Joint Venture with Convergence Partners to Use Orbital's STAR Geosynchronous Satellite to Serve African Market --

-- New Dawn Spacecraft Was Orbital's Fourth GEO Satellite Order in 2008 --

DULLES, Va.Jan. 14, 2009--Orbital Sciences Corporation (NYSE:ORB), one of the world's leading space technology companies, announced today that it has been selected to design, manufacture and test a new commercial communications spacecraft known as New Dawn. In late 2008, Orbital was authorized to proceed on the New Dawn program by Intelsat, Ltd. which formed a joint venture with Convergence Partners to own and operate the satellite. The New Dawn satellite will address the growing needs for fixed satellite services such as voice communications, wireless backhaul, Internet connectivity and broadcast media applications across the continent of Africa.

"Orbital's commercial satellite business ended 2008 on a high note, with our selection for the New Dawn satellite, which was the second order we received during the year from Intelsat," said Mr. Michael Larkin, Orbital's Executive Vice President and General Manager of its Space Systems Group. "We are very appreciative of Intelsat's repeat orders for our STAR satellites and the close working relationship that has developed between our two companies over the past several years."

Mr. Larkin added, "The New Dawn order also represented the fourth order of the year for our communications satellites from all customers, making 2008 another very solid period for our commercial satellite business. Our design, engineering and production staff is now working on a total of 10 GEO satellites and is eager to begin new satellite projects in 2009."

The New Dawn spacecraft will be based on Orbital's proven STAR-2 platform. It will generate approximately 4.8 kilowatts of electrical power to support 16 Ku- and 14 C-band active transponders covering Africa with two deployable antennas. Following the launch and completion of its in-orbit testing process, New Dawn will be located at 32.9 degrees East Longitude. The New Dawn satellite is scheduled to be placed in service in early 2011.

In addition to the New Dawn satellite, Intelsat also ordered the IS-18 communications spacecraft from Orbital in 2008. The company's two other GEO satellite orders in 2008 were the AMC-1R satellite for SES Americom and the Koreasat 6 satellite, for which Orbital is teamed with Thales Alenia Space, for KT Corporation of the Republic of Korea.

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.

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

    Source: Orbital Sciences Corporation