At Cape Canaveral Air Force Station Fla. Mark McManus makes a final inspection of the first stage aft skirt on the Pegasus XL rocket.

At Cape Canaveral Air Force Station, Fla., Mark McManus makes a final inspection of the first stage aft skirt on the Pegasus XL rocket, the vehicle that will launch the High Energy Solar Spectroscopic Imager (HESSI). The primary mission of HESSI is to explore the basic physics of particle acceleration and energy release in solar flares. The launch of PegasusXL/HESSI is scheduled for Feb. 5, 2002, from beneath the Orbital Sciences Corp. L-1011 aircraft seen here