# Talk:Skyhook (structure)

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## 2006/2006

could it be possible to create a skyhook? a 100 mile long cable attached to a space station.Along which tractor units powered by a giant flywheel,which will partsially send these units into orbit or at least half way {the rest of the way they drag themselves} i personally think its not too far fetched all it needs is Bill gates to fund it and we'll have one in orbit within 10 years.where are the Brunnels and the Stevensons when you need them.I betcha if the victorians had even a fraction of the technology that we do.they would have put one up.without worrying about micro meteors they would have delt with those when the time came instead of worrying about them on computer simulation.

Depends on the materials you use. Currently, no.
The space station would have to be somewhere beyond the geostationary orbit to keep the cable up. That gives us at least 35786km of cable. I do not know what kind of cable you are thinking of - let's take for example a high tech climbing rope, which is comparatively lightweight and sturdy. It weighs some 62g/m, and can hold a few tons of weight. At 35786000m of rope, it will have a mass of 2219t. Even though gravity diminishes the more you approach the orbit, you see that it is not even close to holding it own mass. -- 195.37.79.52 11:04, 21 June 2006 (UTC)
The factor of merit that applies to materials in this application is essentially (yield_strength/density), which, once divided by acceleration of gravity g, becomes a length l -- the length of a uniform cable that can support its own weight without breaking. For all current "normal" engineering materials, this is much much less than the radius of the Earth.
Oceanographers encountered this problem decades ago, as they lowered long instrument-carrying cables into the abyss from ships. I suspect the 1966 letter in Science (from Scripps Institute of Oceanography) was partly inspired by their experience. Their solution was to use a tapered cable: as you go up, the diameter of the cable increases so it can always support the weight below, and never breaks. It is easy to show that this leads to a cable design in which the area of the cable grows exponentially, as you go up against gravity. The exponential scale length is essentially just the factor of merit length mentioned above. Bottom line is that the total mass required grows exponentially with the height of the cable, and inverse exponentially with the scale length parameter.
Since gravity changes with height for the space application, you have to multiply length as you go up times the local effective gravity, which includes both the Earth's g, diminishing as 1/r2, and also the centrifugal acceleration due to rotation, which acts upward and is proportional to r. This must be summed (integrated, that is) as you go up.
For a non-rotating spherical gravitating planet, the sum -- with no centrifugal contribution -- is just the radius of the planet, times the surface gravity. We may call this the "potential height" H to be overcome. For the Earth cable extending to geosynchronous orbit (GSO) and rotating at 1 revolution per day, the accumulated centrifugal effect reduces the total by about 20%, to something like 5500 km equivalent 1 g height. Upshot is that for normal engineering materials, the exponential growth kills you as the total mass for a cable with a macroscopic load carrying capacity comes out literally astronomical. But—the good news—is that for carbon nanotubes the Earth-to-GSO case looks challenging, but maybe possible.
Thus we are awaiting the development of real engineering materials that we can actually buy, with yield strengths we can trust, before we can estimate the total mass, and the cost. Wwheaton 01:34, 29 August 2007 (UTC)

It seems to me this whole subject should be under space exploration, as it is pretty remote from any kind of known or terrestrial architecture. I look forward to the day when "Space Architecture" becomes a recognized discipline!

Also, for the Earth-to-GSO case, there are big problems due to the hundreds of billions of dollars already invested in satellites (assets) below GSO (not to mention the tremendous amount of accumulated junk from dead satellites and collision debris), which will pose a constant threat to a surface-to-GSO cable. All that must be pretty much cleared out before the surface can be reached by a cable coming down from above (as it would have to be built in practice).

This main article needs to be expanded to cover the general subject properly, as it is a shadow of the Lunar_space_elevator article that really should build on it. Yet the lunar application has received much less attention, although from lunar surface over Earth-Moon L1 it is vastly easier, as although the length is great, the exponential growth issue mentioned above is not a problem due to the low g and correspondingly small H involved.

The statements and numbers from the previous remark addressing the June 2006 discussion are published in the literature somewhere, but essentially off the top of my memory and/or from my own calculations. I hope this sort of information, perhaps with a caveat, is acceptable for "talk" pages? Anyway, do beware, as I am still new to the Wiki game. Wwheaton 01:34, 29 August 2007 (UTC)

After yet a little more looking around, I see that the really substantial articles on this subject are under space elevator and tether propulsion. I prefer "skyhook" personally for the configurations attached quasi-statically to a planet or satellite surface, but in view of the existing pages, maybe this one should be suppressed, and simply redirect to the appropriate section of the space elevator page? Wwheaton 06:06, 29 August 2007 (UTC)

