SSTO definately isn't impossible, it just requires performance to be prioritized in every design decision. Except for deciding how many stages to use. A single

SSTO definately isn't impossible, it just requires performance to be prioritized in every design decision. Except for deciding how many stages to use. A single stage would be much larger for the same payload to orbit than a reusable two stage rocket. I doubt it would be cheaper to fly one.