On Monday, April 26 at 20:47 UTC, United Launch Alliance successfully launched the NROL-82 mission from SLC-6 at Vandenberg Space Force Base in California. The launch was delayed one minute due to a Collision On Launch Assessment, which means there was a chance of the ascending rocket hitting something already in orbit.

Let’s face it, no one wants to see that kind of a disaster, and thanks to the delay, no one did.

The launch webcast started at around T-15 minutes and counted smoothly down to zero, and the rocket lifted into the air right at the beginning of the window, becoming only the third Delta 4 Heavy to launch on its first attempt. Thirteen Delta 4 Heavies have launched total. This rocket launches so little that it’s not uncommon for there to be issues related to the rocket pad. Faulty ground systems at SLC-37B, the Florida Delta 4 pad, resulted in a dozen scrubs and four months of delays (August-December) in the NROL-44 launch campaign last year. To prevent a repeat of the long delay, ULA took a very close look at the launch pad systems at SLC-6 before this launch.

The rocket featured its standard fireball on ignition which looks scary on the ground but is totally normal. It’s caused by the buildup of excess hydrogen gas at the bottom of the rocket from the engine chill process, which results in a jet of flame shooting up almost the entire length of the first stage. It’s so hot that the flame chars its foam insulation. Somewhat unusual for an NRO launch, a live rocket cam showed the California coast and the Pacific Ocean as the rocket headed to space. It also captured side booster, core, second stage ignition, and fairing separation happening nominally.

NROL-82 was a National Reconnaissance Office mission so the precise nature of the payload and its orbit are classified. After fairing separation, the live broadcast concluded “at the request of our customer” according to the ULA webcast host. Again, that customer was the National Reconnaissance Office. About an hour later, United Launch Alliance confirmed on Twitter that the launch was a success.

More Information

ULA blog

ULA completes Delta IV Heavy pad upgrades ahead of NROL-82 mission (NASA Spaceflight)

Launch video