## A Skyhook is not a space elevator

There is a large conceptual error in this article. The term "skyhook" should not be used interchangeably or as a subset of "space elevators". The term originated from early cable and hook systems the U.S. Air Force used to retrieve packages and people from the ground and midair into cargo aircraft. http://en.wikipedia.org/wiki/Fulton_surface-to-air_recovery_system Likewise in orbital skyhooks, a moving hook grapples with a cargo to be lifted into orbit from the ground or midair. Lazyquasar 02:18, 25 September 2007 (UTC)

I deleted the incorrect sentence. Lazyquasar 02:42, 25 September 2007 (UTC)
I retract the above statement that a "skyhook" is not a "space elevator". Apparently the terms have been used almost interchangeably for quite a while. http://www.frc.ri.cmu.edu/~hpm/project.archive/general.articles/1987/skyhook.ltx It would seem to me that to begin increasing understanding of this technology it would be useful to restrict the use of the term "skyhook" to techniques similar to the moving capture technology that used it originally and the term "space elevator" to stationary attached structures/tethers similar in technical approach to the traditional elevator. What do others think? Lazyquasar 14:17, 25 September 2007 (UTC)
This engineering paper [1] restricts itself to the terms "tether". When the tether is anchored to Earth then it is referred to as an "elevator" or "beanstalk". Lazyquasar 14:24, 25 September 2007 (UTC)
This engineering paper[2] has a short section at front on history and terms "beanstalk" and "skyhook" and "space elevator". Lazyquasar 14:29, 25 September 2007 (UTC)
This engineering paper uses terms rotating space tethers and when tether is anchored to lunar surface refers to the ensemble as a "Lunar Space Elevator". Lazyquasar 14:37, 25 September 2007 (UTC)
Bah! This paper[3] uses the term "Skyhook" as the generic category and then details engineering approaches to building a space elevator ... i.e. a structure or tether anchored to ground. Structure perhaps supported dynamically by internal momentum exchange mechanism. Lazyquasar 14:52, 25 September 2007 (UTC)
More terminology. "Orbital Slings", "Rotovator", Nice diagram showing basics of skyhook or orbital tether operation. Lazyquasar 15:02, 25 September 2007 (UTC)
Bibliography (with many online links) of tech papers on space tethers[4] by a company attempting to patent and control space tether technologies. These seem limited to orbital transfer tethers technically feasible today. Lazyquasar 15:07, 25 September 2007 (UTC)
No help here[5], nice diagrams though. This person at NASA appears to define "space elevator" as anything that changes potential energy in a gravity well. Lazyquasar 15:14, 25 September 2007 (UTC)
Speculative design of a skyhook structure with a dock replacing the traditional grappling hook.[6] Tourists then take an elevator up the skyhook to the orbital waystation on way to elsewhere. Lazyquasar 15:21, 25 September 2007 (UTC)
Authur C. Clark, when writing for popular audiences, uses the terms interchangeably. "The space elevator (alias Sky Hook, Heavenly Ladder, Orbital Tower, or Cosmic Funicular)" [7]] No mention of space tethers, only ground to orbit applications. Lots of good historical detail and basic science and engineering regarding elevators. Lazyquasar 15:28, 25 September 2007 (UTC)
2001 Conceptual design of a "Tether Launch System" between Earth and Mars. No use of term "Skyhook". Lazyquasar 15:43, 25 September 2007 (UTC)
Pearson[8] identifies the term "skyhook" entering the nomenclature ... "Unaware of the work of Artsutanov, a group of American oceanographers led by Isaacs [7] independently discovered the concept in 1966 and proposed a much smaller-scale version which they called a ”skyhook.” They proposed a pair of fine wires which could be alternately raised and lowered by ground-based machines to ”walk” payloads into orbit, and performed a static analysis of the wire strength requirements." The time frame seems appropriate for the term to have been borrowed from U.S. Air Force skyhook operations but it could have been original. Lazyquasar 15:59, 25 September 2007 (UTC)
Basically, you should just copy that lot into the article and tidy it up a bit. The use of the term is really quite inconsistent.WolfKeeper 22:15, 25 September 2007 (UTC)

A graphical representation of the hypothetical skyhook described by the article would be helpful. N2e (talk) 22:33, 28 January 2009 (UTC)

## Quasi-fiction

This and the main Skyhook article, currently a disambiguation page for reasons unclear, both suffer from confusing real objects with fictional and even joke concepts. I've added the refimprove template because most of the assertions in the article have no backup. I urge the authors to come back and provide some references. —Preceding unsigned comment added by Ouilmette (talkcontribs) 20:52, 2 July 2010 (UTC)

## Not architecture

The skyhook concept has almost nothing to do with architecture. Wcmead3 (talk) 16:56, 4 May 2012 (UTC)

## Science fiction?

An orbital skyhook is an extremely speculative concept. Section 1.2 in its current form is superficial and very misleading.

