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After a 24-second test of its engines, the New Glenn rocket is ready to fly

arstechnica.com

81–90 of 148 posts

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#81
post #51
post #50

Earlier quoted context omitted.

Ok, so your argument for Starship not being the best choice for all mission profiles is based solely on cost. If Starship was cheaper, then you'd agree that it serves the mission profiles? An estimate of 2 billion per launch is laughable, and suggests you are not arguing in good faith. 100m is more accurate for a fully disposable launch, and SpaceX has demonstrated great progress on reusability of the booster, which…

2 billion at the high end isn’t actually unreasonable when compared to falcon 9’s costs which are sitting around 100m/launch right now largely due to inflation. There’s a have a fairly linear relationship between rocket payload and size, and for large structures going big tends to increase cost per pound so ~10x the size resulting in ~20x the cost is just mildly pessimistic. If and only if they the thing is both rapi…

> when compared to falcon 9’s costs which are sitting around 100m/launch right now largely due to inflation.

SpaceX's financial situation argues very differently. They have raised relatively little money for a company that is spending multiple billions on two very expensive development programs (Starship and Starlink).

If Falcon cost $100M per launch the 134 launches this year would have bankrupted the company. The $1.7B they raised in spring 2022 was their last major capital injection, and have been self funded since.

If Falcon cost substantially more than $20M to launch SpaceX would need to be getting external money from somewhere. They aren't. Their revenue is well understood and is around $10B per year, and salary costs fot 13,000 people are going to consume most of that. What NASA and the Space Force pay is public knowledge, what they charge for a private launch is known, and the number of Starlink subscribers has been revealed.

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#82
post #80
post #74

Earlier quoted context omitted.

That doesn’t justify why it’s ridiculous, it’s just a coincidence. I doubt SpaceX’s internal costs are ~100m/falcon 9 launch, but companies need a markup to be profitable. 100m - 2B is a huge range covering everything from giving up on reusability and paying back R&D over a small number of flights to significant success resulting in a 90% reduction in costs per kg to LEO. Also, having spent 5B on R&D and doing 5 test…

It's ridiculous because the much ridiculed SLS has a launch cost of 2 billion dollars. If you think SpaceX is throwing billions of dollars into developing a vehicle that costs thisuch to launch, you clearly haven't been following SpaceX at all. You know there is going to be more that 5 flights, and you know people in this thread are not amortizing total R&D into flight costs. People are talking about 68 million per f…

> You know there is going to be more than 5 flights

No, I don’t actually know the future. I can make predictions, but we could have a thermonuclear war tomorrow etc.

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#83
post #27

Earlier quoted context omitted.

I would imagine far less. The LHC captures many channels of sensors (for spatial resolution) and captures at very high frequency (because the time scales involved are fast and also because LHC is doing time-of-flight measurements). I doubt that a rocket has anywhere near as many sensors (have you seen pictures of the LHC’s instruments? They’re basically all sensor), and I also expect that the timescales involved in r…

Combustion in the chamber happens at roughly the speed of sound in the F/O mixture. I don't know what the speed of sound in gCH4 is, but it's probably within an order of magnitude of air - air at 250 bar. This is actually extremely important to model. Early F1 engines (Saturn V, not motorsport) were exploding and the engineers pretty much got lucky with the baffle design. Having a suite of sensors and then a computer…

Still way slower than what particle physics throws at you

(Wolphram Alpha gives me 743 m/s @ 250 bar and 1000C - could be wrong but probably the same OoM)

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#84

Earlier quoted context omitted.

It does if it's still cheaper than any other rocket.

I don't see how that makes any sense. Starship is 100t dry; simply the fuel costs of a launch will necessarily be higher than disposable alternatives.

Fuel is cheap: it's $900,000 per Starship launch, according to Musk [0]. No disposable rocket comes within even a factor-of-10 of that.

[0] https://techcrunch.com/2019/11/06/elon-musk-says-spacexs-sta...

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#85
post #8

How much data do you guys reckon they gather during this 24-second window? Gigabytes? Terabytes? I imagine they have redundant sensors for every measurement, if possible. The LHC generates 1 PB/s, though it filters it down to roughly 200MB/s[0]. I wonder how this compares. 0: https://www.lhc-closer.es/taking_a_closer_look_at_lhc/0.lhc_...

Probably gigabytes. When I worked with other systems in the past we needed to upgrade our gigabit ethernet to handle the full-rate telemetry

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#86
post #8

How much data do you guys reckon they gather during this 24-second window? Gigabytes? Terabytes? I imagine they have redundant sensors for every measurement, if possible. The LHC generates 1 PB/s, though it filters it down to roughly 200MB/s[0]. I wonder how this compares. 0: https://www.lhc-closer.es/taking_a_closer_look_at_lhc/0.lhc_...

Not much, really. Most sensors are low speed: tens to hundreds of Hz. Then you have some high speed sensors, like strain gages, that are up in the 30+ kHz range.

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#87
post #17

Earlier quoted context omitted.

Is Starship really not following the exact step of N-1 && VentureStar?

Computers and materials came a long way since the N1, as Starship’s successful tests can attest to.

But they're still losing roughly as many engines as Russians did in N1, so that sounds like a dubious claim.

What about the latter? Are they really not tracing the footsteps of the X-33 program?

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#88

Earlier quoted context omitted.

Starship is heavy lift / heavy expense. If you want to put 1 small-sat in orbit, you don't use Starship, you use a Rocket Lab Electron. It's MUCH cheaper. Or you wait until you find 600 other small sat users who want to launch into the same / similar orbit. The talk I heard was that New Glenn was supposed to be BO's answer to Starship (or more likely Falcon Heavy) that could launch a bunch of Project Kuiper satellite…

>If we are to believe the published numbers, New Glenn can lift 50 imperial tons to LEO Well 45 tons, but this is in a reusable configuration. >Starship Block III will hoist 200 tons This is definitely not a reusable configuration. Maybe 150 tons if they are lucky. >Falcon Heavy will lift 50-60 depending on how re-usable you want your launch to be. 60 tons for Falcon Heavy means zero reuse, that is a fully expendable…

https://news.ycombinator.com/item?id=9792046>

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#89
post #51

Earlier quoted context omitted.

2 billion at the high end isn’t actually unreasonable when compared to falcon 9’s costs which are sitting around 100m/launch right now largely due to inflation. There’s a have a fairly linear relationship between rocket payload and size, and for large structures going big tends to increase cost per pound so ~10x the size resulting in ~20x the cost is just mildly pessimistic. If and only if they the thing is both rapi…

> when compared to falcon 9’s costs which are sitting around 100m/launch right now largely due to inflation. SpaceX's financial situation argues very differently. They have raised relatively little money for a company that is spending multiple billions on two very expensive development programs (Starship and Starlink). If Falcon cost $100M per launch the 134 launches this year would have bankrupted the company. The $…

[deleted]

Re: After a 24-second test of its engines, the New Glenn rocket is ready to fly

#90

Earlier quoted context omitted.

Combustion in the chamber happens at roughly the speed of sound in the F/O mixture. I don't know what the speed of sound in gCH4 is, but it's probably within an order of magnitude of air - air at 250 bar. This is actually extremely important to model. Early F1 engines (Saturn V, not motorsport) were exploding and the engineers pretty much got lucky with the baffle design. Having a suite of sensors and then a computer…

Still way slower than what particle physics throws at you (Wolphram Alpha gives me 743 m/s @ 250 bar and 1000C - could be wrong but probably the same OoM)

Yes, of course. I was clarifying, not disputing.
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