Questions tagged [communication]

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

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9
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2answers
3k views

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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1answer
309 views

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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2answers
117 views

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 ...
8
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1answer
238 views

“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 ...
9
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1answer
571 views

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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1answer
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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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1answer
250 views

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
133 views

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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6answers
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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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2answers
215 views

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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2answers
422 views

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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5answers
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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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6answers
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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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1answer
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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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2answers
394 views

From whence (what ground stations) do the world's major 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 ...
4
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1answer
163 views

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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1answer
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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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2answers
578 views

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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4answers
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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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3answers
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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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Were there any CAPCOMs who were not astronauts?

The capsule communicator (CAPCOM) is the person in mission control who speaks to the astronauts. The position was invented by NASA's first flight director, Chris Kraft, who believed it would be best ...
2
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2answers
189 views

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
228 views

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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1answer
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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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0answers
717 views

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 and ...
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1answer
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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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2answers
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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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1answer
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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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1answer
258 views

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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677 views

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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0answers
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Did any of Voyagers' receivers' front ends take advantage of the “cold of space” to lower noise?

Most of the Voyagers' electronics are kept warm by electrical heaters powered by their RTG's, and presumably protected by some amount of insulation from the "cold of space" which means loss of heat ...
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2answers
150 views

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 ...
2
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2answers
150 views

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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3answers
583 views

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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1answer
122 views

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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3answers
636 views

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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3answers
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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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2answers
350 views

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, ...
5
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1answer
473 views

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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3answers
613 views

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 ...
3
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1answer
391 views

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 ...
5
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1answer
93 views

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 ...
5
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1answer
184 views

How will the Exomars rover communicate back to Earth?

I see here that the Exomars rover has only two UHF monopole antennas. Two UHF monopole antennas are used to communicate with Mars orbiters, including the Trace Gas Orbiter. Does it mean that it ...
3
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1answer
910 views

What will China's new “space station” in Argentinian Patagonia be used for?

The New York Times (fairly strongly worded) article From a Space Station in Argentina, China Expands Its Reach in Latin America describes a "space station" or base equipped with (among other ...
7
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1answer
291 views

Deep Space Network time budgets per spacecraft - is such statistics available?

Is statistics available about time consumed by different spacecraft for communication wint NASA Deep Space Network (DSN)? It would be interesting to compare which space missions are more downlink-...
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3answers
16k views

How did NASA prevent third parties from spoofing Apollo communications?

The Apollo crews transmitted footage to Earth using SSTV, a ham radio technique that amateurs and pirates can use to send similar messages around the world. Did NASA have any technical ...
3
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1answer
161 views

What nodes were used to send a NASA selfie from Antarctica to the ISS?

The November 29, 2017 NASA video Future-Proofing the Interplanetary Internet says: In a recent demonstration of the technology, NASA sent a selfie from Antarctica to the space station, making ...