Review: Laser-Ablation Propulsion

LASER ablation propulsion (LAP) is a major new electric propulsion concept in which an intense laser beam (pulsed or continuous wave (CW)) strikes a condensed-matter surface (solid or liquid) and produces a jet of vapor or plasma. The laser system involved in LAP may be remote from the propelled object. Pulsed laser ablation can be used into a thrust chamber, the light must pass through absorbing ablation products. An important factor in the improvement of performance figures of merit and of ablation efficiency is choosing an appropriate propellant. For laser intensities high enough to form a fully ionized plasma, the impulse delivered to a target by a laser pulse can be predicted with factor-of-2 accuracy using relationships. The first practical space application of LAP is already built, tested, and awaiting a flight, the laser-plasma thruster. Direct launch into LEO (low earth orbit) with large payloads will be possible if the investment is put in place now.