Orbital Sciences Corporation (NYSE:ORB) announced today that it will release its third quarter 2009 financial results prior to the opening of the market on Tuesday, October 27, 2009. Orbital will also conduct a conference call with financial analysts and investors the same morning, beginning at 9:00 a.m. (ET). The conference call will be hosted by:

• Mr. David W. Thompson, Chairman and Chief Executive Officer
• Mr. Garrett E. Pierce, Vice Chairman and Chief Financial Officer
• Mr. James R. Thompson, Vice Chairman and Chief Operating Officer

To listen to the conference call, dial (888) 541-8767 and use the conference ID number 36976023. A replay of the conference call will be available approximately two hours after the end of the call and will remain active until Tuesday, August 4, 2009. For access to the replay of the conference call, dial (800) 642-1687 (international callers should dial (706) 634-7258) and use the same conference ID number.

For webcast registration and information, please visit Orbital’s web site at http://www.orbital.com/Investor. The company advises participants to register at least 20 minutes prior to the call to download and install any necessary audio software.

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