-- Mission Marks 15th Consecutive Success for Minotaur Launch Vehicles --

Orbital Sciences Corporation (NYSE:ORB) announced today that its Minotaur II+ rocket was successfully launched for the U.S. Air Force Space and Missile Systems Center (SMC) in support of the Missile Defense Agency (MDA) Near-Field Infrared Experiment (NFIRE). The mission was conducted on Tuesday, September 23, 2008, from Vandenberg Air Force Base (VAFB), California. The program office responsible for Minotaur launch vehicles is the Launch Test Squadron of the Space Development and Test Wing (SDTW) at Kirtland Air Force Base, New Mexico. This mission was the eighth for the Minotaur II Target Launch Vehicle (TLV) and the 15th for the Minotaur family, all of which have been successful.

The launch originated from VAFB at approximately 11:57 p.m. (PDT) on September 23. Final targeting for the mission was uploaded to the rocket approximately one and a half hours prior to launch. The vehicle was successfully launched within a one-second launch window, which was required to meet the mission’s precise targeting requirements. The vehicle’s first two solid rocket motors burned for approximately two minutes, at which time the vehicle entered into a coast phase lasting over one minute. After its coast period, the third and final stage ignited, placing the vehicle on course to burn through a precise aim point at an exact time nearly 250 km above the Pacific Ocean. The vehicle was being observed by the NFIRE satellite and a variety of Missile Defense Agency sensors deployed across the Pacific region. At the point of closest approach, the Minotaur target vehicle and NFIRE satellite were within several kilometers of each other. In addition to conducting this Minotaur II+ TLV mission, Orbital also launched the NFIRE satellite in April 2007 aboard a Minotaur I space launch vehicle in a mission conducted from NASA’s Wallops Flight Facility in Eastern Virginia. Orbital also conducted an earlier Minotaur II+ TLV launch that was observed by the NFIRE satellite last year.

Minotaur II+ is an upgraded version of the reliable and proven Minotaur II vehicle, yielding a more capable vehicle for future applications. The major upgrades include a higher performing third stage and larger structures. The new stage and structures enable the launch of larger and heavier payloads or reentry vehicles. The previous Minotaur II+ mission was launched in August 2007 and met all customer requirements, also demonstrating precise timing and targeting accuracy.