In recent years, the International Space Station has become more and more media savvy, thanks to the efforts of astronauts to connect with Earthbound audiences via social media and Youtube. However, the communications setup, which until now relied on 1960’s vintage radio-wave transmissions, was a little outdated for this task. However, that has since changed with the addition of the Optical Payload for Lasercom Science (OPALS) laser communication system.
Developed by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, OPALS is designed to test the effectiveness of lasers as a higher-bandwidth substitute for radio waves and deal with substantially larger information packages. As Matt Abrahamson, OPALS mission manager at NASA’s Jet Propulsion Laboratory, said in a recent video statement:
We collect an enormous amount of data out in space, and we need to get it all to the ground. This is an alternative that’s much faster than our traditional radio waves that we use to communicate back down to the ground.
The OPALS laser communication system was delivered to the ISS on April 20 by a SpaceX unmanned Dragon space freighter and is currently undergoing a 90-day test. For this test, the crew used the OPALS to transmit the “Hello, World” video from the ISS to a ground station on Earth. This was no simple task, since the station orbits Earth at an altitude of about 418 km (260 mi) at travels at a speed of 28,000 km/h (17,500 mph). The result is that the target is sliding across the laser’s field of view at an incredibly fast rate.
According to Bogdan Oaida, the OPALS systems engineer at JPL, this task was pretty unprecedented:
It’s like trying to use a laser to point to an area that’s the diameter of a human hair from 20-to-30 feet away while moving at half-a-foot per second. It’s all about the pointing.
However, the test went off without a hitch, with the 37 second-long video taking 3.5 seconds to transmit – much faster than previous downlink methods. Abrahamson said that the video, which is a lively montage of various communication methods, got its title as an homage to the first message output by standard computer programs.
The OPALS system sought out and locked onto a laser beacon from the Optical Communications Telescope Laboratory ground station at the Table Mountain Observatory in Wrightwood, California. It then transmitted its own 2.5-watt, 1,550-nanometer laser and modulated it to send the video at a peak rate of 50 megabits per second. According to NASA, OPALS transmitted the video in 3.5 seconds instead of the 10 minutes that conventional radio would have required.
Needless to say, the astronauts who contribute to the ISS’s ongoing research programs are pretty stoked about getting this upgrade. With a system that is capable of transmitting exponentially more information at a faster rate, they will now be able to communicate with the ground more easily and efficiently. Not only that, but educational videos produced in orbit will be much easier to send. What’s more, the ISS will have a much easier time communicating with deep space missions in the future.
It’s incredible to see this magnificent beam of light arriving from our tiny payload on the space station. We look forward to experimenting with OPALS over the coming months in hopes that our findings will lead to optical communications capabilities for future deep space exploration missions.
And in the meantime, check out the video from NASA’s Jet Propulsion Laboratory, showing the “Hello World” video and explaining the groundbreaking implications of the new system: