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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]

#151

Post by Tuna-Fish »

joakleaf wrote: post #132
mpweiher wrote: post #128

Earlier quoted context omitted.

> 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…

Indeed these numbers are impressive, but can it even be done? Is it even possible both in terms of climate change/overall environmental impact, and in terms of how much methane (fuel) we actually have. Elon Musk's vision is getting 1 million people to Mars (if I remember correctly) within this century. 100 per starship will require 10000 launches. Distributed over 70 years, that's about 1300 Martian voyages per year.…

> Sorry, but isn't that completely impossible!??

> Not just for the required fuel and environmental impact, but also given how often they just postpone basic launches due to weather.

The environmental impact of a rocket launch is roughly in the same category of the environmental impact of a airliner doing a single long-distance trip. (I did this calculation for F9, SS/SH would be higher but not more than two orders of magnitude higher.) Pre-covid, there were approximately 100 000 airliner flights a day. You do the math.

And that's before we consider that they are fueled with methane, and that there are sources of methane that are potentially not just GHG-neutral, but GHG-negative. (Collecting agricultural methane emissions and burning them is dramatically better than releasing them directly.)

As for weather, it is possible to launch rockets in very bad weather, for example the Russians frequently launch in literal blizzards where no winged aircraft could fly. It's just that ability to fly in inclement weather is something you need to design for -- rocket bodies are generally not strong against transverse loads, and this is made worse by having a high fineness ratio. SS/SH, being much more stubby than most current American rockets, will be much less impacted by weather than them.

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

#152

Post by fsloth »

bfieidhbrjr wrote: post #55

Does anyone else get super depressed by this? I did some great work today. I coded something pretty cool and useful. I built a little deck to explain it. My coworkers loved it. My job security went up. I enjoyed it. The journey is the reward. But these guys are making rockets in tents. Should I be rethinking life? Because that's how it feels. I love it. I admire them. But it feels unobtainable. I want to make that ki…

It sounds like you are not working in a field that is intrinsically motivating to you. Perhaps you should find an employer with a product whose end value you can appreciate?

For example I work in CAD. I'm just a software engineer. But the products we make help engineering companies design huge beautiful monsters of steel an concrete.

Sure, they are not rockets, but they are things that impact peoples lives.

Working on a product, that have users who you appreciate is intrinsically satisfying. At least to me.

I feel the code I write is kind of meaningless, but the work my users do is not. Hence I find meaning in their constributions.

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

#153

Post by kiba »

octaveguin wrote: post #121
zhoujianfu wrote: post #119

Earlier quoted context omitted.

For Star Trek we just need SpaceX + UBI!

The Expanse also has UBI on earth. With it, most people still lack opportunity and live a rather destitute, powerless life. Seems like a pretty good perdition of our future, really. UBI recipients with no labor of value to offer won't have power to change their government for long. It's unfortunate that the authoritarian future of Star Trek probably wouldn't lead to paradise. Or at least, that's how our culture's vie…

IIRC, UBI in The Expanse is not really UBI, and more like minimum amount of services to keep you viable, and extreme scarcity of training.

There should really be no reason that people can't be trained or educated even if most of the skills are utterly useless in the face of automation.

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

#154

Post by ncmncm »

jkn wrote: post #127
octaveguin wrote: post #121

Earlier quoted context omitted.

The Expanse also has UBI on earth. With it, most people still lack opportunity and live a rather destitute, powerless life. Seems like a pretty good perdition of our future, really. UBI recipients with no labor of value to offer won't have power to change their government for long. It's unfortunate that the authoritarian future of Star Trek probably wouldn't lead to paradise. Or at least, that's how our culture's vie…

Star Trek's society is collectivist (as all societies are, to a degree), but is it authoritarian? I suspect that summarizing collectivism as authoritarian is like summarizing libertarianism as selfish: they go well together, but you can also get one without the other. I don't know Star Trek very well, but as a utopia I guess they imagine a form of collectivism that largely preserves individual freedom? Of course most…

Anything said about libertarianism is necessarily hypothetical, because it has never happened. If it ever did, it would instantly dissolve into something certain to be very unpleasant for almost everyone.

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

#155

Post by Someone »

pacificmint wrote: post #135
joakleaf wrote: post #132

Earlier quoted context omitted.

Indeed these numbers are impressive, but can it even be done? Is it even possible both in terms of climate change/overall environmental impact, and in terms of how much methane (fuel) we actually have. Elon Musk's vision is getting 1 million people to Mars (if I remember correctly) within this century. 100 per starship will require 10000 launches. Distributed over 70 years, that's about 1300 Martian voyages per year.…

> we are talking 19 launches per day […] isn't that completely impossible!?? The US uses over 20 million barrels of petroleum every single day. We have 44,000 airline flights every day. I think 19 starship flights won’t even move the needle.

https://en.wikipedia.org/wiki/SpaceX_Starship says a starship uses 3,400,000 kg (first stage) + 1,200,000 kg = 4,600,000 kg of propellant, both methane + liquid oxygen.

Let’s guess making the fuel takes 5,000,000 kg of oil (corrections welcome. I guess that’s a reasonable estimate. Less than 100% of fuel is methane, but the specific energy of methane is about 20% higher than that of oil, and creating liquid oxygen takes energy, too)

Multiply by 19 gives you 95,000,000 kg, or about 700,000 barrels. That’s 3% of the oil usage in the USA.

And that excludes construction, maintenance, and ground operations.

⇒ I think it would move the needle, more so given that we should work hard on getting that number down.

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

#156

Post by ben_w »

plutonorm wrote: post #133
octaveguin wrote: post #121

Earlier quoted context omitted.

The Expanse also has UBI on earth. With it, most people still lack opportunity and live a rather destitute, powerless life. Seems like a pretty good perdition of our future, really. UBI recipients with no labor of value to offer won't have power to change their government for long. It's unfortunate that the authoritarian future of Star Trek probably wouldn't lead to paradise. Or at least, that's how our culture's vie…

I think the star trek universe is highly democratic.

Trek is a mirror of Earth geopolitics from an American perspective in whichever year the show was written.

TOS-TNG: Klingons were Soviet-Russian, Romans were Chinese, the Federation was sexist (but much less so in TNG than in TOS) and pretended gay people didn’t even exist.

DS9: Lesbians and trans people exist, but only as exotic outsiders. Bajor feels inspired by Tibeten Buddhism and the final parts of the Northern Ireland Troubles.

VOY: ???

ENT: Nostalgia gone wrong followed by 9/11

DIS/PIC: Oh no Cold War enemies are a threat again / Oh no A.I.

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

#158

Post by ncmncm »

jacquesm wrote: post #149
llboston wrote: post #43

Earlier quoted context omitted.

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!

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.

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

#159

Post by [deleted] »

nubero wrote: post #120
sabujp wrote: post #114

Earlier quoted context omitted.

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.

I’m glad that not everyone in human history has shared your bright outlook, otherwise we would still live in caves…

[deleted]

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

#160

Post by ben_w »

jacquesm wrote: post #149
llboston wrote: post #43

Earlier quoted context omitted.

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!

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…

Although I’m also not expecting 1 million people on Mars in my lifetime, I think you’re assuming SpaceX never gets close to the Musk price goals.

You might be right to do that — I’m no rocket scientist — but the target price would get a million people there for $200 billion, not your $5 quadrillion.

Yes, I also expect the first few thousand to be in easily damaged domes. I also expect them to bring some of The Boring Company equipment with them, as it is part-owned by SpaceX and the stated raison d'être of TBC being pointless in a future of fully self-driving cars.

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