The Deep Space Optical Communications Project Ground Laser Receiver

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. The DSOC Ground Laser Receiver (GLR) has been developed by the Jet Propulsion Laboratory and installed at the Palomar Observatory 5m Hale telescope in order to receive the optical downlink signal from the FLT, and is capable of processing discrete downlink data rates from 56 kbps to 265 Mbps over the course of the mission spanning an approximate range of 0.06 to 2.7 AU. In this paper we review the architecture of the completed GLR and its subsystems: (i) the GLR Optics Assembly (GLROA) that acquires the downlink signal and couples it to (ii) the GLR Detector Assembly (GDA) that features a superconducting nanowire single photon counting detector (SNSPD) array, (iii) the GLR Signal Processing Assembly (GSPA) that demodulates and decodes the pulse-position-modulated downlink waveform, and (iv) the GLR Monitor and Control software that is used to interface with the Hale telescope and operate the entire system. We discuss GLR operations in response to planned DSOC downlink activities, and present key results from end-to-end performance tests conducted with FLT hardware, as well as operational readiness test results that demonstrate Ground Laser Receiver station readiness to meet DSOC objectives.