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Questions tagged [communication-satellite]

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

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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 ...
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Can a satellite orbit Earth so that it always has the Moon in line of sight?

Could a satellite, without too much fuel consumption for station keeping, orbit the Earth so that it always has a line of sight to the Moon? It would need a near polar orbit which precesses in tandem ...
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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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1answer
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SpaceX's 4,425 satellite constellation - what's the method to the madness?

The BBC article SpaceX aims to launch internet from space discusses the SpaceX proposal for a dense array of over 4,000 LEO satellites for global internet coverage, and links to SpaceX non-...
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2answers
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Why are obsolete geostationary satellites re-orbited above the geostationary belt?

That seems a bit counter-intuitive, because in an orbit above the belt, the satellite would eventually lose gain velocity, so its orbit would intersect the orbital plane of the geostationary ...
16
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1answer
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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",...
14
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1answer
744 views

How many dead sats near GEO?

It's my understanding a geosynchronous satellite will put itself in a graveyard orbit just before it dies. How many dead sats are in GEO or in neighboring graveyard orbits? What is their total mass?
13
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1answer
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Can communication satellites be used in lunar orbit?

Because the moon always has the same orientation to earth, if we want to have communications with manned or robotic explorers on the far side some type of relay would be needed for communication. ...
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1answer
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How much will SpaceX's constellation of Internet satellites cost?

SpaceX has a plan to launch up to 4K satellites to provide global Internet access. Is there a reasonable estimate of how much this constellation would cost to launch? Also, as the minimum number of ...
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2answers
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What (actually) makes Iridium “the world's only truly global mobile satellite communications company”?

In this article about how the SpaceX anomaly will affect Iridium it says: In its official website, Iridium describes itself as "the world's only truly global mobile satellite communications company....
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Are Molniya orbits used apart from Russian communication satellites?

Molniya orbits are popular with Russian communication satellites, because they spend a lot of time at high latitudes. Europe and Canada are also quite far north. Do any European, American, or ...
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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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Why do geosynchronous satellites appear to oscillate in North-Southward direction? How to I trace out their path on the surface of the earth?

During the course of a day, the geosynchronous satellite's position in the sky forms a 8-like figure. I'm having trouble visualizing the movement of geosynchronous satellite when viewed from the ...
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Is it possible to replace Internet with LEO satellites?

Bulk information regarding anything in this world is available in a single touch through Internet. My question is whether it is possible to replace this Internet with a constellation of Cubesats in ...
10
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1answer
919 views

How can OneWeb constellation succeed where Teledesic failed?

Teledesic: 1994 backed by Microsoft Inclination: 98.2 degrees (sun-synchronous) Altitude: 700 km 840 satellites OneWeb: 2014 backed (?) by Google Altitudes: 800 or 950 km 650 satellites This is a ...
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2answers
422 views

How can just making the ground broadcast stronger neutralize a zombie(sat)?

In April of 2010 the Geo-not-so-stationary satellite Galaxy-15 stopped responding to ground commands. It operates as a "bent-pipe" or Transponder system, which means - roughly speaking - it will ...
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1answer
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How does QUESS, China's quantum communications satellite experiment, relay entangled signals?

China launched the Quantum Experiments at Space Scale (QUESS) on the satellite called MOZI or Micius today, which will be used for quantum communications between China and Europe. Popular Science ...
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1answer
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Do antennae on the ISS have to constantly move to maintain data links?

In this question and answer pair I see that the ISS can maintain data links to earth through direct access to ground stations as well as through the TDRSS geostationary satellite network. What kind ...
9
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2answers
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What are these very large, square panels on Inmarsat 5?

Question: What are these very large square panels on Inmarsat 5's? They seem to each have an extremely reflective mirror-like flat/smooth tiled-appearing side, and a nearly black side with a lot of ...
9
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1answer
558 views

Can I use Iridium as a receiver network for my satellite?

One of the operational costs for a satellite in orbit is maintaining a receiver ground station. Would it be feasible to send an Iridium transceiver along with my satellite, and then operate it from my ...
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3answers
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Do satellite uplink/downlink signals spread or leak into space?

Satellite communication generally involves three types of nodes: the ground station (also known as teleport), the satellite in geosynchronous orbit, and the satellite receiver/transceiver. I am ...
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3answers
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Could a smartphone really transmit to satellites in a space based internet system?

Space based internet systems, like the one recently proposed by SpaceX and Google, are said to use satellites to communicate directly with end users, without using cellular ground stations. But how ...
8
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1answer
702 views

Radiation pattern and signal strength of navigation satellite antennas

Where can I find the actual radiation pattern and signal strength of transmitting antennas used by GNSS navigation satellites/constellations (GPS, GLONASS, IRNSS, etc)?
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1answer
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What is the expected lifetime of observable Iridium flares? [duplicate]

I enjoy spotting and occasionally attempting to photograph Iridium Flares: (Iridium flare with airplane trail) They're caused by sunlight reflecting off the antennaes of the satellites that make up ...
8
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1answer
281 views

How do commercial broadcast satellites in GEO produce such carefully shaped signal footprints?