Here's just one example: the description of converting space "waste" into a replacement for high quality rocket fuel. True debris would almost never strike the outer terminus. Obtaining a significant amount of material that would be deflected and timed to hit the end of the skyhook would require enormous high quality infrastructure to create it.

An article like this greatly diminishes my estimation of the quality of Wikipedia's content. The article's importance should be "Low" or "NA". Level of content refinement is below "Start" (perhaps Stub? or Omit?). The scope of the orbital skyhook section should be limited to a definition of the concept, clearly labeled as highly speculative. A few sentences should suffice. Retain a link to "Space Elevator". Wcmead3 (talk) 19:19, 4 May 2012 (UTC)

## Third option?

This is potentially own-research (unless someone can find someone who's suggested it already!). But the choices listed on the page don't seem to include a third option: Why can't the space-elevator/sky-hook extend from beyond geostationary to ~6000km? Importantly I can't visualise whether that would be stable? 6000km is accessible with a fairly cheap rocket (as you don't need to faff about with getting all that speed) and at that distance g~=2.5m/s^2. So the weight of the cable would be less, needing less strength -> less weight -> probably would only need to be 1/16th as strong as a cable to the surface? Obviously climbing the cable would steal some of the cable's energy. This could be recouped by using some of the mass lifted as propellant (and the power can be via the 'standard' laser from Earth). Lionfish0 (talk) 20:05, 20 September 2012 (UTC) [Presumably different orbits would then be achievable for little cost as the energy required for each orbit could be selected by rising to the relevant height (then later propulsion corrections to get into low-earth or whatever). Just a thought! Lionfish0 (talk) 20:05, 20 September 2012 (UTC)

## Historical Note

My father was a flight instructor in the Army Air Corps in WWII (the fore runner to the US Air Force.) The first time I heard the term "Sky Hook" it was as a child. He told me that the instructors used it as a gag. When rookies wanted to know what held the airplane in the sky they told them "sky hooks."

AFAIK this is its earliest usage.

Jeff Kesselman — Preceding unsigned comment added by 71.233.3.185 (talk) 02:28, 11 August 2013 (UTC)

## Proposed merge

I think the suggestion of merging this article with Orbiting skyhooks and making this article redirect to same is a good idea. If there are no objections to this I will perform the merge sometime after the 24th of Feb. Skyhook1 (talk) 16:35, 17 February 2014 (UTC)
• Support the merge. Two articles on the same subject, should become one. However, I would think that the better article name to keep would be Skyhook (structure). Either way, however, I support the merge. The name can always be cleaned up later if there is no clear consensus on the name amongst those editors who weigh in on the proposed merge. Cheers. N2e (talk) 12:14, 18 February 2014 (UTC)
Regarding the name issue. Some possible names for the combined article: Skyhook (orbiting), Skyhook (another kind of space elevator), Skyhooks (space elevator concepts that can be built). Any other suggestions? I agree the combined article needs a good name - but what? I would appreciate any suggestions. Skyhook1 (talk) 17:23, 18 February 2014 (UTC)
The title of this page, Skyhook (structure) is the one that should be kept - so merge Orbiting skyhooks into this one. Roger (Dodger67) (talk) 19:19, 18 February 2014 (UTC)
Completed merge of Orbiting skyhooks into Skyhook (structure) and added redirect on Orbiting skyhooks to Skyhook (structure). Thank you all for your comments and suggestions. Skyhook1 (talk) 19:55, 24 February 2014 (UTC)

## Introduction re-write

The introduction or lede needs to be rewritten. It opens with a hyped sales pitch by a salesman, without even defining what the concept is. Plenty of WP:PEA throughout the introduction and the article itself. Cheers, BatteryIncluded (talk) 18:14, 5 March 2014 (UTC)

• The lead has been rewritten on a couple of occasion per suggestions of others, one of which was that it needed something that grabbed a reader's attention.
• Re: the "sales pitch" in the lead. In the Wikipedia instructions for new authors it says that published claims by proponents may be included as long as it is made clear that these are claims by proponents. The "sales pitch" does that: plus if you check the references you will see that the "sales pitch" comes straight from the references.
• As to the comment about plenty of PEA in the rest of the article: please specify exactly what statements you find objectionable.
• As to the length: it says in the instructions that the lead can be up to 4 paragraphs long. But if the length is really an issue I will be happy to break it into multiple sections.
• Re: the statement that the lead does not define the concept.

"Orbiting Skyhooks come in two types; rotating, and non-rotating. The non-rotating orbiting Skyhook is a much shorter version of the planetary surface to geostationary orbit Space Elevator that does not reach down to the surface of the parent body, is much lighter in mass, can be affordably built with existing materials and technology, and in its mature form, is cost competitive with what is thought to be realistically achievable using a Space Elevator. It works by starting from a relatively low altitude orbit and hanging a cable down to just above the Earth's atmosphere. Since the lower end of the cable is moving at less than orbital velocity for its altitude, a launch vehicle flying to the bottom of the Skyhook can carry a larger payload then it could carry on its own. When the cable is long enough, Single Stage to Skyhook flight with a reusable launch vehicle becomes possible at a price that is affordable to just about anyone."

