Deep Space Optical Communications
{{Short description|Spacecraft communication system using lasers}}
{{Infobox space program
| name = Deep Space Optical Communications Demonstration
| image = Deep Space Optical Communications DSOC 2017.png
| caption= Scheme of the architecture for the planned Deep Space Optical Communications (DSOC) prototype
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| country = United States
| organization = NASA
| purpose = Laser communication in space
| manager = Jet Propulsion Laboratory
| status = Ongoing
| cost =
| duration ={{start date and age| 2017|}}–present
| firstflight =
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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.[https://www.nasa.gov/mission_pages/tdm/dsoc/index.html Deep Space Optical Communications (DSOC).] Jennifer Harbaugh, NASA News 24 October 2017. 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.{{Cite web |date=2024-04-25 |title=NASA’s Optical Comms Demo Transmits Data Over 140 Million Miles - NASA |url=https://www.nasa.gov/missions/psyche-mission/nasas-optical-comms-demo-transmits-data-over-140-million-miles/ |access-date=2024-04-25 |language=en-US}}
Overview
Future human expeditions may require a steady stream of high-definition imagery, live video feeds, and real-time data transmission across 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.[https://web.archive.org/web/20161203150128/http://scienceandtechnology.jpl.nasa.gov/research/research-topics-list/communications-computing-software/deep-space-communications Deep Space Communications]. NASA, 2017.
The precursor technology demonstration for this optical transceiver was launched in 2023 on board NASA's robotic Psyche mission to study the giant metal asteroid known as 16 Psyche. The laser beams from the spacecraft will be received by the 200 inch (5 m) Hale Telescope at Palomar Observatory in California.{{cite web|url=https://www.nasa.gov/directorates/spacetech/tdm/feature/Deep_Space_Communications|title="Lighten Up" – Deep Space Communications via Faraway Photons|publisher=NASA|editor-first=Loura|editor-last=Hall|date=October 18, 2017}} {{PD-notice}} 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.{{cite web | url=https://www.iflscience.com/earth-just-received-a-laser-beamed-message-from-16-million-kilometers-away-71634 | title=Earth Just Received a Laser-Beamed Message from 16 Million Kilometers Away | date=20 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).{{cite web | url=https://www.jpl.nasa.gov/news/nasas-tech-demo-streams-first-video-from-deep-space-via-laser | title=NASA's Tech Demo Streams First Video from Deep Space via Laser | website=Jet Propulsion Laboratory }}
Design
This new technology will employ advanced lasers in the 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 {{convert|0.4|AU|km mi}}, with the downlink reaching 100 Mbit/s at the same distance.[https://www.lpi.usra.edu/opag/july2014/posters/9-DSOC_OPAG_Poster.pdf 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:[https://www.nasa.gov/sites/default/files/atoms/files/tglavich_dsoc.pdf Deep Space Optical Communications] (PDF). Tom Glavich, NASA. 28 July 2015.[https://web.archive.org/web/20170211162245/https://www.nasa.gov/sites/default/files/atoms/files/fs_dsoc_factsheet_150910.pdf Game Changing Development: Deep Space Optical Communications (DSOC)] (PDF). Jet Propulsion Laboratory, NASA.
- a low-mass spacecraft disturbance isolation and pointing assembly for operating in the presence of spacecraft vibrational disturbance.
- a high-efficiency flight laser transmitter;
- a pair of high-efficiency photon counting detector arrays for the flight optical transceiver and the ground-based receiver (a telescope).
''Psyche'' mission
A Deep Space Optical Communication demonstration is included with NASA's Psyche mission, launched on October 13, 2023. The Psyche spacecraft will explore the metal asteroid 16 Psyche, reaching the asteroid belt in 2029.{{cite web |url=https://www.jpl.nasa.gov/news/news.php?feature=6967 |title=Deep Space Communications via Faraway Photons |publisher=NASA{{\}}Jet Propulsion Laboratory |first=Leonard |last=David |date=18 October 2017 |accessdate=4 November 2017}}{{cite web |url=https://www.nasa.gov/mission_pages/psyche/overview/index.html |title=Psyche Overview |publisher=NASA |last=Greicius |first=Tony |date=14 September 2017 |access-date=18 September 2017 |archive-date=10 November 2021 |archive-url=https://web.archive.org/web/20211110192503/https://www.nasa.gov/mission_pages/psyche/overview/index.html |url-status=dead }}{{cite web|url=https://www.jpl.nasa.gov/news/nasas-psyche-mission-on-track-for-liftoff-next-month|title=NASA's Psyche Mission on Track for Liftoff Next Month|publisher=NASA|date=6 September 2023|access-date=19 September 2023}}
DSOC 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.{{cite web|url=https://www.jpl.nasa.gov/news/nasas-tech-demo-streams-first-video-from-deep-space-via-laser|title=NASA’s Tech Demo Streams First Video From Deep Space via Laser|date=December 18, 2023|publisher=NASA/JPL-Caltech}} An additional test in July 2024 demonstrated communication over a distance of 467 million kilometers (290 million miles). {{Cite web |title=NASA’s Laser Comms Demo Makes Deep Space Record, Completes First Phase |url=https://www.jpl.nasa.gov/news/nasas-laser-comms-demo-makes-deep-space-record-completes-first-phase/ |access-date=2024-12-10 |website=NASA Jet Propulsion Laboratory (JPL) |language=en-US}}
See also
- {{annotated link|Laser_Communications_Relay_Demonstration|Laser Communications Relay Demonstration}}