SES-10 will be launched in a few days on Space-X's first commercial launch using a recycled rocket. Screenshots from the three links (Brazil, Central America, South America) on Satbeams page for SES-...
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Could a communication satellite that fails to reach GEO be repurposed?

When a launcher's upper stage fails to put a commercial communication satellite in geostationary orbit, it cannot be used as intended. But could it be used in satellite-to-satellite communication ...
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2answers
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What will be “unique” about upcoming SES-9 GTO transfer profile by SpaceX?

In the SES-9 mission press kit, SpaceX mentions: "Given this mission’s unique GTO profile, a successful landing is not expected." What is considered "unique" about this transfer orbit's profile? ...
7
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1answer
292 views

Why do the geosynchronous TDRS satellites have this distribution of inclinations?

From the Tracking and Data Relay Satellite System (TDRSS) option on Celestrak's NORAD Two-Line Element Sets Current Data TLE page I've compiled current TLE ...
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2answers
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How do communication satellites remain positioned above a particular region?

From what I understand, an object has to keep moving in an orbit to not come crashing down to Earth. (The ISS is the first thing I think of for this.) How then, do satellites which are purpose built ...
6
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3answers
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Could a (differently) inclined orbit remain above a Lunar pole half of every revolution?

Let's say that we want constant communication between the Lunar north pole and Earth. The 5.145° orbital inclination of the Moon means that the (mountain at) the Lunar north pole will have line-of-...
6
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1answer
396 views

How are multiple low orbit communication satellites per launch distributed along an orbital plane for global coverage?

SpaceX talks about launching 4,425 communication satellites into 83 different orbital planes at 1,100 km altitude. That's about 50 satellites per orbital plane. In terms of capacity to LEO, a Falcon 9 ...
6
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1answer
227 views

Cubesat communication services

Is there any known web-based API services that provide downlink/uplink testing facilities to some Cubesat? I don't want to have full hardware setup: antenna, sdr, auxiliary equipment. In same time, ...
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2answers
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What is the most popular programming language in space?

For the purposes of clarification - will include machine code generated by a programming language on earth. - 'in space' includes anything in orbit and deep space transit. - special mentions of ...
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1answer
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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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0answers
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Were solar concentrators on HS-702 just a stop-gap measure until triple-junction PV cells were available?

According to Gunter's Space Page discussion of early versions of the Hughes HS-702 Bus: The first version of the 702 used solar arrays with concentrators. These concentrators tended to early ...
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3answers
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How are geosynchronous satellites launched to such an incredible height?

Most satellites are launched to a mere fraction of the altitude at which geosynchronous satellites orbit. How are geosynchronous satellites carried so high? Do they store a lot of propellant on ...
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2answers
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Difference between Tundra and Molniya orbits?

This excellent answer nicely describes both Tundra orbits and Molniya orbits. They are both repeat groundtrack orbits with periods of rational fractions of a sidereal day, and both have inclinations ...
5
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2answers
338 views

For constellations of circular LEO satellites, are there allocations of available “slots” in altitudes?

The BBC article SpaceX aims to launch internet from space discusses the SpaceX proposal for a dense array of 4,425 LEO satellites distributed among 83 orbital planes in five inclination groups as ...
5
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2answers
404 views

When there is more power than needed, are satellite photovoltaics shunted or open circuit?

I saw the word "shunts" in this answer about DSCOVR's upgraded photovoltaic arrays when it was unmothballed and readied for space. Reading it, I get the idea that shunts are used to dissipate the ...
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2answers
328 views

Is secure communication in space important?

How important is secure communication in space? Science-related research is often made public, but does that mean all communications must be unprotected?
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1answer
500 views

How much time does it take to circularize a GTO orbit using ion propulsion?

SpaceX launched two GEO comsats, and is about to launch two more, that use all-electric ion propulsion. Now, I'm wondering, how much time would it take to actually make a satellite like that ...
5
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1answer
799 views

How many communication antennas does a satellite need if it belongs to a constellation?

I assume (but I may be wrong) that in a communication satellite constellation such as the one spaceX plan to put into service: each full duplex link requires a dedicated antenna each satellite ...
5
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1answer
263 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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1answer
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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
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Can they watch TV at the South Pole? What satellites are used for data, comms, and entertainment?

edit: This answer adds one more piece to the puzzle, at least for data. For navigation, I believe GPS covers the poles. For data, there is at least Iridium (see answers to What (actually) makes ...
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2answers
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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 ...
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2answers
375 views

At what magnitude would adjacent large geostationary communications satellites see each other?

Imagine I'm sitting on a geostationary satellite. I can see the Earth in front of me. It's about the size of a soccer ball at arm's length. To the left and right, I can see similar satellites in the ...
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2answers
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How do we track the exact location of the spacecraft which is millions or billions of miles away from us?

How do we track the exact location of the spacecraft which is millions or billions of miles away from us? What things do we study for tracking purpose? How exactly do we predict?
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1answer
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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 ...
4
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1answer
359 views

Can a satellite scan an entire continent to search for someone?

I've heard that Osama Bin Laden was first found via satellite. I was wondering if it is possible to have a satellite that can scan an entire continent and find a single person or terrorists without ...