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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

#121

Post by sigstoat »

zitterbewegung wrote: post #106
evanlivingston wrote: post #101

I'm someone who doesn't follow a lot about current aerospace capabilities and technologies. Can someone explain why the work SpaceX is doing is so much more exciting than that of United Launch Alliance or Khrunichev or similar systems?

The exciting innovation that SpaceX promises is lower flight costs by making reusable rockets. This is motivated by the desire to land on mars (which factors into their marketing and recruitment). Many people who work there have issues with work life balance and to work there and the pay is lower than other similar aerospace companies. In contrast ULA is higher cost but is more reliable. A great deal of their technol…

> Many people who work there have issues with work life balance and to work there and the pay is lower than other similar aerospace companies.

which is really saying something, as a lot of aerospace employers prey on the cool factor of doing space stuff to keep folks working absurd hours, for well under what they'd make doing similarly difficult work elsewhere.

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

#122

Post by paragraft »

fma wrote: post #96
delecti wrote: post #81

Earlier quoted context omitted.

One big flaw in your argument is that the payload was delivered safely and successfully. They're making great strides towards making components reusable when they never really were before. That they're not perfect right out of the gate isn't reason to give up hope it ever could be.

Actually...the payload was put on the wrong trajectory, so OP's argument still stands. "Elon Musk’s cherry red Tesla sports car and its dummy test pilot Starman were on a new course hurtling towards the asteroid belt on Wednesday after overshooting their planned trajectory." https://www.theguardian.com/science/2018/feb/07/elon-musk-sp...

Guardian is wrong to use "overshoot" as though it was a mistake - it was a burn to exhaustion, the exact limits of which was unknown beforehand (because it was unknown how well the fuel in the second stage would survive the time in higher orbit. Kerosene starts turning to sludge in cryo). Mars-orbit-distance was the lower end of what was expected.

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

#123

Post by nickparker »

StavrosK wrote: post #98
toufka wrote: post #44

Earlier quoted context omitted.

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)

Here's the whole list: https://en.wikipedia.org/wiki/List_of_spacecraft_in_the_Cult... My all-time favorite is "Ultimate Ship the Second".

Minor spoilers, don't read below if you care:

I'm biased by my love for 'The Hydrogen Sonata,' but my favorite will always go to the Mistake Not...

Which is short for Mistake Not My Current State Of Joshing Gentle Peevishness For The Awesome And Terrible Majesty Of The Towering Seas Of Ire That Are Themselves The Mere Milquetoast Shallows Fringing My Vast Oceans Of Wrath.

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

#124

Post by jessriedel »

ReverseCold wrote: post #119
ggchappell wrote: post #85

> about 328 feet from the floating platform Someone doesn't understand precision. (That's 100 meters, so "about 300 feet".)

I think it's not exactly 328 feet, so it's about 328 feet.

Equally well could have said "about 328.084 feet".

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

#125

Post by KiwiJohnno »

fma wrote: post #96
delecti wrote: post #81

Earlier quoted context omitted.

One big flaw in your argument is that the payload was delivered safely and successfully. They're making great strides towards making components reusable when they never really were before. That they're not perfect right out of the gate isn't reason to give up hope it ever could be.

Actually...the payload was put on the wrong trajectory, so OP's argument still stands. "Elon Musk’s cherry red Tesla sports car and its dummy test pilot Starman were on a new course hurtling towards the asteroid belt on Wednesday after overshooting their planned trajectory." https://www.theguardian.com/science/2018/feb/07/elon-musk-sp...

That is bad reporting. SpaceX always planned to burn the 2nd stage until it ran out of fuel.

Elon always said they weren't sure exactly what the final trajectory was, just that the roadster would be sent out as far as possible.

They weren't sure how much O2 would boil off during the 6-hour coast after launch before it departed orbit. That was part of the test.

Also, they weren't heading towards mars - just outwards towards mars orbit. When the roadster crosses mars orbit mars itself will not be nearby. If they wanted to actually reach mars they would have had to launch during a specific launch window when earth and mars lined up at the correct angle. This happens once every couple of years.

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

#126

Post by jdietrich »

evanlivingston wrote: post #101

I'm someone who doesn't follow a lot about current aerospace capabilities and technologies. Can someone explain why the work SpaceX is doing is so much more exciting than that of United Launch Alliance or Khrunichev or similar systems?

SpaceX can reliably deliver payloads to orbit at far lower cost than their competition; as they start to re-use vehicles in earnest, that cost will fall even further. Falcon Heavy is now the most powerful rocket in commercial service by a factor of two. Two years ago they were a highly promising competitor; today, they're the market leader.

