Aiming the laser at the spacecraft so the transceiver knows where to point back is the most difficult part, Wright said. And because Earth and the spacecraft are both moving, the lasers must point to where the destination will be in a few minutes.
https://www.washingtonpost.com/technology/2023/12/19/nasa-laser-video-streaming-space-mars-cat/
“The beam’s so narrow, it can’t just point to Earth. It needs to know exactly where on Earth,” Wright said. “Trying to hit a dime from a mile away while you’re moving at 17,000 miles an hour — that’s the challenge.”
So NASA has been working on this idea for a while now. The invisible laser beam that carried this video file came from the Psyche probe, on its way to the asteroid belt between Mars and Jupiter.
Psyche is 19 million miles away right now. The laser beam took 108 seconds to reach Earth.
Mars and Earth are on average 140 million miles apart and can be up to 250 million miles apart depending on the timing of their respective orbits.
I don’t think lasers are the answer here. A good start, maybe, but you can do the math. Having to wait between 10 to 20 minutes, or more, for a one-way transmission (double that for an exchange of messages) would not be ideal for a human settlement in an emergency.
Star Trek style instant interstellar communication is still just scifi. Unless there’s still something out there we haven’t found yet, even quantum communication will take time…
But at least NASA has finally realized that non-science people like cat videos.
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