Updated December 5th, 2021 at 11:04 IST

NASA's LCRD: How will 2-way laser communication work in space? All you need to know

NASA’s LCRD will be equipped with sensitive components that will provide increased communications and will eliminate the need for direct line-of-sight antennas.

Reported by: Zaini Majeed
Image: NASA | Image:self
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NASA's upcoming Laser Communications Relay Demonstration (LCRD) which will use ‘invisible lasers’ in space to propel two-way communication is a scientific breakthrough straight out of sci-fi fiction. In a glaring reality, however, the agency is set to revolutionize communication with future missions in space via the deployment of laser communications systems that will transmit data back and forth from space to Earth.

The Laser Communications Relay Demonstration (LCRD) will lift off on a United Launch Alliance Atlas V rocket during a two-hour window between 4:04 to 6:04 a.m. EST from Cape Canaveral Space Force Station in Florida, US. NASA’s LCRD is a part of the US Space Force Space Systems Command’s Space Test Program 3 (STP-3) mission and will enable the exploration of laser communications to support NASA’s future lined-up missions to the moon. Here’s how it will work:

Relaying info to and from space via the laser communication system

NASA has, for over years, used radio frequency systems to communicate with astronauts and spacecraft. As NASA’s missions into space enhance, so does the need of improving communications capabilities. Therefore, NASA’s LCRD will leverage the power of laser communications, which uses infrared light rather than radio waves, to encode and transmit information to and from Earth.

NASA’s LCRD will send data to Earth from geosynchronous orbit at 1.2 gigabits-per-second (Gbps) using the infrared lasers which are much different from radio waves due to higher frequency and hence yield more data, and information into each transmission. The radio waves and laser infrared light waves are electromagnetic radiation that is used by astronauts to encode their scientific data into the electromagnetic signals and transmit it back to the earth. 

LCRD will pack more data in a single downlink

NASA gives an example of a ‘revolutionalized’ web that allows high-definition videos, shows, and a lot of information and content that reaches us with the help of high-speed internet with technologies like fibre optic networking. Similarly, the space-based laser communications, LCRD will allow the spacecraft to send high-resolution images and videos over laser links as well as more data at once in a single download. NASA and the aerospace industry will use this technology to their advantage and more missions will use lasers to complement radiofrequency satellites and send hefty data from the spacecraft back into the Earth. 

"Using infrared lasers, LCRD will send data to Earth from geosynchronous orbit at 1.2 gigabits-per-second (Gbps). At this speed and distance, you could download a movie in under a minute," NASA explained in a post. 

Credit: NASA

Two optical modules, or telescopes, for receiving or transmitting laser signals

NASA’s LCRD will be equipped with sensitive components that will provide increased communications and will eliminate the need for direct line-of-sight antennas on Earth. According to NASA, LCRD will be fitted with two optical terminals. “One terminal receives data from a user spacecraft, while the other transmits data to ground stations on Earth,” says NASA.

The digital data will also be translated into laser signals via modems. Encoded beams of light in LCRD’s modems will relay optical modules enabling the payload to both send and receive data to and from the space missions. The modems will be invisible to the human eye and will be, along with some other components, the size of a king mattress.

Info to be transmitted to two ground stations in California and Hawaii

The encoded information on LCRD will be transmitted to the ground stations on Earth that will be fitted with telescopes to receive the beam light and modems signals. This encoded light will be translated into digital data at the Optical Ground Stations (OGS) -1 and -2, located on Table Mountain in Southern California, and on Haleakalā Volcano in Maui, Hawaii.

LCRD payload in the cleanroom at Goddard Space Flight Center. Credit: NASA 

These are locations with clear weather conditions, are remote and isolated and at a high altitude to receive the signals with clarity without the atmospheric disturbances – such as clouds and turbulence that can interfere with the quality of the laser signals once it is transmitted back to the Earth. 

Government, academia, and commercial partners can test laser capabilities 

NASA’s LCRD  will enhance the viability of the laser communications system starting from  – at approximately 22,000 miles above Earth’s surface in an area known as the geosynchronous orbit. The LCRD will invest over two years into more tests and experiments with the help of OGS-1 and OGS-2 that will send the information and data to and from one station and LCRD. NASA, government agencies, academia, and commercial companies will also meanwhile conduct experiments to detect the atmospheric disturbances and methods to make the relay service operations smooth.

Credit: NASA

NASA and the aerospace community will refine the LCRD technology for future implementation on the missions. A team of engineers in Las Cruces, N.M. will begin LCRD’s activation process by turning the payload on once it has been launched. 

Image: NASA

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Published December 5th, 2021 at 11:04 IST