Questions tagged [communication]

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

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How often in NASA history was "Houston, we have a problem" or deviations actually said?

The phrase "Houston, we've had a problem" was said by Jim Lovell after the oxygen tank blew up during Apollo 13, and in the movie Tom Hanks playing Jim Lovell said "Houston, we have a ...
Old Man John's user avatar
2 votes
2 answers
157 views

What is the difference between FSS and MSS?

I am researching NZ's Radiocommunications Regulations for satellite services, which specifies the RF bands reserved for general use. However, different bands have been reserved for different types of ...
moooligan's user avatar
4 votes
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94 views

Is it more common for crewed spacecraft (and spacecraft that interact with them) to have navigation lights, or not?

While trying to find details on the proposed improved Space Shuttle heat shields, I stumbled across a fact I'd forgotten: the orbiters didn't have navigation lights (i.e. red left, green right, white ...
Erin Anne's user avatar
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3 votes
1 answer
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Creating an animation short and need orientation info

I'm creating a short film celebrating Voyager 1's progress out of our Solar home. I would like to be as accurate as possible. Question: What is the craft's normal orientation as it travels? Is the ...
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Live_ISS_Stream stopped?

so I've come across this video, 11 hours of ISS transmissions during 2021 ASAT incident by Russia. The description says the footage was archived from this IBM stream site, so I've looked to see if it ...
user52175's user avatar
1 vote
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How big does a LEO relay satellite optical communication package need to be to support cislunar operations?

One of the things to come out of Artemis 1 was that NASA’s Deep Space Network was very overworked supporting Orion and eight cubesats + normal operations and maintenance. This led to some slightly ...
Barry Jenakuns's user avatar
2 votes
1 answer
124 views

Ground station : DVB-S2 TBS-6903 Receiver to communicate with a LEO Satellite

I am working on a project to develop a ground station that communicates with a LEO Satellite in X Band via the DVB-S2 communication standard using off-the-shelf components. It appears that the TBS-...
M.FAKHFAKH's user avatar
1 vote
1 answer
99 views

How to get contact locator events in GMAT using Python

I am trying to write a python script for GMAT to detect contacts between a satellite and a ground station. I have declared the contact locator as such: ...
aeroengineer's user avatar
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Beginner to simulating communications systems of space missions. I have GMAT, MATLAB and NASA's SPICE library. Where would I start?

I recently managed to load SPICE kernels into GMAT to simulate the trajectories of real missions, and got its MATLAB interface working (still trying to understand how to use the two software together)....
Johan Sondberg's user avatar
3 votes
0 answers
171 views

What is the cheapest/simplest way to deliver a camera to the moon? [closed]

The primary objective is this: to deliver a camera to the moon that live streams to Earth throughout the journey AND once it arrives on the moon. A bonus is if it can then move around on the Moon. An ...
M. Guillaume's user avatar
6 votes
1 answer
211 views

What is "ground station lock" and why does it enable faster communication?

I have come across the terms "ground station lock" and "ground station unlock". For example here and here. I guess that is about phase locking with the uplinked signal. I ...
filo's user avatar
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Turbo code used in New Horizons - encoding coefficient?

I know that New Horizons uses turbo code with r=1/6 for space communication1, however I don’t know which is the encoding coefficient, because I din’t think it could be 6, it seems it high. Could you ...
Spaceman's user avatar
1 vote
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High altitude platform: inter-platform link regulation?

Does anyone know if ITU has a recommendation for HAP-HAP (High altitude platform-High altitude platform) or LAP-LAP * or HAP-LAP links recommendation as for inter-satellite links with frequency, ...
Anna Koroleva's user avatar
3 votes
1 answer
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TLE along track error to miss a contact opportunity in UHF

Update: (following @GregMiller's comment): Lets suppose a spacecraft has performed a boost and not all ground stations received the update, lets suppose the difference between the pre and post ...
patowski1981's user avatar
1 vote
1 answer
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World communication network coverage in % or dead zones

In the paper "Recent Progress and Future Development in Satellite Communication" written by Ju Han, it is given that only 20% of the land area is covered by signals. I have started to search ...
Aid22's user avatar
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How does the Orion communicate with Earth?

Early renders of the Orion spacecraft show a deployed high-gain antenna dish like on the Apollo CSM. The Orion that actually materialised has no such thing. What does it use instead?
Andykins 's user avatar
3 votes
2 answers
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Will or could real-time HDTV broadcasts be possible from the Orion spacecraft during the Artemis I spaceflight around the Moon?

Earhrise, image taken from Apollo 8 by William Anders, Credits: NASA Starting with Apollo 8, there where 4 (!) crewed missions to the Moon in one year time ! (Apollo 8, 10,11 and 12) Will or could ...
Cornelis's user avatar
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what is the cheapest transmitter for a cubesat?

