Questions tagged [geostationary]

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

115 questions
Filter by
Sorted by
Tagged with
82 views

Why would a mission choose a geosynchronous orbit over a geostationary orbit?

I was going to ask "Are there any missions where a geosynchronous orbit is advantageous over a geostationary orbit?" The TL;DR answer to this question (Are there any satellites in geosynchronous but ...
900 views

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: ...
55 views

Inclination and latitude of GEO satellite

My satellite inclination is almost zero, but the latitude that I got was almost 0.1. In my mind, the latitude is should be near zero when the inclination is zero, but as I explain above, I got ...
54 views

STK SGP4 for Geostationary Satellite

I am using SGP4 propagator in STK to propagate my GEO satellite. SGP4 need TLE as an input. In TLE, I found the inclination of my satellite is 0.048. But the inclination result of SGP4 is 0.15. The ...
1k views

Is the risk of explosion-induced damage to operational spacecraft in GEO actually reduced substantially by raising Spaceway-1 by 300 km?

Engadget: DirecTV satellite is at risk of explosion due to battery issues Space News: DirecTV fears explosion risk from satellite with damaged battery say that the spacecraft must move 300 km above ...
26 views

85 views

Analytical treatment of relative positions between satellites?

I have been searching the internet for estimation of relative position between two satellites. However, all sources seem to be pointing to methods used for proximity operations, where the math ...
220 views

How do stable equilibrium points work in GEO? If all geosynchronous spacecraft suddenly lost stationkeeping, would most “fall into” one or the other?

The (currently unanswered) question Quantitatively, how deep are the stable equilibrium points in GEO? How much delta-v to move from one to the other? (also see comments at Delta-v to move from GEO to ...
1k views

Launch system to get a 75,000 kg object to geostationary orbit?

Is there any current launch system that could get a 75,000 kg object to geostationary orbit? If not, am I correct in assuming the Saturn V could have gotten such an object there?
73 views

What was the first unplanned “over-the-air” software update of a spacecraft?

From time-to-time spacecraft have had to be rebooted, in one case Voyager 2 mutinied and had to be reprogrammed and in another Opportunity had it's memory "hacked". As far as I know, deep space ...
30 views

I try to count longitude deadband of geostationary satellite (0.1 degree). But I still confused, where should the longitude I have to start? In the picture, should I start the longitude from the far ...
3k views

Name for geostationary orbit around another planet

A geostationary orbit is a circular orbit in Earth's equatorial plane whose rotation period matches that of the Earth. The "geo" in "geostationary" means Earth, so is there another term to designate ...
162 views

Statites - Are they possible in anything but theory?

In this question someone mentioned the idea of a Statite, a satellite which is stationary above a planet without being in orbit, usually in an orientation which is not possible with an orbit. It seems ...
56 views

Is TEMPO firmly planned to be launched?

The Tropospheric Emissions: Monitoring POllution (TEMPO) instrument (see Smithsonian Institute, EO Portal, or WMO Oscar) is supposed to measure air pollution over North America from a geostationary ...
204 views

Most fuel-efficient deorbit from geostationary

Say a spacecraft in geostationary orbit needs to be deorbited (not very common, but bear with me). How does one decide when and how long should the retrograde burns be, in order to have started with ...
91 views

Inclination maneuvers for GEO satellites

I was wondering about the orbital location to perform inclination nulling maneuvers for GEO satellites. I know from basic astrodynamics that the best place to perform inclination correction is at ...
68 views

How does the “eccentricity-inclination vector separation” technique work for colocated GEO satellites?

This answer to How are co-located satellites positioned relative to each other? links to the paywalled paper Separation of Geostationary Satellites with Eccentricity and Inclination Vector with the ...
58 views

Point Ahead Angle Calculation between LEO-GEO Satellite (ISL Scenario)

So, I have got two reference TLE from 2 different Satellite in LEO-GEO, which are as follows: (1st TLE for LEO, 2nd TLE for GEO) ...
50 views

SGP4 on Systems Tool Kit (STK); how to check if SDP4 deep space correction is implemented?

