Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [geostationary]

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

32
votes
5answers
5k views

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 ...
21
votes
3answers
20k views

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 ...
20
votes
2answers
7k views

How full is the geostationary belt?

The geostationary ring clearly seen in the above picture looks alarmingly crowded. How full is it? How much space does a satellite in that orbit require to operate safely? Surely, (other) ...
17
votes
5answers
2k views

What's salvageable from a dead satellite?

DARPA has proposed orbital maintenance and salvage robots. I had gathered a list of links that was lost when DARPA rearranged their website. But I was able to find this page: Phoenix Makes Strides in ...
16
votes
2answers
3k views

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 ...
15
votes
2answers
5k views

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 ...
15
votes
1answer
34k views

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 ...
14
votes
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
votes
6answers
5k views

Dangle a cable down to earth - fundamental Physics question

If I had the material that had the tensile strength, would it be possible to have it dangle from the lowest most practically possible geostationary object down into the atmosphere? Would it not ...
13
votes
2answers
9k views

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?
11
votes
2answers
1k views

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
11
votes
1answer
1k views

Tethered geostationary orbit

One of the biggest issues that I've heard of in building a space elevator is the high tensile strength of the cord used to tether the the elevator to the ground. If there's a structure that's at ...
11
votes
2answers
2k views

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 ...
11
votes
2answers
376 views

Is it feasible to pump fuel into orbit?

Imagine a huge fuel depot in geostationary orbit. Suppose further that it is tethered to the Earth and that there's a large hose snaking down all the way. Is it feasible to pump fuel up 35,786km? Can ...
11
votes
1answer
720 views

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 <...
10
votes
3answers
3k views

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?
9
votes
2answers
1k views

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 ...
9
votes
1answer
749 views

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 ...
9
votes
1answer
1k views

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 ...
9
votes
3answers
1k views

What kind of liquid propulsion systems do GEO satellites use?

Coming from a question about distances between satellites in GEO, what liquid propulsion systems do a majority of GEO satellites carry to maintain their slot positions? It is easy to find information ...
8
votes
1answer
4k views

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 ...
8
votes
2answers
1k views

Differences between launch injection and transfer orbits for geostationary satellites

I am familiar with all different orbits but I struggle with the new launch injection method in GTO. What are the differences between sub-synchronous and super-synchronous transfer orbits compared to ...
8
votes
1answer
2k views

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 ...
8
votes
2answers
1k views

Are there any CubeSats that have been launched into Geostationary (GEO/GSO) or Geostationary Transfer Orbit (GTO)?

There is one mission by GSFC/NASA - Shields-1 to be launched into GTO. Apart from that I couldn't find any other mission to GTO/GEO. It would be of great help if there is any information on this.
8
votes
1answer
416 views

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 ...
8
votes
1answer
259 views

How does gravitational stability change with the distance from special places such as geostationary orbit and lagrange points?

How rapid do the attractive properties of GEO and lagrange points deteriorate with the distance from optimum? How "large" are such locations? At what distance would station keeping require, say, twice ...
7
votes
3answers
765 views

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 ...
7
votes
1answer
1k views

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?...
7
votes
1answer
355 views

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 ...
7
votes
1answer
881 views

What is the process for allocating GEO slots to commercial satellites?

Building off of this previous question, is there a more detailed summary anywhere of the process that a commercial satellite would have to go through to obtain a GEO slot? The documentation I have ...
7
votes
0answers
87 views

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 ...
6
votes
2answers
2k views

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
votes
1answer
469 views

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 ...
6
votes
2answers
285 views

Is there a synchronous orbital height for Phobos?

My assumption is that any body in the solar system would have it's own specific geo-synchronous orbit height. But when I took a look at Phobos and calculated the GEO height based on the simple formula ...
6
votes
2answers
190 views

Why will GOES-R take a whole year for validation?

I've been reading a few things about NOAA's GOES-R satellite, and I noticed this on the GOES-R site: ...will be placed in the 89.5° checkout orbit where it will undergo an extended checkout and ...
6
votes
3answers
4k views

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 ...
5
votes
4answers
2k views

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. ...
5
votes
2answers
779 views

What is a typical satellite solar panel mass?

Does anyone know a reliable source to find the mass of solar panels on satellites (in particular GEO satellites)? I know they will vary but I am struggling to even find one data point let alone a ...
5
votes
2answers
407 views

Why is the SES launch going to an apogee of 80,000 km?

Why is the apogee of the Falcon 9 SES launch going clear out to 80,000 km? GEO is only 36,000 km or so, it seems like a waste to go so far beyond it.
5
votes
1answer
298 views

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 ...
5
votes
2answers
228 views

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 ...
5
votes
0answers
194 views

extreme longevity of geostationary orbits

I was speculating that geostationary satellites could be around possibly for billions of years (i.e. much beyond the point where plate tectonics would have erased all traces of human civilization on ...
4
votes
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 ...
4
votes
1answer
667 views

What is the minimum rocket mass that can achieve GEO

A tiny model rocket can't get up very high. Massive rockets can make it to GEO. There must be some theoretical mass threshold where the rocket is "big enough" to make it to GEO - what is that mass? ...
4
votes
1answer
133 views

What is typical lifetime of GTO rocket stages before reentry?

Most of geostationary satellites are launched at geostationary transfer orbit (GTO) first by rocket's upper stage. Than satellites separate and circularize the orbit by own propulsion. The upper ...
4
votes
4answers
2k views

For which applications are LEO and GEO substitutable?

This article, this article, and this earlier question indicate that, given enough satellites in LEO, it's possible to substitute between GEO and LEO. The first article and the question have some ...
4
votes
2answers
200 views

Are sun outages having more limited impact in some cases?

Sun outages occur when a satellite, usually one in a geostationary orbit, passes between a ground station and the sun. Seen from the point of view of the ground station, the sun looks like it passes ...
4
votes
1answer
297 views

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 ...
3
votes
2answers
663 views

Determine orbit type from TLE

I was wondering if, and how, one can tell from the values in a TLE whether an orbit is LEO, MEO, HEO, or GEO. I'd like to do this in code eventually, so any formulas or threshold values would be much ...
3
votes
1answer
108 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-...