Oxidiser: Air. Oxidiser.Comments: Ambient air (78 % nitrogen, 21% oxygen, etc.) is scooped up by air intakes and used in turbojet, turbofan, ramjet, scramjet, or other airbreathing engines as an oxidiser.
Fuel: Slush LH2. Fuel Density: 0.09 g/cc. Fuel Freezing Point: -259.00 deg C. Fuel Boiling Point: -259.00 deg C. Slush hydrogen is formed by taking liquid hydrogen down to nearly the melting point. This produces a partly-solidified but still mobile version of the fuel with 20% greater density than liquid hydrogen itself. Proposed for use from the 1980's in air-breathing and rocket-powered single-stage-to-orbit vehicles where maximization of fuel weight to empty weight is absolutely essential.