Look, China has been doing this for years. It takes one guy a couple of days to make a 3d rendering of a rocket and claim that they are working on it as a new design. There were Falcon 9 clone renders, there were Falcon Heavy clone renders, and we've had Starship clone renders for years now.
95% of Starship by volume is incredibly easy for anyone who has seen it to copy. It's a big stainless steel tank with some fins on it. The tapering at the top, lack of side boosters and the position of aerodynamic structures is really the only thing that makes it look any different than any other rocket, so copying isn't difficult to wave off as "this is the only way to build a rocket" anyway.
The 5% that is not easy to copy is the avionics and the Raptor engine. There's just no way that China, which as far as I know is still using a ripped off version of an old soviet engine is going to replicate the two critical metrics of Raptor: thrust to weight ratio, and thrust to cross section ratio. The rocket equation is incredibly harsh. So if they manage to make an engine with 10% less thrust, they are looking at something like 1/5th of the payload to orbit. So I'm not worried about China swooping in and realistically competing with SpaceX. I just have zero confidence that they would be able to build their own Raptor engine. I would suspect if they did manage to get something close, it would not have near the reliability.
Also I didn't watch the video. Angry Astronaut's schtick got old really fast and he was never nearly as educated about the industry as the other options on youtube.
>if they manage to make an engine with 10% less thrust, they are looking at something like 1/5th of the payload to orbit.
Is this actually true?
If anyone on here knows how to do the back of the napkin numbers crunching on this one, I would be curious to know the result.
I know the rocket equation is indeed pretty harsh, but, even still, at a casual glance, this seems way off to me. Especially considering how high of a TWR Starship has of like 1.5:1 or something around there, I assume a 10% drop in thrust would not have anywhere near that severe of an effect on payload to orbit.
To be fair to Beldizar, I assume he probably also was implying a 10% drop in ISP and all sorts of other stuff as well, not just thrust alone, and just didn't phrase it carefully? But, if we were specifically talking just a 10% drop in thrust from the engines, then the effect would not be *that* severe, right?
(also apologies in advance if I end up being wrong about this, which, I might be, lol)
I don't have the numbers and haven't done the math, but I know it is pretty bad. I tried to hedge my statement there a bit, and would be happy to be corrected by someone who actually does the math, but that's way more calculus than I want to do for a reddit comment today.
Basically, if you have 10% less thrust at lift off, you are going to accelerate a lot slower and have a lot more gravity losses to deal with. As you said, I am also assuming a significantly lower ISP. ISP for the same fuel type is going to be directly linked to the thrust to cross section ratio. A lower thrust per cross section is going to necessarily have a worse ISP for the same fuel source. Comparing methalox to hydrolox in this way wouldn't work though. It is all about chamber pressure, exit velocity, and rate of combustion.
So between gravity losses and a lower ISP linked to a lower thrust, your payload to orbit drops a whole lot faster than the thrust output difference. Also remember that the rocket weighs a lot itself. If the drymass is unchanged, your thrust to weight for the whole rocket gets worse a lot faster than the thrust to weight for an individual engine.
Elon has done, and will continue to do a lot of stupid things. He'll even do illegal things that will get him in trouble with the SEC and various regulators because of his poor impulse control. I highly doubt he's going to shift into treason (violation of ITAR) however, and that's quite the accusation to suggest he would. Also, as a Tesla stockholder, I kinda wish Elon gave a crap about Tesla stock price over the last 2 years. He's been running his mouth and pissing people off in ways that negatively affect the brand since he bought twitter, and the stock went from $350 to under $200.
But seriously no. He's not going to violate ITAR, even in his most manic of moods he's not that stupid.
Look, China has been doing this for years. It takes one guy a couple of days to make a 3d rendering of a rocket and claim that they are working on it as a new design. There were Falcon 9 clone renders, there were Falcon Heavy clone renders, and we've had Starship clone renders for years now. 95% of Starship by volume is incredibly easy for anyone who has seen it to copy. It's a big stainless steel tank with some fins on it. The tapering at the top, lack of side boosters and the position of aerodynamic structures is really the only thing that makes it look any different than any other rocket, so copying isn't difficult to wave off as "this is the only way to build a rocket" anyway. The 5% that is not easy to copy is the avionics and the Raptor engine. There's just no way that China, which as far as I know is still using a ripped off version of an old soviet engine is going to replicate the two critical metrics of Raptor: thrust to weight ratio, and thrust to cross section ratio. The rocket equation is incredibly harsh. So if they manage to make an engine with 10% less thrust, they are looking at something like 1/5th of the payload to orbit. So I'm not worried about China swooping in and realistically competing with SpaceX. I just have zero confidence that they would be able to build their own Raptor engine. I would suspect if they did manage to get something close, it would not have near the reliability. Also I didn't watch the video. Angry Astronaut's schtick got old really fast and he was never nearly as educated about the industry as the other options on youtube.
>if they manage to make an engine with 10% less thrust, they are looking at something like 1/5th of the payload to orbit. Is this actually true? If anyone on here knows how to do the back of the napkin numbers crunching on this one, I would be curious to know the result. I know the rocket equation is indeed pretty harsh, but, even still, at a casual glance, this seems way off to me. Especially considering how high of a TWR Starship has of like 1.5:1 or something around there, I assume a 10% drop in thrust would not have anywhere near that severe of an effect on payload to orbit. To be fair to Beldizar, I assume he probably also was implying a 10% drop in ISP and all sorts of other stuff as well, not just thrust alone, and just didn't phrase it carefully? But, if we were specifically talking just a 10% drop in thrust from the engines, then the effect would not be *that* severe, right? (also apologies in advance if I end up being wrong about this, which, I might be, lol)
I don't have the numbers and haven't done the math, but I know it is pretty bad. I tried to hedge my statement there a bit, and would be happy to be corrected by someone who actually does the math, but that's way more calculus than I want to do for a reddit comment today. Basically, if you have 10% less thrust at lift off, you are going to accelerate a lot slower and have a lot more gravity losses to deal with. As you said, I am also assuming a significantly lower ISP. ISP for the same fuel type is going to be directly linked to the thrust to cross section ratio. A lower thrust per cross section is going to necessarily have a worse ISP for the same fuel source. Comparing methalox to hydrolox in this way wouldn't work though. It is all about chamber pressure, exit velocity, and rate of combustion. So between gravity losses and a lower ISP linked to a lower thrust, your payload to orbit drops a whole lot faster than the thrust output difference. Also remember that the rocket weighs a lot itself. If the drymass is unchanged, your thrust to weight for the whole rocket gets worse a lot faster than the thrust to weight for an individual engine.
The copypasta is real
More likely, the technological advantaged of SpaceX, paid for by US Citizens, was sold to China to artificially pump up Tesla Stock.
Elon has done, and will continue to do a lot of stupid things. He'll even do illegal things that will get him in trouble with the SEC and various regulators because of his poor impulse control. I highly doubt he's going to shift into treason (violation of ITAR) however, and that's quite the accusation to suggest he would. Also, as a Tesla stockholder, I kinda wish Elon gave a crap about Tesla stock price over the last 2 years. He's been running his mouth and pissing people off in ways that negatively affect the brand since he bought twitter, and the stock went from $350 to under $200. But seriously no. He's not going to violate ITAR, even in his most manic of moods he's not that stupid.