Delta 4-Heavy launch aborted at T-minus 7 seconds – Spaceflight Now - Spaceflight Now

Another countdown for United Launch Alliance’s next Delta 4-Heavy rocket mission ended without a liftoff Wednesday after a computer sequencer detected a potential problem just before engine ignition.

Here’s a replay of the final seconds of the aborted Delta 4-Heavy countdown tonight.

It was the second abort for the Delta 4-Heavy rocket in the final 10 seconds of a countdown.

29 to a pressure regulator at the Delta 4’s launch pad at Cape Canaveral Air Force Station.

Officials began assessing the cause of Wednesday night’s abort as the launch team “safed” the Delta 4-Heavy rocket and drained it of cryogenic propellant.

Tory Bruno, ULA’s president and CEO, tweeted after Wednesday night’s abort that the countdown automatically stopped after a “sensor reported a fault.” He added that the Delta 4’s automated safety system operated as intended.

Bruno later tweeted it was too early to know how long engineers might need to investigate the cause of Wednesday night’s abort and ready the Delta 4-Heavy for another launch attempt.

A separate Falcon 9 rocket was standing on pad 40 at Cape Canaveral Air Force Station for launch at 9:43 p.m.

26 for the next launch attempt for the NROL-44 mission, but officials delayed the mission again to investigate a concern with the swing arm retraction system at the Delta 4-Heavy’s seaside launch complex at Cape Canaveral.

ULA is retiring the Delta 4 rocket family after five more launches — three more from Cape Canaveral and two froom Vandenberg Air Force Base in California.

The company’s next-generation Vulcan Centaur rocket, scheduled to debut in the second half of next year, will replace ULA’s existing Delta 4 and Atlas 5 launch vehicles.

While the payload on the NROL-44 mission is classified, independent analysts say publicly-known parameters such as the rocket’s capabilities, its launch azimuth, and the launch window suggest the Delta 4-Heavy is set to carry a signals intelligence satellite into geosynchronous orbit.

The Delta 4-Heavy also has a larger payload fairing than the Falcon Heavy, and the mobile shelters at Cape Canaveral and Vandenberg allow ground crews to mate satellites to the rocket in a vertical orientation

Space Force officials said last month that ULA’s next Delta 4-Heavy rocket was scheduled to take off no earlier than December from Vandenberg

The final Delta 4-Heavy rocket is scheduled to launch in 2023

Delta 4-Heavy launch aborted at T-minus 7 seconds

Mobile gantry wheeled away from Delta 4-Heavy rocket at Cape Canaveral