Questions tagged [communication-satellite]
Questions about satellites designed to aid in communications, such as phone, TV and Internet satellites.
184
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Example of an optical phase locked loop (PLL) used (or planned for) free space optical satellite communication
I am looking for examples of an optical phase locked loop (OPLL) used (or planned for) free space optical satellite communication.
I have found one, but in the block scheme there is a photodetector (...
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29 views
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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2answers
107 views
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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1answer
127 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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3answers
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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1answer
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Receiver and transmitter in RF/optic satelite communciation: distance vs datarate.v 2
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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77 views
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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1answer
2k views
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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2answers
49 views
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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2answers
437 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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2answers
171 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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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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1answer
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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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0answers
41 views
Why does higher solar phase angle (SPA) allow 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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118 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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3answers
190 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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2answers
200 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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2answers
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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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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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1answer
262 views
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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2answers
215 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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1answer
484 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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1answer
91 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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3answers
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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1answer
92 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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1answer
77 views
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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4answers
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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0answers
88 views
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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1answer
320 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?
4
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0answers
122 views
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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710 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 ...
5
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1answer
276 views
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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2answers
307 views
How a spy satellite eavesdrop on another satellite?
I recently read about Mentor-4 (also alled USA-202 or NRLO-26), a gigantic US spy satellite (operated by NRO and the CIA) with a possible dish radio antenna of 100 meters in diameter located in GEO. ...
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1answer
360 views
How could RCA Satcom III have been completely lost? (Or was it?)
This answer to What “missing satellite” was part of the story of CNN's debut? quotes the 1981 UPI Article The RCA Satcom III-R commercial communications satellite, designed to... as follows:
The ...
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1answer
411 views
What "missing satellite" was part of the story of CNN's debut?
NPR's Tune In To 'Up All Night' For The Story Of Daniel Schorr And The Birth Of CNN includes the following about the beginnings of Cable News Network
On CNN's rocky debut:
There were so many ...
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1answer
120 views
How much did the cheapest communications satellite cost?
Satellite communication is becoming bigger and better, and I wanted to find out more.
2
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1answer
87 views
Could you theoretically launch your own satellite and transmit satellite phone signals to it?
This is a RF and Space question mix, and I am new here and didn’t know where else to ask, so I asked here! This is in the United States btw.
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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 ...
3
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1answer
146 views
Determine envelopes for the payloads?
I am a mechanical engineer who is trying to expand my domain knowledge in aerospace and am currently reading a book to increase my understanding of it. I am mostly interested in studying the design of ...
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0answers
45 views
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 / ...
2
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1answer
451 views
How to calculate azimuth and elevation angle between aircraft and GEO satellite (in aircraft coordinates)
Given a fixed ground station, it is known how to calculate the azimuth and elevation.
If changing it to an aircraft which is changing its data (location, altitude, angles) and working with same ...
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132 views
How did SpaceX's VisorSat work? How did the sunshade articulate to shade parts of Starlink satellite as it orbits the Earth?
CNET's Elon Musk wants SpaceX to launch the next generation of space telescopes says:
The billionaire entrepreneur said that "VisorSat" satellites equipped with a sunshade to block ...
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0answers
49 views
Any commercial communication satellite in GEO Orbit that supports 25 KW Power?
As I understand, EchosTAR-11, built by Space systems Loral, was the first 20KW Commercial satellite.
(Reference: Recent Successful satellite systems- Visions for future by D.K.Sachdev).
2
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1answer
82 views
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 ...
2
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2answers
153 views
North-South Satellite Manuever
I am doing North-South manuever for GEO satellite. My purpose is to reduce the inclination. My initial inclination is 0.07 deg, and my target inclination is 0.0002 deg. I have tried the maneuver in ...
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1answer
135 views
How do I calculate what antenna I need for my cubesat?
If I want to make a communication satellite, like MarCO, what formulas do I need to calculate the perfect antenna? Is there a difference between the X-Band and the classic UHF? If the cubesat is ...
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109 views
Where can I find data on satellite orbits?
I'm an enthusiast who'd like access to satellite orbital data to simulate / plot trajectories of manmade satellites (of any kind) on my home computer. Where's the best place for me to find this kind ...
3
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1answer
141 views
Will Optical communications be possible between Columbus' Ka-band (COLKa) Terminal at the ISS and EDRS?
The BBC's British radio antenna to arrive at space station says:
The new fridge-sized terminal will route video, voice and data to the ground through satellites that are actually higher in the sky ...
3
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2answers
289 views
Why do orbits in the Iridium constellation have an inclination of 86.4°?
Wikipedia's Iridium_satellite constellation; In-orbit spares says that Iridium satellites have an inclination of 86.4°:
Significant orbital inclination changes are normally very fuel-intensive, but ...