Laser message from space
Radio communications from the International Space Station occur at a very low speed, but things could change in the future. On June 5, 2014, a laser modem was launched on the ISS , which repeatedly transmitted to the Earth a video in HD quality with the words “Hello world”.
The laser is clearly visible in the photograph. If the experiment with a laser system called OPALS (Optical Payload for Lasercomm Science) succeeds, it will become a significant upgrade for the ISS. Scientists compare this upgrade to replacing dialup with DSL: speed will increase 10-1000 times, compared to the current one.
True, this is not so simple: to maintain communication, you need to precisely aim the on-board laser at the receiver in the observatory. This despite the fact that the station moves at a speed of 7.6 kilometers per second relative to the earth's surface.
To set up an orbital laser, it was first “illuminated” from the Earth. OPALS turned on its 2.5-watt laser and sent a coded response pulse in the direction of the original signal.
The test transmission on June 5 lasted 148 seconds, and the maximum transfer rate reached 50 Mbps. One video was copied in 3.5 seconds, although a regular radio modem would transmit it for 10 minutes.
For all 148 seconds of transmission, OPALS successfully held the sight without deflecting the laser beam by more than 0.01 °.
It is also worth noting that OPALS delivered the Space-X Dragon private cargo ship to the ISS in the spring of 2014.
Private spaceships, laser communications in space - maybe we are in the future?