NASA’s Deep Space Optical Communications (DSOC) experiment has beamed a near-infrared laser encoded with test data from nearly 10 million miles (16 million kilometers) away – about 40 times farther than the Moon is from Earth – to the Hale Telescope at Caltech’s Palomar Observatory in San Diego County, California. This is the farthest-ever demonstration of optical communications.
Riding aboard the recently launched Psyche spacecraft, DSOC is configured to send high-bandwidth test data to Earth during its two-year technology demonstration as Psyche travels to the main asteroid belt between Mars and Jupiter. NASA’s Jet Propulsion Laboratory in Southern California manages both DSOC and Psyche.
The tech demo achieved “first light” in the early hours of Nov. 14 after its flight laser transceiver – a cutting-edge instrument aboard Psyche capable of sending and receiving near-infrared signals – locked onto a powerful uplink laser beacon transmitted from the Optical Communications Telescope Laboratory at JPL’s Table Mountain Facility near Wrightwood, California. The uplink beacon helped the transceiver aim its downlink laser back to Palomar (which is 100 miles, or 130 kilometers, south of Table Mountain) while automated systems on the transceiver and ground stations fine-tuned its pointing.
“Achieving first light is one of many critical DSOC milestones in the coming months, paving the way toward higher-data-rate communications capable of sending scientific information, high-definition imagery, and streaming video in support of humanity’s next giant leap: sending humans to Mars,” said Trudy Kortes, director of Technology Demonstrations at NASA Headquarters in Washington.
Test data also was sent simultaneously via the uplink and downlink lasers, a procedure known as “closing the link” which is a primary objective of the experiment. While the technology demonstration isn’t transmitting Psyche mission data, it works closely with the Psyche mission-support team to ensure DSOC operations don’t interfere with those of the spacecraft.
“Tuesday morning’s test was the first to fully incorporate the ground assets and flight transceiver, requiring the DSOC and Psyche operations teams to work in tandem,” said Meera Srinivasan, operations lead for DSOC at JPL. “It was a formidable challenge, and we have a lot more work to do, but for a short time, we were able to transmit, receive, and decode some data.”
Before this achievement, the project needed to check the boxes on several other milestones, from removing the protective cover for the flight laser transceiver to powering up the instrument. Meanwhile, the Psyche spacecraft is carrying out its own checkouts, including powering up its propulsion systems and testing instruments that will be used to study the asteroid Psyche when it arrives there in 2028.