NASA Selects New Explorer Missions

NASA has released plans for two new science missions to study the Sun and the evolution of galaxies, both aboard small, relatively inexpensive spacecraft. The first of the newly selected missions, the Transitional Region and Coronal Explorer, or TRACE, will observe the Sun to study the connection between its magnetic fields and the heating of the Sun's corona. Dr. Alan Title of the Lockheed Palo Alto Research Laboratory, Calif., is the principal investigator. TRACE is scheduled for launch in 1997.

The second spacecraft, the Wide-Field Infrared Explorer, or WIRE, is scheduled for launch in 1998 on a mission to study the evolution of galaxies. WIRE will use a cryogenically-cooled telescope and arrays of highly sensitive infrared detectors for the studies. WIRE was proposed by Dr. Perry B. Hacking of NASA's Jet Propulsion Laboratory, Pasadena, Calif., with co-investigators from the California Institute of Technology, Cornell University, Ball Aerospace Systems Group, and JPL.

The two newly announced missions are part of NASA's Small Explorer (SMEX) Program, which provides frequent flight opportunities for highly focused and relatively inexpensive science missions. Small Explorer spacecraft weigh approximately 500 pounds (227 kilograms). Each mission is expected to cost approximately $50 million for design, development and operations through the first 30 days in orbit.

The missions will be launched by Pegasus, an expendable launch vehicle owned and operated by Orbital Sciences Corp., Loudon, Va., under contract to NASA. The TRACE and WIRE missions join three other Small Explorer missions already in development or operation...

SAMPEX, the Solar, Anomalous and Magnetospheric Particle Explorer, was launched July 3, 1992 and has been successfully investigating the composition of local interstellar matter and solar material, and the transport of magnetospheric charged particles into the Earth's atmosphere.

The Submillimeter Wave Astronomy Satellite, or SWAS, is scheduled for launch in June 1995 on a Pegasus rocket to be released from an L-1011 at NASA Goddard Space Flight Center's Wallops Flight Facility in Virginia. SWAS will for the first time directly measure the amount of water and molecular oxygen in interstellar clouds. SWAS also will measure carbon monoxide and atomic carbon, which are believed to be major reservoirs of carbon in these clouds.

FAST, the Fast Auroral Snapshot Explorer, is scheduled for launch one month after SWAS, in July 1995, from Vandenberg Air Force Base in Lompoc, Calif. FAST will probe the physical processes that produce aurorae, the displays of light that appear in the upper atmosphere at high latitudes.