NASA’s Deep Space Optical Communications (DSOC) experiment has wrapped a two-year technology demonstration, setting multiple Mars-distance laser communications records and exceeding its technical goals. Flying aboard the Psyche spacecraft since 2023, the demo validated reliable high-rate laser links over interplanetary distances, laying groundwork for future human and robotic missions that will require far greater bandwidth than traditional radio systems can provide. Full program details are available on NASA’s project page.
Record-setting results
- Completed its 65th and final optical pass with a closed two-way laser link at a distance of about 218 million miles (351 million kilometers).
- Streamed an ultra-high-definition test video to Earth on Dec. 11, 2023, from over 19 million miles at up to 267 megabits per second.
- Surpassed deep-space optical distance records by downlinking Psyche data on Dec. 3, 2024, from roughly 307 million miles away, farther than the average Earth–Mars distance.
- Delivered a cumulative 13.6 terabits of engineering and test data to ground stations.
- Demonstrated broadband-like data rates and robust link closure at Mars-class ranges.
How the optical link worked
Managed by NASA’s Jet Propulsion Laboratory, DSOC paired a flight laser transceiver on Psyche with precision ground systems. A 3-kilowatt uplink laser from JPL’s Table Mountain Facility sent a beacon that enabled the spacecraft to point its downlink precisely back to Earth. With Earth and Psyche both in motion and one-way light times stretching to several minutes, maintaining alignment demanded exacting pointing and timing.
For downlink reception, the team used the 200-inch Hale Telescope at Caltech’s Palomar Observatory as the primary optical ground terminal. The telescope’s large aperture collected extremely faint, photon-starved signals, which were then processed by a high-efficiency detector array to decode the data. Operations continued through environmental challenges, including weather that periodically closed ground stations, while teams refined procedures and performance over weekly passes.
Hybrid and arrayed reception tests
DSOC also validated hybrid radio–optical reception at NASA’s Deep Space Network (DSN) Goldstone complex. An experimental antenna retrofitted with seven mirrors totaling about 3 feet in diameter received the optical downlink while simultaneously supporting radio-frequency signals. In parallel, the team practiced optical “arraying” by collecting the same signal with Palomar and a 1-meter telescope at Table Mountain, demonstrating techniques to strengthen weak links and add redundancy—methods long used in radio that are now migrating to optical communications.
Implications for Mars and beyond
Deep-space laser links promise major increases in data return—supporting real-time high-definition imagery, faster delivery of science measurements, and more flexible mission operations. As demand grows for bandwidth from the Moon to Mars, optical systems can augment the DSN’s radio infrastructure, easing bottlenecks and enabling richer communications for astronauts and science payloads.
DSOC was funded by NASA’s Space Technology Mission Directorate through the Technology Demonstration Missions Program with support from the Space Communications and Navigation program. The successful conclusion of the demonstration establishes a technical foundation for operational optical terminals on future exploration missions.
Source: NASA
