Laser‐powered lightcraft systems that deliver microsatellites to low earth orbit have been studied for the Air Force Research Laboratory. One result of this Study has been discovery of the significant influence of laser wavelength on the power lost during laser beam propagation through Earth’s atmosphere and in space. Here, energy and power losses in the laser beam are extremely sensitive to wavelength for earth‐to‐orbit missions. And this significantly affects the amount of mass that can be placed into orbit for a given maximum amount of radiated power from a ground‐based laser. © 2004 American Institute of Physics