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Starship Prototype Unveiled

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Re: Starship Prototype Unveiled

#51
post #44

Earlier quoted context omitted.

Starship could have Falcon Heavy level of delays (which I think it will) and still beat SLS.

FH was 5 years+ behind schedule before it was built and launched. Starship already has multiple constructions going on, with multiple prototypes to test and multiple full-size vehicles planned quickly. In 2011, FH was supposed to have "arrival at launch site" by 2H 2012. It first launched in 2018 (after arriving at launch site in 2018 not 2012). The same level of delay would mean the first Starship does not reach orb…

FH is "just" 3 F9 strapped together. Doing that took them more than 5 years than planned.

Keeping that in mind, having 5 year delay on brand new design, using totally different materials, new engine, etc isn't far fetched.

Re: Starship Prototype Unveiled

#52
post #38

Earlier quoted context omitted.

Starship could have Falcon Heavy level of delays (which I think it will) and still beat SLS.

Not entirely sure about that. Have no skin in the game but from what I can tell Starship is just a bigger version of the Falcon 9 second stage. FH on the other hand required a lot of engineering investment to figure out how to bolt three F9s together and how to make the software work between all three. I'm certain it will be a long time until it can get to Mars, but LEO within the next 2-3 years is probably realistic…

> Starship is just a bigger version of the Falcon 9 second stage

Starship is designed to land from interplanetary speeds (not just LEO orbital speeds), can re-fuel in orbit, and has the world'd most advanced rocket engines. The jump from F9 -> Starship is substantially larger than the jump from F9 -> FH.

edit: spelling

Re: Starship Prototype Unveiled

#53
post #49
post #44

Earlier quoted context omitted.

FH was 5 years+ behind schedule before it was built and launched. Starship already has multiple constructions going on, with multiple prototypes to test and multiple full-size vehicles planned quickly. In 2011, FH was supposed to have "arrival at launch site" by 2H 2012. It first launched in 2018 (after arriving at launch site in 2018 not 2012). The same level of delay would mean the first Starship does not reach orb…

Minor: Boeing is BA, if that was the reference

BO = Blue Origin

Re: Starship Prototype Unveiled

#54

380s for ISP for the Raptor vacuum engine seems durn good, considering the tradeoffs between hydrogen and methane. The most efficient engines we've flown, the RL-10 [0] (used on the Delta IV and Atlas rockets as part of the Centaur Upper Stage) and the RS-25 [1], (the Space Shuttle Main Engine) get around 450-460s for their specific impulse. These engines use liquid hydrogen and liquid oxygen. The issue with liquid h…

> The issue with liquid hydrogen is twofold: it is not very dense, and to keep it from boiling away in liquid form, it needs to be really cold

It’s also a bitch to work with. When it’s not trying to immolate or suffocate you it’s busy turning every metal part it touches to garbage [1].

[1] https://en.m.wikipedia.org/wiki/Hydrogen_embrittlement

Re: Starship Prototype Unveiled

#55
post #44

Earlier quoted context omitted.

FH was 5 years+ behind schedule before it was built and launched. Starship already has multiple constructions going on, with multiple prototypes to test and multiple full-size vehicles planned quickly. In 2011, FH was supposed to have "arrival at launch site" by 2H 2012. It first launched in 2018 (after arriving at launch site in 2018 not 2012). The same level of delay would mean the first Starship does not reach orb…

FH is "just" 3 F9 strapped together. Doing that took them more than 5 years than planned. Keeping that in mind, having 5 year delay on brand new design, using totally different materials, new engine, etc isn't far fetched.

There is a quote somewhere (by Elon?) saying that FH is not "just" 3 F9s strapped together. A significant source of the slowdown for FH was the desire to not launch it without full reusability of all 3 stages and not to launch it without significant improvements (block 5 etc).

Starship has none of those potential delays and has already solved most of the hard problems (as evidenced by the Hopper hopping already). Starship has all of the learnings and experience that FH and F9 didn't have.

There will be delays, sure. But we won't be waiting 5+ years again for a single launch. Those days are over, and SpaceX is proving it.

Some context, I haven't read this yet: https://www.quora.com/What-makes-SpaceXs-Falcon-Heavy-more-t...

Edit:

> Keeping that in mind, having 5 year delay on brand new design, using totally different materials, new engine, etc isn't far fetched.

The first full size Starship prototype is already built though (within ~2 years of initial announcement? Not behind schedule basically at all, so far?). IIRC for FH it was a ~5 year delay before SpaceX even starting construction on the first parts. The difference with Starship is staggering. The pace is dramatically faster, the risks are reduced up-front, and the tests are planned on a much shorter timeframe.

We would frequently go 6 months to a year and hear no news at all about FH. There is news, updates and progress available to the public on an hourly or daily basis about the Starship progress. Night and day.

Re: Starship Prototype Unveiled

#58

That was a very dense an informative presentation last night, but I think the main take away is that rapid reusability is a game changer. In fact, game-changer is probably an understatement, basically every intuition and rule-of-thumb we have about space launches and travel will have to be rethought. And this will be true even of SpaceX falls well short of meeting their stated targets (2020 orbit, 150t capability, mu…

I'm a huge fan of spacex, but Elon is, as always, "optimistic".

> Musk stated (I think he just did some mental napkin math at one point) that if they meet their goals, the world's launch capacity will be expanded by two orders of magnitude. How often does any new development in any field bring about two orders of extra capacity? How does this incredible capacity change how you use this thing?

With napkin math is't easy. Adding one zero here, one zero there, and you can easily show that you're increasing world's capacity by two orders of magnitude. Elon is known for big over-simplification in his vision statements.

> A launch would cost fuel + support operations + amortized cost of rocket. The last two will tend towards zero as they can be increasingly automated and will be a small fixed cost.

That's just day-dreaming, that support will tend towards zero. Even if it's design for rapid reuse, and they deliver on it, support is a almost always biggest cost of running any complicated machinery.

Re: Starship Prototype Unveiled

#60
post #43
post #24

Earlier quoted context omitted.

SpaceX is completely changing the opportunities of getting to space. The reduction in price has been nuts. According to NASA the space shuttle was ~$450 million per launch, or $16,364 per kg to LEO. The Delta 4 Heavy is $12,156 per kg. For some launches it's even higher- the Air Force paid $15,109 per kg for four launches. The Falcon 9 is $62 million, or $2,719 per kg to LEO. The Falcon Heavy is $2,351 per kg when ex…

It's the dawn of the true space age. And though Musk isn't a fan, this could even make solar power satellites economical. The monolithic designs from the 1970s would be absurdly expensive, but modern designs like SPS-Alpha get economies of scale by using lots of small identical parts that self-assemble in orbit. According to the book The Case for Space Solar Power , a 2GW satellite would deliver electricity at 15 cen…

Aren't there some pretty serious health and ecological problems with such large-scale microwave transmission?
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