This week, courtesy of NASA, we saw a first in the world of communications: a high-definition video beamed to Earth from 260 miles above the planet—using lasers. This feat in video transfer comes courtesy of the Optical Payload for Lasercomm Science (OPALS) payload, a technology demonstration from NASA’s Jet Propulsion Laboratory currently on board the International Space Station.
OPALS is a proof-of-concept mission that’s testing a new way of transmitting data through space. Rather than using traditional radio waves, OPALS is looking to a future where spacecraft and astronauts will communicate using high bandwidth lasers.
Radio waves and lasers are on opposite ends of the electromagnetic spectrum, at least in terms of communication. Radio waves are longer and can’t transmit as much data in one go, but they are fairly simple to receive, traveling in all directions from their point of origin to be received by large Earth-bound dishes.
Lasers, conversely, are much shorter. They can carry significantly more data in one transmission but they’re harder to receive. Like a laser pointer, laser communications require precision aiming. The beam must hit a receiver at exactly the right spot to transmit its large amount of data.
The capability to receive this highly focused data is what OPALS is demonstrating. During last week’s demonstration, the OPALS instrument first locked onto a laser beacon emitted by the Optical Communications Telescope Laboratory ground station at the Table Mountain Observatory in Wrightwood, California. It then began to modulate the ground-based beam with its own laser, transmitting the "Hello World!" video message.
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