Talk:Heliosynchronous orbit

Split
They mean the same thing, and sun-synchronous is just poor English. What is really needed is another term that means constant-angle-of-illumination-orbit. Hmmm...Sciosynchronous? From the Greek &#963;&#967;&#953;&#945;, shadow (the root is already used in a few scholarly words, such as sciurine and sciuroid [where the -o disappears because the following root starts with a vowel]).
 * For the Earth-orbit, "sun-synchronous" is much more common. Should they be split?
 * &mdash;wwoods 21:56, 7 Sep 2004 (UTC)

Urhixidur 23:10, 2004 Sep 7 (UTC)

I just noticed there are two seperate articles for 'Heliosynchronous' and 'Heliosynchronous orbit'. I suggest they may be fused. (Is there a better way to make such suggestions?)

This article should be split. Yaohua2000 20:37, 8 March 2006 (UTC)

Heliosynchronous orbit and sun-syncronous orbit are the same orbit. A sun-syncronous orbit can be called heliosynchronous orbit correctly. The article must be fused.--Joseygnacyo (talk) 05:26, 1 September 2011 (UTC)

Sun's period of rotation

 * "...a heliocentric orbit where the satellite's period of revolution matches the Sun's period of rotation."

To my knowledge, the sun does not rotate as a rigorous body. The polar regions have different (slower?) angular velocity than the equator. I would assume that heliocentric orbits follow the rotation of the equator, but someone who knows for certain should clarify this in the article. HymylyT@C 14:38, 11 July 2007 (UTC)
 * Agreed. I'm skeptical about this whole notion.  It may be original research.  I think this article should be deleted unless we can find a reputable reference for it.  --Doradus 19:05, 31 October 2007 (UTC)

It's true that the sun rotation period depends on latitude, and, moreover, it has no sense to define as heliosyncronous an orbit around the sun, equivalent to the geosyncronous one around the Earth, because there can be no observer at the sun surface. For this reasons every scientific purpose mission will require the definition of a specific orbit around the sun and the definition of an heliosyncronous orbit appears to be not necessary. I suggest to use heliosyncronous and sunsyncronous with the same mean, as the specialists of the field widely do. 78.13.222.33 (talk) 22:48, 3 March 2010 (UTC)(Aerospace Engineer)

Which kind?
"To date, no satellites have been put in this kind of solar orbit." There are two solar orbits mentioned on the page. Which is this referring to? 69.137.130.101 (talk) 21:22, 15 February 2009 (UTC)

Prod discussion
Regarding the proposed deletion, "heliosynchronous" gets 340 hits on Google Scholar (mostly discussing methods of stabilizing such orbits and why they'd be handy for solar observations), and "heliostationary" gets 38 hits (mostly about various types of sailcraft put in modified versions of this sort of orbit). From the looks of things, this seems to be a niche concept, but one that has been discussed in reputable scientific literature. As a result, I propose that the prod be removed. --Christopher Thomas (talk) 07:05, 22 June 2011 (UTC)


 * Delete - there appear to be two different uses of the term (one as written, and the other used to mean Sun-synchronous), and only a handful of articles about it (most of the Google Scholar results are from the same research groups, or duplicates of a few articles), while "heliostationary" also appears to have at least three definitions (one essentially the same as the second heliosynchronous definition, one referring to a solar sail that can hold a fixed position in a sun-centered, non-rotating frame, and the least commonly used one is the one given in this article). The definition given in this article is really only used in a few papers about the Solar Orbiter, e.g. "During quasi-heliosynchronous phases of the orbit, Solar Orbiter will track a given region of the solar surface for several days..." Because of this confusion, and the rare usage, I'd say either delete it, or expand to include all the definitions and cite a textbook or other secondary or tertiary source. - Parejkoj (talk) 15:35, 22 June 2011 (UTC)


 * comment I've removed the prod tag, since I examined the history and found that this article was split in two and the other article this was split to still exists, so for contribution history reasons, this needs to be kept around, even if only as a redirect. 65.94.47.63 (talk) 05:11, 23 June 2011 (UTC)


 * I'll look at folding in references and clarifying the different uses of the term over the weekend, then, as I'm not sure I'll have the opportunity to do so earlier than that. So please hold off a few days on sending this to AfD or similarly drastic measures, so that I can have a chance to sift through the literature and attempt to address concerns :). --Christopher Thomas (talk) 05:21, 23 June 2011 (UTC)

Proposed article merge (change to a redirect)
This article had been suggested for deletion, with considerable support, per the "Prod discussion" section above. However, since that section is entitled Prod discussion and the Prod proposal was later removed, it appears that the deletion discussion was never completed. Later, the proposal seems to have changed to a Merge, so as to keep the Talk page history intact via changing this article to a Redirect. Finally, as of today (2011-11-03), the link to discuss the proposed deletion takes one to the wrong article Talk page, which is why, I suspect, more editors have not weighed in. (I intend to fix that shortly.)

