Laser Propulsion - A new Technology for Space Flight

Abstract

In the last decades the principle of laser propulsion has been demonstrated by several laboratory experiments all over the world. The primary goal of these investigations was the development of alternative launch concepts for very small satellites (nanosats) from earth’s surface to low earth orbits (LEO). Unfortunately, it turned out, that the required laser power will not be available in near future. The rapid progress in the field of solid-state laser technology triggered the development of powerful compact pulsed laser sources even for applications in zero gravity environments and space. Equipped with this new laser sources laser propulsion technology offers new concepts for position keeping and attitude control of satellites or satellite constellations in orbit. Beam control with active and adaptive optical systems enables long range or remote laser propulsion. A future step may be space missions with sampling probes to asteroids or small planets and the return on a tractor beam. Today, the main objective is the development and evaluation of precise laser thrusters in the range from 0.1 µN to 1 mN. Alternative micro propulsion concepts are absolutely essential for many missions with precise attitude and orbit control. There is a growing demand due to geodesic missions measuring earth’s gravity (successors of CHAMP, GRACE or GOCE), x-ray astronomy with telescopes built out of 2 satellites with highly constant distance, and astronomical missions with arrays of telescopes in a synthetic aperture architecture (Darwin). Due to its high precision and the simple (propellant) infrastructure laser propulsion is an ideal technology for micro thrusters. Precise adjustable thrust can be generated by laser induced ablation of metals or composites with pulsed laser sources. Solar pumped laser systems are an ideal technology for in orbit laser propulsion.