NASA Beams Video from Space Station Through a Laser
On Thursday, 5th June, 2014, NASA successfully beamed a high–definition video message “Hello World!” through a laser from the International Space Station (ISS) to the earth using the Optical Payload for Lasercomm Science (OPALS).
The technology demonstrates NASA’s exploration of higher–bandwidth methods of communicating with the future spacecraft that uses 10–1000 times higher data speed than current space communications. The biggest challenge in the experiment was to maintain extreme precision. The space station moves above the earth’s sky at approximately 17,500 mph. Indicating the right point on the earth, it is equivalent to aiming a laser pointer at the end of a strand of human hair about 30 feet away and keeping it steady while moving. To achieve such levels of precision, OPALS locked a ground beacon emitted by the Optical Communications Telescope Laboratory ground station in California. Once locked, OPALS began modulating the beam from its 2.5W1, a 550–nanometer laser to transmit the video.
The transmission lasted for a whole 148 seconds, which transferred maximum data rate of 50 megabits per second. Moreover, contrary to the traditional downlink method which would take around 190 minutes to transmit a single copy of the same message, OPALS took only about 3.5 seconds. The new technology of lasercomm is fast enough to transmit high definition videos from the satellites as well as from space vehicles. The OPALS instrument was built at NASA’s Jet Propulsion Laboratory in Pasadena, California.