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Questions tagged [communication]

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

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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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3answers
493 views

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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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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1answer
770 views

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
114 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
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 ...
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1answer
153 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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3answers
413 views

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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2answers
185 views

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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3answers
595 views

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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3answers
242 views

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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2answers
246 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
158 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 ...
3
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1answer
469 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 "...
12
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1answer
398 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
255 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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2answers
515 views

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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2answers
2k views

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....
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All Optical Global Network - how does the space-to-ground link avoid clouds?

I just saw the news item in Lightwave's online website: Laser Light to leverage free-space optics in space for Optical Satellite as a Service. All Optical Hybrid Global Network (or HALO, as laser ...
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1answer
355 views

Is it possible for the Deep Space Network to use MSPA and antenna arraying simultaneously?

Suppose Mars Odyssey (ODY) and the Mars Reconnaissance Orbiter (MRO) are being tracked by antenna A (just for example) at the Goldstone Deep Space Network complex in MSPA mode. Is it possible for ...
3
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2answers
504 views

Characteristics of the inter-satellite optical link

I'm currently diving into this topic and as I understand from the brief search there are two main types of inter-satellite link: radio and optical. As I can see, one of the main distinction of optical ...
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1answer
183 views

Is there a fax machine on the ISS ?

I know some older space stations had fax machine (since Sayult 7 at least). Do they still have it on the ISS ? Does is support in/out or only one way communications ?
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Standard communications protocol for cubesats

Is there a well-accepted standard protocol for communicating between a cubesat and ground station? On what basis would I choose the protocol?
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1answer
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Voyager's distance from Earth

If it took Voyager’s radio signal 4 hours to cross the solar system and reach Earth, roughly how far away in AU was Voyager from Earth when it sent that signal?
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1answer
706 views

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 ...
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2answers
309 views

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 ...
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1answer
1k views

Current communication delay to mars

I read that the communication delay between earth and mars is between 3 and 21 minutes. So the delay changes over time (since the distance between earth and mars changes over time). How can I get ...
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0answers
219 views

Frequency responses of Voyager's S-band high gain antenna's feed-horn and receiver front end & IF?

I'm working on this question. This is the farthest (known) communications link humans have ever engineered - an one node is running in deep space on 40 year old technology. Pretty amazing! In the ...
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0answers
338 views

How exactly does the live feed from ISS work?

Using my cell phone in a city to download lots of data very fast is common, thanks due to the dense net of base stations close to me (~1 km). But with the space station about 400 km above ground and ...
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2answers
2k views

When will Juno send us some pictures from it's tight orbit?

Juno probe has sent few pictures as it approached Jupiter from afar, but Jupiter looks as large as Moon on our sky on those photos. After that it went into (intentional) silence while it was trying to ...
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1answer
454 views

How does NASA communicate to spacecrafts? [duplicate]

In Our communication systems we have limitations like signal strength to achieve communication between two points in the same country we have to build towers / etc .. my question is how does NASA ...
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5answers
24k views

How long does it take for a signal to travel between Earth, and Juno at Jupiter?

How long would it take for Juno's communication to reach the Earth? In other words: what is the time delay between perception by Juno and perception by NASA researchers?
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4answers
808 views

What typically ends a satellite's life?

It has been my opinion that running out of station keeping propellent is what usually ends a satellite's useful life. Is this true? How much do different factors play in a satellite's lifespan? Some ...
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1answer
229 views

How powerful an antenna needs to be to signal Earth from other solar systems?

If a probe, equipped with a current state-of-the-art antenna, were to send data to Earth from Proxima Centauri orbit, what power would the antenna need to emit for the signal to be usefully readable ...
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1answer
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Do antennae on the ISS have to constantly move to maintain data links?

In this question and answer pair I see that the ISS can maintain data links to earth through direct access to ground stations as well as through the TDRSS geostationary satellite network. What kind ...
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1answer
141 views

Are there discussions or plans for extending the internet into space beyond Earth?

Many years ago I remember reading about the upcoming implementation of the internet protocol IPv6 - which is now in place. In that article it mentioned that there was some discussion about space - I ...
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Which colleges in the US are researching Astrionics/ Space communication systems?

An example is the Space Engineering Research Center at University of Southern California Viterbi School of Engineering. What other colleges in the US are contributing to research on these topics?
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1answer
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Did USSR discontinue radio transmissions, relocate ships, to aid the US in response to Apollo 13?

In this article there is following statement by Dr. Ernst Stuhlinger: Let me only remind you of the recent near-tragedy of Apollo 13. When the time of the crucial reentry of the astronauts ...
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1answer
2k views

From which Apollo mission is this audio sample?

I found this page where Evgeny Molotov, former head of the Research institute of Space instruments, plays supposed intercepted communication of unknown Apollo mission. Can anyone identify from which ...
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4answers
2k views

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 ...
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Tools to evaluate telecommunications link budget [closed]

Can you name some of the commercially and non-commercially available tools to evaluate the link budget for a space mission? Aside Satellite Tool Kit, of course ;)
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How will Yuri Milner and Stephen Hawking's nanobots decelerate and transmit data upon arrival at Alpha Centauri?

Does anyone know what exactly is their plan, once they get there? How is that nano-thing going to slow down / take images / send data back to us? I couldn't find any information on this.
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1answer
89 views

What is the Mars “network science mission” referred to in NASA's Mars Design Reference Architecture?

I've been reading over NASA's Human Exploration of Mars Design Reference Architecture 5.0. In section 3.1.2, "Scientific objectives for Mars: present and future", when discussing future science ...
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1answer
206 views

What do the different “Testing” codes mean on NASA's Deep Space Network website?

If you haven't seen it, you can monitor the status of the Deep Space Network's radio dishes (which communicate with pretty much all of our space probes and satellites) from this website. At times, ...
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2answers
3k views

How are GPS satellite clocks synchronized with each other in the earth's frame of reference?

I have been looking at different threads. It seems like the receiver clock on Earth doesn't have to be synchronized with the satellite clocks. But I believe the satellite clocks need to be ...
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2answers
1k views

How well can Voyager 1 separate Earth signals from Solar noise these days?

This is a follow-up question to this question and this and this answer. UPDATED: see additional information and discussion below. As it continues to move farther from the Sun, the angular separation ...
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4answers
5k views

Can Voyager 1 receive signals from Earth?

There are answers about Voyager 1 sending messages to Earth, but can Earth still send signals to Voyager 1? I am just wondering if the signal of the Sun will eventually overcome the signal from Earth ...
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1answer
201 views

What is the meaning of: New Horizons' communication rate at 1kbit/s between the probe and Earth?

Is it a real-time communication rate measure? As in it would take one second to receive 1 kbit from Pluto?
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3answers
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Does any satellite communicate only through laser?

I have read (here) and heard (on astronomy podcast) that radio waves decay or are indistinguishable the more distance they travel. Do any of man made satellites communicate with Earth solely by ...
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3answers
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Would it be practical to lay a fiber optic cable to Alpha Centauri?

Would it be possible to lay a fiber optic cable over long distances and use it to transfer information- for example, as a sort of telescope?