Giant Delta IV Rocket Makes History in West Coast Launch

The United Launch Alliance successfully blasted off the largest ever rocket from the West Coast Thursday evening.

At 1:10 p.m. PST, private rocket group the United Launch Alliance successfully launched a The 235-foot-tall Delta IV Heavy rocket -- one of a class of "heavy-lift" rockets designed to carry massive payloads such as satellites. It marked the largest rocket ever to lift off from the West Coast.

The launch was moved back by two minutes from 1:08 p.m. to avoid an object in space, said Michael J. Rein, spokesman for United Launch Alliance, the joint venture of rocket builders Lockheed Martin Corp. and Boeing Co.

The take-off was then a success: The booster rose into the sky over California's central coast and arced over the Pacific Ocean, a spectacle visible over a wide area. Initial reports from launch control indicated the flight was going well, with the rocket hitting speeds of 14,000 feet per second a few minutes into its launch.

The rocket carried a mysterious payload into space on the NROL-49 mission: a clandestine satellite for the National Reconnaissance Office described only as something that will "support the military's national defense mission." The NRO operates satellites that provide information to the Central Intelligence Agency and Department of Defense.

The enormous Delta IV is America’s largest liquid-fueled rocket, with nearly two million pounds of thrust; the Space Shuttle is more powerful, however, with nearly 7 million pounds. The launch from Vandenberg Air Force Base in California required a complete revamp of the SLC-6 launch pad in order to accommodate the gigantic beast, reported SpaceFlight Now.

"We spent the good part of three years ... upgrading the launch pad and the base infrastructure, in total more than $100 million in infrastructure improvements," said Lt. Col. Brady Hauboldt, the Air Force launch director and Vandenberg's 4th Space Launch Squadron commander.

The Delta 4-Heavy is created by taking three Common Booster Cores -- the liquid hydrogen-fueled motor that forms a Delta 4-Medium's first stage -- and strapping them together to form a triple-barrel rocket, then adding a cryogenic upper stage, SpaceFlight Now reported. The combined punch can propel about 50,000 pounds of cargo into polar orbit.

Supplying those four stages with the supercold fluids and commodities, keeping the payload comfortable with conditioned air and the special hardware for servicing the 23-story rocket were among the changes made to the site.

The last heavy lift Titan IV-B was launched at Vandenberg in 2005. In its past, the launch complex was once configured for West Coast space shuttle launches, which were canceled after the 1986 Challenger disaster, and the Air Force's Manned Orbiting Laboratory program, which was canceled in 1969. It was last used in 2006.

The Associated Press contributed to this report.