Update for 2:50 p.m. EST: A United Launch Alliance Delta IB Heavy rocket successfully launched the new U.S. spy satellite NROL-71 into orbit today. Read our wrap story here. Photos | Launch Video!

The United States plans to launch a hush-hush spy satellite Saturday (Jan. 19), and you can watch the liftoff live.

The NROL-71 spacecraft is scheduled to launch atop a United Launch Alliance (ULA) Delta IV Heavy rocket from California's Vandenberg Air Force Base at 2:05 p.m. EST (1905 GMT; 11:05 a.m. local California time). You can watch it live here at Space.com, courtesy of ULA, or directly via the launch provider.

The webcast will be brief; ULA is expected to cut off the live feed after about 6 minutes, to help preserve the secrecy of NROL-71's mission. (The satellite's instruments and activities are classified, as are those of other spacecraft operated by the U.S. National Reconnaissance Office.)

The mobile service tower rolls back from the United Launch Alliance Delta IV Heavy rocket carrying the NROL-71 spacecraft in preparation for launch from Space Launch Complex-6 at Vandenberg Air Force Base, California. The launch is scheduled to take place on Jan. 19, 2019. (Image credit: United Launch Alliance)

Saturday's liftoff is a long time coming. NROL-71 was originally scheduled to take flight in early December, but technical issues and uncooperative weather pushed the launch back multiple times.

Then, ULA nixed a Dec. 19 attempt after noticing a hydrogen leak coming from the Delta IV Heavy. That issue ended up taking several weeks to resolve.

Saturday's liftoff will be the second in five-plus months for the 232-foot-tall (71 meters) Delta IV Heavy, ULA's most powerful rocket. A Delta IV Heavy also lofted NASA's Parker Solar Probe in August 2018.

Mike Wall's book about the search for alien life, "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate) is out now. Follow him on Twitter @michaeldwall. Follow us @Spacedotcom or Facebook. Originally published on Space.com.