I'm building a CubeSat and it's halfway built. I've got a launch for February 2023, and I need a transmitter. If I don't get a transmitter on this thing, the CubeSat will ride to orbit and immediately ...
Deko Revinio's user avatar
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3 votes
1 answer
176 views

What could spacecraft do with much more available power? Are spacecraft power limited?

I'm curious about how spacecraft would benefit having much more power for the same total mass. Solar panels are getting lighter, but would the extra power they could generate bring benefits to space ...
James Craft's user avatar
3 votes
1 answer
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Why were the images from DART encode in a way that cropped the last one the way it did?

The last image from DART only includes about the top ⅒ of the image, but that portion of the image is in full quality. That suggests that the image encoding/compression is mostly a raster encoding. ...
BCS's user avatar
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Free space optical communication simulation in matlab [closed]

I want to do availability assessment of a free space optical link with weather data. However, available weather data are not sufficient and are not in needed standard. Hence, I manipulated with some ...
Ekata Niraula's user avatar
8 votes
2 answers
245 views

What will the live video and audio quality be like when astronauts next set foot on the moon?

What will the live video and audio quality be like when we watch an Artemis crewmember set foot on the moon? The quality of the original Apollo footage from the 1960's is terrible by today's standards....
Wyck's user avatar
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3 votes
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What does it mean when they say "switch to 32K " during the Phoenix Mars entry

In the Phoenix Mars entry video they keep saying "Odyssey switching to 32k", "Stop of Odyssey unintelligible Data and switch to 32k",and "We ...
spaceamoeba1010's user avatar
7 votes
1 answer
831 views

What size are the typical keep-inside boxes of geostationary telco satellites?

Geo sats need station-keeping and the size of their keep-inside box is a design parameter. A smaller box implies more manoeuvres to stay inside the box. All depending on the various orbit ...
Bash Frank's user avatar
3 votes
0 answers
97 views

Where to find the network topology of Iridium-Next?

This is my first post on Space Exploration. I'll preface this by saying that I just started learning how satellite communications work from a technical perspective. Until a few days ago I had never ...
Wippo's user avatar
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5 votes
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How is the maximum data rate of the Psyche mission's Deep Space Optical Communications (DSOC) system expected to scale with distance?

NASA's Mission Page Deep Space Optical Communications (DSOC) includes the following: Key DSOC technologies developed for the project include: a low-mass spacecraft disturbance isolation and pointing ...
uhoh's user avatar
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13 votes
1 answer
2k views

What kind of signals and encodings were used to send tilt/pan commands to TV cameras on the Moon (up through Apollo)?

This answer to Has anyone in space beyond LEO seen or has anything photographed a non-pointer laser from Earth? shows a frame from video shot by Surveyor 7 on the Moon, looking at Earth, and ...
uhoh's user avatar
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3 votes
1 answer
96 views

Mars at its closest is only a few light minutes away -- are different experiments performed when this happens?

While 3 minutes is not exactly real time, it still seems like remotely-controlled experiments of a different nature can be performed that could not be when Mars is farther. Is this correct, that the ...
releseabe's user avatar
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4 votes
3 answers
256 views

Is it possible for a spacecraft to communicate with Earth when a planet is in the way?

I have just read 2001: A Space Odyssey and despite the fact that the author was quite optimistic about the space exploration capabilities, communication between a spacecraft and Earth was not possible ...
Alexei's user avatar
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5 votes
2 answers
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What is this term in the link budget equation from Space Mission Analysis and Design (SMAD)?

Looking at the 3rd edition of Space Mission Analysis and Design by Wertz and Larson, their equation (13-4) presents the link equation, $\frac{E_b}{N_0} = \frac{PL_\ell G_t L_s L_a G_r}{k T_s R}$, with ...
NeutronStar's user avatar
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1 vote
1 answer
214 views

Do we use masers, lasers or infrared lasers to send data from deep space back to Earth? If not, why not?

I have posted in a couple of places (including here) about the recent (in the past year) news about future probes, landers, etc. using strong visible light lasers to send data back to us at much ...
Kurt Hikes's user avatar
6 votes
3 answers
861 views

How were Intelsat 1 “Early Bird” and Telstar 1's "hundreds" of simultaneous telephone conversations multiplexed/demultiplexed?

When did they stop routing long-distance analog phone calls through satellites? What was the maximum volume at its peak? contains images, sources and descriptions of both The Intelsat 1 “Early Bird” ...
uhoh's user avatar
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9 votes
2 answers
1k views

When cis-lunar Artemis astronauts and folks on Earth communicate via audio (e.g. EVAs) will they still step on each other's words like during Apollo?

It's been fifty years since we've heard astronauts and ground folks talk over each other ("step on each other" in 1970's CB radio parlance). Sitting on the floor a few feet away from our ...
uhoh's user avatar
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1 vote
0 answers
93 views

What is a good SNR value for a chipsat in LEO using bpsk?

