-- Cygnus Cargo Logistics Spacecraft Reenters Earth s Atmosphere Over Pacific Ocean --

-- Company s Next CRS Mission to ISS to Take Place in Early May --

DULLES, Va.Feb. 19, 2014-- Orbital Sciences Corporation (NYSE: ORB), one of the world s leading space technology companies, today announced the successful completion of the first of eight CygnusTM operational cargo logistics spacecraft missions to the International Space Station (ISS) as part of the company s $1.9 billion Commercial Resupply Services (CRS) contract with NASA. The Cygnus spacecraft unberthed from the ISS yesterday morning at 6:41 a.m. (EST), completing a 37-day stay at the orbiting laboratory. Today, Cygnus reentered Earth s atmosphere over the Pacific Ocean east of New Zealand at approximately 1:20 p.m. (EST).

We are very proud to have a second flawless cargo mission to the space station brought to a successful conclusion this afternoon, said Mr. David W. Thompson, Orbital s Chairman and Chief Executive Officer. Following Cygnus successful demonstration mission in late 2013 conducted under our COTS research and development partnership with NASA, the picture-perfect execution of the first operational mission is a great way to start the CRS contract. We are looking forward to the next Antares launch and Cygnus cargo delivery mission currently scheduled for early May.

The CRS-1 mission began on January 9, 2014 when Orbital s AntaresTM rocket launched Cygnus into orbit from the Mid-Atlantic Regional Spaceport (MARS) located at NASA s Wallops Flight Facility in eastern Virginia. Cygnus, which carried 2,780 lbs. (1,260 kg.) of cargo and science payloads, rendezvoused and berthed with the ISS three days later on January 12. Prior to its departure from the station, the astronauts loaded the cargo module with approximately 3,250 lbs. (1,477 kg.) of unneeded items for disposal.

Under the CRS contract with NASA, Orbital is using Antares and Cygnus to deliver up to 44,000 lbs. (20,000 kg.) of cargo to the ISS over eight missions, including the CRS-1 flight just completed, through late 2016. For these missions, NASA will manifest a variety of essential items based on ISS program needs, including food, clothing, crew supplies, spare parts and equipment, and scientific experiments.

Preparations are already well advanced for the next Cygnus cargo delivery flight, the CRS-2 mission, scheduled to take place in early May. The Antares rocket for the mission is now undergoing final assembly at Wallops Island, while the Cygnus spacecraft is being prepared for shipment to the Wallops launch site in mid-March. The CRS-2 flight is expected to deliver about 3,630 lbs. (1,650 kg.) of cargo to the Space Station.

About Antares

The Antares medium-class launch vehicle represents a major increase in the payload launch capability that Orbital can provide to NASA, the U.S. Air Force and commercial customers compared to its heritage small-class space launch vehicles such as Pegasus, Taurus and Minotaur. The Antares rocket can launch spacecraft weighing up to 14,000 lbs. (6,400 kg.) into low-Earth orbit, as well as lighter-weight payloads into higher-energy orbits. Orbital s newest launcher has completed three successful missions and is currently on-ramped to both the NASA Launch Services-2 and the U.S. Air Force s Orbital/Suborbital Program-3 contracts, enabling the two largest U.S. government space launch customers to order Antares for right-size and right-price launch services for medium-class spacecraft. For more information on Antares, visit http://www.orbital.com/SpaceLaunch/Antares/.

About Cygnus

Orbital developed the Cygnus cargo spacecraft as part of its Commercial Orbital Transportation Services (COTS) joint research and development initiative with NASA. Cygnus consists of a common Service Module (SM) designed and built by Orbital at its Dulles, VA manufacturing facilities, and a Pressurized Cargo Module (PCM), built by Thales Alenia Space under a subcontract from Orbital. The SM incorporates avionics, power and propulsion systems already successfully flown aboard dozens of Orbital s LEOStar and GEOStar satellite products. The PCM is based on the Multi-Purpose Logistics Module (MPLM) used with the Space Shuttle. For more information on Cygnus, visit http://www.orbital.com/NewsInfo/Publications/Cygnus_fact.pdf.

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. Follow the company on Twitter @OrbitalSciences.

Source: Orbital Sciences Corporation

Orbital Sciences Corporation
Barron Beneski
Public and Investor Relations
703-406-5528
beneski.barron@orbital.com