NASA To Equip International Space Station With Frikkin Lasers (for Comms)

US space agency NASA plans to run a technology demonstration for space lasers using the International Space Station next month, to test how this could be used to transmit terabytes of data back from science and exploration missions.

According to NASA, this demonstration will form the agency's first bi-directional, end-to-end laser communications relay by working with an existing laser-based satellite to communicate with a research laboratory back on Earth.

The ultimate goal of this and other laser demonstrations is to integrate laser communications as a capability within NASA's space communications networks, the Near Space Network and Deep Space Network, the agency said.

This current project involves fitting the space station with a module known as ILLUMA-T, which in the grand tradition of unworkable acronyms is claimed to stand for Integrated Laser Communications Relay Demonstration Low Earth Orbit User Modem and Amplifier Terminal.

The business end of ILLUMA-T is comprised of a telescope and two-axis gimbal which allows it to track the LCRD satellite in geosynchronous orbit. This optical module is described as being the size of a microwave, while the entire unit is comparable to a standard refrigerator.

LCRD, or Laser Communications Relay Demonstration, was launched in December 2021 and is currently being used to test laser communications from geosynchronous orbit by transmitting data between two ground stations on Earth in a series of experiments, NASA said.

The idea of the demonstration is for ILLUMA-T to beam data from the space station to LCRD at 1.2 Gbps, and LCRD will then relay the data down to optical ground stations in either California or Hawaii. From there, the data is transmitted to the LCRD Mission Operations Center in New Mexico, before finally being forwarded to the ILLUMA-T ground operations team at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Engineers at Goddard are set to "determine if the data sent through this end-to-end relay process is accurate and of high-quality," which presumably means checking whether the signal-to-noise ratio is good enough to make this a viable communications link for receiving data from space-borne experiments.

If all goes well, ILLUMA-T could become an operational part of the space station and substantially increase the volume of data that can be transmitted to and from the orbiting laboratory, NASA claimed.

Communications with the space station are typically via the Tracking and Data Relay Satellite (TDRS) network, which use radio signals to send data back, with the most recent generation of satellites offering ground reception rates of 6 Mbps in the S-band and 800 Mbps in the Ku- and Ka-bands.

According to Space.com, ILLUMA-T is set to be lofted to orbit aboard a Cargo Dragon spacecraft as a part of SpaceX's CRS-29 resupply mission, currently scheduled for November 5.

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Earlier this year, the space agency announced another laser trial, the Deep Space Optical Communications (DSOC) experiment, which it was hoped might one day be used for high-speed communications with missions on Mars.

NASA is not the only organization using lasers for space communications. SpaceX's Starlink satellite broadband service uses lasers for mesh network links between satellites that are claimed to be able to transfer data at up to 100 Gbps.

Northumbria University in the UK is also working on a laser communication system for small satellites designed with hardware the size of miniature CubeSats in mind, and is hoping to test this with a pair of prototype satellites in 2025. ®