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

latimes.com

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

#61

Post by meteor333 »

mikeytown2 wrote: post #54
meteor333 wrote: post #25

> 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…

Titanium grid fins is a big reason they recovered the 2 side boosters. This launch and landing will be used to fine tune their simulation parameters. The block 5 variant is designed for 10 launches in a row with 24hr turnaround. With service, over 100 launches is the goal.

Wow! that's impressive!

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

#62

Post by ceejayoz »

vkou wrote: post #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,…

There were plenty of accidents in the the first couple decades and first couple thousand plane flights. Even in the 1970s, airliner crashes were a fairly regular occurrence - they've been made extremely safe by a robust culture of crew training and safety regulation, plus a hundred thousand flights PER DAY worth of practice.

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

#63

Post by jbonniwell »

meteor333 wrote: post #25

> 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…

During the news conference after the launch, Elon commented on being really happy to get the upgraded titanium grid fins back from the side boosters:

https://youtu.be/F7mw2_pfcz4?t=3554

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

#64

Post by Analemma_ »

ashleyn wrote: 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?

I'm not a rocket scientist, but I think I can explain why this happened in a more general probabilistic sense. This error may have been "obvious", but successfully landing a supersonic rocket onto a floating platform probably requires hundreds or thousands of "obvious" things to go exactly right, and if any one of them doesn't, then it explodes. Even assigning a very small probability to each obvious failure mode, compounded together it gives a non-trivial chance that the landing will fail, especially in the maiden launch when there are still lots of "unknown unknowns". If it hadn't been the igniter fluid, it could just as easily have some other "obvious" thing.

Anyway, that's why they do these tests: to make the "unknown unknowns" known.

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

#65

Post by phpnode »

rwmj wrote: post #20
huhtenberg wrote: post #3

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?

In addition to the several million dollar cost of the fairings they represent a production bottleneck - they're carbon composites which take a long time to make and require very expensive tooling. No matter how many reflyable first (and maybe in future, second) stages spacex has in stock, if they can't produce fairings fast enough they cannot go to space.

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

#67

Post by kylegordon »

rwmj wrote: post #20
huhtenberg wrote: post #3

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?

Aside from the actual costs involved in (lengthy) labour and materials, manufacturing fairings also takes up vast amounts of factory real estate.

The numbers are small compared to the rest of the game, but it's one of those things that would make life so much easier if they could just catch the damned thing.

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

#68

Post by stcredzero »

olympus wrote: post #42
ZeroGravitas wrote: post #18

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.

They don't need to catch rockets, they can just link up and make a floating utopia.

Well for that, you'd want to change the hull type from a barge to a spar buoy. Given that, there's no reason why they couldn't do both.

http://www.technip.com/sites/default/files/technip/illustrat...

(Permanent structures in the ocean need to be spar buoys, or some other architecture that are largely immune to Rogue Waves.)

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

#69

Post by dogma1138 »

toufka wrote: post #50
rwmj wrote: post #20

Earlier quoted context omitted.

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?"

Only if the total operational cost of that system would be lower than the amount of cash falling from the sky.

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

#70

Post by jccooper »

ChuckMcM wrote: post #26

Obviously one of the things you don't want "too much of" is a pyrophoric fluid that you need to dump before you can let people near :-). Have they ever published their safeing procedure? I'm wondering if they recover more volattiles than the old shuttle did after it landed.

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 boils off.

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