Questions tagged [radio-communication]

Using radio wavelengths to communicate between multiple spacecraft or between a spacecraft and the Earth.

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Why does the Crew Dragon seem to rely primarily on a low bandwidth downlink for voice communications?

What are the particular reasons that the Dragon Capsule is not communicating via Starlink, or that it seems that the audio and video downlinks from the Dragon Capsule are on separate streams?
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What is the range of frequencies of a deep space channel?

I've been trying to find the values of bandwidth of each Deep Space frequency channel: band S, X and Ka. In the official NASA's documents only appears the center frequency of each one, but it doesn't ...
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How deep could a gas giant communications network penetrate?

I have been wondering what type of communication network could you build to communicate as deep as possible into a gas giant such as Jupiter? Which technologies would you use at what depths? One could ...
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What interstellar data rates are feasible? [closed]

Preamble: Mankind has colonized the galaxy with self replicating machines which build transceivers when they arrive at a new star system which transmit and receive uploaded human minds and AI between ...
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What happened to Voyager 2's tracking loop capacitor? How did it get damaged? What is it for? What's a tracking loop anyway?

On 23-Aug-2021 Voyager 2 tweeted: DSN antenna DSS-43 at @CanberraDSN is starting a 300 min listen to hear the echo of a command tone sent up to me 35 hours ago. This will define the "Best Lock ...
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Just how raw is the rawest signal data that the Deep Space Network routinely records for safety reasons?

When we watch videos of some Spacecraft landing there's a big screen with real-time plots of the data coming from the Deep Space Network's antennas. Presumably the information is recorded in fairly ...
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How were Soviet/Russian aircraft used to track and/or communicate with spacecraft?

Russian Space Web's Russian ground control and tracking network mentions A Soviet Iluyshin-18 aircraft configured to maintain communications with spacecraft. in the sidebar and includes the small ...
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How can SpaceX receive data from Starship during re-entry communications blackout

Surviving re-entry will be one of the initial critical aspects of the Starship development program. If there are locations on the vessel where the heat-shield fails, leading to its destruction how ...
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How does Quantum change it's antenna's shape? (Flagship UK telecommunications satellite just launched)

The BBC's Quantum: Flagship UK telecommunications satellite launches includes the following: A quarter of the world's big telecoms spacecraft are manufactured in Britain, and the new Quantum platform ...
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Why is the Fermi paradox' assumptions so strong? Do they even need to be?

The Fermi paradox first states that it is highly likely that intelligent lives have existed on planets long ago. As in, not just on one planet, but on billions of planets. Then the paradox goes on and ...
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Is or was STARGATE really being used for SpaceX launches at Boca Chica or otherwise?

The 2015 answer to For SpaceX's Texas launch site, what kind of range radar/tracking will they have? links to The Spacecraft Tracking and Astronomical Research into Giga-hertz Astrophysical Transient ...
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Cubesat half duplex communication stack

My understanding is that in half duplex transceivers, you are only able to either transmit or receive. In Cubesats using half duplex comms, which part of their communications stack is performing the ...
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Will there be a command moratorium for Mars spacecraft again in 2021?

About every two years, Earth and Mars are on opposite sides of the Sun (a Mars-solar conjunction). Plasma expelled from the Sun can interfere with radio transmissions between Mars spacecraft and the ...
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Why are deep space "beacons" usually UHF, so low (in freq) that DSN can't hear them? And how unusual is it for a Mars lander to have an X-band beacon?

This answer to Is there independent evidence that China landed a robot on Mars in May 2021? and an extensive comment below it indicate that the Zhurong Mars lander had an X-band beacon, information ...
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How would I determine the power usage for a X-Band High Gain Antenna?

Currently I have that for a X-Band High Gain Antenna functioning at 8 Ghz, diameter of 3 meters, and a power transmission of 13.1dBW (20 watts) at a distance of about 8.5 AU has a Gain of 52.44 dBi, ...
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Are these good specifications for a X-Band High Gain Antenna?

