CAPE CANAVERAL AIR FORCE STATION, Fla. — The United Launch Alliance Delta IV Heavy NROL-44 launch was aborted seconds before liftoff when a sensor reported a fault and triggered an automatic abort.


What You Need To Know

  • ULA president says the engine igniters didn't fire

  • Rocket carrying spy satellite for National Reconnaissance Office

  • This is one of several postponements for the mission

  • ULA has not released a new launch date at this time

  • See the launch schedule here

In a tweet during the early morning hours of Thursday, ULA President Tory Bruno explained that the automated abort system was tripped when the engine igniters did not fire and a sensor reported the fault.

Bruno did say that both the Delta IV Heavy rocket and the National Reconnaissance Office spy satellite it is carrying were not harmed and the automated abort system worked as designed. 

Wednesday night's aborted launch is not the mission's first setback. The Delta IV Heavy rocket, carrying a spy satellite for the National Reconnaissance Office, was originally supposed to lift off over the weekend from Cape Canaveral Air Force Station in Florida.

But launch officials said more time was needed to test and evaluate the swing arm retraction system for the mission, dubbed NROL-44.

ULA set a fourth launch attempt for the Delta IV Heavy for 11:54 p.m. EDT, Wednesday, after weather stopped the launch Tuesday evening. ULA has not issued a new launch date.