Questions tagged [artificial-satellite]

Questions about objects in orbit which are human made, such as communications and GPS satellites, orbital observatories and space stations, and other man-made object in permanent or semi-permanent orbits around the Earth, other celestial objects, aside from the Sun, or even other satellites. Not to be confused with non-orbited man-made objects in space, that are usually referred to as "probes", or simply "spacecraft".

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Tutorial for orbits from TLE data

I've been looking for a new hobby, and have been reading some about satellite tracking. I was wondering if there was a good tutorial that walks through how to use TLE data. So far I have found ...
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When B is directly below A, as shown, what's B’s velocity (in vector notation) relative to A?

Spacecraft A and B are in coplanar circular orbits around the Earth. The orbital radii are as shown in the figure. (Not looking to use C-W equation. Just the equation describing relative velocity ...
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What are the shortest orbital periods used for their repeat ground track properties?

The most well-known repeat ground track orbits are geostationary and geosynchronous orbits, having orbital periods in a 1:1 ratio with the revolution of the Earth. Faster repeat ground track orbits ...
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Is it possible to predict if an orbiting satellite will pass over a given point on Earth after n periods?

I'm learning basic astrodynamics, and I have a question that I cannot find on the Internet (maybe I'm not looking hard enough). My question is, is there a way to predict how many periods would a ...
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What's the current state of Venus orbital infrastructure?

As per this Wikipedia article there have been a total of 5 orbiters successfully deployed to Venus: Venera-15 Venera-16 Magellan Venus Express Akatsuki Of which only the Akatsuki seems to be ...
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What's the current state of Mars orbital infrastructure?

As per this Wikipedia article Mars currently has 6 operational artificial satellites: 2001 Mars Odyssey Mars Express Mars Reconnaissance Orbiter Mars Orbiter Mission Mars Atmosphere and Volatile ...
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163 views

Number of satellites launched per year?

How many satellites were launched every year? Similar question Number of satellites launched by decade? Resources for number of orbiting and active satellites by year?
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106 views

Number of satellites launched by decade?

How many satellites were launched each decade? Including satellites of Mars Moon Venus Sun etc Similar question Number of satellites launched per year? Most busy times in space launches by decade?
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Most expensive satellites of 2010s?

Which were the most expensive Earth satellites in the 2010s? Say first 3 or 5. Zuma satellite (lost) was $3.5 billion, was any other satellite more expensive? Excepting the Space Shuttle which is a ...
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How to determine the delta V required in order for the satellite at pt. A to hit the earth at pt. B?

I'm confused about how would I go about obtaining delta-v in this case. I'm aware of orbital transfers such as bi-elliptical but that is not the answer to this. Kindly help
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What would be the influence of nearby planets on a Dyson sphere or Dyson swarm?

Considering orbital mechanics, I would like to ask what would be the effect of nearby planets such as the Earth or Jupiter on a Dyson sphere. A Dyson sphere is not realistic because of the tremendous ...
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Highest DC voltage ever intentionally produced in space?

Comments on the page Maximum grid voltage of ion thruster got me wondering; what is the highest DC voltage ever intentionally produced by a spacecraft in space? Photomultiplier tubes and micro-channel ...
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Satellite inclination, 3D scanning of earth's surface

Has any attempt been made to change the "plane" of the orbit (not altitude) of a satellite, across earth's diameter, continuously in small steps, from pole to pole for a satellite with zero ...
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Could pressurized steam be an effective propellant for satellites?

If you had a small pressure vessel and a matte black external boiler that could utilize the heat of the sun, would pressurized steam be feasible for maneuvering a small satellite?
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A dataset for Earth satellite size information?

I am lookin for a dataset where I can find or calculate the size information of an Earth satellite as described in the seconds page of this paper. It is basically the radius of the smallest sphere ...
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Where are MEO satellites put at the end of their operational life?

At the end of their operational life, satellites on geostationary orbit and higher are put in a graveyard orbit that is higher than their operational orbit. Satellites in LEO are slowed down so that ...
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What is the simplest way to determine if two or more TLEs describe two or more satellites in lead-follow?

If two more more up to date TLEs have same inclination and the same period they are in the same orbit, but how do I check if they are also following each others path, in a train?
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Difference between collecting satellite data and tracking its position

When people talk about "tracking" a satellite, do they generally mean receiving data / communication from it, or do they mean determining its position. When an organisation sends a satellite ...
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How is satellite position tracked in practice?

How do the increasing number of LEO satellites keep track of their position? I know they use ground stations, but do they employ private companies to keep track for them? It seems like there are way ...
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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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How many navigational satellites are in operation as of 2020?

GPS (USA) - 75 Global Positioning System navigation satellites have been launched, 31 of which are operational, 9 in reserve, 3 being tested, 30 have been retired and 2 were lost at launch Beidou (...
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105 views

What operating systems do Chinese satellites use?

Which operating systems are most frequently used by China for satellites?
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1answer
120 views

Why can't I just use dot product angles to get satellite vision of a point on Earth?

Right now I'm using MATLAB and can easily get the ECEF coordinates of the satellite and the point on the Earth. Since ECEF is cartesian, why can't I just rearrange: $$ r_{es}\cdot r_{ps} = \|r_{es}\| ...
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Is it allowed to interact with research satelites / rovers using the radio?