Proposed deletion, dated 20110621193302:
 * concern = As alreay said on the discussion page: This concept does not exist because there has never existed nor will ever exist a spacecraft in such an orbit. This term was invented here by Wikipedia editors as an analogie to geosynchronous orbit.


 * Delete - there appear to be two different uses of the term (one as written, and the other used to mean Sun-synchronous), and only a handful of articles about it (most of the Google Scholar results are from the same research groups, or duplicates of a few articles), while "heliostationary" also appears to have at least three definitions (one essentially the same as the second heliosynchronous definition, one referring to a solar sail that can hold a fixed position in a sun-centered, non-rotating frame, and the least commonly used one is the one given in this article). The definition given in this article is really only used in a few papers about the Solar Orbiter, e.g. "During quasi-heliosynchronous phases of the orbit, Solar Orbiter will track a given region of the solar surface for several days..." Because of this confusion, and the rare usage, I'd say either delete it, or expand to include all the definitions and cite a textbook or other secondary or tertiary source. - Parejkoj (talk) 15:35, 22 June 2011 (UTC)


 * Support the merge. Heliosynchronous is a meaningless term, and no sources are provided for any of the existing claims.  N2e (talk) 16:56, 3 November 2011 (UTC)

NOTE: very shortly after I made an attempt to clean up this page, and get the merge discussion on track, I noticed that User:Teapeat has formally nominated the article for deletion. I am fine with that; I just want to drive the proposal to closure. So the AfD page (see header at the top of the article page) is probably the best place to put your comments on the deletion/merge. N2e (talk) 17:10, 3 November 2011 (UTC)
 * Delete! Any rotating approximately spherical rigid body (with a sufficiently low rotation rate!) could have a stationary orbit, i.e. a polar circular orbit with radius
 * $$R=\sqrt[3]{\mu\left(\frac{P}{2\pi}\right)^2}$$ where P is the rotational period and μ is the gravitational constant. The Earth has plenty of satellites in geostationary orbit. Also for Mars that is extensively visited/explored it makes sense to have one or several stationary satellites used as telecommunication relays.  But certainly not for the Sun and the term Heliosynchronous (in this sense) does not really exist, it is a "Wikipedia invention". To make this concept additionally absurd, the Sun does not even rotate like a rigid body as correctly pointed out in the section "Sun's period of rotation" above!


 * Stamcose (talk) 09:13, 5 November 2011 (UTC)

This REDIRECT article ought to be deleted
This article, Heliosynchronous orbit, is currently a redirect to Sun-synchronous orbit. However, neither that page, nor the List of orbits page, had a citation. As per the earlier discussion above, the term heliosynchronous orbit appears to be a Wikipedia invention.

On the List of orbits page, a citation needed tag had been added some time ago; so I deleted the unsourced claim completely, today.

On the Sun-synchronous orbit page, the claim that heliosynchronous is a synonym for sun-synchronous had not previously been tagged, so I tagged it with citation needed (lead) today.

In any case, it would appear that this redirect article ought to be deleted, as it supports a claim that a "Heliosynchronous orbit" exists in the scientific literature, and that it is the same as a "Sun-synchronous orbit", as a mere matter of Wikipedia original research.

If anyone has support for the apparently erroneous claim, please add it. Without support, I will—or another interested editor should—propose an AfD in not-too-distant future. N2e (talk) 01:13, 9 July 2012 (UTC)


 * Writing to support your deletion, for exactly the reasons I stated above. I don't know why this wasn't deleted after that previous proposal. - Parejkoj (talk) —Preceding undated comment added 13:53, 9 July 2012 (UTC)


 * "A sun-synchronous orbit, also known as a helio-synchronous orbit" Darkness Shines (talk) 01:55, 12 July 2012 (UTC)