Lisk-Broom: A laser concept for clearing space debris

Abstract

So-called “space junk” forced a change of plan for a recent Shuttle mission. However, ground-based lasers with atmospheric-turbulence-compensating beam directors represent a singularly effective method of de-orbiting space junk, because they use cheap Earth-based power, and because they lend themselves to rapid retargeting. Plasma physics and lasertarget interaction theory dictate the laser parameters for a particular mission. We will discuss a practical laser system and beam director with 20-kW average power at 0.5-µm wavelength that is capable of clearing most low-Earth-orbit objects with mass less than 100 kg in about 4 years. This is a special application of the Laser Impulse Space Propulsion (LISP) concept, by which objects are propelled in space by the ablation jet produced on their surface by a remote laser.