Kryptonian Anti-Gravity

Kryptonian body cells store and process yellow solar/stellar radiation to generate an anti-gravity field like the spindizzy screens in James Blish's Cities In Flight but enclosing only the body and controlled by the Kryptonian brain, thus enabling the organism to fly without causing sonic booms, to survive in vacuum, to repel missiles and to lift objects by extending the field so that super-strength is really psychokinesis.

Vision powers are explained by natural selection in Krypton's dense atmosphere and hostile environment but I also postulate interventions by the god Rao to maintain the human form despite evolutionary changes because his purpose was to generate a hero to be sent to Earth, and later into the cosmos, after the foredoomed destruction of Krypton.

Later: A spindizzy screen would explain faster than light interstellar flight but not time travel.