321–330 of 1001 posts
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The FAA needs more funding at this point. They're not staffed for the rate of launch requests which commercial space has grown too.
Need to remove regulations instead and fast track SpaceX. Every fucking time we don't need to increase the size of the Government. It only gets bigger. Never smaller.
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So, reusable is supposed to reduce the cost. But the space shuttle was reusable and it has been shutdown because it was too expensive. What is the differences between the two?
Economy of scale: starship can be "mass"-produced Material: stainless steel is much cheaper Percentage of reusability: boosters of shuttle cannot be reused, maintenance of shuttle itself is also very expensive (heat shields were pricey). whereas the starship stack has higher reuse percentage and allegedly cheaper to maintain.
Nothing could have prepared me for how that catch looked. I was sure the rocket was careening into the tower at the last second before it straightened out. The control algorithms must be incredible for the landing system to work within those small tolerances.
MIMO and nonlinear control theories are probably some of the hardest topics in all of engineering. SpaceX control system also has to compensate for the fuel moving inside their rockets so the control algorithms probably involve some kind of fast numerical fluid simulation. Another interesting thing SpaceX is doing is to use consumer-grade chips in triple redundancy configurations instead of using $100,000+ radiation-…
This has been known in the high availability and safety systems industry for a while and a good book to learn these reliability engineering techniques is "Reliability Evaluation of Engineering Systems".
The book is available on amazon: https://a.co/d/1nH824K
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I always thought the liquid sloshing would be one of the hardest to simulate (considering how chaotic fluid mechanics is). Interestingly, I think this caused the 2nd Falcon launch to fail (the LOX sloshing).
It is difficult, but there are modeling approaches that work, such as VoF ( https://en.wikipedia.org/wiki/Volume_of_fluid_method ). Basically, in addition to velocity, pressure, temperature, etc., you store an additional scalar in each cell of your computational mesh representing the liquid's volume fraction. Then, you solve an additional equation to transport that scalar.
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Improvements that make space flight more sustainable are welcome ... unless that means an order of magnitude more pollution in a less controllable form, like emissions. [Due to more frequent flights] Daily trips to space likely also mean more debris in space and falling to earth. I hope there is a balance that includes the lives of people near these sites and all of us sharing the same atmosphere.
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Regardless of the (in)accuracy of ChatGPT, you're assuming a lot can be accomplished with those flights. I strongly suspect 600K cars getting people where they need to go has far more utility than 1K flights of anything into / out of NEO.
> Debris is an absolutely non-issue.
Astronomers probably don't want 1000x (or even 10x) as many satelites obstructing their view.
> There is zero environmental downside, only Luddite foot stomping.
Name calling isn't going to help your cause. And the luddites had a good point, they didn't mind innovation. They minded being cut out of the benefits of innovation without any say in the matter.
What does Starship reusability mean for $/kg to LEO? I know there are longer term targets of $10/kg but that supposes efficiencies that aren’t here yet. Would be helpful to understand before Starship reusability where the state of the art was in terms of $/kg to LEO and where we would be with impending Starship reusability.
I don't think we have a number for it yet. But it will definitely be the cheapest launch system at the time of launch. People say 200$/kg just with booster reuse, and 20$/kg with full reuse. Of course this might be too optimistic, but I truly believe we might reach under 50$ in this decade.
Heartfelt congratulations to the folks at SpaceX!
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I don't think we have a number for it yet. But it will definitely be the cheapest launch system at the time of launch. People say 200$/kg just with booster reuse, and 20$/kg with full reuse. Of course this might be too optimistic, but I truly believe we might reach under 50$ in this decade.
Even $50 is within "going to the moon for my honeymoon" range. Wow.
There is a lot of possibilities to make a trip to the moon cheaper though. If we make LEO that cheap, we can build a lot of infrastructure in the space that would make the tourism to moon more affordable. Like keeping a few starships always in orbit as some kind of space-hotel-metro system.
This will probably take a few more decades, though.
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Naive question: I obviously expect there to be flames from the engines, but there were flames on the lower sides for quite a while after the catch – is that expected?
It is common for Starship prototypes to have uncontrolled fires, but it is obviously not a good thing. For example, prototype number 10 exploded 8 minutes after landing [1] because of a seemingly insignificant fire at the bottom. After today's flight there was a long lasting fire in the engine section, with occasional flaming pieces of plumbing raining down from the rocket. Examining the aftermath should help SpaceX…