COMPLETION OF NASA’S TWO-YEAR LASER COMMUNICATIONS RELAY DEMONSTRATION (LCRD) EXPERIMENT PROGRAM

The National Aeronautics and Space Administration’s (NASA) Laser Communications RelayDemonstration (LCRD) completed its two-year experiment program in June 2024. The LCRDgeosynchronous payload includes two laser communications terminals interconnected via an onboardelectronic switch. The payload relays data between two optical ground stations located in California andHawaii and can also exchange data with an RF ground station in New Mexico. The addition of theIntegrated LCRD Low-Earth Orbit (LEO) User Modem and Amplifier Terminal (ILLUMA-T) on theInternational Space Station in 2023 enabled data relay demonstrations between a laser terminal in lowEarth orbit and either one of the optical ground stations or the RF ground station.The experiment program has included a variety of experiments originating within the LCRD project,NASA, and industry. The experiments have included measurements of the effects of the atmosphericoptical channel (turbulence, weather) on the performance and availability of laser communications,adaptive optics characterization, demonstration of optimetrics techniques, and demonstration ofDelay/Disruption Tolerant Networking (DTN). Furthermore, various future operational scenariosincluding robotic and exploration missions and various network service configurations have beenemulated. This conference paper provides an overview and highlights of the LCRD experiment programwith an emphasis on activities and results since the start of the ILLUMA-T testing in December 2023. Adiscussion of the expectations for the next phase of the LCRD mission, as well as how LCRD resultsmay be applied to future applications is also included.LCRD is a joint project involving NASA Goddard Space Flight Center (GSFC), the California Institute ofTechnology Jet Propulsion Laboratory (JPL), and Massachusetts Institute of Technology LincolnLaboratory (MIT LL).