How does this not define the concept?

• Re: inline citations in the lead. I have read other discussions on other talk pages that say inline citations in the lead are distracting and take the reader away from the article, and that un-referenced claims in the lead are ok as long as they are covered in the body of the article.

More to come but I am out of time for the moment. Skyhook1 (talk) 00:48, 6 March 2014 (UTC)

• Re: "sales pitch". What you call sales pitch can also be viewed at notability claims. When a concept such as the orbiting skyhook has such a profound impact on the way things are done, it is difficult to say anything about it in just a few brief words that doesn't sound like a sales pitch. — Preceding unsigned comment added by Skyhook1 (talkcontribs) 18:41, 6 March 2014 (UTC)
The first sentence should briefly state what the skyhook is, not how it can be enjoyed by everyone at an affordable price. BatteryIncluded (talk) 22:33, 6 March 2014 (UTC)

Gentlemen: I am a little overwhelmed, which I suspect was your intent. I did not read all your changes, there were just too many, and all the comments, many which were conflicting, written on the main text instead of here, looked very unprofessional. To the degree that any of the changes I reverted were well intended improvements (and I am sure there were some), I apologize. To the rest, you shame yourselves. Assuming this "overwhelm" stops and becomes an adult discussion, one at a time, here on the Talk page, I will, as time permits, discuss the issues with each and every one of you. If not then I suggest that you revert this page to the pre merger condition and we go our separate ways. Skyhook1 (talk) 01:57, 6 March 2014 (UTC)

You cannot perform 9 reverts in a row and tell us to be ashamed and go away. Please review the Wikipedia tutorial and understand that this is a collaborative effort. Next, you created 2 duplicate articles that do not meet the standards required. If you are really interested in improving this article, be happy, as you've got the attention of experienced editors to assist you. Cheers, BatteryIncluded (talk) 15:16, 6 March 2014 (UTC)

If I cannot revert 9 edits in a row then maybe you should hold yourselves to the same standards and not make so many large edits in a row without any discussion. You have heard of the concept of a double standard?Skyhook1 (talk) 18:45, 6 March 2014 (UTC)

One word for you: WP:Tutorial. Reverting all requests for references is indicative that you have not grabbed the concept of Wikipedia's most basic guideline. BatteryIncluded (talk) 19:05, 6 March 2014 (UTC)

## The word "skyhook" is not a proper noun

It should not be written with a capital "S" except if it starts a sentence. Roger (Dodger67) (talk) 14:03, 6 March 2014 (UTC)

Done. --BatteryIncluded (talk) 22:45, 6 March 2014 (UTC)

## Points of View

A number of you claim that this article has a point of view. I suppose that is true to the degree it is not possible to say anything without having a point of view. But I fail to see how the POV of this article is any different than so many other articles on Wikipedia. A good example of this is the Space elevator article. There is an article about a space transportation concept that cannot be built with existing materials that is discussed as if it were real, and the editors of which will not allow the addition of any material that attempts to insert any reality to it, or even to insert any info on related concepts. Again there appears to be a bit of a double standard here. Skyhook1 (talk) 20:54, 6 March 2014 (UTC)

I know nothing about the "Space elevator" editors or their alleged bias there. The point is citing the research data/information as supposed as your own WP:point of view. The researcher may state how the concept works and how it will change humanity for best, but in Wikipedia you only inform how the concept works, and omit the author's sales pitch as much as possible.
In brief, I am addressing the severe lack of inline citations, apparent original research and encyclopedic style (Wikipedia:Manual of Style). CHeers, BatteryIncluded (talk) 23:05, 6 March 2014 (UTC)

## Original Work

There have also been claims of this article containing original work. Maybe those of you making those comments should read the references before making such statements.Skyhook1 (talk) 20:54, 6 March 2014 (UTC)

Maybe you should add the inline citations requested, instead of reverting the requests. BatteryIncluded (talk) 22:22, 6 March 2014 (UTC)

## Other Changes

• I also notice that the section "A Possible Earth-Mars Transportation System" was eliminated. Why?Skyhook1 (talk) 20:54, 6 March 2014 (UTC)
Lack of references. Besides the tether is a propulsion system more than a space transport. BatteryIncluded (talk) 22:29, 6 March 2014 (UTC)
• Also: the column in the Comparison Table regarding if they could be built with existing materials was removed. That makes a lie out of the data in the table and makes me question the bias of the person making the edit.Skyhook1 (talk) 20:54, 6 March 2014 (UTC)
You entered that it can be done with existing materials, but YOUR reference states the opposite: "Jillian Scharr, "Space Elevators On Hold At Least Until Stronger Materials Are Available, Experts Say", Huffington Post, May 29, 2013". Who is biased? Cheers, BatteryIncluded (talk) 22:26, 6 March 2014 (UTC)