Currently, I have that for a X-Band High Gain Antenna functioning at 8Ghz, diameter of 3 meters, and a power transmission of 13.1dBW(20Watts) at a distance of about 8.5AU has a Gain of 52.44dBi, free ...
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Have solid dish antennas on deep space spacecraft (as opposed to meshes) ever provided any other helpful function? As meteor shields perhaps?

This answer to Which deep space spacecraft had main dish antennas that were perforated or made from mesh? tells the tale: Galileo's troubled high gain antenna was made from "a gold-plated ...
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Does the Ingenuity helicopter on Mars have a radio call sign?

This Deep Space Network page lists some of the call signs of various robotic spacecraft. For example, Curiosity is MSL, and Perseverance is ...
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How do the small radio receivers on space probes catch enough of a signal to communicate with us?

From Scientific American, March 2021: Optics. Traveling Photons. Joanna Thompson. Much of today's space communication relies on radio signals. But these diffract and broaden as they travel, as ...
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What does it take to upgrade a radio antenna to receive from the surface of Mars?

All the discussion about receiving transmissions from Mars rovers got me thinking, what determines the capability of a radio antenna, and what goes into adding the capability of listening to a Mars ...
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Even small countries have a few ~30 m diameter parabolic antennas but nobody reported signals coming from the landers on Mars. How is it possible? [duplicate]

The parabolic antennas with diameters of ~30 meters are all over the world. Even small countries have them. However, nobody, except DSN or other entities controlled by the US government, has ever ...
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Can anything at Mars speak 900 MHz ZigBee besides Ingenuity helicopter and Perseverance rover?

Interest is piqued by What could be strong arguments against Ingenuity following Perseverance at a safe distance when the flight test program has been a success? Question: Can anything at Mars ...
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What's the most intense beam ever sent from Earth?

By a freak coincidence sensors on a passing alien ship a hundred light years away had picked up a faint artificial blip from Earth, thereby discovering our inhabited planet. But which blip was it? ...
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Why are minimum three artificial satellites required for radio-communication all around the Earth?

Artificial satellites orbiting the Earth have important applications for radio-communication around it. To avoid the blockage of radio-communication around the Earth, multiple satellites can be ...
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How long did the plasma blackouts of Perseverance's signals to MRO and direct-to-Earth last during its seven minutes of terror?

Congratulations to NASA JPL and the Perseverance Team and everyone else who participated and contributed in some way! Watching the live feed of the EDL seven minutes of terror I heard there was a ...
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Does SPICE function gftfov account for occultations?

I need to determine when an antenna on a spacecraft can see a ground station on Earth at particular epochs. I have generated all the necessary SPICE kernels necessary as well as using the NASA ...
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Does the Juno spacecraft have an "open signal, by design"?

The click-bate title'd Space News article China quietly used NASA’s Jupiter probe to test its deep space network contains the quoted material below. Everybody listens to everybody else's spacecraft's ...
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What is a Beam Waveguide dish and why do deep space communications stations use them?

NASA Spaceflight.com's Deep Space Network upgrades and new antennas increase vital communication capabilities says: NASA’s Deep Space Network, commonly referred to as the DSN, has welcomed a new dish,...
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First Ham Radio contact from space; what frequency, what kind of antenna, and how did they route the coax out the window?

From Phys.org's Earthlings and astronauts chat away, via ham radio: NASA astronaut Doug Wheelock was just a few weeks into his six-month mission at the space station when feelings of isolation began ...
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When our Moon is hiding Mars, is it possible to create a radio communication between Earth and Mars?

According to this link Mars is hiding behind the Moon ... It’s a twice-a-year occultation; like the eclipse When such situations happen, can we communicate with the Mars rovers, and in the future - ...
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How did Argentina, Namibia, and Pakistan help China monitor and communicate with Chang'e 5?

At the end of The Hill's article Chinese official unveils future moon mission plans including possible lunar base it says: The most recent Chang'e 5 probe was assisted by the European Space Agency, ...
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How will the closure of the Arecibo dish impact deep space communications?

Earlier today, the U.S. National Science Foundation announced that it is decommissioning the Arecibo radio telescope. The 305 meter dish is famous for the 1974 message for extra-terrestrial ...
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What is the bandwidth (in hertz) of the Voyager 2 radio receiver?

