Company to Carry Out First of Three "Dual" Missions Scheduled Over the Next Nine Months as both Satellite Manufacturer and Launch Services Provider in Support of NASA's Science Satellite Programs Equatorial Launch from Kwajalein Atoll to Reach the Highest Apogee Ever for a Pegasus Mission; IBEX Satellite's Highly Elliptical Orbit to Reach 80% of the Distance to the Moon


Orbital Sciences Corporation (NYSE: ORB) today announced that it is in final preparations to launch the Interstellar Boundary Explorer (IBEX) satellite that the company designed, manufactured and tested at its Dulles, VA production facilities. The targeted launch date is Sunday, October 19, which is subject to final pre-launch preparations and testing activities at the launch site, as well as acceptable weather conditions at the time of the launch. The IBEX satellite will be launched aboard Orbital's Pegasus(R) air-launched rocket in a mission that will originate from Kwajalein Atoll in the Marshall Islands located near the Equator in the mid-Pacific Ocean. The available launch window for the IBEX mission extends from 1:44 p.m. to 1:51 p.m. (EDT).

The powered flight sequence for the IBEX mission is expected to take approximately eight minutes, from the time the Pegasus rocket is released from the L-1011 carrier aircraft to the time that the satellite and its flight system is deployed into its initial orbit. Afterward, the IBEX satellite will use a combination solid rocket motor and hydrazine propulsion system to reach its final high-altitude elliptical orbit beyond the Earth's magnetosphere.

The IBEX mission will be followed in 2009 by two other "dual" missions involving an Orbital-built scientific satellite and an Orbital-supplied launch vehicle. In early 2009, the Orbiting Carbon Observatory (OCO) Earth science satellite will be launched aboard the company's Taurus(R) ground-launched rocket. Later in 2009, another Orbital-built Earth science satellite known as Glory will be launched aboard a Taurus rocket. Both missions will originate from Vandenberg Air Force Base, CA.

About the IBEX Mission

For the IBEX program, Orbital is teamed with the Southwest Research Institute's (SwRI) Principal Investigator Dr. David McComas. The IBEX mission is funded through the National Aeronautics and Space Administration's (NASA) Small Explorers (SMEX) science satellite program, which is managed by the Goddard Space Flight Center in Greenbelt, MD.

The mission of the IBEX satellite program is to make the first comprehensive map of the boundary between the Solar System and interstellar space, where hot solar winds collide with the cold expanse of space. Measuring this interstellar interaction is important for understanding man's protection from galactic cosmic rays, which are energetic particles from beyond the Solar System that could pose health risks to future astronauts exploring deep space.

To gather this data, the IBEX satellite will orbit the Earth every eight days on a highly elliptical path that will take it to an apogee of about 200,000 miles (320,000 km), which is approximately 80% of the distance to the Moon, and a perigee of about 4,400 miles above the Earth. It will use two narrow-band image sensors (IBEX-Hi and IBEX-Low) to detect neutral atoms, enabling Dr. McComas and his scientific team to map the boundary between the Solar System and interstellar space.

About the Pegasus Rocket

Pegasus is the world's leading launch system for the deployment of small satellites into low-Earth orbit. Its patented air-launch system, in which the rocket is launched from beneath Orbital's "Stargazer" L-1011 carrier aircraft over the ocean, reduces cost and provides customers with unparalleled flexibility to operate from virtually anywhere on Earth with minimal ground support requirements. The IBEX mission will be the 40th flight of the Pegasus rocket since its debut in 1990.

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

    Note to Editors:

    --  More information about the Pegasus rocket is available on
        Orbital's web site at:


    --  High-resolution images of the Pegasus rocket are available on
        Orbital's web site at:


    --  For more information about the IBEX mission information, visit
        the following web sites:



    Source: Orbital Sciences Corporation