The Deep Space Optical Communications project ground laser transmitter

The Deep Space Optical Communication (DSOC) project will conduct its technology demonstration concurrently with NASA's Psyche mission, which hosts the DSOC flight transceiver (FLT) on its spacecraft and will operate it over an approximate range of 0.05 to 3.0 AU. The DSOC Ground Laser Transmitter (GLT), located at the Jet Propulsion Laboratory's Optical Communication Telescope Laboratory (OCTL) near Wrightwood, CA, has been developed to provide a high-power optical uplink beacon that serves as a line-of-sight FLT downlink pointing reference and delivers low rate (1.8 kbps) uplink command data to the FLT. In this paper we present an overview of the completed GLT and its subsystems: (i) the multi-beam Uplink Laser Assembly (ULA) capable of transmitting up to 7 kW of average power, (ii) the Uplink Data Formatter that modulates the ULA, (iii) the GLT Optics Assembly that manages the ULA high power output beams and couples them to the OCTL telescope, (iv) the Uplink Laser Safety Assembly that automatically avoids hazardous laser irradiation by shuttering the laser output, and (v) the custom-developed Monitor and Control software used to test and operate the entire system. We discuss various implementation and operational challenges, and review results from key system performance verification and operational tests, indicating the readiness of the Ground Laser Transmitter station to fulfill the DSOC technology demonstration objectives.