Questions regarding information transfer between spacecraft, and between spacecraft and Earth.
Questions tagged [communication]
369 questions
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Does communications with spacecraft red shift the further away they are?
As Voyager 1 and 2 proceed further away do the radio waves red shift (change frequency)?
If so, then don't we have to compensate for that red shift by modulating the frequency so that it arrives at the expected frequency at the…
Van
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11
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How do non-Earth-facing vehicles communicate with Earth?
I know that many artificial satellites are tide-locked with Earth, which allows them to always face a directional antenna towards their ground station. But some vehicles, such as space telescopes, and orbiters observing other bodies are required to…
Dan Hulme
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9
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1 answer
What is the rationale behind the allocation of micro-wave bands for space communication?
The onus for Spectrum management lies with ITU. What little I know - Space communications (as against Satellite communication) are allocated frequencies out of the S, X bands. Other bands may be allocated too - the ITU Space Service document was…
Everyone
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9
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What makes an antenna "high gain", and high gain as opposed to what alternative(s)?
Whenever communications to/from a space vehicle are described or discussed, there is inevitably a reference to the vehicle's "high gain" antenna. What is it about such an antenna (specific technical features) that makes it "high gain", and what…
Anthony X
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8
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Is it possible to communicate in space while the sun is between parties?
If a hypothetical space colony were on the other side of the sun from earth, would it be possible for them to communicate?
If so how would this work?
The only thing I can think of would be bouncing waves off other bodies orbiting the sun that share…
brysgo
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7
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Can we "Communicate" with Tau Ceti?
It seems like four earth-like planets were found near Tau Ceti as per this article
A new study by an international team of astronomers reveals that four Earth-sized planets orbit the nearest sun-like star, tau Ceti, which is about 12 light years…
VSO
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6
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Relativistic effects in space mission communications
How important are relativistic effects in communication with space missions?
I am doing some work on Mars Pathfinder and want to know if effects like gravitational deflection of microwaves matter in the communication with Earth - and if so how the…
Davide Zamblera
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6
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2 answers
What frequency wavebands are used for communication in LEO?
What are the most commonly used wave bands for communications between satellites in LEO and ground station, and what is the minimum frequency used?
Hash
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4
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Is it possible for a spacecraft to communicate with Earth when a planet is in the way?
I have just read 2001: A Space Odyssey and despite the fact that the author was quite optimistic about the space exploration capabilities, communication between a spacecraft and Earth was not possible while a planet was obstructing the line of…
Alexei
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4
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Quantitatively, why will optical communication be better than X-band for deep-space communications?
In a question about communicating with Voyager, an answer asserts:
[70 meter dish antennas deployed in space] just isn't done, and it probably won't be, since optical communication is definitely the way to go in the near future. We've already had…
Phil Frost
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How are signals transmitted in space?
In space, there is a lot of electromagnetic radiation from sun and other space objects. Amidst these, how are signals from Mars rovers and other space probes received?
I see images of Mars by rovers, how is it noise-free and sharp? Wouldn't the…
AyyMani17
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4
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What communication protocols are used with latencies going into hours?
What communication protocols are used to communicate with probes that are many light minutes or even hours away?
Not only the signal will be weak and badly damaged by background noise, we can't just go confirming each packet upon receiving it, or…
SF.
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3
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Why are polar codes not being used in space communications (error correction)?
From what I have read, satellite communications work mostly using turbo codes since the 90s, but most recently (2009) the polar codes were developed, which seem to be also faster and easier to implement.
These are being used by Huawei's 5G network.…
Ediolot
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2
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2 answers
Why does the UN not have its own satellites?
Be it weather, crops, global warming, atmosphere, ocean, roads, birds, forest, intelligence, safety, connectivity, land/space transmission, why does the UN not have its own satellites? It could provide immense benefit to 200+ poor UN member nations…
Isrorian
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High altitude platform: inter-platform link regulation?
Does anyone know if ITU has a recommendation for HAP-HAP (High altitude platform-High altitude platform) or LAP-LAP * or HAP-LAP links recommendation as for inter-satellite links with frequency, latency and etc.??
Some ITU-R studies estimated that…
Anna Koroleva
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