Questions tagged [communication-satellite]
Questions about satellites designed to aid in communications, such as phone, TV and Internet satellites.
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How has the brightness of SpaceX's Starlink constellation changed since May?
Shortly after the launch, before full orientation of the solar panels and raising of the orbits, the Starlink satellites were surprisingly bright and easily seen with the naked eye.
Back then, I heard ...
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1answer
29 views
Point Ahead Angle Calculation between LEO-GEO Satellite (ISL Scenario)
So, I have got two reference TLE from 2 different Satellite in LEO-GEO, which are as follows: (1st TLE for LEO, 2nd TLE for GEO)
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Velocity Vector Transformation for Point Ahead Angle and Doppler Shift Calculation for Inter-Satellite Link
So, I have the Radial and Tangential Velocity Vector (like in Figure 1) and also the Cartesian coordinate of 3D velocity vector. For reference, you can see in this link. Where, $o_{dot}$ vector matrix ...
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49 views
Point Ahead Angle and Doppler Shift Frequency Changes Calculation with the tangential/radial velocity component for Inter-Satellite Link
While calculating the Point Ahead Angle we work with Tangential Velocity vector component and to calculate the Doppler shift i.e changes in frequencies, we work with Radial Velocity Vector component.
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Does Surrey Satellite's Pathfinder lunar communications relay have customers lined up, or is it “If you build it, they will come”?
After about 24:00 in the BBC podcast Do We Need More Space Stations? BBC reporter Marnie Chesterton talks with Charles Cranston, the project manager for lunar ...
3
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1answer
209 views
How were the 100+ antennas around Telstar 1 and 2 configured?
Telstar 1 and 2 demonstrated routing of telephone, television and other communications types between continents.
The Smithsonian Air and Space Museum pages below contain images of the satellites. ...
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78 views
When did they stop routing long-distance phone calls through satellites? What was the maximum volume at its peak?
I have read that in the early 1960's Telstar 1 and 2 were the first satellites to route long distance telephone calls.
I seem to remember that long, long ago, long distance (overseas?) phone calls ...
1
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1answer
50 views
Understanding line of sight between two satellite with oblate Earth using “scaling k-component”
I have been doing some reading on accuracy of determining line-of-sight between two satellites give a WGS84 oblate earth. The paper Rapid Determination of Satellite Visibility Periods (Alfano, Negron ...
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117 views
How does a Hall effect ion thruster have a sea-level Isp of 800? Operates at 1 atmosphere?
Astronatix's SPT-100 lists the following:
Stechkin electric rocket engine. Used on Meteor and Gals satellites.
In Production. 1.35 kW Hall thruster.
Thrust variable 2 to 20 kgf.
...
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How does a “hybrid orbital raising system” based on R-4D (N2O4/MMH) + SPT-100 (Hall effect) work exactly? (Intelsat 38 & 39)
Astronatix's Intelsat 39 lists the two engines
SPT-100 Stechkin 1.35 kW Hall thruster.
R-4D Marquardt N2O4/MMH rocket engine. 490 N.
Question: Why is this combination on Intelsat 39 called "hybrid" ...
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Why do these satellite antennas look so weird? (strangely shaped with little white dots…)
The NASA Spaceflight article Arianespace press onward with dual-passenger Ariane 5 launch shows a photo of Intelsat 39 during testing. The dish reflectors are strangely shaped:
rather than being ...
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1answer
42 views
Video standard used on Intelsat 1 (Early Bird)
I was watching a documentary on Intelsat 1 (also known as Early Bird) and some of the first live television sent over it.
Was there any particular video format or modulation used, special for the ...
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1answer
75 views
Impact of having two antennas on link budget calculations
I'm working on link budget of a cubesat mission that needs to have two dipole antennas that are perpendicular to each other. I want to know if having two antennas affect the link budget? losses, and ...
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68 views
What is a “critical mass” equivalent of number of satellites on LEO that would initiate chain reaction of destruction if 2 of them collide?
If a satellite is destroyed and blown to multiple small pieces of debris, each one of these pieces has tiny probability of destroying another satellite, creating more debris which now will have even ...
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29 views
Relation between beamwidths of E-plane and H-plane
Is there any relation between E-plane and H-plane beamwidths of an antenna when steering in azimuth and elevation directions?