Does anybody know the bandwidth of the Voyager 2 radio receiver's front-end? I know that the current data rate of the receiver is of order tens of bits per second, and I have one estimate of 18 Hz. ...
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When, if ever, did deep space probes start using encryption?

What, if any, mechanisms prevent unauthorized commands? Asks what measures are taken for spacecraft, although the answer doesn't go much farther than pointing to the What would one need to do in order ...
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Problems receiving Iridium messages during the middle of the 'day' in the far North

I have some scientific instruments using Iridium modems for communication active at around or higher than 82°N. At the time of writing this message, we are in middle of August, i.e. the polar day ...
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Is GNU Radio being used for any Deep Space Missions in development?

GNU Radio is an open source collection of code and tools to build various radio elements for a "Software Defined Radio" or a radio implemented with the help of an FPGA that is programmed to ...
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Are NASA (and ESA?) deep space spacecraft now generally able to store and forward messages between themselves?

There are discussions under the current answer to Will Curiosity and the Mars 2020 rover be able to communicate with each other via a Mars orbiter? about the feasibility of MRO receiving a message ...
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Interactions between rocket exhaust and radio communications?

Rocket exhaust is bright in visible light, we can still see through it but when there's hot, glowing soot it's so bright that we think it's opaque, but it's not. See answers to How does the camera ...
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Does Russian mission control still use the callsign "Zarya", and how did that not conflict with the ISS module?

The Wikipedia page for the Salyut space station claims Initially, the space stations were to be named Zarya, the Russian word for 'Dawn'. However, as the launch of the first station in the ...
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What does "clearing of C-band spectrum" mean and why will it cost Intelsat a billion dollars?

From "Intelsat files for bankruptcy" One of the primary catalysts for restructuring the balance sheet now is Intelsat’s desire to participate in the accelerated clearing of C-band spectrum under ...
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Curiosity / MRO UHF connection and weak signal modulation

In the case of MRO and Curiosity communications via UHF, an active feedback system was implemented in which Curiosity monitored the quality/SNR of the connection and commanded Curiosity to increase / ...
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Encryption in radio system

We know that radio waves are used in communication with rockets, space crafts and satellites. Now, radio system basically consists of transmitter and receiver. If there is frequency match between ...
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Why did Moon missions state their number in radio context?

I'm not sure if this still happens, so the question may be broader, but in the Apollo transcripts the astronauts would begin a call with something like "Houston, 13". I get that they may have been on ...
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UHF transceiver for cubesats network

I already asked things related to this topic. But this time I will try to divide it by points to make it more understandable. Features of my cubesats: Would have 8 cubesats 3U in Earth's orbit The ...
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Alternatives to the X-Band

is there any other band that can do something similar to what the x-band does? Any that require a smaller antenna and more electrical power?
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Why was Canberra able to listen to Voyager 2 but not talk to it?

The New York Times's When Voyager 2 Calls Home, Earth Soon Won’t Be Able to Answer explains that because Voyager 2's trajectory has taken it way below the ecliptic, of the three 70 meter dishes in the ...
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Why did Sputnik-1 transmit on both 20 and 40 MHz?

Wikipedia's Sputnik 1 and this answer to Why did Sputnik 1 have four antennas? say that Sputnik transmitted at both 20 and 40 MHz. Why two different frequencies? Why so far apart? It's worth noting ...
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What did Sputnik-1 sound like? Did it use multiple tones?

Radio transmissions from Sputnik-1 could be heard on short wave radios around the world. Questions: A carrier signal only would not be particularly audible to an AM radio listener, was it modulated ...
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How does SpaceX transmit the video feed from the first and second stage cameras back to Earth?

There appear to be at least 1 reasonably high-res (500+ px vertical res) live video stream being transmitted from both the SpaceX F9 first and upper stages all the way up into LEO throughout their ...
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What was the transmitting power of the Apollo astronauts' PLSS VHF radio transmitters?

I'm assuming many of you are familiar with Larry Baysinger. A radio amateur who independently detected and recorded the transmissions from the Apollo 11 EVA using a homemade antenna. Larry Baysinger ...