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SpaceX test flight of Starship SN-5 [video]

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Re: SpaceX test flight of Starship SN-5 [video]

#211

Post by chriswarbo »

dgritsko wrote: post #208
martythemaniak wrote: post #205

I really love the out-in-the-open development process. It doesn't cost SpaceX anything, yet they attract lots of internet media where people set up streams, discuss progress etc. The next year should be pretty exciting as they develop things further. Starship has a number of big innovations, which are: - the raptor engine. This was developed behind closed doors and is sort of finished. We won't see much of it, but it…

> the most advanced rocket engine ever made Would love to learn more about this, can you expand? What makes Raptor so unique?

The raptor is a "full flow staged combustion engine" https://en.wikipedia.org/wiki/Staged_combustion_cycle#Full-f...

AFAIK it's the only flying, non-research example of such an engine.

Re: SpaceX test flight of Starship SN-5 [video]

#212

Post by martythemaniak »

dgritsko wrote: post #208
martythemaniak wrote: post #205

I really love the out-in-the-open development process. It doesn't cost SpaceX anything, yet they attract lots of internet media where people set up streams, discuss progress etc. The next year should be pretty exciting as they develop things further. Starship has a number of big innovations, which are: - the raptor engine. This was developed behind closed doors and is sort of finished. We won't see much of it, but it…

> the most advanced rocket engine ever made Would love to learn more about this, can you expand? What makes Raptor so unique?

Tim Dodd explains it very well: https://everydayastronaut.com/raptor-engine/

It's basically a sweet-spot between being very powerful, very efficient, cheap and easy to operate and highly reusable. To get all these, they implemented a design that never got past the basic demo stage before, which included independently working out the secret sauce of the best Russian-made engine.

Re: SpaceX test flight of Starship SN-5 [video]

#213

Post by Already__Taken »

dgritsko wrote: post #208
martythemaniak wrote: post #205

I really love the out-in-the-open development process. It doesn't cost SpaceX anything, yet they attract lots of internet media where people set up streams, discuss progress etc. The next year should be pretty exciting as they develop things further. Starship has a number of big innovations, which are: - the raptor engine. This was developed behind closed doors and is sort of finished. We won't see much of it, but it…

> the most advanced rocket engine ever made Would love to learn more about this, can you expand? What makes Raptor so unique?

This might be the way to go - https://www.youtube.com/watch?v=Sdwy9fzQzl4

Re: SpaceX test flight of Starship SN-5 [video]

#214

Post by swader999 »

nfoz wrote: post #182
sekai wrote: post #174

Earlier quoted context omitted.

Let's look at this way, humanity needs to become multiplanetary species to prevent extinction if some sort of cataclysm happens on Earth: nuclear war; Yellowstone erupts, etc. Compared to that, any other problem seems insignificant.

This will sound weird, but I have no idea why anyone cares about the abstract "survival of human species". I care very deeply about the lives of people actually living here right now. But if Earth is wiped out, what does it matter that some humans are alive somewhere? Except of course that I'm glad for them that they didn't get killed. But we're talking about generations from now anyway, and there are more direct way…

Because our code must live on.

Re: SpaceX test flight of Starship SN-5 [video]

#215

Post by cplex_go_nogo »

dgritsko wrote: post #208
martythemaniak wrote: post #205

I really love the out-in-the-open development process. It doesn't cost SpaceX anything, yet they attract lots of internet media where people set up streams, discuss progress etc. The next year should be pretty exciting as they develop things further. Starship has a number of big innovations, which are: - the raptor engine. This was developed behind closed doors and is sort of finished. We won't see much of it, but it…

> the most advanced rocket engine ever made Would love to learn more about this, can you expand? What makes Raptor so unique?

The raptor uses a full flow staged combustion cycle. This makes a very efficient engine but increase the complexity. Everyday astronaut and Scott Manly on youtube do an excellent job explaining this in more detail

Re: SpaceX test flight of Starship SN-5 [video]

#216

Post by phkahler »

martythemaniak wrote: post #212
dgritsko wrote: post #208

Earlier quoted context omitted.

