Update: ULA called off the launch less than 12 hours after a fifth attempt was scheduled to take place. Another try won’t happen until at least Dec. 30. Read KTLA’s updated story here.
The United Launch Alliance hopes the fifth time will be the charm as it prepares to blast off a Delta IV Heavy rocket out of the Central Coast’s Vandenberg Air Force Base on Thursday evening.
Four previous tries to launch the sky satellite into orbit have been scrubbed since Dec. 7, including one slated for Wednesday evening. The day before, on Tuesday, high winds prompted ULA to again abort the NROL-71 mission.
An unexpected condition that developed seven seconds before liftoff on Dec. 8 prompted the cancelation of the second attempt. And the first try, which took place a day earlier, was delayed for an unspecified reason.
ULA has yet to comment on the exact reasons for the postponement of Wednesday’s launch, but said another attempt would be made 24 hours after it was scheduled to take place, at 5:31 p.m. Thursday.
The launch should be visible to most of Southern California within minutes of liftoff. For those who can’t be outdoor or are elsewhere, it will be streamed live online. Commentary is expected to start sometime around 5:24 p.m.
The 233-foot-tall rocket is set to deploy a classified satellite for the U.S. National Reconnaissance Office.
About four minutes after liftoff, the rocket jettisons its two side booster engines, leaving the center booster engine to throttle to its full power, according to a video posted by ULA. The rocket will be traveling at more than 13,281 mph and more than 115 miles in altitude as it approaches its main engine cutoff.
Then, a little over six minutes after liftoff, the protective cone around the satellite is dumped and the payload is deployed.
This will be ULA’s second Delta IV Heavy launch in under four months, and the private space launch company’s 132nd mission overall.