-- Spacecraft Arrives at Baikonur, Kazakhstan Launch Site Following Shipment from Orbital's Dulles, VA Satellite Manufacturing Facility --

DULLES, Va.Jun. 2, 2009-- Orbital Sciences Corporation (NYSE:ORB), one of the world’s leading space technology companies, today announced that the MEASAT-3a commercial communications satellite has arrived at its launch site at Baikonur, Kazakhstan. The MEASAT spacecraft is scheduled to be launched into geosynchronous transfer orbit aboard a Land Launch rocket. The launch is currently scheduled to take place in late June 2009.

The arrival of MEASAT-3a at Baikonur marks the return of the spacecraft to the launch site following a six-month process to decontaminate, diagnose, repair and retest the spacecraft after it was damaged during crane operations at the launch complex and returned to the company’s Dulles, VA facilities. The accident resulted in postponement of the satellite’s initial launch date and the initiation of a series of processes by Orbital to repair and retest the satellite that focused on ensuring mission success.

“We are very pleased to have helped our MEASAT customer get to the point of final launch preparations for the MEASAT-3a spacecraft,” said Mr. Mike Magoffin, Orbital’s Program Director. “Our efforts throughout the repair and retesting activity were focused on returning the spacecraft to the program’s original mission assurance standards, which we have verified through thorough inspection and testing. Preparing the satellite for launch in this short amount of time is testimony to Orbital’s ability to react quickly to unforeseen events and our focus on total customer support.”

The MEASAT-3a satellite was designed, developed, built and tested by Orbital under a contract awarded to the company in 2005 by MEASAT Satellite Systems of Malaysia. Originally designed to replace the MEASAT-1 spacecraft, MEASAT-3a will be MEASAT’s fourth communications satellite, providing C-band communications services throughout Asia, the Middle East and Africa, and Ku-band direct-to-home television broadcasting to Malaysia and Indonesia. The spacecraft will be located at an orbital slot of 91.5 degrees East longitude and will generate approximately 3.5 kilowatts of payload power.

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 Editors:

High-resolution images of the MEASAT-3a satellite in testing (photo) and in orbit (artist rendering) can be downloaded from Orbital’s web site at: http://www.orbital.com/NewsInfo/ImagesMultimedia/Images/SatelliteSpaceSystems/index.shtml

Source: Orbital Sciences Corporation

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