Questions tagged [communication]

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

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2answers
1k views

How to design a ground antenna for sending & receiving from a satellite?

Let's suppose there is a wifi router or a cell phone or similar transmitter in an orbit of 3000 km. How could one make a dish antenna to connect and receive the signal from that wifi router or cell ...
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Apollo 17; what is a barber pole, and what did “it is gray” mean?

Following the links in this comment by @Uwe I've found some interesting sources of information on Ham (amateur) radio operators trying to listen in on Apollo transmissions. At the bottom of Sven ...
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1answer
2k 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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107 views

How many ways of communication with ground can ISS crew use?

I'm currently writing fictional story which is happening at ISS and I have so many questions about this topic, but this one is the most important to me. How many possibilities of communication they ...
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77 views

How to determine an available planetary communication window using orbital mechanics?

For class I have an orbit around Mars at an inclination of 63.4 deg and a base site of 55 deg North and was wondering how to work out the communication window, using orbital mechanics. Orbital ...
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1answer
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Why were Sónar Calling GJ273b messages called secret?

Sónar Calling GJ273b is in the news, at the time of this question, for sending messages into space in an attempt to contact aliens. Some news sites are calling the messages "secret". Does anyone know ...
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Are there any protocols the space station follows if there is an Earth-wide catastrophe?

Are there any protocols the space station (or any space explorer) follows if there is a massive catastrophe on Earth where the responsive parties on the ground would not be available for support/...
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Would adding satellites between Earth and Mars improve communications latency?

Would adding satellites along the path from Earth to Mars decrease the amount of time it takes to send and receive messages between them?
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432 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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133 views

Does SETI perform search of extremely low bandwidth signals?

Sending a signal at interstellar distance requires enormous power - something of order not too far from energies of the stars. Even if we harness the power of stars, modulating that signal would take ...
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What is this NASA Spaceflight article trying to explain?

The NASA Spaceflight article Extended Russian EVA complete – conducts satellite deployments contains a very long discussion about the timing of the CRS-12 launch. Had it missed the "single shot launch ...
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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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Terminology for CubeSat telecommunications

I'm looking at a brochure for the Iris V2 Deep Space Transponder by JPL. At the end of the brochure there is some data on suggested antennas. For each antenna the bps at approximately 1 AU is shown ...
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What is a transmitting radio telescope's peak power consumption?

I am currently designing specifications for a human-inhabited station on Mars. Said station would require communications with Earth, to do so requires power. Apparently, a radio telescope is capable ...
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Space Shuttle “go at throttle up”

On all of the launch videos and recordings for the Space Shuttle, the mention is made from Houston (after getting through Max-Q) of "go at throttle up", indicating that the launch is ok for going back ...
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1answer
274 views

How many antennas does Kurz use in toto, and what are each of their functions?

I learned about the Kurz docking system in this answer, then found out what they looked like in this and in this answer. Those images show several tiny dish antenna structures sticking out from ...
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Signals to a deep space network

First of all, sorry for the general context of the question but I’m very inexperienced. I hope I'm not breaking the rules. Simplifying, in the short sci-fi novel I’m writing there’s a super-...
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1answer
304 views

Will there be “Near Space” Ka-band allocations for TESS?

update: More information in Phys.org's news item TESS mission to discover new planets moves toward launch, including a video of the telescope array's final assembly. Also see GSFC's TESS page. The ...
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1answer
359 views

Inter-Satellite Link (ISL) for TV broadcast

Is ISL used for TV carriers? The information I found is that it is used for IP connectivity. I did not find any information on TV broadcast. If not, what are the applications of ISL?
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Why was SpaceWire designed with nine wires?

I just learned about SpaceWire in this great answer about the slip-ring rotating electrical connection between its solar panel and attached sun-pointing instrumentation, and the body of the craft with ...
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1answer
788 views

Real time communications in space

Today we use audio and video communications (using UDP protocol) over IP networks (VoIP) for communicating (Skype, Whatsapp, FB messenger). This works fine on planet Earth (although there are various ...
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417 views

How do those little dish antennas sticking out of the HST track their target independent of telescope pointing?

Almost all the photos I see of the HST show the two small dish antennas at the ends of the two long, opposing booms with the "top" one pointed straight ahead at 12-o'clock, and the "bottom" one at 3-o'...
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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 close to two years and seven months now, have any of the 'gift' transponders been used or at least tested yet by the gift recipient nation? The BBC ...
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What type of comms traffic for deep-space missions needs to be prioritized?

I am currently studying DSN related stuff, and for that purpose, I need to know some details. I am currently studying the Deep Space Network, and I am trying to get a better picture of how DSN ...
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186 views

What are these dishes looking at?

In this CSA video CSA Astronaut Chris Hadfield describes the attitude control of the ISS and its importance for things like communication with Earth. At 00:30 here ...
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388 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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How do landers communicate with Earth when facing away?

