The 469-pound TRACE satellite was built under NASA's Small Explorer (SMEX) program, which is managed by the Goddard Space Flight Center and provides frequent flight opportunities for highly focused and relatively inexpensive space science missions. TRACE is designed to observe the Sun over a one-year period, studying the connection between its magnetic fields and the heating of its corona. These observations will provide insight into dynamic solar events that have the potential to endanger astronauts, as well as disrupt the use of space-based satellites for critical functions such as communications, navigation, weather forecasting and national security. The spacecraft was designed and developed under the leadership of the program's principal investigator, Dr. Alan Title of the Stanford Lockheed-Martin Palo Alto Research Laboratory in California.

The TRACE mission will originate from Vandenberg Air Force Base, California, and is subject to final preparations and testing, as well as acceptable weather conditions at the launch site. This launch will represent the second Pegasus mission of 1998 and Orbital's third overall space launch mission for the year, including the company's successful Taurus launch in February.

Pegasus has conducted 20 missions to date, including a perfect five-for-five record in 1997. The most recent launch occurred on February 25, 1998, when Pegasus successfully launched NASA's Student Nitric Oxide Explorer (SNOE) and Teledesic's T1 satellite.