A method of launching a spacecraft into low Earth orbit using a non-line-of-sight optical power transfer system. The method includes generating optical power at a base station and using an optical fiber to transmit the optical power generated to a launch vehicle via an actively cooled fiber spooler thereon. The optical power received by the launch vehicle is converted to another form of energy usable by the launch vehicle. The optical power is optically focused into a reaction chamber to impinge on a refractory target. A working fluid is regeneratively fed to a heat exchanger contained within the actively cooled fiber spooler. The working fluid is pre-heated within the heat exchanger and injected into the reaction chamber where the working fluid heats and expands. The exhaust is channeled through a rocket nozzle to produce thrust. In an alternative embodiment, the optical fiber expended during launch of a spacecraft is recovered.