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SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

latimes.com

41–50 of 185 posts

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#42

He also announced the 3rd drone ship's name on twitter as "A Shortfall of Gravitas".

Going all in on the Culture ship names. I'd be happy if he just made 100(ish) more just to name them after every ship that Iain M. Banks named. They don't need to catch rockets, they can just link up and make a floating utopia.

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#43
post #17

Perhaps some rocket scientist can explain why this seemingly-obvious error even happened? Shouldn't it be possible to calculate the precise amount of fuel used, and therefore required?

They probably used a simple model (and experience) to determine the needed amount. But the model was wrong because, well, it encountered the real world. So they'll adjust in the future. Probably they could have analyzed the heck out of it for years, and gotten it right, but then that would take years and cost buckets.

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#44

He also announced the 3rd drone ship's name on twitter as "A Shortfall of Gravitas".

That's a great name to add to the stable of Autonomous Spaceport Drone Ships:

- Of Course I Still Love You

- Just Read the Instructions

- A Shortfall of Gravitas

(and doubly great for you, u/ZeroGravitas)

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#45
post #17

Perhaps some rocket scientist can explain why this seemingly-obvious error even happened? Shouldn't it be possible to calculate the precise amount of fuel used, and therefore required?

It's traveling at hypersonic velocities when it's first relit. It's also far too large to fit in any wind tunnel to test that situation.

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#46
post #13

I like hearing that the problem is something as (relatively) trivial to solve as this. I know carrying more fuel with the rocket isn't exactly an easy thing to do, but far easier than finding out there's something fundamentally wrong with the design. SpaceX is amazing and I'm glad they're doing the hard stuff.

It apparently ran out of TEA-TEB ignition fluid, not fuel: https://space.stackexchange.com/questions/15403/why-is-tea-t... I can't find any info on how much TEA-TEB is carried on-board, only that it's ground supplied for initial launch with the on-board TEA-TEB being used only for restarts. (I'm not even an amateur rocket scientist: I just googled all this.)

If I'm not mistaken, the SR-71 and A12 had enough TEB for 15 restarts. After doing an aerial refueling, they had to use TEB to get back to afterburner.

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#47

> Those two boosters, which were used in previous launches of SpaceX's workhorse Falcon 9 rocket, will not be reused again, Musk said in a post-launch news conference last week. Why did SpaceX spend resources to get them to safe landing then? I presume, they rather maintain their routine and maintain the success of landing the booster. It would probably be expensive to change their standard procedure. Does any know h…

Demonstrating that the system can work as intended is the point of the test, and that includes recovery. The boosters in particular have different aero. Even though these won't be reused, they serve to demonstrate that future vehicles can be.

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#48
This is one of the reasons why space travel will never be 'routine'.

A million and one things can go wrong, and any one of them can destroy the spacecraft. Compare that to commercial air travel - where a number of unlikely events have to happen, to down an airplane.

Some time ago, there was a HN discussion about traveling from continent to continent in minutes, using a sub-orbital hop. I don't know about anyone else, but I'll pass on being strapped to a skyscraper filled with LOX and RP-1.

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#49
post #40

I 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)."

It says right there in the article that it used up the fuel while attempting to re-lights the engines (without success).

Sure, but that system was in place for all the Falcon 9 relights as well. Presumably there's something different about the FH - minor architectural differences, flight profile, etc. - that caused this previously reliable system to run out.

Re: SpaceX's Falcon Heavy center booster lacked ignition fluid to re-light engines

#50
post #20

Has anyone seen any updates on how their fairing recovery attempt went? They had the ship done and seemingly ready back in December - https://imgur.com/gallery/MQcEE

Isn't the fairing just a simple pair of metal casings. Why bother to recover it?

I think they cost on the order of magnitude of $1M each.

As I've heard it been put - "Imagine if there was a pallet of $1M in cash falling from the sky. And you knew where and when it would fall. And you'd expect the rate of 'cashfall' to increase to tens, even hundreds of times a year. Would you try to develop a system to catch it?"

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