Moves to Bolster Technical Capabilities and Support Fast-Growing Business Areas

(Dulles, VA 27 August 2012) – Orbital Sciences Corporation (NYSE: ORB) today announced three high-level executive promotions designed to strengthen the company’s engineering, manufacturing, test and mission assurance capabilities and to continue its robust growth in human spaceflight and national security space programs. The new appointments, which will become effective on September 10, are as follows:

* Dr. Antonio L. Elias, currently Executive Vice President and General Manager of Orbital’s Advanced Programs Group (APG), will become Executive Vice President and Chief Technical Officer, responsible for the company’s overall technical operations. In this new corporate capacity, Dr. Elias will oversee a 2,600-person functional organization consisting of the company’s engineering, production, supply chain, test and operations staff, as well as its safety and mission assurance professionals, in Virginia, Arizona and other locations. A 26-year veteran of Orbital, Dr. Elias has led APG since 1997, during which time the group has grown from less than $50 million to approximately $450 million in annual revenue. Earlier, he was the chief designer of the company’s Pegasus air-launched rocket and the technical leader of various advanced satellite and launch vehicle programs. Before coming to Orbital in 1986, Dr. Elias was a professor of aeronautics and astronautics at the Massachusetts Institute of Technology and a technical staff member at Draper Laboratory.

* Mr. Frank L. Culbertson, currently Senior Vice President for Human Space Systems in APG, will become Executive Vice President and General Manager of the group. In his new role, Mr. Culbertson will be responsible for program execution, business development and financial performance of the company’s human spaceflight and national security satellite activities, including some of Orbital’s largest and most important programs such as NASA’s Commercial Orbital Transportation Services (COTS) and Commercial Resupply Services (CRS) initiatives as well as various defense-related programs. Mr. Culbertson joined Orbital in 2008 and has headed the company’s COTS, CRS and other human spaceflight programs since then. Previously, Mr. Culbertson was senior vice president at SAIC and earlier served as a NASA astronaut and Naval Aviator. He flew on three Space Shuttle missions between 1990 and 2001 and commanded the International Space Station’s Expedition 3 crew in 2001. He also was NASA’s program manager of the Shuttle/MIR program in the mid-1990’s.

* Mr. Christopher C. Long, currently Vice President for National Systems in APG’s National Security Space Division, will become Senior Vice President for the division. In this new position, Mr. Long will direct military and intelligence space systems programs in support of various defense-related mission areas. He joined Orbital in 2010 when the company acquired the Space Systems Division of General Dynamics Corporation. Previously, Mr. Long held engineering, project management and business development positions with General Dynamics and Motorola’s Space Electronics Group.

Mr. David W. Thompson, Orbital’s President and Chief Executive Officer, noted, “Antonio’s promotion to Chief Technical Officer rounds out the company’s senior executive team with the talents of one of America’s most creative and respected technical leaders. Frank’s and Chris’s advancements will ensure that our critical human spaceflight and national security systems programs continue to exhibit strong execution and robust growth.”

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 exploration 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 U.S. Government agencies and laboratories.

More information about Orbital can be found at http://www.orbital.com