## Request for Arbitration

It is my understanding that Wikipedia has an arbitration process for settling disagreements. I would like to request arbitration to address what is going on here. Skyhook1 (talk) 20:54, 6 March 2014 (UTC)

Cleanup of WP:OR, and requesting/adding inline citations is not a "disagreement", is a requirement. BatteryIncluded (talk) 22:19, 6 March 2014 (UTC)
What he said. You can ask at WP:3O but they'll probably tell you to read up about how Wikipedia works. Citations are required; opinions are not; advocacy and "original research" are frowned upon. andy (talk) 22:26, 6 March 2014 (UTC)
Please proceed: Wikipedia:Arbitration/Requests. Cheers, --BatteryIncluded (talk) 22:48, 6 March 2014 (UTC)
There is nothing here that needs arbitration - the article simply needs to be brought into line with the relevant policies and manual of style. Unilaterally undoing the agreed merge is a destructive, not constructive, act. Please do not subvert the work that experienced editors are doing to improve the article in accordance with the established rules, standards and procedures of the English Wikipedia. Roger (Dodger67) (talk) 07:29, 7 March 2014 (UTC)

## You Win!

You have made it clear, you own Wikipedia. Congratulations!

A few comments. After reading the instruction on original work, I agree with you, my entire article was original work. Every last word of it. So I have reverted everything back to the way it was before I began. Sorry. I wish I had found that instruction before I started. Goodbye Skyhook1 (talk) 07:47, 7 March 2014 (UTC)

There are no winners or losers here. Wikipedia is a co-operative venture, we work together to gather the world's knowledge about notable subjects into this mega-encyclopedia. Confrontation and a competitive outlook is not to anyone's advantage, least of all the project's. We definitely need to improve on the information given to new editors so that misunderstandings such as this do not occur. Roger (Dodger67) (talk) 08:10, 7 March 2014 (UTC)
Skyhook1, it is definitely not a matter of editors, editor's preferences, and winning. The editors are rather secondary to the entire endeavor. But we are attempting to build a quality encyclopedia here, which is why the community has established a number of guidelines and practices over the past decades or so. N2e (talk) 16:17, 7 March 2014 (UTC)
FWIW, I posted a comment on Skyhook1's Talk page as well, encouraging the assumption of good faith. N2e (talk) 17:34, 8 March 2014 (UTC)

## The section on Hypersonic Skyhooks

1) The material in this section was a cut and paste from the reference which is copyrighted and was removed as a result (the reference is still there, see page 19). 2) In addition, the removed material was about non-rotating skyhooks, not a hypersonic skyhook. Hypersonic Skyhooks are rotating skyhooks and this section should discuss rotating skyhooks. — Preceding unsigned comment added by 192.34.40.26 (talk) 16:57, 17 April 2014 (UTC)

The following is a cut and paste from the reference. It is copyrighted material and can not be used in this article. Just using the first and last sentence doesn't mean it is no longer copyrighted material. Just changing an adjective or two is not enough either. Read it, make sure your rewrite is sufficiently different, and then remove this quote.

"In 1995 Zubrin proposed the “Hypersonic Skyhook” as a solution to the mismatch between the attainable atmospheric speeds of a hypersonic airplane and the orbital speeds of space tethers. Since the orbital speed of the space tether decreases with increasing altitude of the tether system center-of-mass, he proposed the use of very long non-spinning tethers or “skyhooks” reaching down from very high altitudes (thousands of kilometers). His analysis showed that because a hanging tether must be tapered to support its lower end in the gravitational field of the Earth, achieving a HyperSkyhook tether tip rendezvous with a 5.0 km/s (16 kft/s or Mach 16) airplane would require a HyperSkyhook tether mass of 25 times the payload mass. Trying to lower the tether tip speed to 4.0 km/s (13 kft/s or Mach 13) would require a HyperSkyhook tether mass greater than 200 times the payload mass. In general, the non-spinning tether HyperSkyhook concept does not look competitive with the spinning tether concepts. We will, however, revisit this concept in our Phase II studies." — Preceding unsigned comment added by 72.199.145.35 (talk) 01:40, 18 April 2014 (UTC)

Dear IP editor. Please do not continue your edit war. You were already explained, and then blocked for your edits and reverts. Instead of working against the system, ask yourself how you can collaborate constructively. Thanks, BatteryIncluded (talk) 18:30, 18 June 2014 (UTC)

## Trolling

The reference and data you are deleting is not on a paper about space elevators as you claim.[9] Hint: look at its title: Hypersonic Airplane Space Tether Orbital Launch System Look at the chapter: HyperSkyhook page 66 (e.g: Zubrin's skyhook).

