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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

Low-frequency dusty plasma waves with frequencies much smaller than the frequency of charging collisions of plasma particles with dust particles are considered taking into account elastic and charging collisions of plasma particles with dust and neutrals. The usual dust sound waves with an upper frequency equal to the dust plasma frequency are found to be present only for wavelengths much smaller than the plasma particle effective mean free path due to the effective collision frequency. The effectice collision frequency is found to be inversely proportional to the square root of the product of the charging frequency and the frequency of particle momentum losses, involving processes due to elastic plasma particle-dust collisions and collisions with neutrals. It is shown that when the wavelength of the wave is much larger than the mean free path for effective collisions, the properties of the waves are different from those considered previously. A negative mass instability is found in this domain of frequencies when the effective mean free path of ions is larger than the effective mean free path of electrons. In the absence of neutrals, this appears to be possible only if the temperature of ions exceeds the electron temperature. This can occur in laboratory experiments and space plasmas but not in plasma-etching experiments. In the absence of instability, a new dust oscillation, a dust charging mode, is found, whose frequency is almost constant over a certain range of wave numbers. It is inversely proportional to the dust mass and charging frequency of the dust. A new dust electron sound wave is found for frequencies less than the frequency of the dust charging mode. The velocity of the dust electron sound wave is determined by the electron temperature but not the ion temperature, as for the usual dust sound waves, with the electron temperature substantially exceeding the ion temperature

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