Post #5758

What does it take to call home from the Moon? For most of human spaceflight history, the go to for communications has been radio waves, a technology that has served us remarkably well, but one that is beginning to show its age. When NASA's Artemis II mission carried four astronauts around the Moon in April the year, engineers quietly tested a laser communications terminal that could one day rewrite the rules of deep space exploration. Bolted to the exterior of the Orion spacecraft, the Orion Artemis II Optical Communications System that was developed by MIT Lincoln Laboratory, became the first laser communications terminal ever to support a crewed mission at lunar distance. Rather than radio waves, the device used invisible infrared light to carry data between the spacecraft and receivers on Earth, exploiting the fact that the shorter the wavelength, the more information you can squeeze into a single beam. Traditional radio systems, operating at the distances involved in a lunar mission, were limited to single digit megabits per second. The optical terminal routinely achieved downlink speeds of 260 megabits per second, and ground stations at NASA's Jet Propulsion Laboratory and White Sands Complex set a record of their own. In just under an hour, they received, processed it and retransmitted it to mission control! Until I had fibre installed, this was far superior than my home broadband system. Over the course of the roughly ten day journey, the system transferred 484 gigabytes of data between Orion and the ground in total. Those figures weren't just impressive on paper, they translated directly into the images that stopped the world. The striking photographs of Earthset, Earthrise, and the solar eclipse captured from the Moon's far side, images that circulated across front pages and social media feeds within hours of being taken. It all came home via that laser link. Source:Universe Today @EverythingScience