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Questions tagged [communication]

Questions regarding information transfer between spacecraft, and between spacecraft and Earth.

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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 ...
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What channel does a launch vehicle telemetry system see? Is it AWGN?

What is the kind of channel seen by a communication system (for telemetry data) on-board a launcher during various phases of launch. Is it a fading channel or AWGN channel? (Additive white Gaussian ...
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Why not send Voyager 3 and 4 following up the paths taken by Voyager 1 and 2 to re-transmit signals of later as they fly away from Earth?

Voyager 1 and Voyager 2 spacecrafts are on their journey out of solar system. They collected so much of important data that helped us understand our solar system. As these spacecrafts moving out of ...
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What is the lowest latency achievable in reliable Earth - Moon communications?

I know that radio waves travel at the speed of light in vacuum so the minimal latency to communicate between Earth and Moon would be about 1.25 second each way. This latency figure will then increase ...
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What kind of signal Voyager 1 is sending to us?

I was reading on wiki about Voyager 1 mission and I found very interesting! One thing I did not manage to find: what is the signal Voyager 1 is sending to us? Is it simply a sinewave or something more ...
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Would communication with Houston still be possible in a LEO debris cascade?

In the film Gravity (2013), the astronauts on STS-157 & the ISS lose communications with mission control in Houston, supposedly due to the chain reaction of debris collisions taking out ...
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why do astronauts in the ISS still use wired microphones?

While I watched the DM-1 hatch opening, I noticed that astronauts use the wired microphone to talk to Huston. It was particularly strange seeing that even because during hatch opening, they were ...
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Pictures from Mars

How is it that NASA receives broadcasts from 300 million miles away but Sprint needs to install transmitters every 500ft for 5G wireless?
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What is the meaning of “T.M”?

In the movie, First Man (2018), Neil Armstrong is getting into Gemini 8 space craft. He overhears capcom voice: CARNARVON CAPCOM: Guaymas, read you loud and clear. We have S band track. We have ...
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When scientific and engineering data are sent from space probes, are the signals repeated to minimize transmission error?

I would think that this would be the case. In any one transmission there will be a systematic error due to the fundamentals of the transmitter / receiver. Is there also a transient or stochastic error ...
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“Luckily with no Lunar Module, Tidbinbilla was able to keep tracking with no interruption…” Why is no LM significant?

@PearsonArtPhoto's answer links to the page Apollo 8, 21 – 28 December 1968 by Hamish Lindsay at honeysucklecreek.net. The page describes a problem with one of the dish antennas that needed to be ...
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What was the last message Opportunity sent?

Everybody seems to be abuzz with the idea that Opportunity's last transmission was "My battery is low and it's getting dark." Of course, that would be a human interpretation of some sort of ...
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What was the last message to Opportunity today (13 Feb '19)?

Several articles have mentioned that the last ever commands were sent to the unresponsive Opportunity rover today by NASA. Now, I know that it wasn't a verbal message, but was there anything digital ...
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How do you calculate the lat and lon of a point on the earth using azimuth and elevation seen from a geostationary satellite?

I am given the longitude of a geostationary satellite and a pointing vector from the satellite in the form of azimuth and elevation angles looking from the satellite towards the earth (where zero ...
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1answer
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Would radio / wifi and other communications work on Jupiter's moons?

I've read that Jupiter emits a lot of EM radiation, and can also be heard on ham radio. If you were much closer would it drown out radio and other forms of communication, or is it confined to specific ...
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Why no recent information about or photos of Ultima Thule?

It's been two weeks since New Horizons flew past Ultima Thule but the most recent news on the Johns Hopkins site is dated the fourth of January The image gallery has had no new pictures since the ...
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How to communicate with a lunar polar mission?

We can easily communicate with a spacecraft on the Moon on the near side. The Far Side allows for a L2 halo communication relay satellite easily enough. How would a polar mission communicate with ...
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Do moon rovers on near side need a relay communication satellite?

Wikipedia says direct communication is not possible from the far side of the moon. So I'm guessing it should be possible for the satellite to communicate directly without relay satellite from the near ...
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Transmission time per day for Chang'e 4?

Congratulations for the sucessfull landing on the back side of the Moon. There is continuous line of site available for radio connection from the lander to the Queqiao relay satellite at the Earth-...
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Could we use a narrow paradigm, say laser, to get info faster from New Horizons? (With a moon base.)

There was just a question (actually, on Astronomy) about why the data rate from New Horizons is low. Of course, even with the most directional radio antennas, the spread is enormous. I guess ...
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1answer
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What is carrier lock and bit lock?

I'm not sure if this question belongs here or in Amateur Radio, but during the acquisition of signal from New Horizons on New Year's Day, I heard the controllers call out "carrier lock", "symbol lock",...
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Can I text on my cell phone from the ISS to Earth?

We know from Can we detect the cell phone, satellite phone, or walkie talkie of someone walking on Mars from Earth? that cell phone signals on Mars are potentially observable on Earth. I am not an ...
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Is the prompt relay of landing telemetry by the MarCo cubesats to Earth really a “first”?

The MarCo cubesats travelled from Earth to Mars alongside InSight and relayed signals from InSight (UHF) to Earth (X-band) during it's descent and landing on the surface of Mars. The NPR podcast and ...
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From whence (what ground stations) do all the world's space agencies receive signals from their missions?

The ISRO web page Ground Segment says: SRO Telemetry Tracking and Command Network (ISTRAC) will be providing support of the TTC ground stations, communications network between ground stations and ...
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Satellites around outer planets that act like amplifier to signals from voyager like objects

One issue of deep space exploration is that once the object (like Voyager) is far out in the solar system the physical distance is so great that the signal reaching Earth is very weak. I was wondering ...
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If a Voyager crashes into something, would we know?