My team and I are working on a chipsat and we are planning on launching it to LEO, we've also planned using bpsk. However our use case is a bit different, all we need once it is in LEO is a ...
Aamod Varma's user avatar
1 vote
0 answers
51 views

Are there any selfies of Curiosity or Perseverance with their high gain antenna deployed and "looking up"?

The Curiosity and Perseverance rovers have high gain antenna arrays on a mechanical arm that can rise up and point towards Earth and communicate directly. Has the Curiosity rover ever communicated ...
uhoh's user avatar
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3 votes
2 answers
506 views

How will the LICIACube cubesat transmit DART impact images back to Earth? What kind of antenna and radio will it use?

MarCO The Mars Cube Ones or MarCOs were 6U cubesats that were deployed in deep space during the InSight mission to observe it during a critical, dynamic period of its mission, in this case the N ...
uhoh's user avatar
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18 votes
3 answers
4k views

What is an "octet" in the context of NASA's LunaNET Interoperability Standard? ("internet on the Moon")

The PDF Draft LunaNet Interoperability Specification, LN-IS Baseline V001 September 2, 2021 (found at https://esc.gsfc.nasa.gov/projects/TEMPO?tab=lunanet) has found its way to the popular press. 4.2 ...
uhoh's user avatar
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13 votes
1 answer
919 views

Tracking of spacecrafts of the Mercury project

In the absence of any communication satellite in 1958, back in Mercury times, how did the tracking centers, which were spread world across, communicated with each other, passed on their data to the ...
Niranjan's user avatar
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14 votes
3 answers
3k views

Is it possible for LEO satellites to detect a usable signal from regular mobile phones on the ground?

Background Recently I came across a company called ASTS that claims they will be able to launch LEO satellites with the capability to talk with regular mobile phones. I initially wrote their claims ...
0xbad1d3a5's user avatar
2 votes
0 answers
79 views

Modifying Starlink / Dragon for orbital communication

In this answer @uhoh notes: The Starlinks currently have three types of internet-related communication: downwards with customers fixed on the Earth's surface below the satellites (except an ...
Nathan's user avatar
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3 votes
0 answers
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What did Intelsat-1 do in 1990 for its 25th anniversary brief reactivation? Could it be reactivated again? Is there a secret code?

Ouch! The 1960s From This Is What Broadband Satellite Communication Looked Like in 1965 The Intelsat 1 “Early Bird” communications satellite, built by Hughes Aircraft Co., was able to relay 240 ...
uhoh's user avatar
  • 149k
3 votes
1 answer
522 views

How exactly did ground stations track the early Molniya satellites?

Wikipedia's Orbita (TV system) says: Orbita (Russian: орбита) is a Soviet-Russian system of broadcasting and delivering TV signals via satellites. It is considered to be the first national network of ...
uhoh's user avatar
  • 149k
8 votes
2 answers
795 views

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 ...
YaelChAv's user avatar
2 votes
1 answer
526 views

What connection do Mars rovers use to send data to Earth?

How do Mars rovers send data back to Earth? Do they have some kind of built in WI-FI routers or is there any other connection?
RANSARA009's user avatar
7 votes
1 answer
194 views

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 ...
Sidharth Ghoshal's user avatar
7 votes
1 answer
231 views

Why are modern satellite ground station and deep space communications dishes with secondary mirrors almost always Cassegrain?

The simplest dish antennas have a concave reflector and their feed horns at the primary focus which is "up in the air". That has several inconveniences, it's hard to go up there to do any ...
uhoh's user avatar
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4 votes
0 answers
69 views

Currently, how many communications channels can a single DSN dish maintain at the same time? Are there plans to increase this in the future?

DSN NOW screenshot 2021-07-10 at 07:14 UTC DSN NOW screenshot 2021-07-10 at 09:48 UTC The screen shots show Canberra's Dish 35 simultaneously transmitting and receiving, and above it is written MRO, ...
uhoh's user avatar
  • 149k
6 votes
0 answers
103 views

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 ...
soleados's user avatar
1 vote
0 answers
154 views

How (the heck) is it possible that with China's future 6G satellite network I'll be able to download 1000 movies per second?

The reasonably credible Wall Street Journal has a YouTube channel and the new video SpaceX vs. China: The Quest for Satellite Internet | WSJ says that with Starlink's data rate I can download a 1 Gb ...
uhoh's user avatar
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2 votes
0 answers
112 views

How is Prospero doing now? Was it really heard in 2004 and have there been recent attempts to contact it?

Screenshot from the excellent historical review in Curious Droid video Black Arrow : The Lipstick Rocket - A Very British Space Program with a photo of Prospero or at least a representation thereof. ...
uhoh's user avatar
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