جهشي عظيم در صنعت ارتباطات : ارسال يک ويديو از ايستگاه فضايي بين المللي به زمين با ليزر

International Space Station beams a video back to Earth using lasers (video)

In April, NASA sent special equipment to the ISS that'll be able to test if laser beams can effectively transmit large amounts of data from space. Sounds like the project (called Optical Payload for Lasercomm Science) is going well thus far, because it successfully beamed a 27-second "Hello, World!" video back to Earth for the first time. The entire transmission lasted 148 seconds, but it took the system only 3.5 seconds to send each copy of the video clip to the project's ground station at the Table Mountain Observatory in California. It would've taken the ISS' radio waves-based technologies 10 minutes to do what OPALS did for less than two; the connection even reached a peak of 50 megabits per second.

To make that happen, the hardware on the ISS had to detect a beacon fired by the ground station before it can send signals over the laser beam back to the ground. That's extremely difficult to do, as the ISS orbits the planet at 260 miles above ground, with a speed of 17,500mph — in fact, NASA compares the feat to shining a laser pointer to the tip of someone's hair 30 feet away and keeping it at that point while they go around moving. The agency's doing all these not just to provide the ISS a faster connection, though. OPALS is actually part of NASA's efforts to find a better means of communication for future spacecraft right out of sci-fi flicks meant for real-life deep space exploration.