From Florida, ULA Delta IV Heavy lifts off for final time

April 9 (UPI) -- For the final time, a Delta IV Heavy rocket roared skyward from Florida on Tuesday.

The United Launch Alliance oversaw the final deployment of the Delta IV Heavy as it lifted a National Reconnaissance Office satellite into space on a national security mission.

The rocket lifted off at Launch Complex 36 at Cape Canaveral Space Force Station after its scheduled 12:53 p.m. EDT liftoff.

This mission is one that originally was scrubbed on March 28.

"This is the final Delta IV Heavy as United Launch Alliance transitions its future missions from the East and West coast to our new Vulcan rocket," ULA said in a statement on its website before the launch. "The NRO develops and operates the world's most capable and innovative overhead reconnaissance systems to collect intelligence for U.S. national security and to support disaster relief and humanitarian efforts."

The Delta IV Heavy was loaded with 470,000 gallons of liquid oxygen and liquid hydrogen before takeoff. Weather balloons were released at about 9 a.m. to accurately measure the speeds and directions of upper winds around the launch site.

After liftoff, the rocket's two boosters were jettisoned about four minutes into the flight, according to Space.com, which said first stage then separated one minute and 45 seconds later.

A single RL10C-2-1 engine then took over before launch coverage stopped because of national security concerns, the report stated.

Of the 16 missions that the Delta 4 Heavy rocket flew, 12 of them were in support of NRO missions, officials said.

Before Tuesday's launch, ULA President and CEO Tory Bruno said that the ground wind limit was one of the reasons the first launch was scrubbed, according to SpaceFlightNow.com. He said there was also an issue with a gaseous nitrogen pump.