Let's say I have a SDR (software defined radio) like the HackRF One at home, access to a huge amplifier circuit and a giant antenna (at my university). Is there a law that prohibits receiving / ...
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An orbit in the corner of isosceles right-angled triangle

Is it possible to have a non-escape orbit that is equidistant to two celestial bodies (for example, Earth and Mars) at all times? If possible, how much does it cost to keep an object (which is much ...
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132 views

Why does the Deep Space Atomic Clock have such a short mission?

The Deep Space Atomic Clock has a short mission of only two years. How it can be useful for space operations if its operating for such a short time? Additionally I would like to ask if there are or ...
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What does the [-] symbol mean in satellite names?

Some satellites in the databases have this "[-]" mark at the end. For example "IRIDIUM 39 [-]" and "GLOBALSTAR M038 [-]", which in databases like www.space-track.org or ...
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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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What stage of a Scout G-1 rocket enters orbit?

Last night I saw a Scout G-1 rocket body part called 1986-088B (according to COSPAR) with my binoculars. I researched a little and found that these rockets had 4 stages, called Algol, Castor, Antares ...
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Is the use of whipple shields on satellites common?

How common is the use of whipple shields or of any micro-meteor and debris shields in general for satellites in low earth orbit , I couldn't find any relevant statistics on the internet, a rough ...
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When did photographic film stop being used in satellites?

Some early observation satellites took pictures on photographic film and the film was dropped towards Earth and picked up by airplanes (e.g. Corona). What was the last satellite to use photographic ...
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135 views

Get dates when a satellite has performed maneuver from historical TLE data (python)?

I have been recently acquainted with orbital mechanics and am trying to do some analysis on the subject. Since I don't have subject matter expertise, I am at a crossroads with trying to decide that ...
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105 views

Can the solar panels on satellites (such as Juno) rotate?

Can the solar panels on deep space satellites (specifically Juno) rotate? Do the antennae on deep space satellites (specifically New Horizons) rotate? Or is everything static and the entire satellite ...
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Do space organisations take the positions of space junk and satellites into account when launching?

There are so many satellites orbiting Earth now at various altitudes and there is quite a lot of space junk floating around as well. Now although there are so many satellites and so much junk up ...
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Why does NORAD make TLE data public?

If I understand correctly, NORAD tracks thousands of satellites as well as pieces of space debris and publishes TLE files representing their orbital position and motion that are updated regularly. It ...
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Have any satellites been lost or damaged on their way to the launch site (ground/sea transport)?

On our sister site Travel Stack Exchange, someone asked about carrying a cubesat on a plane in hand luggage and is worried about damage or loss (or not being allowed on the plane). Several answers ...
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1answer
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Does every satellite operator build and operate their own ground station?

I'm thinking especially of small-time operators. Like if a high school team puts a cubesat into space, do they also put an antenna on the school building and just put up with limited accessibility ...
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How do large thermonuclear explosions on the ground affect satellites in LEO?

High altitude nuclear explosions will completely render electronic devices on the ground useless (unless protected, with lead coating for example). How are satellites affected by such explosions? ...
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1answer
98 views

How are satellite operating modes implemented?

It is pretty simple to find documentation about satellite operating modes behaviour when trying to develop satellite onboard software (example of safe mode behaviour on wikipedia, or on researchgate), ...
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How are satellites, rocket launches and other space programs affecting the earth’s rotation? How will it be affecting living beings?

Want to know the effects of the active satellite, rocket launches and space programs that affect earth rotation? how? And their effects on living beings due to effect in earth rotation?
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Considerations in producing satellite to smartphone communication

Recently, the company Lynk has been able to conduct direct satellite to smartphone communication. While the article only references the capacity for downlink to the phone, what difficulties must be ...
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99 views

long sequence of satellites moving west to east?

yesterday (27/3/2020), 20:00, I was on high ground in central switzerland and looked south. in the clear night sky, I saw what I think could have been satellites: linear trajectory, high speed, ...
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What did I see just before the ISS but on a different trajectory?

I live at 49.99N, 8.57E. Today we had exceptionally clear skies. I was looking out a window towards the South between 7:48pm and 7:52pm local time (central european) when I noticed a strange light ...
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3answers
339 views

Could a horseshoe magnet help a satellite stay in orbit?

If a horseshoe magnet was attached to a satellite orbiting the Earth, would the interaction of the Earth's magnetic field and the horseshoe magnet's magnetic field result in the magnet being propelled ...
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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 ...
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Are there any related groups of satellites that are in a line of 6 or more in a row?

02/03/20 0450hrs, in Bradford, West Yorkshire, Uk. I saw a satellite going across the sky, it was not too bright and was followed by another and then 4 more they were equally spaced. I would say they ...
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Was there a spacecraft that was clearly the first to be put in a polar orbit?

Was there a first spacecraft put in a polar orbit? It might not be clear if it's too hard to say what high inclination orbit is or is not polar, for example if 91 satellites were launched in 0, 1, 2.....
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Use of carbon nanotube based black colourings like Vantablack in space

I've seen several articles talking about the ways in which Vantablack and similar substances could be used in space as a replacement for black paint. For example, they could be used on the optical ...
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Why does Himawari-8 have problems with the Sun from 19th February to 19th April?

This weather site uses provides meteorological imaging from the Himawari-8 Earth observing satellite in GEO. https://www.cwb.gov.tw/eng/ The web site contains the following item: ...
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What percentage of a satellite's total budget goes into its launch?

Been trying to do some personal market analysis of the space market, and realized that there doesn't seem to be any kind of statistic or average regarding how much percentage the launch of a satellite ...

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