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Starship Update [video]

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Re: Starship Update [video]

#191
post #183

The Raptor 2 engine is just an absurd. The original specs were already kind of insane. But Raptor 2 is an monster. They really pushed already significantly into a second generation design before first flight. Raptor 2 is not just a slight upgrade, its a huge upgrade. If it can actually launch multiple times a day without any refurbishment, it will simply totally break space travel as we have known it. This engine mak…

>This engine makes everything else possible. I have seen lot of tweets ( from highly intelligent people and engineers ) suggesting Starship is not possible. Raptor 2 is not possible. But now it seems it really is coming. It is easy to fault him for robotaxi and FSD, which a lot of people do. But sometimes he really does the impossible.

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Re: Starship Update [video]

#192
post #183

The Raptor 2 engine is just an absurd. The original specs were already kind of insane. But Raptor 2 is an monster. They really pushed already significantly into a second generation design before first flight. Raptor 2 is not just a slight upgrade, its a huge upgrade. If it can actually launch multiple times a day without any refurbishment, it will simply totally break space travel as we have known it. This engine mak…

>This engine makes everything else possible. I have seen lot of tweets ( from highly intelligent people and engineers ) suggesting Starship is not possible. Raptor 2 is not possible. But now it seems it really is coming. It is easy to fault him for robotaxi and FSD, which a lot of people do. But sometimes he really does the impossible.

The chamber is still melting. Hopefully they can figure that one out.

Re: Starship Update [video]

#193

Earlier quoted context omitted.

You're presenting a false dichotomy. Our options aren't only (a) live only on Earth, and (b) live on Earth and Mars and potentially other planets. There is, for example, (c) live in man-made structures orbiting the sun at a distance of 1AU, which is debatedly much more sensible than trying to live on Mars.

How many tons would you need to get out of the gravity well before you had enough orbital manufacturing capacity to begin building that sort of thing? I mean, I love the dream, but I don't know how you can make it a reality.

In the video Elon makes an estimate of a million tons to Mars (if I remember correctly) in order to establish an entirely self-sufficient colony there. Building orbital manufacturing would be a different kind of problem, but in some respects it's kind of similar. I suspect it'll make sense to establish a foothold on Mars first (which has a lot of necessary resources and less gravity means you can transition from the planet to orbit much more cheaply) and then maybe use Phobos and/or Deimos as manufacturing hubs for space-based hardware like habitats. Or maybe it makes sense in the short term (before Mars has the necessary infrastructure for big projects) to do manufacturing on the moon.

Re: Starship Update [video]

#194
post #108

The Raptor 2 engine is just an absurd. The original specs were already kind of insane. But Raptor 2 is an monster. They really pushed already significantly into a second generation design before first flight. Raptor 2 is not just a slight upgrade, its a huge upgrade. If it can actually launch multiple times a day without any refurbishment, it will simply totally break space travel as we have known it. This engine mak…

My theory is that they aim to disrupt Earth travel (airlines). Elon pointed out that the reliability of Starship would exceed that of commercial airplanes, and the fuel costs are not that different than, say, a 747. Fewer moving parts than an airplane, less human costs, order of magnitude faster...

I'm not sure what you mean by this. Can you explain what you are comparing?

https://en.m.wikipedia.org/wiki/Thrust-specific_fuel_consump...

My understanding is that rockets are good at getting a small mass to move really quickly. They will never win moving a lot of mass within the atmosphere. The fuel costs are radically different.

A 747 can lift and land ~80% of Starship's design cargo but uses something like 7 times less fuel.

Re: Starship Update [video]

#196
post #127

Earlier quoted context omitted.

There is no way the cost per trip (airline) is in the $1K - $10K range. The Boeing 787-8 has a fuel capacity of 33,500 gallons. I don't think an intercontinental flight costs significantly less than $1M

In round numbers, airlines’ cost basis is ~$0.15 per available seat mile. So a trip from NYC to Rome of 4,300 miles in a 777-300ER with 350 passengers would cost in the ballpark of $225k. LA to Shanghai at 6,500 miles in the same capacity plane would be more like $350k. $1M wouldn’t make much sense because with 350pax you’d need them to pay $2,900 each leg just to cover the operating costs. So a round trip flight to…

I’m sure they would find their customers. The Concorde from NY to Paris ran about 10k USD round trip. There are many more millionaires now than there were in the 90s.

