The impact and mitigation of satellite constellations on astronomical laser propagation

Abstract U.S. adaptive optics telescopes using laser guide stars for an artificial reference source are impacted by the presence of satellite constellations (SATCONs) because of the requirement to follow Department of Defense laser deconfliction protocol as administered by the U.S. Space Command’s Laser Clearinghouse. The Laser Deconfliction protocol is designed to protect damage to satellites and their operation due to inadvertent illumination. As SATCONs begin to dominate the number of satellites in orbit they contribute highly to the number of closure windows when the astronomical lasers cannot be propagated. If left unchecked, the proposed number of SATCONs over the next decade will severely impact the laser open-shutter time, especially for the U.S. extremely large telescopes (US-ELTs) reducing the competitiveness of U.S. astronomical adaptive optics. Mitigation of the closure windows is therefore important.