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Questions tagged [communication]

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

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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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1answer
254 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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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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2answers
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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 ...
24
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5answers
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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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0answers
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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 ...
93
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3answers
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How did NASA achieve their live TV broadcast in 1969?

In 1969, NASA not only went to the moon, but broadcast the whole thing live on TV. How did they achieve the TV broadcast? What technology did they need to use to send a video and audio signal from ...
9
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1answer
166 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 ...
3
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1answer
74 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 ...
3
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1answer
223 views

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 ...
2
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0answers
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How have the 'gift' transponders on ISRO's GSAT-9 been used by other countries?

edit: It's been seven months close to two years now, have any of the 'gift' transponders been used or at least tested yet by the gift recipient nation? The BBC news item India launches 'invaluable' ...
7
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1answer
95 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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2answers
12k views

Apollo communication between the Earth and Moon

How was it possible for astronauts to send back tv/radio signals to earth from the moon? I have just been teaching my son about waves behavior and understand that radio waves are reflected back to ...
3
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2answers
68 views

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 ...
4
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2answers
107 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 ...
11
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1answer
425 views

How long did New Horizons take to upload all of its data from the Jupiter encounter?

It's a pretty well known fact among the regulars of this site that New Horizons will take up to 18 months to completely upload the data from the Pluto encounter. When it was at Jupiter, it was much ...
4
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2answers
276 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-...
3
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1answer
766 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 things) a ...
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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 ...
16
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1answer
2k views

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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5answers
3k views

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
59 views

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 ...
3
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1answer
158 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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2answers
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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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1answer
178 views

What would an XCOM transmitter look like?

The NASA news article NASA’s NavCube Could Support an X-ray Communications Demonstration in Space — A NASA First mentions the potential use of X-ray wavelengths for improved range of deep space ...
3
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1answer
94 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 ...
21
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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 ...
7
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3answers
606 views

Is it possible for Curiosity to broadcast live HD television from Mars to Earth?

Current Mars rovers collect large amounts of data and image sequences on Mars and store them in memory, and usually they then transfer the data to a spacecraft in Mars orbit for rebroadcast to Earth ...
5
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3answers
880 views

Are Martian winds as strong as portrayed in “The Martian”?

I read Andy Weir's "The Martian" and saw the movie, which is supposed to be realistic science fiction. And I immediately saw a couple of huge flaws, one of which I'd like to tackle with this question: ...
5
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1answer
403 views

Why is Queqiao's dish antenna so big? (Chang'e-4 relay satellite) Largest ever on/near the Moon?

Source: Chinese language blogpost The NASA Spaceflight article Queqiao relay satellite launched ahead of Chang’e-4 lunar mission describes the communications relay satellite that will be used to ...
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3answers
267 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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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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2answers
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What bitrates are currently achievable for communication with interplanetary space probes?

In communication with interplanetary space probes, it is clear that one has to take the delay caused by speed of light into account. Besides that, what are current limits for the data upload and ...
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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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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 ...
2
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3answers
379 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
932 views

Difference in communication delay on ISS

What cause the difference in communication delay, about 11 seconds in this video: and apparently almost no delay on this one: ...
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1answer
271 views

What does the ISS Mission control center do?

This related question asks about Mission Control's responsibilities during a hurricane. But there's a more general question underneath: what do the people in Mission Control do, what are their ...
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2answers
479 views

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 wasn't there a communication delay when Neil Armstrong landed on the moon? [closed]

My understanding is that there was supposed to be a delay between the communication from the moon to Earth. Why were the communication instantaneous?
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3answers
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Is there any way to communicate with Pioneer 11 through Voyager 1 or 2?

The position of Pioneer 11 is between Voyager 1 and 2, that means Pioneer 11 is closer to Voyager 1 and 2 than to Earth. According to the Wikipedia article on Pioneer 11 we lost communication with it ...
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0answers
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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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1answer
319 views

What are the main sources of radio noise & interference limiting deep space data rates and availability?

Let's call "radio" anything electromagnetic below 300 GHz (1 millimeter), unless there is a compelling reason to do otherwise. The as yet unanswered question How well can Voyager 1 separate Earth ...
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5answers
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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-...
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2answers
420 views

Have guidelines for red & green navigation light placement on spacecraft been established?

I am curious if guidelines for the placement of red/green navigation lights on spacecraft been established. In maritime and most aviation situations, right/left have meaning because up/down does. A ...
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0answers
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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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2answers
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Why is Sentinel 3B's dish antenna overwrapped with metallized film?

The Spaceflight Now article Photos: Sentinel 3B satellite prepared for launch from Plesetsk Cosmodrome has of course lots of photos. One of them shows a dish antenna covered with shiny, metallized ...
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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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1answer
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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 ...