So stop your trolling and removing Boeing's critique of the skyhook concept. BatteryIncluded (talk) 19:52, 18 April 2014 (UTC)

The reference on hypersonic skyhooks is primarily about rotating skyhooks. The comments in that reference about non-rotating skyhooks are for cable lengths that are much longer than what are discussed and referenced in the section on non-rotating skyhooks in this article and as a result are not relevant.

As to the references about space elevators not being possible until new materials are available; they are correct and are already listed in the lead. They do not apply to either rotating skyhooks, or non-rotating skyhooks, that are less than 4,000 km in length. — Preceding unsigned comment added by 192.34.40.26 (talk) 20:36, 18 April 2014 (UTC)

By the way, what is your problem with the reference to the NASA report on Space Elevators by D. Smitherman? It is a valid reference that is relevant to this article. — Preceding unsigned comment added by 192.34.40.26 (talk) 20:48, 18 April 2014 (UTC)

Also, why did you remove the reference to the Tethers in Space Handbook? It is also a valid reference that is valid to this article. — Preceding unsigned comment added by 192.34.40.26 (talk) 21:04, 18 April 2014 (UTC)

In the RefToolbar at the top of the edit formbox, click on Cite and then on Error Check. Tick the three boxes and then click on Check. You will see the referencing errors you are creating. -- 79.67.250.185 (talk) 22:35, 18 April 2014 (UTC)

We are aware that Sarmont was promoting his design. But Wikipedia is not a marketing tool. Using Sarmont's statement from 1994 that the needed tether materials are available, is incorrect and proven to be false. Notice he never said what his mystery tether material is. This article now cites multiple updated references stating that the needed tether material does not exist yet, so feel free to stop peddling spam. Cheers, BatteryIncluded (talk) 11:53, 19 April 2014 (UTC)

Actually I did include a link to the material that was used in the references, you removed it. Also the new references also specify existing materials that they used in their studies. I suggest you try reading them before making false claims. — Preceding unsigned comment added by 72.199.145.35 (talk) 00:08, 20 April 2014 (UTC)

By the way, since you seem to be interested in who I am, I am an aeronautical engineer, a rocket scientist, a former test pilot, and probably the largest single contributor to former President Bush's "Vision for Space Exploration". I have 4 degrees. According to your bio you are an expert in molecular biology and genetics and interested in space science. Has it occurred to you that maybe you should leave space science to the space scientists? You continue to make claims that skyhooks can not be built with existing materials and I have provided evidence to the contrary on a number of occasions. Still you do not listen and you continue to remove the evidence. I am curious as to your motivation. You say you are interested in space science but your actions appear to indicate otherwise. Most people who are interested in space science get excited about spaceflight and anything that will further that activity. Of all the ideas for making spaceflight mass market affordable that have articles here on wikipedia, very few of them can be built with existing materials and technology. Of the few that can, only one provides both low cost to Earth orbit, low cost to higher orbit, and low cost to Earth escape velocity. That is the non-rotating skyhook. And that is the one you attack like a rabid dog. Why? — Preceding unsigned comment added by 72.199.145.35 (talk) 00:49, 20 April 2014 (UTC)

Yes, it is very clear that you are in denial. How can we clear that up? Would you like me to walk you thru a basic stress calculation? — Preceding unsigned comment added by 72.199.145.35 (talk) 01:17, 20 April 2014 (UTC)

I am sure that the one degree you do have is in BS. Show one reference that states that your magic material, the one shall not be named in Wikipedia has the tensile strength required for a space tether and is available now. All related references state the opposite. Carbon nanofibers composite may or may not an option in 15-20 years, so we know that is not it. --BatteryIncluded (talk) 01:27, 20 April 2014 (UTC)

T1000 carbon fibers on the TORAY Industries Carbon Fiber Data Sheet http://www.torayca.com/en/index.html — Preceding unsigned comment added by 72.199.145.35 (talk) 01:33, 20 April 2014 (UTC)

For technical papers see references 5, 9, 10, 11, 12, and 18 in thew article. — Preceding unsigned comment added by 72.199.145.35 (talk) 01:43, 20 April 2014 (UTC)

Your comment, "SYNTHESIS, OR", what are you attempting to say?

