— Company’s 32nd Commercial Geosynchronous Spacecraft Set to Launch Today from Cape Canaveral in Florida —

(Dulles, VA 6 January 2014) – Orbital Sciences Corporation (NYSE: ORB), one of the world’s leading space technology companies, today announced that it is in final preparations for the launch of the THAICOM 6 communications satellite, a hybrid Ku-band and C-band satellite built for THAICOM Plc., that will provide coverage for Southeast Asia and Africa. Designed, manufactured and tested at Orbital’s Dulles, VA satellite production facilities, THAICOM 6 is scheduled to be launched aboard a Space Exploration Technologies Falcon 9 rocket from Cape Canaveral, Florida, at approximately 5:00 p.m. EST on Monday, January 6, 2014.

Following its launch, the satellite will undergo several weeks of in-orbit testing and verification that all subsystems are operating as planned. Once testing is complete and the spacecraft is positioned at its final orbital location of 78.5 degrees East Longitude, day-to-day control of THAICOM 6 will be handed over to THAICOM’s satellite operations staff.

“We are ready to begin 2014 in the best way possible, by providing our THAICOM customer with a great beginning for the next satellite in their network,” said Mr. Christopher Richmond, Orbital’s Senior Vice President of Communications Satellites. “We are looking forward to a successful launch and are eager to begin our in-orbit activation and testing operations in the first few days of the new year.”

At launch, THAICOM 6 will weigh approximately 3,330 Kg.  It carries a hybrid Ku- and C-band payload that will operate on approximately 3.5 kilowatts of payload power. The Ku-band payload is comprised of eight active transponders (9×36-MHz Transponder Equivalent) providing services to Thailand, Laos, Cambodia, and Myanmar. The C-band payload features 12 active C-band transponders providing services via a regional beam to Southeast Asia and six active C-band transponders (12×36-MHz TPE) providing services to Africa.

The THAICOM 6 communications satellite is based on Orbital’s highly successful GEOStar spacecraft platform, which is able to accommodate all types of commercial communications payloads and is compatible with all major commercial launchers.  The GEOStar design is optimized for satellite missions requiring up to 7.5 kilowatts of payload power.  In many instances, the affordable GEOStar satellites can be built and delivered in 24 months or less.

About THAICOM Public Company Limited

THAICOM Plc, established in 1991, has more than 20 years of experience in the satellite business.  THAICOM is Asia’s leading satellite operator with a unique proposition in providing integrated solutions for satellite broadcast and broadband services.  The company has launched five satellites since its inception, including THAICOM 5, a “Hot Bird” broadcasting satellite for Thailand and Southeast Asia, boarding more than 500 TV channels, and THAICOM 4 (IPSTAR), the world’s first broadband satellite providing broadband services to 14 countries across Asia-Pacific.  The company’s launch of THAICOM 6 will provide additional capacity to strengthen THAICOM’s “Hot Bird” position, and will also serve the African market under the name “Aficom-1”.  Furthermore, THAICOM-7 will also be launched in 2014 to expand THAICOM’s service capabilities and coverage in the regions.

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.  Follow the company on Twitter @OrbitalSciences.

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For More Information Contact:

Barron Beneski (703) 406-5528

Public and Investor Relations

Orbital Sciences Corporation

beneski.barron@orbital.com

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