BY JUSTIN RAY Follow the countdown and launch of the U.S. Air Force Titan 4B rocket and the Defense Support Program-21 satellite. Reload this page for the very latest on the mission.				Snapshots Top: Titan 4B rocket lifts off (Spaceflight Now photo); Botton: DSP-21 mission patch (USAF photo). Flight data file Vehicle: Titan 4B/IUS (B-31) Payload: DSP-21 Launch date: Aug. 6, 2001 Launch window: 3:28-7:28 a.m. EDT (0728-1128 GMT) Launch site: SLC-40, Cape Canaveral, Fla. Pre-launch briefing Launch timeline - Chart with times and descriptions of events to occur during the launch. Titan 4B vehicle data - Overview of the rocket to be used in this launch. DSP-21 - Description of the Defense Support Program satellite system.