DSOC, an experiment that could change the way spacecraft communicate, has sent data using a laser to and from the Moon for the first time. The transmitted data takes the form of bits (the smallest units of data that a computer can process) encoded in laser photons—quantum particles of light.
NASA’s Deep Space Optical Communications (DSOC) experiment aimed a near-infrared laser encoded with test data nearly 10 million miles (16 million kilometers) away—about 40 times farther than the Moon from Earth—at the Hale Telescope at Caltech’s Palomar Observatory. This is the furthest demonstration of optical communication yet.
Aboard the newly launched Psyche spacecraft, DSOC is set to send high-throughput test data to Earth during a two-year technology demonstration while Psyche travels to the main asteroid belt between Mars and Jupiter. NASA’s Jet Propulsion Laboratory in Southern California operates both DSOC and Psyche.
A technical demonstration of the technology was conducted early on the morning of November 14 after the flight laser transceiver – an advanced instrument on board Psyche capable of sending and receiving near-infrared signals – was detected on a high-power uplink laser beacon transmitted from the Optical Telecommunications Telescope Laboratory at the Jet Propulsion Laboratory’s Table Mountain Base near Wrightwood, California. The uplink beacon helped the transceiver point the downlink laser back to Palomar (which is 100 miles or 130 kilometers south of Table Mountain), while automated systems at the transceiver and ground stations fine-tuned its guidance.
The achievement is one of DSOC’s many major milestones in the coming months, paving the way for higher data speeds capable of transmitting scientific information, high-definition images and streaming video in support of humanity’s next giant leap: sending humans into space. Mars,” said Trudy Cortez, director of technology demonstration at NASA Headquarters in Washington.
Test data was also sent simultaneously through the uplink and downlink lasers. This procedure, known as “channel closure”, is the main purpose of the experiment. While the technology demonstration does not transmit data to the Psyche mission, it works closely with the Psyche mission support team to ensure that DSOC operations do not interfere with spacecraft operations.
“Tuesday morning’s test was the first to fully utilize ground assets and the flight transceiver, requiring DSOC and Psyche operations teams to work in tandem,” said Meera Srinivasan, DSOC operations manager at JPL. “It was a significant challenge and we still have a lot of work to do, but in a short time we were able to transmit, receive and decode some data.”
Before this achievement, the project needed to verify the installations at several other stages, from removing the protective cover from the flight laser transceiver to turning on the instrument. Meanwhile, the Psyche spacecraft is conducting its own checks, including activating propulsion systems and testing instruments that will be used to study the Psyche asteroid when it arrives there in 2028.
Following a successful initial launch, the DSOC team will now work to improve the systems that control the downlink laser pointing on board the transceiver. Once this is achieved, the project can begin demonstrating support for high-speed data transmission from the transceiver to Palomar at various distances from Earth. This data takes the form of bits (the smallest units of data a computer can process) encoded in laser photons—quantum particles of light. After a special superconducting high-efficiency detector array detects the photons, new signal processing techniques are used to extract data from the single photons arriving at the Hale telescope.
The goal of the DSOC experiment is to demonstrate data rates 10 to 100 times faster than current radio frequency systems used on spacecraft today. Both radio and near-infrared laser communications use electromagnetic waves to transmit data, but near-infrared light combines data into much denser waves, allowing ground stations to receive more data. This will help future human and robotic exploration missions and support higher resolution scientific instruments.
“Optical communications are a boon for scientists and explorers who always want more from their space missions and will enable human exploration of deep space,” said Dr. Jason Mitchell, director of the Advanced Communications and Navigation Technologies Office at NASA’s Space Communications and Navigation Directorate. (SCAN) program. “More data means more discoveries.”
The Psyche mission is led by Arizona State University. JPL is responsible for overall mission management, systems engineering, integration and testing, and mission operations. Psyche is the 14th mission selected from NASA’s Science Mission Directorate’s Discovery Program, which is managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. The launch service was managed by NASA’s Launch Services program, based at the agency’s Kennedy Space Center. Maxar Technologies in Palo Alto, California, provided the spacecraft chassis with high-power solar electric propulsion.
