Last second for the launch of the Delta 4 Heavy spy satellite

An unsuccessful attempt to launch a National Defense Bureau classified spy satellite at the top of a Delta 4 rocket at Vandenberg Air Force Base northwest of Los Angeles was aborted at 7 , 5 seconds, Saturday night, when a problem was detected by computers orchestrating the countdown of the terminal

Flares were already lit at the base of a rocket of 23 floors to burn the excess hydrogen, a common safety precaution, when the order of abortion has been ordered. It took half a second before the first of three Delta 4 Heavy's side-by-side Common Booster Core engines was fully lit and accelerated, followed by two seconds later by the central and left-handed CBCs.

Instead, a flight controller called "waiting, waiting, waiting" when the countdown stopped. The flames of the hydrogen igniters were rising from the base of the rocket as they continued to burn for a few moments, which was somewhat frightening considering the fact that the 1.6 million pound rocket was loaded with 465 000 gallons of liquid hydrogen and oxygen boosters.

United Launch Alliance engineers quickly "secured" the vehicle and pushed back the countdown to mark T-minus 4 minutes while checking for telemetry. A few minutes later, the flight is cleaned up for the day and the engineers begin to unload the Delta's fuel load.

ULA has not set a new launch date or provided immediate details on what caused the abandonment. As a result, it was not immediately known what type of inspection or repair might be needed before a second launch could be attempted.

This was the ninth ULA launch in 2018 and the second in a row of the massive Delta 4. Heavy. The satellite payload identity, known as NROL-71, is classified, but independent analysts speculate that it could be a spacecraft advanced imaging reconnaissance for an unusual near polar orbit.