Did you go to the TORAY website and find the tensile strength of the T1000GB fibers? Do you need an explanation of the units? — Preceding unsigned comment added by 72.199.145.35 (talk) 01:54, 20 April 2014 (UTC)

Let me clarify: this Wikipedia article does not need to state which tether material you think is most appropriate, but we can quote a quality reference (see: WP:SOURCE) stating something like "the skyhook tether could be built with X material." We have 2 options: to quote the Boeing report (2000) which states by name that the skyhook is 1) not competitive, and 2) it cannot be built with current materials. Or use your ranting. Show and quote HERE at least one reference stating the name of your mystery space tether material that shall not be named and that it is available now. Your reverting the page is not really a compelling argument against the cited references that state that not even carbon nanofibers are up to the job (2014). I have a real life to take care of so I will say good night for now. BatteryIncluded (talk) 02:02, 20 April 2014 (UTC)

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I have no problem with the Boeing report, but its conclusion is for tether lengths that are much longer than the ones that are being discussed in this article. This is where your lack of knowledge about engineering is a problem. The mass of a space tether goes up with length. Assuming it could take the thermal environment, you can build a space tether out of kite string. But there is a limit on how long this space tether could be made based on the strength to weight ratio of the string. This is where designers start making tapered lines that have more cross sectional area in the middle than at the ends. Even with this there are still limits on the length based on cost and total mass. You can make an Earth surface to geostationary orbit space elevator using kite string but it will be larger than the Earth, hence not practical. That doesn't mean that you still can't use that kite string to fly a kite, obviously you can. The difference is in the length. The space elevator is 100,000 km long. Your kite string is only a few hundred feet at most. The same applies to skyhooks. You could build a 100,000 km long space elevator out of T1000GB carbon fibers but it would have near planetary mass and as a result isn't practical. But like the much shorter kite string for flying a kite, a skyhook made of carbon fibers in the 200 km to 4,000 km range is possible. As to the references not all being open source on the internet there is not much I can do about that. You will need to either pay for them or go to a university library that pays for access to them and have them downloaded. References 7, 18, and 19 are open source. Reference 19 is only for the part of that paper that covers non-rotating skyhooks and does not include the entire paper. If you want to see the entire paper do a search using the title on google, it is open source. Quite simply the information is out there but you will have to do a little digging or pay for it. You will also need a basic understanding of engineering and orbital mechanics in regards to space tethers. For that I recommend the "Tether in Space Handbook", it is also open source on the internet, see reference 7. You could also just read the abstracts for the non-open source papers and you will get an idea that this is a workable concept. Or you could just notice who is writing these reports; NASA, reference 19, Lockheed Martin, references 5, 8, 9, and 10, and Smithsonian Astrophysical Observatory, reference 7. Do you really think these organizations would be wasting their time and money on a lie?

To conclude with the Boeing report. The Boeing report says 1) "His analysis showed that because a hanging tether must be tapered to support its lower end in the gravitational field of the Earth, achieving a HyperSkyhook tether tip rendezvous with a 5.0 km/s (16 kft/s or Mach 16) airplane would require a HyperSkyhook tether mass of 25 times the payload mass."

5.0 km/s is 64% of low Earth orbit velocity. A tether mass of 25 times payload mass can be built. I have no argument with this.

2) "Trying to lower the tether tip speed to 4.0 km/s (13 kft/s or Mach 13) would require a HyperSkyhook tether mass greater than 200 times the payload mass."

4.0 km/s is 51% of low Earth orbit velocity. A tether mass of 200 times payload mass sounds about right and it is highly unlikely that such a tether length would be economic. Again no disagreement.

The tether tip speeds for the non-rotating skyhook examples in this article, and in all the references I have listed, start at 96% of low Earth orbit velocity and go to approximately 70% of low Earth orbit velocity. There is no reason to go any lower. As a result, the final line of the Boeing quote, "In general, the non-spinning tether HyperSkyhook concept does not look competitive with the spinning tether concepts. " does not apply for two reasons. 1) It doesn't apply to the skyhook lengths in the article, and 2) it is an unfounded over generalization that falls under the category of sales BS that is promoting rotating skyhooks.

Do you now understand how the Boeing quote that you are so fond of does not apply to the non-rotating skyhooks in this article?

PS The reference numbers are for the article as I have written it. Since you keep deleting references with your changes, the reference numbers keep changing, hence you will need to use the article as I have written it if you want the reference numbers quoted here to mean anything.

So please, read this until you understand it and do your research to confirm what I and many others are saying. If you run into any problems that you cannot resolve easily, write me here and I will do what I can to assist you. — Preceding unsigned comment added by 72.199.145.35 (talk) 04:17, 20 April 2014 (UTC)

