BY JUSTIN RAY Follow the preparations and launch of the Orbital Sciences Pegasus rocket with NASA's HESSI solar flare research spacecraft. Reload this page for the very latest on the mission.				Flight data file Vehicle: Pegasus XL Payload: HESSI Launch date: Feb. 5, 2002 Launch window: 3:21-5:21 p.m. EST (2021-2221 GMT) Mission staging site: Cape Canaveral, Fla. Pre-launch briefing Launch timeline - Chart with the key events to occur during the launch. HESSI - Facts and info on the NASA satellite being launched. Pegasus - Overview of the air-launched Orbital Sciences rocket.