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Comment by mickronome | Hacker News Reader

It's a bit sad, I do long for the stars and planets.

However, rramatically improving rockets might be like trying to improve the carriage to get a much faster personal transport, while keeping the horse.

It seems to be the case, that the cost of launching commercial payloads are still "low" enough compared to the cost of the payloads since there are few big budget ventures that tries to make lifting much cheaper through alternative methods.

I'm not saying that space elevators or other alternative lift devices are feasible, but we tend to get huge investments even into tech that seems absolutely implausible if there is a big market. The lack of these makes investments makes it plausible that the current launch costs are actually acceptable for all current, and expected near future commercial actors.

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The nice thing about rockets is that you can start as small as you'd like and build progressively larger and larger rockets and get the engineering details right before you have to worry about getting into space.

Space elevators, skyhooks, and launch loops are all big enough that it's an all-or-nothing deal. You can test individual components, but a whole end-to-end space elevator has to be exactly the distance between ground and geosync or else it just doesn't work. At best, you could build smaller versions of this stuff on the moon first and then scale up to Earth-size later, taking into account such factors as water, atmosphere, and the fact that the Earth is not tidally locked with the sun. But that requires hauling metric fucktons of parts and equipment to the moon, even if you're using lunar resources to build the space elevator itself, so there's no guarantee you end up ahead in the end.

The basic physics behind rockets is simple as all hell, and it still required von Braun to spend his entire adult life building progressively bigger and bigger rockets and refining the design details. The V2 only needed to be able to land nose-first 200 miles from where it was launched, but without that knowledge and experience, the Saturn V would have been impossible. That's the kind of iteration that's fundamentally impossible with these other launch systems.

With a space elevator, don't you need a mass some distance above geosync to hold the weight of the cable and the payload as it ascends?

I think the counterbalance is more to make sure that the center of gravity is actually the thing in geostationary orbit.

Yeah, it's not the type of thing you can iterate on and get usable results for without the whole thing. It's not like you can build a tiny space elevator and use it to bomb London, for example.

I'm not sure the cost of payloads is independent of launch costs.

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