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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]

#231
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.

Just a slight correction: this prototype is 30m tall. Still absolutely bonkers how big this is and ALSO that it's not the full height yet.

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

#232

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?

In addition to being full-flow, Raptor runs on methane (CH4, the simplest hydrocarbon), which already exists many places in the solar system (including Mars), and is easier to manufacture than kerosene or liquid hydrogen. SpaceX developed an incredibly advanced simulator to make it happen: https://www.youtube.com/watch?v=vYA0f6R5KAI

Slight clarification: while there have been traces of methane detected on Mars, there's probably not enough to be able to easily use it as fuel. Methane is still beneficial for refueling on Mars, though, because you can make it in place out of water (which is plentiful on Mars as water ice) and CO2 (also plentiful, in the atmosphere) using the Sabatier process. So it remains the case that methane as fuel lets you avoid needing to bring enough fuel for a round trip.

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

#233
post #33

No one has seemed to have mentioned it yet, but the game changer of Starship will be full reusability of both the first and second stage of the rocket. Falcon 9's reusability of the first stage was a huge step towards making access to space a lot cheaper. If SpaceX can realize full reusability with Starship it will enable things like large scale moon bases, space hotels and mars colonization. They still have a lot of…

> game changer Absolutely, and the quantitative analysis is just stunning. In 2018 all of humanity launched a total of 111 payloads into space (out of 114 attempts). At around 5t per launch, that would be 555 tons. Starship is supposed to have a payload to LEO of > 100 tons. So 5-6 launches would handle all of that, by weight. But SpaceX says their goal is to fly these up to 3 times a day. So let's assume they can do…

Perhaps a stupid and naive question, but is there even the demand to lift that much mass into orbit? I may just be lacking in imagination.

Obviously most of that mass would have to leave orbit in order for it not to end up looking like an LA freeway in rush hour.

edit: i guess propellant/fuel would be one of the heaviest and important payloads we would need to get up there.

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

#234
post #201
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.

I hate this argument. There is no foreseeable disaster that would make Earth less habitable than any other solar system body. Even if every nuke we have was detonated, it would still be orders of magnitude easier to survive on what remains of Earth than to live in Mars. I'm not saying there are no existential risks at all, but being on other planets would not make us any more likely to survive to them than to simply…

Every comment of this nature overlooks the challenge of politics and territory. Any significant social experiment is basically impossible on Earth because every space and person is claimed property by an existing state.

Mars would also offer cultural redundancy. Also, sometimes people choose to do things brcause they are hard.

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

#235
post #114
post #33

No one has seemed to have mentioned it yet, but the game changer of Starship will be full reusability of both the first and second stage of the rocket. Falcon 9's reusability of the first stage was a huge step towards making access to space a lot cheaper. If SpaceX can realize full reusability with Starship it will enable things like large scale moon bases, space hotels and mars colonization. They still have a lot of…

Future of space as presented in shows like the Expanse. controlled by trillionaires and their companies and powerful people in governments all killing each other over space rocks. We're a long way from Star Trek, that's going to take a more fundamental advance not at all related to technology.

Many of the colonies that make up the US and Canada were at one time controlled by the rich elite of the time. A few hundred years and they rebel to the point nobody even remembers them.

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

#236
post #33

No one has seemed to have mentioned it yet, but the game changer of Starship will be full reusability of both the first and second stage of the rocket. Falcon 9's reusability of the first stage was a huge step towards making access to space a lot cheaper. If SpaceX can realize full reusability with Starship it will enable things like large scale moon bases, space hotels and mars colonization. They still have a lot of…

Another significant thing is that Starship is designed to be mass manufactured at a relatively low cost. SpaceX can crank out thousands of Starships, fly them to Mars and build a million people colony. Starship is truly a game changer!

This is a very key point.

The Falcon 9 isn’t cheap because of reuse (yet). It’s cheap because of mass manufacturing. The Rs-25 engine costs over $100m each, Ariansoace Vulcains around $20M, typical large rocket engines over $10M.

SoaceX Merlin costs about $200,000 each to make. The Raptor will be close to that. Thats why SpaceX can pursue the large number of redundant smaller engines design strategy so successfully.

Reuse has lowered Falcon 9 costs internally, and increased its private discounts, but not it’s public pricing. When the cost benefits of reuse finally cascade through public pricing and through the entire stack with Starship, you have a SuperHeavy launch system putting 150 tons in orbit even cheaper than a single Falcon 9 launch.

For comparison, the Shuttle was over $40,000 per pound to Orbit. The SLS will be around $10,000/lb to orbit if you don’t count developmental costs at least 3x that.

The Falcon 9 is $1,500/lb to orbit, and Falcon Heavy $1,100/lb to orbit. Starship will lift more payload to orbit than the SLS, and 4x as much as the Shuttle, for between $100 and $300 per pound.

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

#237

Earlier quoted context omitted.

They are testing on a path to be able to land from orbit. Starting with short hops by prototypes that get iteratively improved is the same methodology that allowed them to be able to land their currently operating Falcon 9. They are the only one to ever achieve this. It's a big deal because everyone else builds a $100M rocket and then throws it away because it can't land. Reusable rockets have the potential to make a…

So the idea isn't to literally hop? They ultimately want to land it the same way the F9 rockets land now, and this is just a test?

Bingo. They did similar tests with a Falcon 9 test article called "Grasshopper" - https://www.youtube.com/watch?v=9ZDkItO-0a4

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

#238
post #9
post #3

Earlier quoted context omitted.

Just did a minute ago, it worked! 6:57 in the the timestamp on the top right, I dont think I can link to a time in a live youtube video

Yes you can. FYI -> https://youtu.be/NJR4gZBLMNw?t=2190

That 'copy video at current time' option wasnt available until the livestream ended though. I should have tried manually adding it.

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

#239

Earlier quoted context omitted.

Was it really shown? Is there a single country that did not replace stress of violence and starvation with economic stress? Do we have at least one larger example of what would happen if the general population was rich?

> Do we have at least one larger example of what would happen if the general population was rich? We have birth rate comparison between "first world" and "third world" countries plus migration experience studies (basically, even one generation after migration from a poor to a rich country, there is a massive drop in birth rate, and after something like 3 generations the birth rate is equal to the rest of the country)…

The simple explanation for these numbers is that rural children are economically useful, while urban children are a burden.

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

#240
post #112

Earlier quoted context omitted.

Is it just me or does the workmanship look like a step up?

They've been interating on the construction process with each one built. I've been welding (DIY) for 30 years, and the first ones looked pretty bad to me - lots of distortion, and I actually thought the first one was just a mock-up. But the process is clearly improving with each build. I still think the nose cone looks like it will improve in the future, as it doesn't look as precise as the main body is now looking,…

It's also worth pointing out that the new prototypes, like SN5 that flew today, are made with significantly thinner steel over what "Star Hopper" was made with last year. They have spent a lot of effort perfecting their manufacturing technique so they can make these things as light as possible and still achieve the safety margins that they need to support manned flight. That's why they need the 22 ton weight on the top for this flight, because they can't throttle a single Raptor engine low enough to hover these new designs.
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