Correct me if I'm wrong:Troubleshooting a redundant circuit in the holdfire circuitry is what scrubbed the first launch attempt.Scrubbing the second launch attempt at T-7.5 seconds would have required the use of the holdfire circuitry?
Someone suggested around the time of the Parker Solar Probe scrub, that this vehicle gets a lot of scrubs because it just doesn’t fly very often?
Quote from: yokem55 on 12/09/2018 03:35 amHas Delta (any variant) had an ignition time abort before?Apparently not:
Has Delta (any variant) had an ignition time abort before?
To confirm, we did have engine start on the DIVH. Abort was triggered almost right at that time. MECO was confirmed by ULA engineers several (several) seconds thereafter. The "fire" was the start of the nominal burn off of the ambient LH2 the surrounds the DIVH.
Quote from: ChrisGebhardt on 12/09/2018 03:22 amTo confirm, we did have engine start on the DIVH. Abort was triggered almost right at that time. MECO was confirmed by ULA engineers several (several) seconds thereafter. The "fire" was the start of the nominal burn off of the ambient LH2 the surrounds the DIVH.The abort happened before engine start.
Quote from: Newton_V on 12/10/2018 01:01 amQuote from: ChrisGebhardt on 12/09/2018 03:22 amTo confirm, we did have engine start on the DIVH. Abort was triggered almost right at that time. MECO was confirmed by ULA engineers several (several) seconds thereafter. The "fire" was the start of the nominal burn off of the ambient LH2 the surrounds the DIVH.The abort happened before engine start.Then I'm confused. If the engines didn't start, why did they confirm MECO?
Quote from: Lee Jay on 12/10/2018 02:55 amQuote from: Newton_V on 12/10/2018 01:01 amQuote from: ChrisGebhardt on 12/09/2018 03:22 amTo confirm, we did have engine start on the DIVH. Abort was triggered almost right at that time. MECO was confirmed by ULA engineers several (several) seconds thereafter. The "fire" was the start of the nominal burn off of the ambient LH2 the surrounds the DIVH.The abort happened before engine start.Then I'm confused. If the engines didn't start, why did they confirm MECO?It’s the dark secret of rocket launch broadcasts... most of the time they read off a script. :-) All providers do this more or less.
Quote from: Lars-J on 12/10/2018 03:26 amQuote from: Lee Jay on 12/10/2018 02:55 amQuote from: Newton_V on 12/10/2018 01:01 amQuote from: ChrisGebhardt on 12/09/2018 03:22 amTo confirm, we did have engine start on the DIVH. Abort was triggered almost right at that time. MECO was confirmed by ULA engineers several (several) seconds thereafter. The "fire" was the start of the nominal burn off of the ambient LH2 the surrounds the DIVH.The abort happened before engine start.Then I'm confused. If the engines didn't start, why did they confirm MECO?It’s the dark secret of rocket launch broadcasts... most of the time they read off a script. :-) All providers do this more or less.Yeah...but it sounded like it came from the loop, not the announcer, and it was quite a bit after the event. Also, the announcer wouldn't have MECO in the script until many minutes later and even then, only if there were a launch.
So did the TCSR command the abort or was it manually initiated following some telemetry observation?