NASA hopes to use lasers to shoot data to and from the International Space Station and Earth at gigabit-per-second rates by 2021.
The Laser Communications Relay Demonstration (LCRD) has the potential to become “the high-speed internet of the sky,” the American space agency said on Wednesday. The plan is to encode digital data packets into beams of light fired between the orbiting science lab and our home world.
We're told NASA will first send a payload of LCRD equipment into geosynchronous orbit around our planet. This hardware will include a switching unit that routes data in and out of two onboard optical terminals, beaming and receiving laser-encoded communications to and from Earth. It will also have a normal radio system to fall back on. This prototype craft will exchange data with bases in California and Hawaii.
The design requires the optical modules to be perfectly aligned with the ground stations to receive and transmit data efficiently. Any future spacecraft hoping to use the LCRD designs will need to have suitable control electronics to point and steady the equipment, too.
Developing technology that can sustain data rates 10 to 100 times faster than today's radio links will “revolutionize space communications,” we're told. Laser systems are less bulky than radio hardware, allowing them to have less stringent weight and power requirements.
Faster uplink and downlink rates means boffins back home can get test results faster from probes, and they will improves communications with astronauts – which is vital for human missions to far-flung places like Mars.
NASA's Steve Jurcyzk said the LCRD effort “is the next step in implementing NASA’s vision of using optical communications for both near-Earth and deep space missions.”
LCRD is still being developed and tested. If all goes smoothly, the prototype hardware will be launched into orbit in the summer of 2019. Two years later, another laser terminal will sent to the space station so astronauts on the orbiting platform can communicate with Earth via light beam. That's the idea, anyway.
“We plan to fly this new terminal in 2021, and once tested, we hope that many other Earth-orbiting NASA missions will also fly copies of it to relay their data through LCRD to the ground,” said the agency's Don Cornwell.
This work is a successor to NASA’s Lunar Laser Communications Demonstration (LLCD), an experiment in 2013 that showed it was possible to transmit data from lunar orbit to Earth at a rate of 622 megabits-per-second. Last year, LLCD was successfully used in the Lunar Atmosphere and Dust Environment Explorer (LADEE) probe, sent to sample the Moon’s atmosphere for 100 days. ®