-- Deployment of Three New Spacecraft for Department of Defense Marks 10 Missions Conducted in Past Five Weeks by Company --

DULLES, Va.Aug. 1, 2014-- Orbital Sciences Corporation (NYSE: ORB), one of the world s leading space technology companies, announced today that three satellites the company designed, built and tested for the U.S. Air Force were successfully deployed following their launch aboard a Delta IV rocket from Cape Canaveral, FL on July 28, 2014. These deployments continued Orbital s summer surge of operational activity that has included the fourth launch of its Antares rocket which deployed the third Cygnus cargo logistics spacecraft, a launch of the company s OBV long-range missile defense interceptor, the deployment of the Orbiting Carbon Observatory-2 satellite for NASA, and the successful launch of three suborbital research rockets, all of which took place since late June.

This week s launch carried two Orbital-built satellites for the Air Force s Geosynchronous Space Situational Awareness Program (GSSAP). The spacecraft will operate in near-geosynchronous orbit, collecting Space Situational Awareness (SSA) data for more accurate characterization of man-made objects in Earth orbit. The goal of the program is to enhance the country s knowledge of the geosynchronous orbit environment for more timely and accurate orbit predictions to improve spaceflight safety.

The Delta IV rocket also carried the Automated Navigation and Guidance Experiment for Local Space (ANGELS) satellite, another Orbital-built spacecraft for the Air Force Research Laboratory (AFRL). As part of AFRL s research in the SSA field, the ANGELS program will examine techniques for providing a clearer picture of the environment around the country s vital space assets. The ANGELS spacecraft will conduct experiments in close proximity to the spent upper stage of the Delta IV rocket that launched it into orbit. The Air Force will use the results to evolve the ability of future space systems to responsively perform SSA activities from a safe distance from observed objects.

The capabilities of the GSSAP and ANGELS satellites demonstrate Orbital s innovative operational approaches in support of our customers vital missions, said Mr. Christopher Long, Orbital s Senior Vice President of National Security Satellite Programs.

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
beneski.barron@orbital.com