A
single-stage-to-orbit (or
SSTO) vehicle reaches
orbit from the surface of a body without jettisoning hardware, expending only propellants and fluids. The term usually, but not exclusively, refers to
reusable vehicles. No Earth-launched SSTO launch vehicles have ever been constructed. To date, orbital launches have been performed either by
multi-stage fully or partially
expendable rockets, the
Space Shuttle having both attributes.