Patent ID: 8393582

Claim:
A method of fueling a secondary payload delivery system that is launched into orbit or beyond in association with a primary payload delivery system, comprising: a) providing primary payload delivery system comprising a launch vehicle with a booster stage, an upper stage interconnected to the booster stage, the upper stage including a first tank for holding a propellant and a secondary payload delivery system including a second tank for holding the propellant; b) providing the first tank with propellant prior to launch and providing the second tank without or substantially without propellant prior to launch; c) when the upper stage and secondary payload delivery system are in space, directing flow of the propellant from said first tank to said second tank; d) filling said second tank in space with a predetermined amount of propellant; e) ceasing the flow of propellant from said first tank to said second tank in space; and f) separating said upper stage and said secondary payload delivery system in space.