Orbital Sciences Corporation , one of the world’s leading space technology companies, today announced that it is in final preparations to launch a Minotaur IV rocket in support of the Air Force’s Space Test Program-S26 (STP-S26) mission. The rocket will carry four microsatellites, two CubeSats, and perform a technology demonstration into low-Earth orbit. Subject to final preparations and favorable weather conditions, the mission will originate from the Kodiak Launch Complex on Kodiak Island, AK on November 19, 2010, with a targeted launch time of 8:24 p.m. (EST) and a 90-minute available launch window that extends until 9:54 p.m. (EST).

The STP-S26 launch will be the second Minotaur IV orbital mission in less than two months, following the successful launch of the U.S. Air Force’s Space-Based Space Surveillance (SBSS) satellite in late September from Vandenberg Air Force Base, CA. It will also be the third overall launch for the Minotaur IV vehicle, which debuted in April 2010 with a successful suborbital flight, launching the Defense Advanced Research Projects Agency’s HTV-2a mission.

The STP-S26 mission will be demonstrating a new capability for Minotaur IV, called the Multiple Payload Platform (MPP), addressing the needs of small satellite customers. Several key facts about this new capability are as follows:

* The addition of a restartable Hydrazine fifth stage enables the deployment of spacecraft at multiple orbital altitudes, allowing unique mission tailoring and cost sharing. Small satellites requiring different orbits can share the cost of the same vehicle.

* The MPP enables the deployment of up to 12 small satellites, consisting of four ESPA-class satellites, four smaller secondary satellites (up to 11 cubic feet each), and four P-POD carriers.

“Orbital is privileged to be supporting the Air Force on this important mission for the Space Development and Test Wing. Building upon the success of the first two Minotaur IV launches, we are excited about delivering this new capability for the small satellite community,” said Lou Amorosi, Orbital’s Senior Vice President for Minotaur launch vehicles.

The Minotaur IV rocket is the latest in the family of highly reliable, cost-effective Minotaur launchers that Orbital has developed for the U.S. Air Force. The STP-S26 mission will be the 19th overall mission for the Minotaur product line over the last 10 years. The previous 18 missions have all been successful.

Orbital is conducting the Minotaur IV launch under the U.S. Air Force’s Orbital/Suborbital-2 contract, which is managed by the Space and Missile Systems Center (SMC), located at Los Angeles Air Force Base, CA. The Space Development and Test Wing, based at Kirtland Air Force Base in Albuquerque, NM, oversees Minotaur launches for SMC.

About Minotaur IV

The Minotaur IV is a four-stage space launch vehicle that uses flight-proven propulsion, avionics and other subsystems. It leverages the experience of the Air Force’s Peacekeeper ICBM program, along with the extensive flight heritage of Orbital’s Minotaur I, Pegasus(R) and Taurus(R) space launch vehicles to produce a highly reliable launcher for U.S. government space programs. The space launch configuration of Minotaur IV is made up of three decommissioned Peacekeeper solid fuel rocket motors that Orbital has upgraded and integrated with modern avionics and other subsystems, and a solid fuel commercially-supplied upper stage. The Minotaur IV rocket is capable of launching payloads up to 4,000 lbs. (or 1,800 kg.) to low-Earth orbit.

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.

Note to Editors: High-resolution images of the Minotaur IV rocket can be found at: http://www.orbital.com/NewsInfo/ImagesMultimedia/Images/SpaceLaunch