Deep Space Optical Communication(DSOC)

Deep Space Optical Communication(DSOC)

News: NASA’s Psyche spacecraft, currently over 16 million kilometres away in space, successfully fired a laser signal at Earth on November 14.

Background:
• The spacecraft is on its way to a unique metal-rich asteroid, orbiting the Sun between Mars and Jupiter. Scientists believe this asteroid is the nickel-iron core of an early planet, studying which could provide unique insights into the impenetrable iron core of our own planet.
• Simultaneously, it will also carry out another mission that might hold the key to future space exploration.

What is Deep Space Optical Communication?
• Deep Space Optical Communication (DSOC) is a NASA experiment that uses laser beams to transmit data between a spacecraft and a ground network.
• DSOC aims to achieve a 10 to 100 times improvement in data rate and efficiency over conventional radio frequency (RF) systems, without adding more mass, volume, power, or spectrum.
• DSOC is part of the Psyche mission, which is scheduled to launch in 2023 and explore a metal-rich asteroid.
• DSOC requires a laser beacon from Earth to assist in pointing and stabilizing the downlink laser beam. DSOC is the first demonstration of optical communication beyond the Earth-Moon system.

How does DSOC work?
• Transmitter and Receiver: The DSOC system consists of a near-infrared laser transmitter to send highrate data to Earth, and a sensitive photon-counting camera to receive ground-transmitted low-rate data. The transceiver is mounted on an assembly of struts and actuators that stabilizes the optics from spacecraft vibrations.
• Laser Beacon: The architecture of DSOC is based on transmitting a laser beacon from Earth to assist in line-of-sight stabilization and pointing back of the downlink laser beam.
• Error-Free Communications: Efficient codes are used for error-free communications1. The system must correct for background noise (scattered light) from Earth’s atmosphere and the Sun.
• Ground Infrastructure: For the purposes of DSOC, two ground telescopes have been updated to communicate with the flight laser transceiver. A high-power near-infrared laser transmitter has been integrated with the Optical Communications Telescope Laboratory at JPL’s Table Mountain facility near Wrightwood, California.
• DSOC achieves precise pointing through the use of near-infrared lasers, isolation from spacecraft vibrations, and adaptive systems to compensate for changing positions, making it a revolutionary approach for deep space missions.

Conclusion
• DSOC is a significant advancement in space communication technology, enabling the transmission of higher data rates from deep space, which will better enable future human and robotic exploration missions.