Orbital Sciences Corporation announced today that it successfully launched its Orbital Boost Vehicle (OBV) ground-based interceptor (GBI) as part of the Ground-Based Midcourse Defense (GMD) system industry team led by The Boeing Corporation . The mission, designated Flight Test-1 (FT-1), originated from the Ronald Reagan Missile Site at Kwajalein Atoll in the Marshall Islands at 10:04 p.m. (EST) on December 13, 2005. Following its launch from a silo, the OBV flew downrange over the Pacific Ocean. A simulated target was used as the basis for this flight test.

Following a preliminary post-flight analysis of the data collected from the mission, Missile Defense Agency (MDA) and the GMD team confirmed that all primary objectives for FT-1 were achieved. These included validating the GMD system’s ability to track, acquire and provide the interceptor with data for a hit-to-kill intercept of an enemy ballistic missile warhead in the midcourse of its flight. Other FT-1 objectives were the demonstration of the integration of the various elements of the GMD system, engagement operations, pre-launch built-in-test functionality and further verification of the OBV’s flight characteristics.

“We are very pleased with the performance of the OBV interceptor during Flight Test-1, and happy to be back in the flight test mode of operations,” said Mr. Ron Grabe, Orbital’s Executive Vice President and General Manager of its Launch Systems Group. “For the past several months, our OBV team has worked hard to support Boeing and MDA in the process leading up to the resumption of flight testing. With the success of the Flight Test-1 mission, we are looking forward to a more active flight test program in 2006.”

Orbital’s GMD boost vehicle is a three-stage rocket based on flight-proven hardware that has flown over 50 times on missions carried out by the company’s Pegasus®, Taurus® and Minotaur space launch vehicles. Orbital is developing, manufacturing and testing interceptor vehicles under a multi-year contract from Boeing.

Orbital’s space launch vehicles, missile defense interceptors and related suborbital rockets are primarily produced at the company’s engineering and manufacturing facility in Chandler, Arizona and its vehicle assembly and integration facilities at Vandenberg Air Force Base in California. The launch vehicles are used by commercial and government customers to deliver small satellites into low altitude orbits above the Earth and in missile defense systems, both as threat-simulating target vehicles and as interceptor boosters for U.S. national defense systems.

In addition to its launch vehicle systems, Orbital’s other primary products are satellites and related space systems, which are also used by commercial, civil government and military customers. These products include low-orbit, geostationary and planetary spacecraft for communications, remote sensing and scientific missions. In addition, Orbital offers space-related technical services to government agencies and develops and builds satellite-based transportation management systems for public transit agencies and private vehicle fleet operators.

More information about Orbital can be found at http://www.orbital.com.