Talk:Geocentric orbit

————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————————— QUESTION about the section "Tangential velocity" at the foot of the page. I am not a scientist, I am attempting to understand how a vehicle such as the shuttle in LEO exits the orbit for return to earth. In popular texts it seems always to be stated "the vehicle makes a de-orbit-burn tail-first to reduce velocity" and this seems to be a straightforward case of cause and effect, reduce the velocity and the altitude decreases. I may have misunderstood the information in the tangential velocity table however comparing the LEO value 6.9-7.8km/s with the Geostationary value 3.1km/s seems to imply that a lower velocity is associated with a greater altitude. Perhaps I have misunderstood, or perhaps there might be an error in the data? Thanks Ted in NY. 216.6.185.102 (talk) 17:49, 5 February 2020 (UTC)[reply]

Hi Ted, the articles right. When a satellite is slowed down it drops in altitude, but gains kinetic energy, which causes it to speed back up again! Space is weird. --Spacepine (talk) 11:34, 1 September 2020 (UTC)[reply]

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Not heard this term used before, though I like the idea behind it. Maybe we just need to clean up the Earth orbit article rather than move to geocentric orbits. Earth orbit is more intuitive than geocentric orbits - Taka2007 18:51, 5 September 2006 (UTC)[reply]

I agree that "earth orbit" is a bit more intuitive, however it is a slang term used to describe geocentric orbits. I would say that we should redirect "earth orbit" to "geocentric orbit" since they are synonymous, but geocentric is more scientifically correct. Both support and rebuttal of this point would be appreciated.
kf4yfd 08:40, 10 September 2006 (UTC)[reply]

Agree, the term is just "slang" and covers everything that's covered in this article, with less detail I might add. I think I might see what can be salvaged from the "Earth" article and redirect after merging. If I've been too bold just revert my changes. Radagast83 05:28, 11 November 2006 (UTC)[reply]

This page is a work in progress. More information and cleanup soon.
kf4yfd 08:40, 10 September 2006 (UTC)[reply]

I like this page. Very space dynamics oriented Subheight640 06:02, 10 April 2007 (UTC)[reply]

High Earth Orbit vs Highly Elliptical Orbit

I have corrected the existing confusion between the two terms by changing the relevant articles:

High Earth orbit
High Earth Orbit
Geocentric orbit
HEO

Here is a example of correct definitions:

A High Earth Orbit is any orbit above geosynchronous (above 35,786 km). A Highly Elliptical Orbit is an orbit of low perigee (about 1000 km) and a high apogee over 35,786 km).^[1]

Some remarks:

High Earth Orbit and Highly Elliptical Orbit are two different things.
Highly Elliptical Orbits are a subset of High Earth Orbits.
Some High Earth Orbit satellites are not in a Highly Elliptical Orbit. An example is given in High Earth Orbit.

Morana (talk) 10:03, 8 May 2008 (UTC)[reply]

I agree with remarks 1 and 3, but is there a reference for Remark 2? An "orbit above geosynchronous" to me means that at least the mean orbital distance (if not the perigee) is above 35,786 km, not just the apogee, so a Highly Elliptical Orbit need not be a high Earth Orbit. --Roentgenium111 (talk) 17:29, 17 April 2012 (UTC)[reply]

The definitions I am familiar with agree with the current definition in Highly_elliptical_orbit "A highly elliptical orbit (HEO) is an elliptic orbit with high eccentricity" which includes Molniya_orbits with a roughly 12 hour period which puts them well below the definition of a High_Earth_orbit. -- Annette Maon (talk) 07:59, 13 July 2018 (UTC)[reply]

References

^ http://gcmd.nasa.gov/User/suppguide/platforms/orbit.html

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"Earth orbit" listed at Redirects for discussion

The redirect Earth orbit has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 July 30 § Earth orbit until a consensus is reached. fgnievinski (talk) 22:37, 30 July 2023 (UTC)[reply]

[1] ttp://gcmd.nasa.gov/User/suppguide/platforms/orbit.html

[1]