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1answer
42 views
Data Rates and Radios with Satellites [closed]
I am new to using radios and was wondering why do data rates matter when you use a radio to pull info from somewhere else. Also what does it mean when a satellite sends a wide band signal. Thank you ...
2
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1answer
279 views
What is meant by “a high-energy geostationary orbit”? (SpaceX Arabsat 6A)
The Teslarati article SpaceX’s April 7th Falcon Heavy launch a step toward new commercial markets says:
While there is some inherent uncertainty surrounding the (once again) fairly new rocket, ...
3
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1answer
330 views
What is OneWeb's constellation's “progressive pitch” and how does it avoid interference with Ku-band satellites in GEO everywhere on Earth?
The Wikipedia article section OneWeb satellite constellation; Design characteristics tells us:
The satellites will operate in the Ku band, communicating in the microwave range of frequencies in the ...
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1answer
398 views
What is considered a good SNR for satellites?
When performing a link budget for satellite communications, a key component is defining an acceptable signal-to-noise-ratio in order to obtain the necessary bit-rate. How does one determine what the ...
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40 views
How much of the piggybacked Aireon system rely on its Iridium Next hosts?
The NBC News article Next-generation satellites gave federal officials key data in Boeing 737 Max investigation says:
The Federal Aviation Administration, or FAA, grounded Boeing's 737 Max ...
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1answer
163 views
How do Inmarsat 5 F4's beams correspond to all of these antennas and feeds?
note: This is an old-style @uhoh question meaning that it is a bit on the long side. In this case I think it really needs to be since the question is a bit complex; I'm trying to understand how all ...
2
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1answer
119 views
What is the lowest power signal that the DSN can detect?
It is said that the Deep Space Network can detect low-power signals sent from Voyager in the range of 10^-16 W. I can't seem to find any sources that indicate what the minimum power requirement of a ...
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0answers
159 views
Have the Starlink precursor Tintin satellites been talking to each other? If so, how?
Tintin A and B are the first two exploratory and testing spacecraft for SpaceX's Starlink program.
It looks like they are in very similar orbits in both space and time, and are probably that way so ...
2
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1answer
218 views
Is it possible to capture geostationary satellites with DSLR?
DSLR is to be mounted on a tripod and pointed at sky with a zoom lens.
Would a sufficiently long duration of exposure reveal these non-moving satellites as bright "stars" amongst the streaks caused ...
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2answers
324 views
How to lease a transponder on a GEO satellite?
I have an interesting question. I was thinking about it a year ago when the es'Hailsat 2 was not launched.
There was an organization called "Outernet" that promissed to broadcast files (including ham ...
3
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2answers
318 views
What is a satellite trap?
I keep hearing about satellite traps, which have something to do with receiving and transmitting satellite communications, but I can't seem to find a definition.
The securityaffairs.co blogpost Hack ...
3
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1answer
214 views
How often does a geostationary satellite enter into a Lunar shadow?
Is there a chance for the many geostationary satellites to enter into the moon’s shadow?
If so, how frequently do such eclipses happen and how long do they typically last?
Are such eclipses pre-...
16
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1answer
2k views
What is carrier lock and bit lock?
I'm not sure if this question belongs here or in Amateur Radio, but during the acquisition of signal from New Horizons on New Year's Day, I heard the controllers call out "carrier lock", "symbol lock",...
3
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1answer
140 views
Satellites around outer planets that act like amplifier to signals from voyager like objects
One issue of deep space exploration is that once the object (like Voyager) is far out in the solar system the physical distance is so great that the signal reaching Earth is very weak. I was wondering ...
4
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2answers
81 views
How close will the cubesats be when numerous of them are launched simultaneously?
Checking the onboard video of PSLV C43 gives a feel like the CubeSats are released in very proximity.
Does this mean that these CubeSats will be orbiting in such very close proximity through out ...
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1answer
669 views
How low is VLEO? (FCC's newest approval for SpaceX)
Engaget's SpaceX gets FCC approval to deploy thousands more internet satellites says
SpaceX's plan to build a global, high-speed wireless internet network using satellites has taken another step ...
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424 views
What technology will SpaceX's StarLink satellites most likely use for sat-to-sat linking?
The question How does SpaceX plan to make money with StarLink Broadband? has got me thinking about how the satellites will link to each other.
Wikipedia says it's something greater than 10,000 GHz ...
