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Questions tagged [geostationary]

Questions about orbits whose position in the sky remains the same for a stationary observer on the primary body.

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Thrust and rotation strategy to circularize a standard GTO orbit using ion propulsion?

The previous question How much time does it take to circularize a GTO orbit using ion propulsion? has a good, quantitative answer based on a known delta-v. But I'm wondering how would you actually ...
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If we build a space elevator from Earth surface to GEO, could I step off it at GEO and remain in GEO?

Ignore for a moment the question of whether building such a space elevator is practical. Let's also ignore the minute delta-v involved in "stepping off" something in orbit. If we were to build a ...
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How closely spaced are satellites at GEO?

As the picture below (kind of) shows, there are lots of satellites in geostationary orbit. Couple this with the fact that certain longitudes are more desirable than others (like above North America or ...
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Are any geosynchronous satellites visible with the naked eye?

It is very easy to spot LEO satellites during dusk or dawn. I am wondering if satellites further out in a geosynchronous orbit are also visible. Of course, if even possible, these would appear more ...
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What is the reason for the Ariane 5 launcher with Intelsat 29e losing altitude?

After reaching a peak altitude of 222 km the Ariane 5 launcher with Intelsat 29e starts to lose altitude. What is the reason for this trajectory? Youtube video Paper on Ariane 5
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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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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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What factors would make station-keeping of an Areostationary Mars satellite necessary?

This answer introduced me to the word Areostationary Orbit - (hint, comes from Ares), an orbit that would remain stationary above a point on the equator of Mars. The article mentions that ...
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What is the current cost per kg to send something into GSO/GEO?

I was reading this article and thought it was reasonably cheap, probably because I mistook LEO for GEO. What is the going rate to get something into GeoStationary Orbit and Geosynchronous Equatorial ...
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At which point would two GSO/GEO satellites with similar orbital elements be closest to each other?

While I was answering another question on How closely spaced are satellites at GEO I came to realize I can't really word it with much conviction how two close proximity satellites in GEO/GSO orbits ...
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How is the launch window decided for GTO launches?

What launch vehicle, spacecraft and target orbit parameters decide the time of launch to GTO for satellites destined for GEO? The target orbital slot is always in the same relative position to the ...
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How much “wobble” does a typical geostationary satellite experience?

Recall that geostationary satellites are placed into an orbit which is designed to stay above a fixed point on the Earth's surface. If the Earth and the satellite were both spherical cows in an ...
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Orbital altitudes, are some better than others and why?

The geostationary orbit of about 35,786 km above mean sea-level allows satellites to rotate at the same speed as the Earth on its axis, making them seem as if they don't move relative to the ground. ...
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Do geosynchronous satellite launches require a tight launch window?

I thought only launches to rendezvous (resupply, repair, space station expansion etc) and direct launches into interplanetary trajectory require precisely timed launch window. Then I read: Geosync ...
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Geosynchronous orbits around other Solar System objects

Earth's geostationary orbit has many human-made satellites which have helped vastly with communications and research. Aside from this artificial collection, are there any other objects orbiting a ...
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What is the maximum mass of a satellite that can be placed in GEO?

What is the maximum mass of a satellite that can be placed in GEO? Or can satellites of any mass be placed in GEO?
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How much is a geostationary satellite expected to deviate from the geostationary orbit?

I've read this already and some Wikipedia articles, but found no real estimates on how much does a satellite deviate from its standard location. Say that the standard sub-satellite point (SSP) is <...
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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 ...
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Given the orbital radius of a satellite, how is the orbital period calculated?

I know I can find the orbit radius of a satellite from the equation: $$r=\sqrt[3]{\frac{T^2GM}{4 \pi^2}}$$ but what determines the orbit period $T$? If I assume a geosynchronous orbit, would that ...
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How long does it take for a satellite to reach GEO?

Specifically for the SpaceX SES-8 mission going on right now. But, generally, how long does it take for a satellite to reach GEO at a minimum?
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Are there cubesats in GEO?

This answer to the question How often do reaction wheels require desaturation, normally? says: One practical example I know of is for a 6U in GEO that is always sun pointed, there's a thruster ...
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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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Needed height from the release of a space elevator to get a stable elliptical orbit?

As we know, something released from around 36000 km height from a space elevator will remain in geostationary orbit around the Earth. Things released from lower will go into an elliptical orbit ...
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How stationary is geostationary?

When a satellite is in geostationary orbit, it is supposed to stay above one spot of the earth and rotate around the earth at the same rate the earth spins. But how exact does that equality need to be?...
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Delta-v to move from GEO to GEO

To move a satellite in geostationary orbit, 166°55′E, to the antipode, 13° 4' 3.2" W, what delta-V would be needed for this to be accomplished? As for time constraints, I do not know what are the ...
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What's the closest that an Apollo mission passed GEO on its way to the moon?

@Uwe's comment No astronaut ever visited geostationary orbit at 22-23k miles to maintain or deploy satellites. The Apollo astronauts just rushed by on their way to the Moon and back. below the ...
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CZ-5 plus YZ-2 put SJ-17 in GEO - third stage or separate spacecraft?

CZ-5 = Long March 5 YZ-2 = Yuanzheng 2 SJ-17 = Shijian 17 Gunter's Space Page says: SJ 17 (Shijian 17) is a Chinese experimental satellite flown on the maiden CZ-5/YZ2 launch. It is ...
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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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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 ...
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Quantitatively, how deep are the stable equilibrium points in GEO? How much delta-v to move from one to the other?

This answer discusses a spacecraft in GEO using a two-impulse (circular → elliptical → circular) raise & lower maneuver to move (phase) itself by 180 degrees in longitude then return to synchrony. ...
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How have the 'gift' transponders on ISRO's GSAT-9 been used by other countries?

edit: It's been seven months close to two years now, have any of the 'gift' transponders been used or at least tested yet by the gift recipient nation? The BBC news item India launches 'invaluable' ...
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ViaSat's 18 kW solar array - largest ever for a commercial telecom satellite?

Now that the protests at Kourou Space Center in French Guiana are over, Arianne has launched both EutelSat 172B and ViaSat-2 as 2017-029A. While EutelSat 172B has a ...
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What GEO relay satellite will the ISS use for end-to-end optical communication with a ground station?

This LEMNOS page on NASA's Explorations and Space Communications site says: The Integrated Laser Communication Relay Demonstration (LCRD) Low-Earth Orbit (LEO) User Modem and Amplifier Terminal (...
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Why would the orbit of a satellite in GEO climb by 21 km in altitude over six months by itself?

This answer mentions several effects that tend to move geostationary satellites out of their "box" over time, but one really surprised me. According to the plot below (from there, but uncredited) the ...
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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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Can I transmit signals from a wristwatch to geostationary orbit?

In comments below this answer to the question Which satellites can hear emergency signals from Scott Kelley's watch? we are (or at least I am) trying to figure out definitively if a wristwatch can ...