Questions tagged [communication-satellite]

Questions about satellites designed to aid in communications, such as phone, TV and Internet satellites.

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How does one calculate the look angle for non-geo satellites (i.e. LEO, HEO, etc.)

I'm trying to find a way to calculate look angles to not just GEO satellites, but LEO, MEO, and HEO sats. The only calculator I've found myself is here, which was referenced for a similar problem on ...
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How does one generate a formula(s) for an artificial satellite's location at time t given a set of known locations at discrete times?

Given a set of spatio-temporal points in space {(Lat_1, Lon_1, Alt_1, Time_1), ... (Lat_n, Lon_n, Alt_n, Time_n)}, I need a function (i.e. a formula) that takes these points (or subset of points) as ...
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How does a spacecraft know what communication network to use?

Spacecrafts use different networks like TDRSS, DSN, ... to accomplish uplink/downlink. But how does it know which one to use during the mission? At what point does it find TDRSS more suitable than DSN ...
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3 votes
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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 ...
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How do satellites ensure they are orientated towards the Earth to allow of clear connections? [duplicate]

As the title says, How do satellites ensure they are orientated towards the Earth to allow of clear connections, whilst having their solar panels face the sun? I understand reaction wheels are ...
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How to compute the satellite footprint latitude and longitude for different countour?

Given a satellite coordinates, the antenna gain pattern of the satellite (example a dish antenna at given frequency and with known diameter), the off-nadir angle and the satellite slant range i need ...
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1 vote
1 answer
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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 ...
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3 votes
1 answer
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Radio antenna used to communicate with the Telstar 1 satellite in 1962

Related to Why was Telstar 1 put in a 952 x 5933, 2.6 hour 44.8° MEO orbit?. The satellite ground station at Andover, Maine, that was used to communicate with the Telstar 1 satellite was a horn ...
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4 votes
1 answer
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Why was Telstar 1 put in a 952 x 5933, 2.6 hour 44.8° MEO orbit?

Wikipedia says that Telstar 1 was put into a 952 x 5933, 2.6 hour 44.8° MEO orbit but doesn't really say exactly why this particular orbit was selected. Did it perhaps behave roughly like a Molniya ...
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6 votes
3 answers
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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” ...
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-3 votes
1 answer
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Inter-satellite range: how to compute max. range? [closed]

How to compute a distance between 2 satellites if I know its orbit altitude? I know LEO-LEO satellite distance is from 1000 km until ~7000 km. But it should have a calculation equation? EDIT 1 S1, S2, ...
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4 votes
2 answers
218 views

How to compute each of these link budget terms?

The terms in Equation are all in decibels (dB), which is logarithmically scaled. In Equation, $P_{rx}$ is the received peak power, $P_{tx}$ is the transmitted peak power, $G_{tx}$ is the transmitter ...
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2 votes
1 answer
92 views

Transmit power for low/high wavelength [closed]

I am reading the book: Kaushal, H., Jain, V.K. and Kar, S., 2017. Free space optical communication. New Delhi: Springer India. I have asked before about a reason of choice of wavelength for beacon ...
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2 votes
1 answer
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operating wavelength of lasercom

I am reading the book: Kaushal, H., Jain, V.K. and Kar, S., 2017. Free space optical communication . New Delhi: Springer india. The operating wavelengths for beacon and data transmission were ...
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Methods and techniques for correction for atmospheric effects

What are methods and pieces of hardware which can limit these effects? In one of the last my question, User Polar_Bear mentioned, but there are many methods and pieces of hardware which can limit ...
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1 answer
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PAT (Pointing Acquisition, and Tracking) system in lasercom

After reading some articles and posting questions 1, 2 I think, the main challenges are PAT (Pointing Acquisition, and Tracking) system and operating environment. We must put the beam onto the ...
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4 votes
1 answer
351 views

Data rate in optical free space communication systems

Mynaric is one of the main suppliers of laser terminal for free space communication. In one of its latest publications I have read, they will increase the data rate of the last lasercom terminal up to ...
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4 votes
1 answer
212 views

There are only a few suppliers of optical terminals: what is the reason?

I am conducting research into optical free space communication and small/nano satellites in LEO. I have found only a few companies which supply lasercom (laser communication) terminals (transmitter/...
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1 vote
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Minimum data required to predict passes

What is the minimum amount of information that is required to predict satellite passes. Can it be done with the period, inclination, apogee, perigee and eccentricity only? Thanks
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1 vote
2 answers
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How to compute footprint(size) of beam of sat.system?

I need to compute the footprint (ground area that its transponders offer coverage) of beam diameter. Given different frequencies, distance between a satellite and ground station. I have found the same ...
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2 votes
1 answer
135 views

Optic communication: day and night

Will launched time of a laser satellite teminal affect to transmission parameters, as data rate, power …? As I know , the main limitation of lasercom is a direct line-of-sight path exists between a ...
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13 votes
3 answers
2k 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 ...
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1 vote
1 answer
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Receiver and transmitter in RF/optic satellite communication: distance vs data rate v2

The first version of this question is here. I have read the article "Optical communications work best over relatively short distances in space." by Toyoshima, M., Leeb, W., Kunimori, H. and ...
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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 ...
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12 votes
1 answer
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Why do Teledesic satellites look so weird? What are these structures and where's the satellite bus?

source enlarged and sharpened To my untrained eye I see a weird claw or flower-like antenna array with eight petals in the shape reminiscent of concave dish but not really, that look like they might ...
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0 votes
2 answers
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First cylindrical Earth satellite? Last?

