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Nice_Chest4335 t1_ixyz263 wrote

They talk about the fuel it takes for a rocket launch: what about the fuel or energy required for the vehicle or elevator to climb the massive distance till weightlessness?

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danielravennest t1_ixz1sit wrote

In principle climbing the elevator takes the same energy as putting a payload in orbit with a rocket (33 MJ/kg). But the payload is only 2% of a rocket's weight. You eliminate the structure and fuel of the rocket stages below the payload.

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DBDude t1_ixzolna wrote

Aside from what was mentioned, a big problem with rockets is gravity loss. They don't just have to accelerate to get to the speed they want, they also have to accelerate an extra 9.8 m/s2 to overcome gravity every second they're in the air. Think about it, just for a rocket to hover like a Falcon 9 requires 9.8 m/s2 of acceleration. That's a lot of wasted fuel.

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