For example, how do the Mars landers communicate when Mars is between them and the Earth? The MRO is in a low orbit; does it store and forward data?
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Is Deep Space Network (DSN) technology sufficient for a crewed Mars mission?

Almost every single space enthusiast is excited about a Mars mission and when we are sending our scientists there. But from the communications point of view, are we ready to test the recent ...
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451 views

Faster than light communications in space [closed]

Today communication with different spacecraft is limited to speed-of-light. Around the Earth it is not such a problem, but when you have to work with a spacecraft on the surface of Mars, it becomes an ...
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1answer
958 views

Cubesat Space Protocol and AX.25

Are there any good sources to understand how to use Cubesat Space Protocol (CSP) and AX.25? I am supposed to use them for the network in an MSP430 microcontroller between a transceiver (which has an ...
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157 views

Copernican principle based question about ET

As mentioned, I'm following the Copernican principle for this line of questioning. Yes I've considered and read many other possibilities, but this question is for Copernican-style answers ONLY. Your ...
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1answer
308 views

Characteristics of the modern satelite radio transmitters

I'm trying to find some data concerning current Earth-satellite radio communication systems, namely general characteristics of the equipment currently used on satellites. Specifically, I'm interested ...
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Frequency progressive signals vs time progressive signals?

I am not very experienced with signals, but something that has occurred to me while reading on various ways we are searching for ET signals, is that it seems most people rule out a signal unless it's ...
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How are the tiny spacecraft proposed by Project Starshot supposed to communicate with Earth?

Between power limitations and aperture-limited diffraction I just can't see how it's possible.
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771 views

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

update: Cropped screen capture from SpaceX Demo-1 Crew Dragon Docking to ISS - Part 2 after about 00:25:00 in the video: I am curious if guidelines for the ...
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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, ...
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1answer
163 views

How will NavCube (actually) be important for the XCOM testing and demonstration?

According to the NASA news article NASA’s NavCube Could Support an X-ray Communications Demonstration in Space — A NASA First: The new technology, called NavCube, combines NASA’s SpaceCube, a ...
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1answer
307 views

What will the X-ray communications (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 ...
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217 views

How different is communication between passive and active ADCS?

How different is the communication to ground stations between passive and active ADCS? Also, is there any data or insight into probabilities of ground station contact with passive?
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Why don't signals from rovers on Mars get lost on the long trip to Earth? [duplicate]

I read that there is a satellite orbiting Mars that the rovers send data to but I still find it amazing how that satellite can send signals tens of millions of miles to earth without any ...
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Details of Apollo 11 video transmission [duplicate]

NASA has the video of Neil Armstrong on the moon. I'm interesting in the technology how the signal was created and transmitted. There are some details about it in Wikipedia but I'd like to know in-...
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How many earth stations had astronauts on-site during John Glenn's orbit in Friendship-7?

The Washington Post just republished it's February 21, 1962 article covering the launch, Earth orbit, and safe re-entry and recovery of (Senator) John H. Glenn, in recognition of his service and ...
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Are there Practical Methods to Measure the Distance between a Spacecraft and an Astronomical Body?

I came across this detailed article on NASA's JPL website about how mission teams are able to calculate the trajectories (and by extension the position) of spacecraft at faraway distances. However, I ...
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265 views

What do scientists see when they track space probes?

First, I already understand the basics of radio communication at this point, as that is all I've found searching elsewhere on the web for my question. (For example, How does NASA get information from ...
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3answers
171 views

How could a private organization ensure access to communications with a deep space probe or rover?

Regarding a private organization what would be there options for communication with a probe or rover in deep space such as Mars or farther. Would they be able to use the Deep Space Network? If so what ...
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1answer
587 views

What caused New Horizon's so-called “40-year glitch”?

The Discover Magazine article How New Horizons Survived the 40-Year-Glitch and Made it to Pluto is a little confusing. It wraps NASA history together with several different space missions to get the "...
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1answer
489 views

Has DSS-43 ever been used in high power mode (>>20 kW) for an emergency situation?

This answer notes that while most Deep Space Network transmitters are 20 kW of power or less, one dish (DSS-43 in Canberra) is equipped with a transmitter capable of 400 kW. As described in 101, 70-m ...
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2answers
285 views

Earth-Mars Radio Blackout: Is it possible to define an extended solar radius to solve this as a geometric problem?

Solar atmosphere causes difficulties in communication during opposition (when Mars is almost behind the sun w.r.t. Earth). The question is: is it possible to define an extended radius for the sun, ...
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Why are there so many satellites around the moon if they are blocked out of radio communication half the time?

They state there are about 500 or so satellites orbiting around the moon. However according to NASA back when they said we landed on the moon, when the astronauts orbited around the dark side of the ...
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What (actually) makes Iridium “the world's only truly global mobile satellite communications company”?

In this article about how the SpaceX anomaly will affect Iridium it says: In its official website, Iridium describes itself as "the world's only truly global mobile satellite communications company....