Orbital Re-focusing of High Energy Laser Beams from Ground for Laser-ablative Post-Mission Disposal and Debris Removal

Ground-based laser power beaming enables propulsion solutions for post-mission disposal (PMD) and active debris removal (ADR). In our conceptual study we find that the demand for large laser pulse energies (~100 kJ in ADR) can dramatically be lowered if the laser beam is refocused in orbit, enabling the usage of currently available laser technology. For PMD beam re-focusing onboard a satellite would power its laser-ablative propulsion unit. With 29 J pulses at 580 Hz repetition rate and less than 2 kg of propellant, the perigee of a small satellite at 600 km altitude could sufficiently be lowered within two years. For ADR a relay satellite would divert 400 J laser pulses and focus them over up to 40 km distance. Regarding 10k debris objects and a beam relay at 550 km altitude, debris irradiation in a triple conjunction of ground station, relay, and debris is possible several times per day.