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2answers
624 views
How does SpaceX plan to make money with StarLink Broadband?
To me, it seems obvious that ground based optical fibres will be cheaper than a space based system by an order of magnitude. So unless say, everyone starts sea-steading and a space based broadband is ...
4
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1answer
198 views
What prevents all these man-made objects flying in space from colliding with each other?
Does NASA know the location of every object in orbit and they calculate satellite and shuttle launches around not hitting these objects or are they just rolling the dice that the probability of ...
2
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1answer
147 views
Given a working satellite, would it be possible to build a homemade transmitter/receiver?
Given existing low-orbit and geo-synchronous satellites, would it be possible to build a device that could send a signal to a satellite and then have that signal received on another device? ...
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4answers
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Does the International Space Station get TV?
For obvious reasons the ISS cannot get cable TV. Can the ISS get the new digital air TV or satellite TV using an issued dish and receiver like a house? How would that be done compared to how it is ...
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2answers
90 views
How did Syncom-3 achieve eight stages of frequency doubling? I only see seven in the block diagram
@BlueCoder's nice answer to Syncom-3 was the first geostationary satellite. Anyone know of a description of the onboard electronics? mentions that the the master oscillator was doubled eight times to ...
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1answer
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Syncom-3 was the first geostationary satellite. Anyone know of a description of the onboard electronics?
I am interested in any description of the electronics on Syncom-3, the first geostationary satellite. I've been able to find quite a bit of general information. There was a pair of 2 Watt TWTs and ...
2
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1answer
75 views
Looking for info about commercial usage of satellites with examples [closed]
I'm doing research for an article and I'm looking for info about usage of satellites by commercial companies. For instance, usage of small satellites by insurance companies (imaging and etc.) or ...
0
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1answer
221 views
How will Astrocast's upcoming IoT (Internet of Things) network in space work? What kind of “things” will be networked?
The Space Daily article Astrocast signs contract with GomSpace Sweden to deliver propulsion systems says in part
GomSpace Sweden - a subsidiary of GomSpace Group AB, has received an order from ...
0
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1answer
68 views
What is the planned orbital configuration of Astrocast's planned IoT constellation?
The Space Daily article Astrocast signs contract with GomSpace Sweden to deliver propulsion systems says in part
GomSpace Sweden - a subsidiary of GomSpace Group AB, has received an order from ...
4
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1answer
426 views
How many different countries operate a satellite?
Looking over the list of recent launches, I find communication satellites for countries who do not have their own space program. How many different countries operate a satellite as of 2018? Is that ...
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1answer
147 views
What technologies are to used to broadcast signal from space?
I have seen a lot of companies offering a satellite phone service. But I have not seen anyway to broadcast my own signal from space.
What technology (that I can google) do they use to send their ...
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0answers
285 views
What kind of power is referred to in “the…most powerful all-electric propulsion communications satellite ever produced”
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. Next to this tiny image of (presumably) ...
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Are commercial communications satellites in GEO being constantly monitored by telescopes?
I was trying to look up GOES-17 in Spaceflight101 but got sidetracked in the search result and ended up reading this thread about AMC-9, which links to the YouTube video Rough cut video of AMC-9 ...
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1answer
107 views
What are these two very large, round panels on opposite sides of AngoSat-1?
The Spaceflight101 article AngoSat-1 Satellite Overview Shows several images of the large communication satellite designed for GEO.
Two color photos show that the spacectraft has two large (roughly ...
6
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1answer
274 views
How does dispute resolution work with the ITU.
I keep reading about disputes on allocation of satellites or spectrum - is there a way to read about them on the ITU sites - similar to reading the WTO dispute reports.
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4answers
4k views
What would be the first noticeable consequences to the general public of widespread satellite destruction?
What would most likely be the first thing I, as an average citizen of a developed nation, notice, if within a matter of hours, all major commercial and government satellites were to be destroyed in a ...
4
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1answer
55 views
What are the regulatory steps to be taken by a private aerospace company in India to launch a satellite?
The idea is to launch a satellite with ISRO or any other foreign launch service provider like SpaceX. The satellite in question is a simple CubeSat for basic remote sensing.
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0answers
41 views
Which materials make up a Commercial Satellite?
I'm writing a story based on the premise that an already-existing moon base is used to mine, construct, and launch a bunch of commercial satellites to GTO (the lunar surface is way "closer" to GTO ...
