Questions tagged [communication]

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

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6
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1answer
225 views

Relativistic effects in space mission communications

How important are relativistic effects in communication with space missions? I am doing some work on Mars Pathfinder and want to know if effects like gravitational deflection of microwaves matter in ...
7
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1answer
156 views

Laser communication for interplanetary probes - aiming is impossible without beacon?

Laser communications are considered very promising for interplanetary probes because of potentially much higher data rates. I found that laser communication at large distances (over 3 a.u. ~ 450 ...
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1answer
146 views

Data from Cubesat as web API

I’m doing some research for possible cubesat mission and I spent days on the internet and in books trying to find a simple answer to my dumb question. I’m completely new in this field so I’m not sure ...
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2answers
156 views

Why is SES-12 "…basically two satellites in one…”?

The Florida Today article On second flight, SpaceX Falcon 9 rocket to launch 'brute' of a satellite from Cape describes the upcoming SpaceX launch of SES-12. At roughly 12,000 pounds, the SES-12 ...
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1answer
282 views

Attitude requirements for inter-satellite laser communication

Previous questions have address the beam divergence angles and the expected signal attenuation for laser communication between spacecraft. However, I was wondering what is a typical receiver aperture ...
5
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1answer
633 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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2answers
347 views

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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191 views

Feasibility of Interstellar Probe Communication

So, I understand that to transmit information across interstellar distances, you need to use a lot of power (or less bandwidth?), something for example a small space probe wouldn't exactly have. If we ...
2
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1answer
127 views

Is communication from a spacecraft in SEL1 disturbed by the Sun?

A spacecraft at the Sun Earth Lagrange point one (1% of an AU, or one Solar diameter, from Earth towards the Sun) would have the Sun as its background. Is the Sun emitting strongly enough at ...
2
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2answers
161 views

Stethoscope as a backup communication device

I'm curious about the use of stethoscopes as a backup communication source. This would be used between two spacecrafts, such as 2 astronauts in spacesuits, and help bridge the vacuum between them. ...
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3answers
746 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 ...
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1answer
159 views

Was the Orbit Pavilion triggered by real communications events?

The October 2016 NASA JPL news article Art Turns Public Eyes (and Ears) Toward Space describes an artistic interpretation of the communications between a number of NASA Earth satellites and ground ...
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Do satellite uplink/downlink signals spread or leak into space?

Satellite communication generally involves three types of nodes: the ground station (also known as teleport), the satellite in geosynchronous orbit, and the satellite receiver/transceiver. I am ...
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Was Houston able to control to the Apollo spacecraft if needed? [duplicate]

Was every aspect of a flight, aside from liftoff, solely the responsibility of the crew? Or was Houston able to command parts of the spacecraft and its computers remotely in an emergency or if ...
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5k views

First call to the moon 1969

During the Apollo 11 mission to the moon, there was a phone call where the POTUS at that time, Richard Nixon, was able to speak to astronauts Neil Armstrong and "Buzz" Aldrin. How was this possible?
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576 views

Frequency and modulation mode(s) for the SpaceX Tesla roadster mass in space

As an Electrical Engineer (emphasis in RF and radar, class of '74) who has followed the space program(s) since Mercury, and a prior flight test telemetry engineer, I was wondering if anyone knows what ...
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1answer
796 views

Why would SpaceX limit Starman’s Tesla signal transmission to 12 hours and not use solar power? [duplicate]

I'm as smitten as everyone else by Elon’s Starman cruisin' his Tesla through the cosmos. But I'm even more curious why we were limited to a signal transmission architecture with a mere 12-hour life ...
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1k views

How did the communication work between the SpaceX Tesla and Earth?

With a Tesla launched in space and HD cameras put on it, I can imagine its not easy to receive a signal from that slowly spinning, multiple ten-thousand km away new artificial object in our solar ...
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3answers
4k views

Will the Tesla Roadster return any telemetry?

Is there any equipment fitted to the Tesla Roadster to send signals back to Earth, even for a short time after launch?
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95 views

How long is a satellite orbiting at 300 miles going to be visible from horizon to horizon?

Elon Musk has a plan for satellite internet that involves LEO and VLEO satellites. The question I have is how long would a satellite at these altitudes actually be within range before having to ...
3
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2answers
2k 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 ...
13
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2answers
5k views

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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109 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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81 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 ...
3
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1answer
198 views

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 ...
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2answers
328 views

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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2k views

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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488 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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1answer
139 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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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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1answer
96 views

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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2answers
370 views

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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2answers
4k views

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 ...
6
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1answer
308 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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3answers
2k views

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-...
2
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1answer
336 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 ...
2
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1answer
379 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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2answers
2k views

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 ...
2
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1answer
850 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 ...
3
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1answer
437 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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0answers
190 views

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 over three years now, have any of the 'gift' transponders been used or at least tested yet by the gift recipient ...
2
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1answer
175 views

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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1answer
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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439 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 question How well can Voyager 1 separate Earth signals from Solar ...
2
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1answer
123 views

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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2answers
525 views

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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1answer
465 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 ...
5
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1answer
1k 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 ...