A recent question asked about the feasibility of using Voyager 2 to detect objects in the Oort cloud. The answers indicate, among other issues, the instruments on-board the Voyagers would likely be ...
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What is the delay of the YT live stream for ISS?

On YT, we can see a live stream from ISS. What is the delay here (given you have a modern high speed internet access)?
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Is Quantum Entanglement technology possible for interplanetary communication in future to achieve low real-time latency?

There is a small debate over the comment session in NASA Lands InSight on Mars video uploaded by JPL. The 1 minute and a half video is about the essential part of InSight's EDL event cropped out from ...
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Could “live” video be transmitted from Mars?

With the approach of InSight to Mars today, and the two cubesats watching it, much is being made about seeing "Live Video" from the cubesats. I'm pretty sure that simply can't happen, but I'm ...
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Radio Telemetry from Parker Probe?

Given that the Sun emits wide band RF noise at high levels, how is the Parker probe going to transmit its data collection to Earth (Terrestrial) when it reaches its closest proximity to the Sun in ...
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2answers
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Why will radioastronomy telescopes be used to listen to InSight's entry into Mars' atmosphere instead of DSN?

The JPL News article How NASA Will Know When InSight Touches Down is interesting and worth a read. It says that during the atmospheric entry, descent and landing, the Mars InSight probe will be ...
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1answer
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Are there plans or a program for an optical relay pathfinder for deep space?

In Glenn Research Center's Richard Reinhart's slides Space Communication and Navigation TestbedCommunications Technology for Exploration for the 2013 ISS Research and Development Conference I saw an ...
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Can astronauts on an EVA communicate directly with ground stations?

Can astronauts/cosmonauts performing spacewalks at the International Space Station communicate directly with radio stations on the ground (even if only as a back-up)? Or do they need to relay their ...
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What technology will SpaceX's StarLink satellites most likely use for sat-to-sat linking?

The question How does SpaceX plan to make money with StarLink Broadband? has got me thinking about how the satellites will link to each other. Wikipedia says it's something greater than 10,000 GHz ...
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Yet another OSIRIS! Has the DLR/GOM Space test of the cubesat optical communications link happened yet?

Speaking of "all things OSIRIS" I just ran across the OSIRIS optical communications system for cubesats and smallsats. OSIRIS (Optical Space Infrared Downlink System) highly compact optical ...
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Did NASA's Borg Collective-designed antennas work? Have similar designs ever been used in spacecraft beyond testing?

This interesting answer to the question Do antenna farms on spacecraft make any sense or are they purely aesthetic? in Worldbuilding SE links to the NASA Ames page 'Borg' Computer Collective Designs ...
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Is it possible to use the planet earth as a giant smoke signal to communicate across space? [closed]

I have had a theory that maybe by placing an object like a large satalite rotating disc a certain distance away from the planet earth. We can rotate the satalite at a reasonable speed to perform ...
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Given a working satellite, would it be possible to build a homemade transmitter/receiver?

Given existing low-orbit and geo-synchronous satellites, would it be possible to build a device that could send a signal to a satellite and then have that signal received on another device? ...
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How to calculate azimuth and elevation angles from satellite point of view of a ground station?

How to find azimuth and elevation from satellite of a ground station when yaw, pitch, roll, lat, long position of satellite and lat, long position on ground are given? ...
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Can a swarm of nano-probes act as a phased antenna of a greater power?

One problem with nano-satellites and generally any small spacecraft is that you can't fit a powerful power source and antenna - their usability outside vicinity of 'adult' satellites or Earth is thus ...
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Which Live satellites can the public view of earth? [closed]

Does anybody know if there is a LIVE satellite? Like a cross between Google Earth (zoom) and GOES 16 (LIVE)? So WE can see what's really going on around here? I want to see inside of the crater in ...
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Has the Curiosity rover ever communicated directly with Earth via its high-gain antenna? Signal strength & data rate?

In the question How does Curiosity know how to point and move it's high gain antenna in real time? I show an image of the hexagonal, articulated high gain antenna on the curiosity rover, as well as ...
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Do the rovers in Hayabusa-2 communicate directly with the spacecraft or use the landers as relay?

I can't infer this from this documentation or the presentation: Do the ROVER-1A and ROVER-1B communicate with MINERVA-II-1, and it then relays to the Hayabusa2 "mothership", or do they communicate ...
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Why were the antennas on the spherical surface of some early satellites spiral-shaped?

In the question What's the spiral pattern on this satellite? I show this image of a spiral-shaped pattern on the spherical surface of a (presumably) vintage satellite or model thereof. @OrganicMarble'...
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Can we detect the cell phone, satellite phone, or walkie talkie of someone walking on Mars from Earth?

We certainly cannot see a person walking on Mars from Earth. But what if the person is trying to use a cell phone, walkie talkie, or satellite phone? Although he won't have much luck using any of ...
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Is telerobotic surgery logistically feasible in orbit?

A recent comment said telerobotic surgery might be used in space, a follow up comment said that multiple minute light delays would complicate it. But I wonder if just the fact that being in orbit, ...
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What is astronaut Alexander Gerst signaling with this K-shaped hand signal?

In this AP/WISN news item Air leak at International Space Station temporarily plugged by a thumb they show a file photo of German astronaut Alexander Gerst at the Baikonur cosmodrome, making what ...
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What are the prospects for comms with cubesats using “normal” internet connections?

Can a cubesat in orbit be operated like a R/C airplane in real time? edit: if the link here and the end aren't clear, I'm interested in the ease and convenience of access, the frequency of possible ...
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1answer
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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 ...
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Synchronizing spacecraft communication

When NASA is giving commands to a distant spacecraft like Juno, how is that done in terms of timing and protocol? For example do they: give a command to burn for 15 seconds upon receiving the ...