Talk:Geostationary transfer orbit

Comments cancelled. There are several different GTO orbits.

Confusing
I'm not terribly well versed on this subject, but I thought it'd be an interesting read. I can't even get through the introduction. Is there any way this article can read a little more plain-English. I know all of you editing know a lot more than me, I hope one of you can dumb it down for me.

I will echo this comment. Why is a GTO important? Why don't spacecraft go directly to a geostationary orbit? What is the primary purpose?89.6.235.189 (talk) 21:59, 19 July 2014 (UTC)

Redundancy throughout
The article's copy seems very redundant. I was just passing through, so perhaps I'm wrong. Anyone keeping an eye on this article? Could you double check my observations? - Davandron | Talk 04:41, 5 January 2007 (UTC)


 * I didn't get far enough to look for redundant parts. I spaced out wondering how this page can rearranged to better cover the subject matter. An SVG image of approximately where the GTO is would be good. Maybe someone will be bold and rearrange it? I'm too spaced out (haha) to be bold right now. Jeff Carr 18:51, 19 September 2007 (UTC)

Breeze-M 5-burn mission design
In this overview of the upcoming Nimiq 4 launch, ILS will use a Breeze-M upper stage to inject the satellite into GTO. I assert this vehicle is the "best" example available of current industry practice for GTO launches from high-latitude launch sites. (Baikonur is 46°N.) Close examination of the diagram showing the various orbits and orbital maneuvers shows that ILS does not describe the orbit which places the spacecraft's apogee at 35,809 km as a "GTO". It isn't until the inclination is reduced by a subsequent burn from 49° to 12° that ILS describes the orbit as GTO. So the text in our article currently that reads, "The GTO inherits the same inclination [as the launch site]" does not match current state-of-the-art (i.e. ILS) usage. It isn't a GTO until the orbit is close to equatorial. (sdsds - talk) 23:00, 2 September 2008 (UTC)
 * Wow, you're right. What a complicated orbital transfer!  I can't quite figure out the purpose of all the burns, but from looking at the Russian documentation, it looks like a lot of this is that they want to do part of the transfer with the third stage of the Proton, and part with the Breeze upper stage.  I think a good part of the rest of it is designed to put the orbit into the right phase while keeping the burns in view of particular ground stations.  In essence what they are doing is making the apogee kick burn in two parts, the first (and largest) kick being done with the Breeze stage, which puts the satellite (and the Breeze) almost into GEO, getting the orbital phase right that the satellite will be in the right position at the next nodal crossing, and doing most of the inclination change.  This is labeled "GTO" in the pdf you gave, but it's called "targeting orbit" in Russian.  Then the Breeze stage does a "withdrawal burn," and the final apogee kick into GEO is presumably done by the satellite.
 * In any case, I added a paragraph at the bottom of the calculation section mentioning that the above was just the simple case, and that more complicated transfer orbits exist, with a wiki link to the Proton M and a reference to the ILS link you gave. Geoffrey.landis (talk) 14:12, 3 September 2008 (UTC)

Geostationary vs Geosynchronous
Geostationary transfer orbits are a subset of Geosynchronous transfer orbits, and this article seems to cover both, so should this article be moved to geosynchronous transfer orbit? -- G W … 16:53, 11 February 2009 (UTC)

My Revisions
Since I'm familiar with a lot of booster manuals, I decided to tackle the citations problem w.r.t. Delta IV performance (in the process finding out that both the Delta IV performances and the Proton link were outdated.) The standard Proton ascent uses three intermediate orbits, not four, as the second perigee maneuver is two burns simply because the Breeze-M upper stage can't jettison its auxiliary propellant tank while running its engine. I'm not sure how to write the concept into the article, but the vast majority of modern GEO spacecraft use at least four maneuvers of their own to complete their ascents after separating from the launch vehicle. Ion propulsion is starting to work its way into apogee maneuvering (which is now often called orbit raising.) I don't know how to write it in or reference it because I discovered by crunching the numbers myself, that supersynchronous transfers require less delta-v when the original LEO inclination exceeds 42.1deg (LEO altitude 200km.) Featherwinglove (talk) 22:34, 27 July 2013 (UTC)

