All Questions
4
questions
4
votes
1
answer
213
views
Why did Apollo missions open the propulsive Hydrogen vents during the coast phase?
According to Figure 2-1 of the SA-503 flight manual the LH2 continuous vent was opened during the coast phase, and closed during the ullage stage of the S-IVB restart T_6 + 0:00:42.0 (but open for ...
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3
votes
2
answers
547
views
Ullage control with single engine stage?
How does a single-engine upper stage, like that of Falcon 9, do ullage control before starting the engine? Does it fire its cold gas thrusters? Does it fire the engine at minimum throttle for a second ...
user39728
0
votes
1
answer
65
views
Ullage control on stage shutdown?
Is ullage control a thing only engine startup? Would a rocket like the Saturn V or Falcon 9 leave an engine running for a second or two longer just for ullage control?
user39728
9
votes
2
answers
604
views
Why did the ullage motors for the S-IVB TLI burn shut down prior to S-IVB ignition?
I found "Technical Information Summary AS-501: Apollo Saturn V Flight Vehicle" when looking for info about the Saturn V staging sequence. It contains a nice diagram on pages 14-16 showing the various ...
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