Deep Space Optical Communications

Deep Space Optical Communications (DSOC) is a laser space communication system in operation that improved communications performance 10 to 100 times over radio frequency technology without incurring increases in mass, volume or power. DSOC is capable of providing high bandwidth downlinks from beyond cislunar space.

The project is led by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. In April 2024, the system successfully communicated with the Psyche spacecraft at a distance of 140 million miles.

Overview

Future human expeditions may require a steady stream of high-definition imagery, live video feeds, and real-time data transmission across Outer space, deep space to enable timely guidance and updates during the long-distance journeys. Even at its maximum data rate of 5.2 megabits per second (Mb/s), the Mars Reconnaissance Orbiter (MRO) requires 7.5 hours to transmit all of its onboard recorder, and 1.5 hours to send a single HiRISE image to be processed back on Earth. New high-resolution hyperspectral imagers put further demands on their communications system, requiring even higher data rates. Laser beams to the spacecraft will be sent from a smaller telescope at the Table Mountain Observatory in California.

First light was achieved on 14 November 2023.

The first video successfully beamed from space using the technology occurred on 11 December, 2023 from a record-setting 19 million miles away (31 million kilometers, or about 80 times the Earth-Moon distance).

Design

This new technology will employ advanced lasers in the Infrared#Regions within the infrared, near-infrared region (1.55 μm) of the electromagnetic spectrum. The architecture is based on transmitting a laser beacon from Earth to assist line-of-sight stabilization and pointing back of the downlink laser beam. In addition, efficient codes are used for error free communications. The system must correct for background noise (scattered light) from Earth's atmosphere and the Sun. Given the current hardware (1 m ground transmit, 5 m ground receive, 22 cm spacecraft telescope), the uplink is expected to reach 292 kbit/s at a distance of , with the downlink reaching 100 Mbit/s at the same distance.Deep Space Optical Communications (DSOC)
(PDF). Overview Poster. Biswas NASA July 2014. The transmitted beam-width is inversely proportional to the frequency used, so the shorter the wavelength used, the narrower and more focused a beam can be made. The downlink bandwidth will depend on the ground telescope diameter and will be less during daytime.

Three key DSOC technologies developed for the project include:

A Deep Space Optical Communication demonstration is included with NASA's Psyche (spacecraft), ''Psyche'' mission, launched on October 13, 2023. The ''Psyche'' spacecraft will explore the metal asteroid 16 Psyche, reaching the asteroid belt in 2029.

DSOC First light (astronomy), first light was achieved on November 14, 2023. The experiment successfully transmitted a 15-second ultra-high definition video on December 11 from a location 19 million miles away from Earth (31 million kilometers, or about 80 times the Earth-Moon distance). The pre-loaded video of a cat named Taters was sent at the system’s maximum bit rate of 267 megabits per second (Mbps) and took 101 seconds to reach Earth. An additional test in July 2024 demonstrated communication over a distance of 467 million kilometers (290 million miles).

See also

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References

{{Lasers

Laser communication in space