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Reliability is not based on a system that cannot fail. It is based on a system that can survive failure.
The canonical paper on handling software failures: https://erlang.org/download/armstrong_thesis_2003.pdf
Algorithms can be faulty as well.
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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-…
> Another interesting thing SpaceX is doing is to use consumer-grade chips in triple redundancy configurations instead of using $100,000+ radiation-hardened aerospace/defense grade chips. 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 amaz…
The Fukushima and Deepwater Horizon disasters show that this knowledge has not penetrated other industries.
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Edited: Was asking what were all these deleted comments. Got my answer: it's a theory that SpaceX is a partner for the US DoD and is not just an internet provider.
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I'm just so happy to see this level of progress. This another big step for opening up space. To think that one day this will be considered normal. 150 Metric tons sent on a fully reusable rocket. Thats like a 747 to space.
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?
One of the design goals of Starship is for the booster and ship to relaunch with zero refurbishment. To literally land over the launchpad, refuel, and go back to orbit within hours without people even approaching them. The heat shield is the biggest risk to that goal IMO, and we saw today that it definitely sustained serious damage despite improvements. But if they ever get there then per-launch costs will be a tiny fraction of the Shuttle with 6x the payload.
SpaceX is really incredible in how regular the improvements are coming. Something in their structure is well balanced.
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.
I know the control algorithms are the mind-blowing part here but, does anyone have any literature about how the Rocket localized itself with respect to the chopstick arms? It must've been some combination of GPS and Radar pings to the arms? And then the onboard IMU to make sure it hits it straight.
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When Musk first proposed this, I thought he was crazy. It seemed like something a school boy would draw up. Now I think this will become routine and forgettable after a few more successes. Is there a word for that - something out of fiction becoming mundane?
I thought it was plausible given the accuracy of F9 landings, though I still wonder how it will work at scale if one failure destroys the landing site. That could ruin the cost benefits. Where his vision hit a lot of speed bumps is second stage reusability. Starship is a beautiful second stage to throw in the ocean. They’ll probably get it landing but the heat tiles will require a lot of refurbishment between flights…
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I'm completely mind-blown that not only can they do this, but we get 1080p video for almost the whole time. What cameras do they have that can look at something 30 KM up in the air that well?
The thing that impresses me even more is the kinds of cameras they mount on the rocket. How do they shield it from all the heat and debris with a material that's optically clear?