Vandenberg AFB launch schedule has listed the nation’s largest rocket for August 28, 2013 to lift off at 10:52 a.m. PST. Residents of Lompoc, just 9 miles from the base will be able to see and hear its take-off. Residents to the south in Santa Barbara and to the east will have more difficulty with interference from hills for visual view of the takeoff.
The 235-foot Delta IV rocket is the tallest ever to be launched from the base. W.J. Hennigan of the L.A. Times reports in its August 27, 2013 edition that the rocket is 'carrying a massive, top-secret spy satellite for the federal government.' This payload will travel into polar orbit for the U.S. National Reconnaissance Office, the agency responsible for operating the country's fleet for spy satellites.
Justin Ray in Spaceflight Now reports that for 'the first time its three main engines will be ignited in a staggered sequence.' This is a new strategy employed to reduce the hydrogen flames generated during the startup of the three Aerojet Rocketdyne RS-68 main engines. The sequence will start the first ignition 2 seconds before the next ignition.
The rocket built by United Launch Alliance designed the new staggered process to lessen the pre-liftoff fire before the 23-story-tall Heavy takes to the sky. Vandenberg AFB released countdown to liftoff at 10:52 a.m. local time, the Terminal Countdown sequencer will take control at T-minus 10 seconds and the starboard engine begins to ignite at T-minus 7 seconds.
The Delta 4-Heavy is America's largest unmanned rocket currently in service, and is designed for this type of satellite service.
Vandenberg Air Force Base is named after late General Hoyt S. Vandenberg, architect of today’s modern air force. It is located 9.2 miles from Lompoc, Ca. It is under the jurisdiction of the 30th Wing, Air Force Space Command. Vandenberg AFB is a Department of Defense space and missile testing base. It is intrinsic to the defense of the US west coast.
Launch Alliance's website at http://www.ulalaunch.com