-- Company s Cygnus Cargo Logistics Spacecraft Successfully Unberthed from Station and Reentered Earth s Atmosphere --

-- First of Eight Operational Cargo Resupply Missions Using Antares and Cygnus Currently Scheduled for December --

DULLES, Va.Oct. 23, 2013-- Orbital Sciences Corporation (NYSE:ORB), one of the world s leading space technology companies, today confirmed that its Cygnus cargo logistics spacecraft reentered Earth s atmosphere over the Pacific Ocean east of New Zealand at approximately 2:15 p.m. (EDT). Cygnus unberthed from the International Space Station (ISS) yesterday following its 23-day stay at the station. The successful conclusion to its demonstration mission also completes the Commercial Orbital Transportation Services (COTS) joint research and development initiative with NASA. Orbital is now ready to begin regularly scheduled resupply flights to the station later this year as part of a $1.9 billion Cargo Resupply Services (CRS) contract with NASA.

The moment of release of Orbital's Cygnus spacecraft was captured on NASA TV yesterday in this scree ...

The moment of release of Orbital's Cygnus spacecraft was captured on NASA TV yesterday in this screen shot that shows the International Space Station's robotic arm, known as the "Canadarm" releasing the spacecraft during the departure procedures. Today, at approximately 2:15 p.m. (EDT), the Cygnus spacecraft reentered Earth's atmosphere, marking the end of the highly successful cargo resupply demonstration mission Orbital conducted with its NASA partners. (Photo: Business Wire)

Upon the successful unberthing and departure from the ISS yesterday, NASA Administrator Charles Bolden said, Congratulations to the teams at Orbital and NASA who worked hard to make this demonstration mission to the International Space Station an overwhelming success. Orbital s success today is helping make NASA s future exploration to farther destinations possible.

For the COTS demonstration mission, Orbital launched its Antares rocket carrying its Cygnus cargo logistics spacecraft on September 18 from the Mid-Atlantic Regional Spaceport (MARS), located at NASA s Wallops Flight Facility in eastern Virginia. Following its launch and in-orbit testing and demonstration maneuvers, Cygnus rendezvoused and berthed with the ISS on September 29. Prior to its departure from the station yesterday, the astronauts loaded the cargo module with nearly 3,000 lbs. of unneeded items for disposal.

With the COTS development phase now successfully completed, we are now turning our full attention to the eight operational resupply missions covered by our Commercial Resupply Services contract with NASA, said Frank Culbertson, Orbital s Executive Vice President and General Manager of its Advanced Programs Group. Each Cygnus is capable of delivering a large quantity of pressurized cargo, totaling up to 20,000 kg over the eight missions, including crew supplies, spare parts and equipment, and scientific experiments for the ISS. We are looking forward to starting these missions in December.

Over the past five years, Orbital privately developed the Antares launch vehicle to provide low-cost, reliable access to space for medium-class payloads, while also developing the Cygnus spacecraft in conjunction with NASA under the COTS program to meet the stringent safety requirements for ISS operations. Together these products showcased Orbital s ability to apply commercial business practices and engineering approaches to significantly shorten development timelines and lower operational costs of sophisticated space systems as compared to traditional government-run programs.

About Cygnus

Orbital developed the Cygnus cargo spacecraft as part of its COTS joint research and development initiative with NASA. Cygnus consists of a common Service Module (SM) and a Pressurized Cargo Module (PCM). The SM incorporates avionics, power, propulsion and communications systems already successfully flown aboard dozens of Orbital s LEOStar and GEOStar satellites. The PCM, designed and built by Thales Alenia Space under a subcontract from Orbital, is based on the Multi-Purpose Logistics Module (MPLM) previously used with the Space Shuttle. With a full load of cargo and fuel, the standard-configuration Cygnus weighs about 11,000 lbs. at launch and generates 3.5 kw of electrical power while in orbit. It is capable of extended-duration missions of a year or longer in space.

About Antares

The Antares medium-class launch vehicle provides a major increase in the payload launch capability that Orbital can provide to NASA, the U.S. Air Force and commercial customers. The Antares rocket can launch spacecraft weighing up to 14,000 lbs. into low-Earth orbit, as well as lighter-weight payloads into higher-energy orbits. Orbital s newest launcher 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. Antares made its debut earlier this year with a fully successful inaugural launch on April 21, followed up by another successful launch of the COTS demonstration mission on September 18.

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.

Source: Orbital Sciences Corporation

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