Questions tagged [satellite-constellation]

A network of satellites carrying out a specific mission or serving a targeted purpose based on an increased area of cover or relative position differences.

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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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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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LVLH to ECI Conversion

I'd like to transform LVLH coordinates to ECI coordinates. I've been looking at academic papers and other answers on here and other websites and have only seen the transformation in the other ...
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Special Case Constellation Analysis Approach: Walker Constellation with Circular (e = 0) orbit in LEO

I am familiar with the general approach to propagate orbits using orbital parameters, and how to account for basic J2 perturbations. I am looking to perform some analysis on large walker ...
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Larger data rate, Oneweb or Starlink? [closed]

Which satellite constellation will provide the larger downlink data rate, in total and per satellite, Oneweb or Starlink? My consideration: starlink will operate in a lower orbit, with more ...
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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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What is the largest number of identical satellites launched together?

What is the largest number of (essentially) identical satellites launched together? Form factor alone (e.g. 1U, 3U cubesat) is not enough to make satellites identical, they need to be the same ...
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Most challenging aspects of a reusable satellite scheme like this?

What would be the most challenging aspects of a reusable satellite scheme similar to the one shown in this video? For the kilo-constellations (e.g. SpaceX's StarLink with 4,500 to 7,500 satellites) ...
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What does the StarLink constellation look like now? Numbers of planes and inclinations?

In the question SpaceX's 4,425 satellite constellation - what's the method to the madness? I took the orbital parameters in SpaceX's filing SpaceX non-Geostationary Satellite System Attachment A - ...
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Celestrak GLONASS TLE's showing satellite numbers not listed in the GLONASS constellation, others missing

For a project, I'm retrieving TLE information live from http://celestrak.com/ and using them to simulate satellite orbits. The TLE's for the GLONASS constellation (http://celestrak.com/NORAD/elements/...
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Mass manufacturing of satellites

Airbus has announced a mass-manufacturing unit for OneWeb constellation of satellites. See for example Space News' With a new satellite factory in the U.S., Airbus eyes opportunities in military space ...
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How is a satellite constellation launched?

If want 10 satellites chasing each other around the earth (evenly spaced) all one the same plane, these satellites would be evenly distributed around the globe after launch by slightly raise or lower ...
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Tesseral Part of the Geopotential

I am working on the design of a constellation for academic purposes. I try to describe a phenomenon that appears in the simulations by means of analytic expression and I can't really find a good ...
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What is this gap in the GNSS satellite trajectories?

I've recently bought a USB-connected multi-constellation GNSS-receiver with a U-blox 8 chip in it. I've downloaded the U-center software that can display a lot of details about the received signals. ...
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Why are there no LEO satellites in the earth's equatorial plane?

From my elementary school understanding of Satellite orbits, I know that GEO satellites are placed in equatorial plane, MEO satellites are placed in an smaller degree inclined plane while LEO ...
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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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How are co-located satellites positioned relative to each other?

I'm trying to learn about co-located GEO satellites. When I first heard about them, coming from a planetary orbital mechanics background, the first thing I pictured was based on the epicyclic ...
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Which satellites can hear emergency signals from Scott Kelley's watch?

In this July 2018 tweet by Cdr. Scott Kelley, with the north face of Mt. Everest over his shoulder, he mentions his "Emergency" watch. I've searched and then found the Hodinkee.com article Hands-On: ...
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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 ...
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Number of spectral bands on radar satellites

I have learned that optical earth observing satellites have spectral bands often in groups (e.g. panchromatic, multi-spectral, SWIR, etc.). What about radar satellites such as RADARSAT-1? It seems it ...
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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 ...
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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 ...
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Small aircraft launchers

I have read that Stratolaunch carrier from ALTAIR project has a 117 m wingspan, it will weight in at over 540,000 kg including the fully fueled launch vehicle and will require a runway at least 3,700 ...
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What checks are supposed to be carried out to prevent illegal satellite launches?

In January, the PSLV launch delivered 28 satellites to orbit, with 4 SpaceBee satellites among that number, despite them not having an FCC licence (due to size, visibility and tracking concerns) As ...
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How many SpaceX Starlink Internet-service satellites could be deployed in a single Falcon 9 launch? Falcon Heavy? BFR?

The mass of the two test satellites being launched this month is 400 kg, but I don't believe that includes the antennae and the structure to hold and release them. Is total mass the only constraint or ...
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Can a launch vehicle put several different satellites into different RAAN in one launch?

I am trying to see how frequently I can acquire a link for 1,2,3,4,5 or more satellites. When I began, I just decided to separate satellites by True anomoly, because that made the most sense. But now ...
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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 ...
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What is the biggest satellite constellation in space right now?

What is the biggest, by the means of satellite amount, satellite constellation in space right now?
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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 ...
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What goes into the planning and execution of the deployment of groups of LEO satellites?

I was among many watching SpaceX's exciting OrbComm-2 mission (Falcon-9 Flight 20, 22-Dec-2015), and besides the first successful landing of a 1st stage after an orbital mission, the deployment of the ...
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Is 75 meters an exceptionally close distance for two satellites to pass at >6,000 m/s?

While researching for this question I ran across something called Celestrak Socrates. I requested the ten closest predicted approaches, and saw distances of closest approach of the order of 100 ...
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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-...