In-flight transfer of reactant from a towing or carrying airplane to an attached rocket or rocketplane

A process of launching a high altitude vehicle designed to fly to high altitudes above 100,000 feet comprising the steps of:

• connecting a tow cable and fuel and oxidant transfer lines between a towing airplane and the high altitude vehicle for towing the unpowered high altitude vehicle behind the towing airplane from takeoff and for an initial portion of a flight, the high altitude vehicle having a fuel tank and an oxidant tank and having less than 10% fuel and oxidant in the respective tanks from takeoff and for the initial portion of the flight;
• transferring fuel and oxidant from the towing airplane to the high altitude vehicle via the fuel and oxidant transfer lines at a desired altitude above 25,000 feet and at a desired flight speed sufficient for lift of the high altitude vehicle to support the vehicle, transferred fuel, and transferred oxidant in flight;
• disconnecting the tow cable and fuel and oxidant transfer lines from the high altitude vehicle;
• and
• commencing powered flight of the high altitude vehicle substantially at the desired altitude and at the desired flight speed,
• whereby the high altitude vehicle commences flight from takeoff with a minimal amount of fuel and oxidant and with a concomitant lower structural weight and smaller wings than if configured for self-powered takeoff and flight with sufficient fuel and oxidant in the respective tanks for independently achieving the desired altitude and desired flight speed and, after transfer of the fuel and oxidant from the towing airplane to the high altitude vehicle, the high altitude vehicle commences self-powered flight with maximum fuel and oxidant while substantially at the desired altitude and desired flight speed, enabling achievement of a higher altitude and speed and/or to carry a larger payload than if configured for self-powered takeoff with fully loaded fuel and oxidant tanks.