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Capable of receiving both radio frequency and optical signals, the DSN\u2019s hybrid antenna has tracked and decoded the downlink laser from DSOC, aboard NASA\u2019s Psyche mission.<\/em><\/p>\n An experimental antenna has received both radio frequency and near-infrared laser signals from NASA\u2019s Psyche spacecraft as it travels through deep space. This shows it\u2019s possible for the giant dish antennas of NASA\u2019s Deep Space Network (DSN), which communicate with spacecraft via radio waves, to be retrofitted for optical, or laser, communications.<\/p>\n By packing more data into transmissions, optical communication will enable new space exploration capabilities while supporting the DSN as demand on the network grows.<\/p>\n The 34-meter (112-foot) radio-frequency-optical-hybrid antenna, called Deep Space Station 13, has tracked the downlink laser from NASA\u2019s Deep Space Optical Communications (DSOC) technology demonstration since November 2023. The tech demo\u2019s flight laser transceiver is riding with the agency\u2019s Psyche spacecraft, which launched on Oct. 13, 2023.<\/p>\n The hybrid antenna is located at the DSN\u2019s Goldstone Deep Space Communications Complex, near Barstow, California, and isn\u2019t part of the DSOC experiment. The DSN, DSOC, and Psyche are managed by NASA\u2019s Jet Propulsion Laboratory in Southern California.<\/p>\n \u201cOur hybrid antenna has been able to successfully and reliably lock onto and track the DSOC downlink since shortly after the tech demo launched,\u201d said Amy Smith, DSN deputy manager at JPL. \u201cIt also received Psyche\u2019s radio frequency signal, so we have demonstrated synchronous radio and optical frequency deep space communications for the first time.\u201d<\/p>\n In late 2023, the hybrid antenna downlinked data from 20 million miles (32 million kilometers) away at a rate of 15.63 megabits per second \u2013 about 40 times faster than radio frequency communications at that distance. On Jan. 1, 2024, the antenna downlinked a team photograph that had been uploaded to DSOC before Psyche\u2019s launch.<\/p>\n In order to detect the laser\u2019s photons (quantum particles of light), seven ultra-precise segmented mirrors were attached to the inside of the hybrid antenna\u2019s curved surface. Resembling the hexagonal mirrors of NASA\u2019s James Webb Space Telescope, these segments mimic the light-collecting aperture of a 3.3-foot (1-meter) aperture telescope. As the laser photons arrive at the antenna, each mirror reflects the photons and precisely redirects them into a high-exposure camera attached to the antenna\u2019s subreflector suspended above the center of the dish.<\/p>\n The laser signal collected by the camera is then transmitted through optical fiber that feeds into a cryogenically cooled semiconducting nanowire single photon detector. Designed and built by JPL\u2019s Microdevices Laboratory, the detector is identical to the one used at Caltech\u2019s Palomar Observatory, in San Diego County, California, which acts as DSOC\u2019s downlink ground station.<\/p>\n \u201cIt\u2019s a high-tolerance optical system built on a 34-meter flexible structure,\u201d said Barzia Tehrani, communications ground systems deputy manager and delivery manager for the hybrid antenna at JPL. \u201cWe use a system of mirrors, precise sensors, and cameras to actively align and direct laser from deep space into a fiber reaching the detector.\u201d<\/p>\n Tehrani hopes the antenna will be sensitive enough to detect the laser signal sent from Mars at its farthest point from Earth (2 \u00bd times the distance from the Sun to Earth). Psyche will be at that distance in June on its way to the main asteroid belt between Mars and Jupiter to investigate the metal-rich asteroid Psyche.<\/p>\n The seven-segment reflector on the antenna is a proof of concept for a scaled-up and more powerful version with 64 segments \u2013 the equivalent of a 26-foot (8-meter) aperture telescope \u2013 that could be used in the future.<\/p>\n DSOC is paving the way for higher-data-rate communications capable of transmitting complex scientific information, video, and high-definition imagery in support of humanity\u2019s next giant leap: sending humans to Mars. The tech demo recently streamed the first ultra-high-definition video from deep space at record-setting bitrates.<\/p>\n Retrofitting radio frequency antennas with optical terminals and constructing purpose-built hybrid antennas could be a solution to the current lack of a dedicated optical ground infrastructure. The DSN has 14 dishes distributed across facilities in California, Madrid, and Canberra, Australia. Hybrid antennas could rely on optical communications to receive high volumes of data and use radio frequencies for less bandwidth-intensive data, such as telemetry (health and positional information).<\/p>\n \u201cFor decades, we have been adding new radio frequencies to the DSN\u2019s giant antennas located around the globe, so the most feasible next step is to include optical frequencies,\u201d said Tehrani. \u201cWe can have one asset doing two things at the same time; converting our communication roads into highways and saving time, money, and resources.\u201d<\/p>\n DSOC is the latest in a series of optical communication demonstrations\u00a0funded by NASA\u2019s Technology Demonstration Missions (TDM) program and the agency\u2019s Space Communications and Navigation (SCaN) program. JPL, a division of Caltech in Pasadena, California, manages DSOC for TDM within NASA\u2019s Space Technology Mission Directorate and SCaN within the agency\u2019s Space Operations Mission Directorate.<\/p>\n For more about NASA\u2019s optical communications projects, visit:<\/p>\n<\/p>\n