A Little More Fire Than Expected

11-0-26 ... Not my photo. ... Taken from a newsletter I subscribe to. ... This was the 1-20-11 launch of the "Delta IV Heavy" rocket from California. ... The previous launch of this type of rocket was from Florida. ... This first West Coast launch was a big success.

But when I first saw this photo I was surprised to see flames engulfing the rocket and scorching the exterior paint. ... I immediately sent an email to one of my former coworkers saying "Is this a new procedure now ? ... To set the whole rocket on fire." (Grin)

He replied: "... the engine start procedure begins with flowing liquid hydrogen (LH2), a delay, then flowing liquid oxygen (LO2) and ignition. Hence, that LH2 rich start yields a bunch of LH2 that burns off. Rather discomforting if you’re not used to it."

I replied: "How come the 11-21-10 launch didn't show the same scorching ? ...www.flickr.com/photos/landoni/5285841453/ ... That's why I thought something was wrong with the first VAFB [West Coast] launch."

He replied: The RS-68 [rocket engine] requires a fuel lead (LH2 precedes the LO2) at start to fill the coolant circuits and push LH2 through the injectors before engine ignition. Prevailing winds, direction and speed, as well as which pad it is launched from (believe it or not they are not all the same – duct size, shape, flow resistance, etc.) all affect the degree of scorching."

He continued: "There is a [task] to investigate the flames on this launch because while they are expected, this was [unusual] ... ."
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Here's the launch announcement from www.foxnews.com/scitech/2011/01/20/largest-rocket-set-bla...

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 [1-20-11] evening.

At 1:10 p.m. PST, private rocket group the United Launch Alliance successfully launched a 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.