> the most advanced rocket engine ever made Would love to learn more about this, can you expand? What makes Raptor so unique?

Tim Dodd explains it very well: https://everydayastronaut.com/raptor-engine/ It's basically a sweet-spot between being very powerful, very efficient, cheap and easy to operate and highly reusable. To get all these, they implemented a design that never got past the basic demo stage before, which included independently working out the secret sauce of the best Russian-made engine.

>> which included independently working out the secret sauce of the best Russian-made engine.

Another hurdle was that there was no material available for some of the parts. SpaceX - so we'll get some materials science people to develop a new alloy that does what we need. Not an easy sub-task but one that needed a solution, so they found one.

Re: SpaceX test flight of Starship SN-5 [video]

#217

Post by Jach »

ncmncm wrote: post #158
jacquesm wrote: post #149

Earlier quoted context omitted.

You write that as if it is a done deal. Mars' atmosphere is roughly .5% of that of Earth and almost exclusively CO2. Temperature ranges are well out of what they are on Earth. It is hard for technology to survive there, it is impossible for people to survive there until there has been an unbelievable investment in infrastructure. If you think there will be a million people colony on Mars in your lifetime than you are…

To get a sense of the difficulty, imagine sending a million people to the South Pole to set up a self-sustaining colony. That would be much more than 1000 times easier than establishing such a base on Mars.

Easier is a downside.

Re: SpaceX test flight of Starship SN-5 [video]

#218

Post by njarboe »

dgritsko wrote: post #208
martythemaniak wrote: post #205

I really love the out-in-the-open development process. It doesn't cost SpaceX anything, yet they attract lots of internet media where people set up streams, discuss progress etc. The next year should be pretty exciting as they develop things further. Starship has a number of big innovations, which are: - the raptor engine. This was developed behind closed doors and is sort of finished. We won't see much of it, but it…

> the most advanced rocket engine ever made Would love to learn more about this, can you expand? What makes Raptor so unique?

I am not a rocket scientist, but one of the main reasons it is so unique is that it will be the first full-flow staged combustion rocket engines to successfully be used on rockets.

Rocket engines have powerful turbo pumps to move large amounts of fuel quickly to the combustion chamber to create thrust. Usually these pumps are powered by burning some of the propellant in a turbine and exhausting the resulting gas on the side of the engine. A full-flow engine mixes this turbo pump exhaust gas back into the main combustion chamber. This makes the engine more fuel efficient but it is a difficult engineering problem. All previous types of these engines blew up too often to be used on spacecraft. Check out the Wikipedia page for more info [1].

[1]https://en.wikipedia.org/wiki/SpaceX_Raptor

Re: SpaceX test flight of Starship SN-5 [video]

#219

Post by swader999 »

Diggsey wrote: post #25

What you don't get a sense for in the video is the size of this thing... It's absolutely bonkers. 9m (30 ft) in diameter 50m (160 ft) in height (or would be with the nose-cone) That's the height of a 12-story building. And this is the upper stage of the full rocket.

The commentator likened it to flying a giant grain silo.

Re: SpaceX test flight of Starship SN-5 [video]

#220

Post by buzzwordninja »

hugs wrote: post #200
shireboy wrote: post #185

Earlier quoted context omitted.

I’ve often said the same thing. South Pole and underwater cities would be easier than mars or even moon colony. As much as I want the later to happen- I think 1 million people on Mars or Moon will require something that makes them more appealing than even the worst Earth locations. That has to be something pretty drastic. Elon says motivation will be “it’d be cool”. I don’t think that is enough motivation. Still, I’d…

A science outpost, specifically as a place to put telescopes, seems the most compelling. The rest of the population would then grow along side the science outpost to service it (food, transportation, etc.) A looong time until a million people, though.

Why would you put a telescope in a gravity well though?

Would it not be easier to build large structures in orbit or at one of the Lagrange points?

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