Structure comment
There is a problem in the first paragraph. It reads

"A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a Hohmann transfer orbit used to reach geosynchronous or geostationary orbit.[1] It is a highly elliptical Earth orbit with apogee of 42,164 km (26,199 mi).[2] (geostationary (GEO) altitude, 35,786 km (22,000 mi) above sea level) and an argument of perigee such that apogee occurs on or near the equator."

The third sentence makes no sense, and I don't know what the author was trying to say. Removing the parenthetical information should make the problem more clear:

"A geosynchronous transfer orbit or geostationary transfer orbit is a Hohmann transfer orbit used to reach geosynchronous or geostationary orbit. It is a highly elliptical Earth orbit with apogee of 42,164 km. and an argument of perigee such that apogee occurs on or near the equator."

I think it's possible the author may have meant something like this:

"A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a Hohmann transfer orbit used to reach geosynchronous or geostationary orbit.[1] It is a highly elliptical Earth orbit with apogee of 42,164 km (26,199 mi) and an argument of perigee such that apogee occurs on or near the equator." — Preceding unsigned comment added by 65.28.181.33 (talk) 10:05, 8 September 2013 (UTC)

Orbital period?
What are some typical orbital periods (time it takes to complete one orbit) of typical GTO orbits? I know that it is hours, and considerably less than the 24h period of a Geostationary orbit. I would think the article would be improved with this info if we can find a good source for it. N2e (talk) 12:25, 28 April 2014 (UTC)


 * One example (there are others) where this information might be useful to readers of the Wikipedia: I believe (but am not super knowledgeable about such things) that half of a GTO orbital period is how long a typical upper stage would have to stay live/useful if it were to be able to efficiently fire a second burn (near its apogee) that would lower it's perigee and thus help reduce space debris by shortening the number of months/years that the spent GTO upper stage will remain derelict orbiting Earth.  It is my understanding that many upper stage designs may not have sufficient duration (battery power, temperature design margins, etc.) to operate for a period of hours long enough to do that, even if they were to retain a  bit of  propellant reserves to do so.  N2e (talk) 12:37, 28 April 2014 (UTC)

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Article
A little complex for an encyclopedic article. Oceanic84.ca (talk) 03:23, 25 February 2019 (UTC)

GEO?
The article uses but doesn’t define GEO. Is it another name for GSO? --JWB (talk) 16:05, 6 June 2020 (UTC)
 * I rewrote the introduction and addressed this issue. GEO = geostationary orbit, GSO = geosynchronous orbit. GEOs are a subset of GSOs. --EduardoW (talk) 20:37, 11 November 2020 (UTC)

How precise is "apogee is as high as geostationary"
On pages like [] discussions occur about whether a sub-synchronous transfer orbit should be shown as a GTO. So far the concept of being an intermediate step to a final GEO/GSO seems to have been considered more important. Therefore I would be inclined to change this article to say:

A GTO is highly elliptic. Its perigee (closest point to Earth) is typically as high as low Earth orbit (LEO), while its apogee (furthest point from Earth) is roughly as high as geostationary (or equally, a geosynchronous) orbit. The ideal case of apogee being exactly at GSO altitude is a Hohmann transfer orbit between LEO and GSO.

I didn't want to boldly make this change if other editors know better than me how precisely the apogee needs to be near GSO altitude and could do a better job of editing this. But it should be clearer whether/when a sub-synchronous (and super synchronous) transfer orbits can be called a GTO or if the GTO term only applies to the ideal cases where apogee = GSO altitude. The reason for them could also be added to - more about rocket lacking the power to get to GEO with the payload so put fuel on satellite which benefits from staging - rocket and its engines don't have to be lifted to GEO. C-randles (talk) 15:07, 3 November 2022 (UTC)