The launch of a United Launch Alliance (ULA) Delta IV Heavy rocket carrying the NROL-44 mission for the National Reconnaissance Office is planned for Sept. 26, 2020 following an abort Aug. 29 just three seconds before liftoff from Cape Canaveral.
The launch period is 12:01-1:35 a.m. EDT. The team has reviewed all data and ground support equipment and determined that a ground system regulator internal component failure was the cause of the on-pad abort. Out of an abundance of caution the regulators associated with each of the three common booster cores are being replaced and retested.
A United Launch Alliance (ULA) Delta IV Heavy rocket will launch the NROL-44 mission for the National Reconnaissance Office (NRO). Liftoff will occur from Space Launch Complex-37 at Cape Canaveral Air Force Station, Florida.
This will be 141st mission for United Launch Alliance and our 29th for the NRO. It is the 385th Delta launch since 1960, the 12th Delta IV Heavy and the 8th Heavy for the NRO.
A computer automatically called the abort Aug. 29 after one of the rocket’s three Aerojet Rocketdyne RS-68A main engines had already ignited. ULA said Thursday that the launch team determined “a ground system regulator internal component failure was the cause of the on-pad abort.”
Three flow rate regulators are used in the high-pressure helium gas system that spins up the turbines on the Delta 4-Heavy’s three Aerojet Rocketdyne RS-68A main engines. The rocket’s starboard engine fired up normally, but a regulator for the center engine’s regulator did not open.
The Delta 4-Heavy is made of three common booster cores, each powered by a single Aerojet Rocketdyne RS-68A engine. The engines are timed to ignite in a staggered sequence in the last few seconds before launch, beginning with the starboard engine and followed by the center and port engines.