-- Carbon Dioxide-Measuring Spacecraft for NASA Set to Launch on July 1 from Vandenberg Air Force Base, CA --

-- OCO-2 Is 151st Orbital-Built Satellite Delivered to Government and Commercial Customers Around the World --

DULLES, Va.Jun. 30, 2014-- Orbital Sciences Corporation (NYSE: ORB), one of the world s leading space technology companies, today announced it is in final preparations for the launch of the Orbiting Carbon Observatory-2 (OCO-2) satellite. Orbital designed, built and tested the carbon dioxide-measuring spacecraft at its satellite manufacturing facility in Gilbert, AZ for NASA s Jet Propulsion Laboratory (JPL). NASA s first satellite to make space-based measurements of atmospheric carbon dioxide (CO2), OCO-2 is scheduled to launch aboard a Delta II rocket from Vandenberg Air Force Base in California on Tuesday, July 1 at 2:56 a.m. (PDT).

We want to thank JPL for its confidence in Orbital on this important mission, which will help scientists understand the sources of carbon dioxide emissions and the natural process that removes it from the atmosphere, said Mr. Mike Miller, Orbital s Senior Vice President of Science and Environmental Satellite Programs. OCO-2 will ultimately reveal how increasing CO2 concentrations are driving climate change around the globe. We are looking forward to a successful launch tomorrow and are eager to begin in-orbit testing and, later, operating the satellite for JPL.

Following its deployment, the OCO-2 satellite will undergo several weeks of in-orbit testing to verify that all major subsystems are operating as planned. Once testing is complete, the spacecraft will be commanded to maneuver into a 438-mile altitude, near-polar orbit with five other scientific satellites as part of the Afternoon (A-Train) Constellation. This international constellation of Earth-observing satellites circles the globe once every 98 minutes in a Sun-synchronous orbit that crosses the equator near 1:30 p.m. local time and repeats the same ground track every 16 days. OCO-2 will be inserted at the head of the A-Train.

Orbital will perform the day-to-day mission operations of OCO-2 for JPL from the company s Mission Operations Center in Dulles, VA. OCO-2 is a 990-pound (449-kilogram) observatory with single-axis articulated arrays and three-axis attitude control to ensure high precision in positioning. It is designed to operate for at least two years.

Orbital s newest satellite delivery represents the 151st spacecraft the company has completed for customers in the past 32 years, spanning the global commercial, civil government and military and intelligence space systems markets. Of these, 78 have carried out commercial communications and imaging missions and 73 have supported government scientific, national security and space exploration missions. Orbital-built satellites have now amassed approximately 1,100 years of in-orbit experience, a number that will continue to grow as the company is scheduled to deploy up to nine spacecraft in 2014 for commercial communications, space station logistics, scientific research and national security missions.

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, 703-406-5528
Public and Investor Relations