The Pegasus XL launch vehicle arrives at Cape Canaveral Air Force Station will study and measure solar irradiance as a source of energy in the Earth's atmosphere.

The Pegasus XL launch vehicle, with the Solar Radiation and Climate Experiment (SORCE) satellite aboard, arrives at Cape Canaveral Air Force Station (CCAFS), Fla. SORCE, built by Orbital Sciences Corporation (OSC), will study and measure solar irradiance as a source of energy in the Earth's atmosphere. The launch of SORCE is scheduled for Jan. 25 at 3:14 p.m. from CCAFS. The drop of the Pegasus will be from OSC's L-1011 aircraft at an altitude of 39,000 feet over the Atlantic Ocean approximately 100 miles east-southeast of Cape Canaveral..