PALS — The optimal laser for determining optimal ablative laser propulsion parameters?

Ablative laser propulsion (ALP) could revolutionize space travel by reducing the 30:1 propellant/payload ratio needed for near‐earth orbit 50‐fold. To date, experiments have demonstrated the necessary efficiency, coupling coefficient, and specific impulse for application, but were performed at pulse energies and spot sizes much smaller than required and at wavelengths not usable in the atmosphere. Also, most experiments have not simultaneously measured the properties of the ions produced or of the ablated surface, properties that would allow full understanding of the propulsion properties in terms of ion characteristics.Realistic measurement of laser propulsion parameters is proposed using PALS (Prague Asterix Laser System), whose parameters, except for pulse rate and wavelength — pulse energy (∼1kJ), pulse length (400ps), beam diameter (∼29cm), and flat beam profile — equal those required for application. PALS wavelength is a little short (1.3μm vs. >1.5μm) but is closer than any other laser available an...