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I mean you still need to carry propellant: the stuff that is ablated away. It's just that the exhaust velocity is much higher.

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Air from the atmosphere may be the propellant [1]. If sufficient velocity can be achieved before leaving the atmosphere, then no propellant is needed to be carried up on the way to orbit.

[1] https://www.youtube.com/watch?v=XhUasBcoj-Q

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