Posted on 10/25/2020 8:49:28 AM PDT by BenLurkin
Spacecraft have relatively weak receivers, so you need to beam a strong radio signal to them. They also transmit relatively weak signals back. You need a large sensitive radio dish to capture the reply. For spacecraft beyond the orbit of Earth, this is done through the Deep Space Network (DSN), which is a collection of radio telescopes custom designed for the job.
The DSN is already being pushed to its data limits... Human missions would require orders of magnitude more bandwidth.
When we return to the Moon and place our first footsteps on Mars, we will want not only scientific data but live video feeds, high-resolution images, and even tweets from the astronauts. Imagine trying to stream gigabytes of data between Earth and Mars. Even the most sophisticated radio network isn’t capable of that level of bandwidth. While NASA is working on modern radio designs, radio communication might not meet all our needs.
A new study looks at an alternative. It uses visible light rather than radio. While visible light can carry more data due to its shorter wavelengths, it also scatters more readily and loses fidelity over a shorter distance. To overcome this, the team proposes combining the signal with a second reference signal. The whole thing is then passed through a non-linear optical fiber, which generates a third signal known as an idler wave. All three of these are then amplified and sent on their way. On the other end, the signals are captured and processed. Because the idler wave depends on the other two signals, it can be used to reconstruct the original signal without much data loss. In lab experiments, the team reached a data-rate of more than 10Gb/s, which is ten times higher than current technology.
(Excerpt) Read more at universetoday.com ...
We’re still limited by the speed of light but this makes things a little more high fidelity. Hope they get some practical application satellites on the test stands soon.
When we return to the Moon and place our first footsteps on Mars
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Oh good...we can spread our earthly troubles to other planetary bodies.
“The DSN is already being pushed to its data limits”
That’s cuz itz ridiculously out of date, like 1553 data buses
RS-232 forever!
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There's nothing quite like FREeyore optimism...
TXnMA '-}
I like it
LOL
Satellite already use laser for communication. Old tech, really.
https://en.wikipedia.org/wiki/Optical_parametric_oscillator
https://en.wikipedia.org/wiki/Optical_parametric_amplifier
Still trying to figure out how they minimize laser spread and thus signal loss over very long distances. When you bounce a laser off the retroreflectors on the moon you are detecting individual photons rather than a continuous signal. When I was in grad school I had a professor who was working on a laser with a axial distribution that was a Bessel function squared rather than Gaussian because it would reduce spread.
As discussed in the article, traditional light wave technology suffers from some limitations. Adding a side channel and an idle channel will help with lossy communications prevalent in technology we use today.
How do you know that’s now already done?
This is just the technology that Biden has needed to convert his rambling (dispersed?) speeches & conversations to coherent thoughts and language...
There’s nothing quite like FREeyore optimism...
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Some seem to believe that peace will guide the planets, and
love will steer the stars. The dawning of the age of Aquarius. LOL
Because they said in the article that it’s not...
How do they know? Do they know all space systems?
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