How to watch ULA's 2nd-ever Vulcan Centaur rocket launch on Oct. 4

United Launch Alliance (ULA) is set to launch the second test flight of its Vulcan Centaur rocket on Friday morning (Oct. 4), and you can watch the action live online.

Vulcan Centaur's second mission, a test flight called Cert-2 , is scheduled to lift off from Space Launch Complex-41 (SLC-41) at Florida's Cape Canaveral Space Force Station during a three-hour window that opens at 6 a.m. EDT (1000 GMT). You can watch the launch live here at Space.com, courtesy of ULA, or directly via the company .

Cert-2 is the second flight of Vulcan Centaur after January's Cert-1, which sent Astrobotic’s Peregrine moon lander to Earth orbit. Cert-2 is a demonstration mission required to certify the rocket for future use by the U.S. Space Force .

Vulcan Centaur was rolled out to SLC-41 on Monday (Sept. 30). The rocket had a successful “wet dress rehearsal” on Tuesday (Oct. 1), during which the company completed a fueling test and practice countdown.

ULA aims to launch two Space Force missions, called USSF-106 and USSF-87, with Vulcan Centaur by the end of the year. A successful Cert-2 launch will be a big step toward that goal, though post-flight data reviews are required to formally certify the rocket.

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The Cert-2 test flight will carry an inert "mass simulator" and instrumentation that will allow ULA to assess the rocket’s upper stage. The mission was originally supposed to fly Sierra Space's robotic Dream Chaser space plane, but the spacecraft wasn’t ready in time for launch.

ULA will share mission updates on its blog from launch control beginning at 12 midnight EDT (0400 GMT). The launch webcast will start at 5:40 a.m. EDT (0940 UTC). You can also follow the launch activities online here at Space.com — be sure to check back for updates on the mission.