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Comment by pvsukale1 | Hacker News Reader

I know people have valid reasons to be skeptical about such projects. But maybe after 50 years or so when this kind of transport will be very common we will remember this day as one of the most historic events in the course of humanity.

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And if it becomes that common, in 150 years time, New York will be under water. I remember reading that the instantaneous power output of one Apollo rocket taking off is roughly the equivalent of the entire average electricity load of the UK. Surely burning a country's worth of rocket fuel every time you want to travel long distance is not sustainable?

Well, New York City probably will be largely underwater in 150 years anyways, but not because of the BFRs. SpaceX plans to synthesize the fuel by using water, solar power and captured carbon dioxide from the earths athmosphere - just like it will be done on mars.

Is it true that an extrapolation of existing trends puts NYC underwater in 150 years?

If there only were some sort of technology that could make it possible to keep water away.

Also, you can just generate that fuel from the air and make it carbon neutral if that was really the issue.

Fusion power can't come soon enough. Maybe it's time for Musk to start working on that. He actually said in an older interview that he would like to tackle it eventually.

He recently said (paraphrasing) that it wasn’t particularly productive investing in Fusion when there’s a giant, very efficient fusion reactor in the sky. We’d be better off improving solar panel efficiency and energy storage solutions.

He's also said rockets are the only transportation where electric wont work.

Fusion power doesn't really help with rocketry, though.

It helps a hell of a lot, once you're in orbit!

Could probably have a smaller rocket too

How?

This was brought up in the presentation as well - they have plans to eventually use the same technology they will use on Mars, on Earth as well, to take CO2 out of the air and combine it with water to create methane and oxygen. If it happens, the rockets would be carbon-neutral.

Ah ok, that's not in the linked video, but in the following one that autoplays afterwards.

And if it becomes that common, in 150 years time, New York will be under water.

If it becomes that common, it will be well within the major power's ability to block 1.5% of the sunlight that hits the Earth by posting sunshades at L1.

Surely burning a country's worth of rocket fuel every time you want to travel long distance is not sustainable?

It doesn't take that many airliner flights to match that power output.

Indeed, a Falcon 9 takes only the amount of fuel used by 2 long-distance 747 flights. BFR might be, say, five to seven times that, though it's a different fuel (natural gas instead of kerosene.)

It won't make sense for most people for the first 30-50 years. That much is clear. However, it still has to make business sense from day one for some people. Otherwise the project is dead and forgotten, just like it happened to the Concorde.

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