Khrunichev are out of the game. The old Proton vehicles are cheap, but they're very unreliable due to a barely-modernised 1960s design and poor construction. They flew four launches in 2017, versus SpaceX's eighteen; by all accounts their order book is looking very sparse indeed. Their new Angara vehicle hasn't flown since the first orbital test flight in 2014 and has attracted no real commercial interest.

ULA can't even begin to compete on cost. Without the capability and readiness contract from the US government, they'd be out of the game entirely. They didn't even bother to bid for the GPS-III contract. The SLS won't be ready until next year, it'll only have about 10% more payload capacity to LEO than Falcon Heavy and it'll cost at least three times as much, with no possibility of reuse.

EADS are attracting a good amount of commercial launches, but their competitive advantage is fading rapidly. Ariane 5 is reportedly 3-4x more expensive than Falcon 9 and has less payload capacity to LEO. The planned Ariane 6 will be considerably cheaper than Ariane 5, but it'll have less payload capacity and still won't be price-competitive with Falcon 9. EADS have not announced plans for a heavy launch vehicle.

Blue Origin are chasing SpaceX's tail. The New Glenn vehicle won't begin test flights until 2020, it has less payload capacity than Falcon Heavy, shows no signs of being cheaper and isn't as reusable. Even if everything goes to plan, they'll still be badly trailing behind SpaceX.

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

#127

Post by justin66 »

Zardoz84 wrote: post #109
justin66 wrote: post #103

Earlier quoted context omitted.

SpaceX is still the only company to land a real first-stage booster, and the Falcon Heavy was the largest rocket (in terms of payload capacity) to fly since the Saturn V.

false! The energia and the N-1 flow before and they was more powerful that the Falcon Heavy.

From the N-1's wikipedia page:

Each of the four attempts to launch an N1 failed; during the second launch attempt the N1 rocket crashed back onto its launch pad shortly after liftoff and exploded, resulting in one of the largest artificial non-nuclear explosions in human history.

Energia's a more interesting comparison, since it's hard to know if its advertised payload was at all accurate, but it did fly. I'd say that if it could have delivered its advertised payload reliably, the design probably would have flown more than twice and would have survived the fall of the Soviet Union. I have no idea what a half-finished Buran weighs...

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

#128

Post by outworlder »

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,…

A million and one things can happen to airplanes as well. We have learned about them, sometimes at the cost of lives. This is how we arrived at the current level of redundancy and maturity in safety procedures. Not to mention regulation and enforcement.

The energies involved are much greater, that's for sure. This will require more engineering effort.

But "never" is too strong a word. There is no good reason why we can't master this.

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

#129

Post by vkou »

mulmen wrote: post #91
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,…

An airliner is on a building scale and carries a slightly less refined petroleum fuel. RP-1 and Jet Fuel are both refined petroleum fuels. Rockets only carry LOX because they go into space where there is no atmospheric oxygen to burn the fuel. Airliners are fully capable of turning themselves into fireballs. It doesn't happen often because we have a lot of experience operating them. The same safety levels are possibl…

> An airliner is on a building scale and carries a slightly less refined petroleum fuel. RP-1 and Jet Fuel are both refined petroleum fuels. Rockets only carry LOX because they go into space where there is no atmospheric oxygen to burn the fuel.

That's true, but a 747 does not burn its weight in fuel in 397 seconds. A Falcon 9 does. It's the difference between igniting a gas barbecue in your back yard, and igniting the propane tank that feeds it. One of those things is something I do on the 4th of July. For the other, I'd prefer to be taking cover in a foxhole.

> Airliners are fully capable of turning themselves into fireballs. It doesn't happen often because we have a lot of experience operating them. The same safety levels are possible with rockets over time.

It's also because the possible margins for safety with airplanes are much higher. You can engineer redundant systems, and overbuild, because you aren't fighting the tyrrany of the rocket equation.

There is no one thing that can go wrong on a 747 that will down the aircraft. The dozen SpaceX launch/landing failures were almost all due to 'one thing went wrong, there went $60-100m USD.'

Incidentally, most other catastrophic launch failures (Including ones that claimed lives) were also due to 'one particular thing went wrong, everyone died.'

Rocket engineers aren't stupid, there's a reason that rockets don't have the amount of rendunancy and capability for failure recovery that a commercial airliner does.

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

#130

Post by jacquesm »

JshWright wrote: post #86
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?

It's not "fuel" in this case, it's the highly reactive compounds that are used to ignite the engines (TEA/TEB are pyrophoric, so they ignite spontaneously when exposed to air). The precise amount they'll need depends on how quickly and reliably the engines restart. If the engines take a couple extra shots to light, then you may run out.

In this case they ran out because they were relighting three times as many engines.
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