Earlier quoted context omitted.
Probably not as expensive as losing the entire booster, though.
Expensive as in, if you apply it to everything, the booster doesn't work.
True.
SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines
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Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines
#182I bet it didn't randomly lack fluid due to some stupid miscalculation. It's probably more like: "Due to unforeseen circumstances it needed more fluid than expected. But we adjust our numbers and next time we expect more (in the hopes that it will be enough, which it will probably be)."
From what I understand, the problem was because the second burn was when the rocket was going tail-first through the atmosphere at hypersonic speed, and much faster than a Falcon 9 booster.
That's a problem because the amount of igniter fluid depends on the air pressure in the rocket chamber, and it was not possible to determine this exactly beforehand through either testing or modeling. So they took a guess and it turned out wrong, but they got lots of data on the rocket chamber pressures, and will adjust accordingly in the future.
Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines
#183Earlier quoted context omitted.
They intentionally aim off-target, and have the final engine burn steer them back into the landing. If an engine relight doesn't happen, they won't hit the barge. I think the biggest danger to the barge is a final engine relight without enough fuel, or with a guidance and nav systems failure or error.
-OT, but related - for the same reason, offshore vessels set their autopilot targets say, half a mile off the oil rig/whatever they are headed for - just in case someone doesn't pay attention as they approach. I once saw a nice enamelled sign on a bridge stating 'Whoever programs a target on target will be promoted to figurehead prior to arrival at said target.' (And, in that position, being the first to regret their…
Super interesting. Something I wouldn't have ever thought about, but makes perfect sense.
The world is just frighteningly complex, sometimes.
Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines
#184What is ignition fluid, exactly?
Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines
#185Earlier quoted context omitted.
It doesn't have as much nasty as Shuttle. The TEA-TEB takes care of itself by combusting when vented, but that's the only hazardous material. Shuttle had hypergolics on board which F9 doesn't use (just kerosene, oxygen, nitrogen, and helium.) The rest of the passivation will mostly be purging the engines, closing valves, and releasing pressure in the various tanks and vessels. LOX venting might take a while as it all…
Man, TEA-TEB is a hypergolic pair
No, it is not. It's a pyrophoric mixture. It is hypergolic with oxygen.