Re: Starship Update [video]

#197

Earlier quoted context omitted.

The basic idea is to not have all your eggs in one basket. We are one asteroid strike away from losing all human life on earth. Having 2 habited planets spreads the risk. Obviously having those planets in different solar systems would be even better, but we don’t have the technology for that, yet.

Gonna be interesting to see how many people actually pony up to really take part in that kind of vision. Are there any economic incentives for colonizing Mars? Asteroid mining makes sense and bases on and around the Moon make some kind of economic sense at least. I don't know how Mars fits into that picture in the 50-100 year "medium" term picture.

Economic incentives include government-funded basic science, mining, tourism, real-estate speculation (i.e. claim a bunch of land while it's cheap), entertainment (sports and movies/TV shows), the ability to do things in a presumably lax regulatory environment that might not be allowed on Earth, and long-term care for those who have disabilities that would require a wheelchair in full gravity but not on Mars, and the establishment of Mars as a more convenient source of food/fuel/raw materials for any human presence in the belt or outer solar system.

Re: Starship Update [video]

#198
post #124

Earlier quoted context omitted.

I thought 100k HP was either too incredible or a typo. Then I looked it up: “You def don’t want electric pumps on a rocket engine! Raptor turbopumps alone need 100,000 horsepower per engine. That’s not a typo.” —Elon Musk x 32 engines. Amazing! For comparison, this is an internal combustion engine with 100k HP: https://www.zmescience.com/science/biggest-most-poweful-engi...

That is interesting, so could you replace the biggest and most powerful internal combustion engine in the world that weighs 2,300 tons by [whatever powers] turbopumps from a raptor engine and get the same power output? Where is the catch? Less fuel efficient? Less torque? Edit: What I meant to ask was: Can one use "whatever is powering the turbopumps and delivering the 100k HP" to power say a ship propeller, instead…

The raptor burns highly purified methalox for a couple minutes at most. The ship engines have to work for weeks and years economically running on bunker fuel. From fundamental thermodynamics, the bigger an engine is the more efficient it is but you obviously need to compromise on that in a rocket.

Re: Starship Update [video]

#199

"It's gonna be cramped, dangerous, difficult, very hard work. You might die." -- Elon's sales pitch for Mars, in his own words. I wonder if any billionaire (or their children) will be doing the early work. It's an interesting game of "Who values their life the least?" knowing that their sacrifice will make for a better future. Of course, it's not a foregone conclusion that there will be a disaster. But over the cours…

The quality of life on Mars poses the greatest risk to SpaceX's plan to create a self-sustaining city there.

I'm sure there will be plenty of people who will go to Mars because it is a fantastic adventure.

However, i doubt that many will want to stay there for more than 26 months. If too many pioneers choose to return to Earth, the project fails. You need a fairly large number of settlers to create something self-sustaining.

Re: Starship Update [video]

#200
post #13

"It's gonna be cramped, dangerous, difficult, very hard work. You might die." -- Elon's sales pitch for Mars, in his own words. I wonder if any billionaire (or their children) will be doing the early work. It's an interesting game of "Who values their life the least?" knowing that their sacrifice will make for a better future. Of course, it's not a foregone conclusion that there will be a disaster. But over the cours…

Why do we need to fly 3 months to some inhospitable planet that is in worse condition than Earth would be (even after nuclear wars and global warming) to make progress? I suppose there's an idea we could apply everything done on Mars to Earth, but like... seriously, what we just took all the prep for mars and just put it in the middle of the Empty Quarter, the Saraha, Antarctica? People barely want to live in the arc…

> I would love to see all the energy put into space exploration to simply be put in rehabilitating existing land.

Quote from my past posts [1] on this point:

> It's impossible to predict what tech can come out of such efforts that will be of use here on Earth in the future. The amount of money going to space exploration is peanuts so I think it's well justified if it has even a trace of potential to improve future of humanity and that has been true historically - e.g. satellites (GPS, weather, etc), medicine (MRI), and whole bunch of NASA spinoffs and more.

> I think SpaceX to date has received less than 10 billion (say 20 to be safe) in total for everything! That's 20 years of research, development, coming up with never done before re-usable rockets, etc.

> People spent nearly half a trillion dollars (not billion) on cosmetic products in a single year! You want to point fingers, point at something you can actually locate. Money spent on space is negligible to the point that it doesn't even warrant justifying spending it.

[1]: https://news.ycombinator.com/item?id=29189753

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