Launched in 2023 aboard the Psyche spacecraft, the technology demonstration has proven that information encoded in laser light can be reliably transmitted, received and decoded across vast interplanetary distances. The system recently completed its 65th and final trial, successfully exchanging laser signals with Psyche from 351 million kilometres away – a distance comparable to Mars.
“NASA is setting the United States on the path to Mars, and developing laser communications technology brings us closer to streaming high-definition video and returning large volumes of science data from the Red Planet faster than ever before,” acting NASA administrator Sean Duffy said. “Technology unlocks discovery, and this is another step in enabling a new era of exploration.”
The demonstration established its first link just a month after launch, proving the laser terminal aboard Psyche could send a signal back to Earth. According to NASA’s associate administrator for the Space Technology Mission Directorate, Clayton Turner, the system went on to perform beyond expectations.
“Over two years, DSOC showed it could deliver data rates similar to household broadband internet from record-breaking distances,” he said. “This included returning engineering and test data across millions of kilometres.”
The project notched several historic milestones, including transmitting an ultra-high-definition video to Earth from over 30 million kilometres away in December 2023 at speeds of 267 megabits per second, and setting a new optical communications distance record in December 2024 by downlinking data from 494 million kilometres – farther than the average Earth–Mars separation. In total, the system delivered 13.6 terabits of data.
Managed by NASA’s Jet Propulsion Laboratory (JPL) in Southern California, the demonstration involved a flight laser transceiver mounted on Psyche and a network of powerful ground stations. A three-kilowatt uplink laser at JPL’s Table Mountain facility helped guide the spacecraft’s transceiver, enabling it to return an optical signal precisely back to Earth.
Because both Earth and Psyche are moving at high speeds through space, and because light itself takes minutes to traverse the gulf, establishing a stable link required pinpoint precision from both ground- and space-based lasers.
The project also tested receiving extremely faint signals using Caltech’s Palomar Observatory, whose 200-inch telescope captured the returning photons, allowing data to be processed with specialised detectors.
Despite challenges such as poor weather and wildfires near facilities, the JPL team persevered. “We constantly refined the system and pushed the limits of what deep space optical communication can achieve,” project technologist Abi Biswas said.
Further trials included routing signals through a hybrid radio–optical antenna at NASA’s Deep Space Network site near Barstow, California, and combining signals from multiple telescopes to boost reliability – a technique known as “arraying”.
Deputy associate administrator for NASA’s Space Communications and Navigation (SCaN) program, Kevin Coggins, said the trial paves the way for next-generation missions.
“As exploration continues to evolve, astronauts on the moon and Mars will need to send back high-resolution imagery and scientific data,” he said. “Combining traditional radio systems with optical communications gives NASA the capacity to meet those demands.”
The DSOC project is the latest in a series of optical communications demonstrations supported by NASA’s Space Technology Mission Directorate and SCaN program. The Psyche mission itself is led by Arizona State University, with JPL – operated by Caltech – responsible for mission management.