Wednesday, June 7, 2023

ULA Successfully Completes the Flight Readiness Firing

This afternoon, I saw a notice that United Launch Alliance (ULA) was planning their Flight Readiness Firing of the engines on the first Vulcan booster this afternoon with a live stream starting at 6PM local, from SLC-41 at Cape Canaveral Space Force Station.  I thought that was a great thing to post tonight and kept a browser tab open as the afternoon thunderstorms went through the area.

Well, a 6 PM firing never happened.  It read T minus 7 minutes and holding no matter when I looked until finally at about 8:40 PM, they announced the FRF would be at 9:05 ET, 0105 UTC.  Finally, after waiting five hours, the engines were fired for around 6 seconds.  This screen capture is moments before shutdown.  The two streams spraying into the engines at about 3/4 of way up on right side are not water streams.  They were streams of sparks apparently used to ignite the main engines and stayed on until several seconds after the engines were shut down.

While no official statement was made, it appears to have been a completely successful test and the BE-4 engines performed as intended.  The problem that caused the delay the first time appears to have been completely resolved.


  1. I am actually surprised. Good for them. Still waiting for BE4s to fly, and do so successfully.

  2. Bruno tweeted that the test was successful shortly after the static test fire per the NSF guys.