I am doing orbit propagation for a geostationary satellite which requires the deep space corrections of SDP4. See my previous question SGP 4 for Geostationary Satellite. I am using SGP4 on STK, but, ...
73 views

SGP 4 for Geostationary Satellite

I have read some sources that say that SGP4 is for satellite which have orbital period less than 225 minutes. For orbital period more than 225 minutes, we should use SDP4 instead. I need a ...
168 views

Why do these satellite antennas look so weird? (strangely shaped with little white dots…)

The NASA Spaceflight article Arianespace press onward with dual-passenger Ariane 5 launch shows a photo of Intelsat 39 during testing. The dish reflectors are strangely shaped: rather than being ...
1k views

Could an areostationary satellite help locate asteroids?

Could NASA put an artificial radar telescope satellite in geosyncronous orbit around Mars to help locate dangerous asteroids on a trajectory that would place them on a path to strike Earth?
4k views

Are there any satellites in geosynchronous but not geostationary orbits?

I know there are a lot of geostationary satellites out there, but I'm wondering - are there any geosynchronous satellites that are not geostationary (ie - have a notable inclination to their orbit)?
621 views

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 ...
81 views

How often are satellites in GEO moved to follow customer demand?

The BBC News article Inmarsat lays big satellite order with Airbus says: The firm is buying three new spacecraft to augment its Global Xpress system, which provides connectivity to on-the-move and ...
83 views

Getting from LEO to a station in geostationary orbit and docking with it using a Hohmann transfer?

How long would it take for a spacecraft with a mass of 30,000 kg, to go from LEO to reach and match the speed of a space station in geostationary orbit so it could dock with the station, using a ...
4k views

Why aren't space telescopes put in GEO?

I don't know of any space telescope that has been placed in geosynchronous orbit among the communication satellites. I wonder why not? In GEO, a space telescope could use a single stationary radio ...
111 views

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 ...
148 views

ECEF to LLA Test Numbers

i have a list of GEO x,y,x coordinates and using Justin Mooney's R Script to convert to latitude, longitude, altitude(km). I'm looking for some test case numbers to verify Justin's xyz2lla function ...
190 views

Are geostationary orbits impacted by changes to earths magnetic field?

Would geostationary satellites be pushed to different orbits by changes in the magnetic filed or even more so by shifting poles or even a reversal?
339 views

Determining GEO Orbital Slot from TLE

I'm trying to figure out the equation based on TLE data which orbital slot a GEO satellites occupies. I have the TLE data imported into R and I wish to know what satellites are in adjoining GEO ...
370 views

What is meant by “a high-energy geostationary orbit”? (SpaceX Arabsat 6A)

The Teslarati article SpaceX’s April 7th Falcon Heavy launch a step toward new commercial markets says: While there is some inherent uncertainty surrounding the (once again) fairly new rocket, ...
405 views

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 ...
228 views

How do Inmarsat 5 F4's beams correspond to all of these antennas and feeds?

note: This is an old-style @uhoh question meaning that it is a bit on the long side. In this case I think it really needs to be since the question is a bit complex; I'm trying to understand how all ...
173 views

How do you calculate the lat and lon of a point on the earth using azimuth and elevation seen from a geostationary satellite?

I am given the longitude of a geostationary satellite and a pointing vector from the satellite in the form of azimuth and elevation angles looking from the satellite towards the earth (where zero ...
268 views

Is it possible to capture geostationary satellites with DSLR?

DSLR is to be mounted on a tripod and pointed at sky with a zoom lens. Would a sufficiently long duration of exposure reveal these non-moving satellites as bright "stars" amongst the streaks caused ...
187 views

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 ...
255 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-...
265 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 ...
254 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 ...
83 views

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. ...
549 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 ...
111 views

Atmospheric re-entry speed

What would be the difference in atmospheric re-entry speeds from LEO and GEO, assuming a Hohmman transfer orbit from GEO to re-entry? If I am getting the transfer orbit concept correct?
160 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 ...
98 views

Meteosat 11 big deboost/reboost

Before Feb 2018, the meteosat 11 (MSG-4) were periodically reboosted approximately every 85 days: EDIT: added the orbital inclination plot to show the clearly visible variation to both semi-major ...
725 views

Is two-way communication really required to use BeiDou GNSS?

The BBC's How China's GPS 'rival' Beidou is plotting to go global mentions a scenario where end-users can send signals to other Earth locations using BeiDou and later says: But despite its ...
2k 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 ...
92 views

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 ...