Sputnik 1 was a shiny metal sphere, as were it's immediate followers. These days Earth satellites are generally rectangular prisms, either one or a few stuck together. Basically big metal chassis ...
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8 votes
2 answers
492 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 ...
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3 votes
2 answers
219 views

What is the theoretical smallest size limit for a phased array antenna that can reach LEO?

Now that one provider is operating a phased array ground-to-satellite internet comm system, others will follow. A frequently asked question is "When can we use Starlink with a sat phone?". ...
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2 votes
0 answers
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How to calculate when an areostationary satellite would be unable to talk to earth?

Consider an areostationary (geostationary but for Mars) satellite that communicates to Earth. Since on some orbits, Earth would be behind Mars from the point of view of the satellite, I imagine that ...
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1 vote
1 answer
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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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3 votes
1 answer
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Puzzler: Why higher solar phase angle (SPA) allows for many more feasible FastKD (kinetic deflection) communications satellite “hijacking” missions?

Space.com's advert-laden Repurposed communications satellites could help save humanity from an asteroid impact ends with: The study results were presented at the Planetary Defence (sic) Conference ...
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1 vote
0 answers
131 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 ...
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1 vote
3 answers
215 views

Can a LEO based satellite constellation revive the analog radio or TV era?

Many analog terrestrial radio and tv transmitters have been replaced by digital ones like DTT and DRM technologies. Analog radio signals include FM, MW and even SW. Although the quality of reception ...
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3 votes
2 answers
270 views

Are relay stations possible between planets?

I recently participated in a hackathon where we were looking at various space-related challenges and one that we considered was communications between Earth and Mars. The hackathon is over now but I ...
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25 votes
2 answers
4k views

Is it normal for the US Space Force to warn companies about a possible collision (conjunction)?

I've read a German news article today (Golem.de) stating that there was a conjunction between a Oneweb satellite on its ascension course and a SpaceX satellite. The US Space Force warned Oneweb that ...
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1 vote
0 answers
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Why so many little pieces of "space tape" on this communications satellite?

Maxar's own blogpost Power and Propulsion Element: Five Questions with Maxar’s Tim Cole contains an image with the caption The ABS-2 spacecraft at Maxar’s Palo Alto, California factory before its ...
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9 votes
1 answer
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What do large, modern communications satellites look like inside (roughly at least)?

Modern communications satellite in GEO are big, majestic beasts. They are quite large and voluminous. They can sport quite an array of antennas and handle huge bandwidths and multiple communications ...
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2 votes
2 answers
228 views

Has anyone developed a reliable deep space battery that doesn't need to be kept warm?

Has anyone developed a reliable battery for use in cold deep space applications? Something that doesn't need to be kept warm? For exampe lithium batteries certainly has its constraints due to the ...
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4 votes
1 answer
1k views

Why 53º orbits for Starlink?

In the UCS satellite dataset, I see a very modest number of non-Starlink LEO satellites around 53º (see graph below). Conversely, Starlink satellites are regularly deployed around that inclination. ...
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Satellites | Debris & EMR

Over time we are launching plethora of communication satellites into space, with old ones reaching their lifespan and new ones replacing them. My Question is two folds: Are we simply creating more ...
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4 votes
1 answer
104 views

Satellites Orbital Parameters

I want to access satellites' orbital parameters like inclination, right ascension of ascending node and argument of perigee. Unfortunately, I haven't been able to find this information. Is there a ...
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5 votes
3 answers
2k views

Main differences between 5G and Starlink? [closed]

I wonder who is better in terms of whole if considered. Speed, latency, reach, accessibility and affordability.
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2 votes
1 answer
109 views

"...extending the Starlink network using longer-range laser comms and relay satellites to reach Mars and Starships in-transit" (Musk & Shotwell)

I have it on good authority that SpaceX's Elon Musk and Gwynne Shotwell: ...have talked about extending the Starlink network using longer-range laser comms and relay satellites to reach Mars and ...
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0 votes
1 answer
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S-Band transceiver schematics [closed]

I'm working on a cubesat, and I want to communicate in the S-Band, arround 2.4GHz. And I'm searching for schematics of a transceiver example with arround 35 dBm of output power. If any have a .pdf, ....
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4 votes
4 answers
1k views

Quantum technology for starship communications and landing on Mars

Based on practically proven Quantum-Entanglement principle, any entangled quantum switch in this universe can be flipped instantaneously from elsewhere. Can it be used to send information from far off ...
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3 votes
0 answers
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How will Amazon's constellation differentiate itself from SpaceX's and OneWeb's?

The New York Times' Amazon Satellites Add to Astronomers’ Worries About the Night Sky says: Much of the attention on these strings of satellites has been placed on the prolific launches of SpaceX and ...
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10 votes
1 answer
491 views

How much krypton is stored on a Starlink satellite?

How much krypton (fuel) is there for the krypton-powered ion thrusters on Starlink satellites and how long does it last?
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4 votes
0 answers
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Once Starlink is fully deployed how many satellites will be visible at any given moment?

So the GPS system has 31 satellites in an orbit of 20,180 km. Most of the time there are at least 3-4 satellites 'visible' (visible from a signal reception point of view) at any given moment. The ...
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1 vote
0 answers
1k views

What is the average weight and price of a telecom satellite?

I found a source estimating the average weight of commercial communications satellites and then I think maybe there is more such data about price and launch price too. And then my question is about ...
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5 votes
2 answers
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After 21 years of silence how and by whom was OSCAR-7 first identified as functional?

This 2017 comment below an answer to What is the oldest artificial satellite still in use? says: But it should be mentioned that AMSAT-OSCAR 7 was silent between 1981 and 2002 for 21 years. It was ...
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