NASA will soon demonstrate a laser-based communication system between ground facilities and the International Space Station (ISS). The technology will boost data transmission speeds by 10 to 100 times the current capabilities, potentially paving the way for a new standard in deep space comms.
Radio has been the standard communication tech for spacecraft since the very beginning, but it’s showing its age as the amount of data being beamed to and from space surges. Data can be encoded far more densely into light than radio waves, so optical systems are being explored for high-speed connections between spacecraft and facilities on the ground.
NASA is planning a major step towards that goal, with the launch and test of its first two-way, end-to-end laser communications system. It’s known as the Integrated Laser Communications Relay Demonstration Low Earth Orbit User Modem and Amplifier Terminal (ILLUMA-T), which is due to launch in November aboard SpaceX’s Dragon spacecraft.
ILLUMA-T, which consists of a telescope and a two-axis gimbal, will be installed on the exterior of the space station. From there, it will track and communicate with the Laser Communications Relay Demonstration (LCRD) satellite, which NASA launched in December 2021. The LCRD, parked in geosynchronous orbit, will then beam the signals down to ground stations in California and Hawaii. After it arrives on the ground, the data will be forwarded on to the ILLUMA-T team at Goddard Space Flight Center to check that it’s still accurate and high quality at those speeds.
The data will be relayed at speeds of 1.2 gigabits per second, which is up to 100 times faster than the old radio communications and twice as fast as previous laser-based demonstrations. However, other teams have managed even faster data transmission speeds using lasers, including the TBIRD satellite which transmitted data at 100 Gbps in a test last year.
If the experiment is a success, NASA hopes that laser communication could become a regular part of operations not only on the ISS, but for the Near Space Network – which would cover satellites orbiting Earth and the Moon – and the Deep Space Network, which communicates with spacecraft exploring farther away in the solar system.