The first NASA spacecraft to image and map the dynamic interactions taking place where the hot solar wind slams into the cold expanse of space will be launched on Sunday, Oct. 19, at 1:48 p.m. EDT, during a launch window that extends from 1:44 p.m. to 1:52 p.m. The two-year mission will begin from the U.S. Army's Reagan test site at Kwajalein Atoll, a part of the Marshall Islands in the south Pacific Ocean.

Called the Interstellar Boundary Explorer, or IBEX, the spacecraft will conduct extremely high-altitude orbits above Earth to investigate and capture images of processes taking place at the farthest reaches of the solar system. Known as the interstellar boundary, this region marks where the solar system meets interstellar space.

Carrying the IBEX spacecraft into orbit will be a Pegasus XL rocket built by Orbital Sciences Corporation of Dulles, Va. The Pegasus will be deployed from the Orbital Sciences L-1011 aircraft over the Pacific Ocean about 125 miles north of Kwajalein. The spacecraft also was built by Orbital Sciences.

Live coverage of the IBEX launch will be provided via the Web. No live NASA Television coverage is planned. The live streaming video of the countdown and launch will be available on the NASA home page at:

http://www.nasa.gov

Audio coverage of the launch will be available at 321-867-1220, 1240, 1260, and 7135. Streaming video and audio coverage will begin at 12:15 p.m. on Oct. 19. It will conclude after spacecraft separation from the Pegasus, approximately 12 minutes after launch.

For more information about IBEX, including a launch blog, visit:

http://www.nasa.gov/ibex