Nasa testing laser system to help ISS communicate 10 times faster with Earth

The ILLUMA-T (Integrated Laser Communications Relay Demonstration Low Earth Orbit User Modem and Amplifier Terminal) payload will be launching to the International Space Station (ISS) next month to show how missions in low Earth orbit can benefit from laser communications.

The system works by using invisible infrared light to send and receive information at higher data rates, allowing spacecraft to send more data back to Earth in a single transmission.

Space laser communications technology could provide 10 to 100 times higher data rates than traditional radio frequency systems can, for the same mass and power.

The test of the technology follows the launch of Nasa’s LCRD (Laser Communications Relay Demonstration) in December 2021. This 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.

The experiments include studying atmospheric impact on laser signals, confirming the technology’s ability to work with multiple users, testing network capabilities over laser links, and investigating improved navigation capabilities.

Once ILLUMA-T is installed on the exterior of the ISS, the payload will complete Nasa’s first in-space demonstration of two-way laser relay capabilities. Its optical module is comprised of a telescope and two-axis gimbal that allows pointing and tracking of LCRD in geosynchronous orbit. The module is about the size of a microwave and the payload itself is comparable to a standard refrigerator.

The device should be able to relay data from the space station to LCRD at 1.2 gigabits-per-second. LCRD will then send the data down to optical ground stations in California or Hawaii.

ILLUMA-T deputy project manager Matt Magsamen said: “With LCRD actively conducting experiments that test and refine laser systems, we are looking forward to taking space communications capabilities to the next step and watching the success of this collaboration between the two payloads unfold.”

After its experimental phase, ILLUMA-T could become an operational part of the ISS and substantially increase the amount of data that Nasa can send to and from the orbiting laboratory.

Since its completion in 1998, the space station has relied on the 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 with constant contact with Earth because they can see the spacecraft and a ground antenna at the same time.