Laser Propulsion for Ground Launch

Abstract

Ground-to-orbit launch using laser propulsion requires a thermal system. A number of such thermal thruster concepts have been developed in the past. Thus far, only the laser-supported detonation thruster concept has led to a flight vehicle, the Lightcraft. It is shown via flight simulations and measurements with the Lightcraft that there are no inherent limitations for a ground-to-orbit launch vehicle using laser propulsion. A planar geometry laser-supported detonation thruster using a CO 2 laser is considered and its performance evaluated. A 10-km height flight vehicle using existing lasers is proposed. Nomenclaturespecific enthalpy of gas, height h P = Planck's constant h lsr = laser site altitude h ref = atmospheric scale height I abs = laser intensity absorbed by gas I sp = specific impulse k = absorption coefficient k B = Boltzmann's constant m = mass _ m= mass flow rate n X = number density of X P = power p = pressure q = specific heat added to gas r = radius r hot spot = vehicle hot-spot radius r lsr = laser main deflector radius T = temperature u = velocity in shock-fixed reference frame v = velocity in laboratory reference frame abs = atmospheric absorption coefficient R slant = slant range = efficiency = semivertex angle = longitude = wavelength = density = laser frequency = latitude e = Earth's rotational velocity

Basic Research Investigations into Multimode Laser and EM Launchers for Affordable Rapid Access to Space (Volumes 1 and 2)

“…The work concludes with an analysis of the most promising concepts and provides suggestions for further experiments. Within this work, a basic first-order analysis of the trajectories and dynamics of the Myrabo Lightcraft was carried out(Resendes et al, 2007). This…”