NASA is demonstrating laser communications on several missions demonstrating the benefits of infrared light for science and research missions transmitting terabytes of critical data. This November, the International Space Station will host a “flashy” technology demonstration. The ILLUMA-T (Integrated Low Earth Orbit Integrated Laser Communications Display Modem and Amplifier) ​​payload was launched to the International Space Station to demonstrate how missions in low Earth orbit could benefit from laser communications.

Laser communications uses invisible infrared light to send and receive information at higher data rates, allowing spacecraft to send more data to Earth in a single transmission and accelerating discovery for researchers.

Led by NASA’s Space Communications and Navigation (SCaN) program, ILLUMA-T works with the agency’s LCRD (Laser Communications Relay Display) to complete NASA’s first bidirectional end-to-end laser communications relay. LCRD was launched in December 2021 and is currently demonstrating the benefits of laser communications from geosynchronous orbit by transmitting data between two ground stations on Earth in a series of experiments.

Some of LCRD’s experiments include studying the effects of the atmosphere on laser signals, proving LCRD’s ability to work with multiple users, testing networking capabilities such as delay/interruption tolerant networking (DTN) over laser links, and investigating advanced navigation capabilities. Once installed outside the space station, ILLUMA-T will complete NASA’s first in-space demonstration of two-way laser transmission capabilities.

How does it work

The ILLUMA-T optical module consists of a telescope and a two-axis gimbal, allowing the LCRD to be guided and tracked in geosynchronous orbit. The size of the optical module is roughly similar to a microwave oven, and the load itself is comparable to an ordinary refrigerator.

ILLUMA-T will transmit data from the space station to the LCRD at a rate of 1.2 gigabits per second, which will then send the data to optical ground stations in California or Hawaii. Once the data reaches these ground stations, it will be sent to NASA’s LCRD Mission Operations Center at the White Sands complex in Las Cruces, New Mexico. The data will then be sent to ILLUMA-T ground operations teams at Goddard Space Flight Center in Greenbelt, Maryland. Here, engineers will determine whether the data sent through this end-to-end transfer process is accurate and of high quality.

“NASA Goddard’s primary role is to ensure successful laser communications and payload operation with the LCRD and the space station,” said ILLUMA-T Deputy Project Manager Matt Magsamen. “With LCRD actively conducting experiments testing and improving laser systems, we look forward to taking space communications capabilities to the next level and monitoring the success of this collaboration between the two payloads.”

The end-to-end laser communication experiment begins when ILLUMA-T transmits the first beam of laser light to the LCRD through the optical telescope. After an experimental phase with the LCRD, ILLUMA-T could become a working part of the space station, greatly increasing the amount of data NASA can send to and from the orbiting laboratory.

Transmitting data to relay satellites is not a new development for the space station. Since its completion in 1998, the orbiting laboratory has relied on a fleet of radio frequency relay satellites known as NASA’s Tracking and Data Relay Satellites, which are part of the agency’s Near Space Network. Relay satellites provide missions that are in constant contact with the Earth because they can see the spacecraft and the ground antenna simultaneously.

Laser communications could be a game changer for researchers on Earth conducting scientific and technological research aboard the space station. Astronauts study biological and physical sciences, technology, Earth observation, etc. in an orbiting laboratory. Conducts research in fields for the benefit of humanity. ILLUMA-T can provide higher data rates for these experiments and send more data to Earth simultaneously. In fact, at 1.2 Gbps, ILLUMA-T can transfer data equivalent to an average movie in less than a minute.

The ILLUMA-T/LCRD end-to-end laser relay communications system is one small step for NASA, but a giant leap for space communications capabilities. Along with past and future demonstrations, NASA is demonstrating the benefits of laser communications systems for both the Earth’s environment and deep space exploration. The goal of these demonstrations is to integrate laser communications as a capability into NASA’s space communications network: the Near Space Network and the Deep Space Network. Source