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Comment by tombert | Hacker News Reader

While I agree with your point on this, just to play devil's advocate I have to point out that a lot has changed since the 1960's. We have designed more efficient rockets, we have much better computer guidance systems, we have much lighter-weight synthetic materials that could save on fuel, etc. Conceivably if we were to go to the Moon today, it would be substantially cheaper.

That said, I did feel like this project was overly ambitious. Even with my previous points, rockets are expensive, and space R&D is pricey.

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Conceivably if we were to go to the Moon today, it would be substantially cheaper.

This seems contrary to experience. In constant dollars, a jetliner today is 5-10X the price of a jetliner of the 1960s. Mass transit rail miles are >10X. The solutions may be better, but they don't seem to be cheaper.

Launch costs do seem to have fallen quite a bit in very recent history though. So maybe?

Is that 5-10x the upfront cost? What's the cost comparison in operating costs over the lifespan of the plane?

It's not that I don't believe 5-10x, it's that I'm pretty sure the net savings are on the backend, which is where a huge amount of airplane engineering has gone--better fuel efficiency, faster servicing, etc. I'm not an expert in this area, so I'm genuinely curious.

Jet technology is much more complex to meet environmental, safety and efficiency goals. Fuel was much cheaper in the 1960's, I wonder what the cost of a jet is in terms of it's operating life?

Rail and other ground works have got much more expensive as labour costs (in the developed world) have risen. I expect that rail costs in China are not 10x? I would be interested to know !

In term of moonshots I think that safety and risk would mean that a modern mission would be much more expensive than Apollo.

A better comparison is how much it has cost SpaceX to get to where they are (and still at least 3 years left to go for their Mars mission) - $2.5B in equity funding + $10s of billions in revenue over the last 10 years.

question..how does spacex make revenue? or I might just google...

People pay them to put things into space

Should be their moto.

out: "SPACEX DESIGNS, MANUFACTURES AND LAUNCHES ADVANCED ROCKETS AND SPACECRAFT"

in: "SpaceX: We put things in space so you won't have to"

Don’t they sell space launch services?

They are in the commercial space launch business. They deliver satellites and other payloads to orbit and the ISS.

A lot of their initial revenue came from Air Force and other military contracts to launch satellites to space. GPS satellites, spy satellites etc. E.g here's an article from 2016 about them launching a GPS satellite for ~$90M: https://www.reuters.com/article/us-space-spacex-launch-ula-i... More recently they also launch private satellites. Iirc, Facebook has plans to launch their next satellites on a SpaceX rocket (an earlier attempt failed).

The fundamental Tsiolkovsky rocket equation and delta v required to get to Mars hasn't changed since the 60s. Some technology has improved, but the major difficulty is just lifting enough fuel out of Earth's gravity well to get anywhere.

The fuel is minimal part of the cost - putting 100ton of it into LEO even at $10K/kg is just $1B. And with BFR it will be even much cheaper than that.

$1B is a lot of money and LEO is a long way from mars.

LEO is about half way to Mars

Looks like more than halfway. Assuming you can arrange aerobraking on Mars, soft-landing on Mars is slightly nearer than soft-landing on the moon!

Getting back is a different kettle of fish though.

https://en.wikipedia.org/wiki/Delta-v_budget#/media/File:Del...

That difficulty changes substabtially if you have rapidly reusable rockets.

The fuel itself is cheap, it's throwing away a rocket per launch that makes it infeasible.

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