Adding fuel to a spacecraft in orbit can effectively extend the lifetime of spacecraft. However, the traditional method of establishing a sophisticated space fuel supply system is costly. This article proposes a low-cost space fuel supply system that consists of four kinds of spacecraft: a rocket upper stage, a fuel station, a supplying spacecraft, and a supplied spacecraft. The supplying spacecraft extracts residual fuel from a disused rocket’s upper stage and transports it to the fuel station for collection and storage. When the supplied spacecraft requires propellant, the supplying spacecraft retrieves the fuel from the fuel station and delivers it to the supplied spacecraft. By turning waste into treasure, it is possible to greatly reduce the maintenance cost of spacecraft. Engine tests demonstrate that the fuel used by launch vehicles can also be used by spacecraft. Economic analysis of the proposed system deployed on a sun-synchronous orbit reveals that the orbital difference is an important factor affecting the refueling cost. To make the system becoming a reality, technologies such as residual fuel measurement, propellant transport in space, and engines using mixed fuels need to be improved.