"I have no problem with the Boeing report, but its conclusion is for tether lengths that are much longer than the ones that are being discussed in this article." ~ 72.199.145.35
False and dishonest answer. The Boeing report states BY NAME that the "skyhook is not competitive" and that it is "non-engineerable" because there are "no materials available" for it. For the nth time: as of March 2014, (inline citations included) carbon nanofiber composite breaks down at lengths of only micrometers length. So, what is the mystery material that shall not be named that does the job and is available? Another assay won't do; please see WP:Identifying reliable sources. BatteryIncluded (talk) 13:46, 20 April 2014 (UTC)
Not false and dishonest, it is your ignorance of basic engineering that is the problem. As to the so-called mystery material, for the nth time it is T1000GB carbon fibers (see the TORAY Industries website!). Carbon fibers are not carbon nanotubes, they are two different items, just like skyhooks are different from space elevators, and non-rotating skyhooks are different from rotating skyhooks.
So you haven't done your homework, you refuse to read or listen to the answers to your questions and then you delete the references that have them. You are quite a piece of work. What happened to freedom of speech and free open honest discussion where people can be swayed by reasoned thought? ~ 72.199.145.35
There is no "freedom of speech" at Wikipedia. The site works to specific rules that you seem incapable of understanding or following. You were asked, several times, to read the manual on how references that are referred to multiple times should be formatted. You failed to do so. On this talk page there is an instruction to sign your posts. The page history shows you are incapable of following even this simple instruction. - 79.67.254.178 (talk) 20:19, 20 April 2014 (UTC)
There is not much point in spending time fixing references when someone keeps deleting them or twists the text of the article around to make a lie out of it. As to the reference format I have used, I copied it from other wiki articles. If there is a better way to do it great, but I am not going to worry about it until the larger issues are resolved. If you are attempting to imply that this lockout is due to my referencing format then you are one very clueless individual or you think I am.

As to freedom of speech - is wikipedia open to input from everyone or not? I have attempted to write an article on an accepted acknowledged space transportation concept. I have supplied the references to support everything I have included. It is not like wikipedia doesn't have many other articles on other space transportation concepts. As best I can tell the only one that was previously not included was the non-rotating skyhook, a lack that I have attempted to correct. Yet in the process of attempting to do this I have encountered non-stop resistance, distortions of the truth, and outright lies. Why? As to not signing my posts, why should I? All I got are rude childish comments. As a result I no longer read the messages that people send. If someone has something to say to me, say it here, where it is out in the open for everyone to see.

I am curious what all the other wiki editors who have been following this think. Of course it will be difficult for them to research the sources you have removed and now locked out. How about that. ~ 72.199.145.35
References have not been locked out. They are available for review in the older archived copies of the page. However, they are now spread out over ~300 edits. - 79.67.254.178 (talk) 20:19, 20 April 2014 (UTC)
Yes that is true, but how many will bother to go to the trouble of finding them?
Suggestion: if you were really as honest as you like to think you are, you would put both articles on the page for everyone to read and vote on. Yours as it now is, and mine as I last left it. ~ 72.199.145.35
There is no need to have two articles on a page. Indeed, that is a ridiculous notion. Editors can refer to the versions made by different editors by referring to the article history. Additionally, Wikipedia does not have a voting system. It works on consensus. - 79.67.254.178 (talk) 20:19, 20 April 2014 (UTC)
When there is a disagreement such as this one maybe there is. And if that is really the truth, why not lock the article as I wrote it instead of what is there now? And how is a consensus different from a vote? You are splitting hairs.
Another thought, if wikipedia really is consensus based, then unlock the article, stop with your heavy handed editing and distortions to the truth, and let the article evolve on its own without your ignorance based opinions. — Preceding unsigned comment added by 72.199.145.35 (talk) 22:00, 20 April 2014 (UTC)
It says in the instruction to new editors to assume good faith. That has not been my experience of you, and from my point of view, you have now demonstrated that beyond any doubt. ~ 72.199.145.35
Good faith is assumed until there is systematic repeated breaking of the rules. Rather than proceeding with 25 sets of reverts spread over ~300 edits, it would have been far better to stop many weeks ago and make a list of points you wanted to add and then discuss them. The discussion that I have seen, rejects many of those points. - 79.67.254.178 (talk) 20:19, 20 April 2014 (UTC)
I have requested and offered discussion many times and received silence or insulting rude comments, but little to no discussion. On the few occasions when there has been discussion it has always degenerated to stubborn intransigence and an unwillingness to acknowledge or checkout the sources.
There are other issues here. Everywhere I look in wikipedia I see poorly written, out of date articles, or articles with messages requesting that someone update them. I am curious how many others have had similar experiences to what I have had here and who have lost interest and moved on? Does anyone keep track of wikipedia's hit count and how it has changed over the years? Or the number of active wiki editors? I wouldn't be surprised one little bit to find out it both have leveled out and gone into decline. If so, has it occurred to you that that might be a signal of some sort?
This issue also points out another major flaw in wikipedia; the fact that a single admitted non-expert in a field of study can override multiple experts from NASA, Lockheed Martin, JPL, etc., on a topic as you have done here. ~ 72.199.145.35
You have some serious issues here. I will be interested in seeing how you resolve them, assuming that you can. Or will this article remain as it now is, another stone in the constipated belly of wikipedia, for years to come? ~ 72.199.145.35
I just had an idea. I am going to put the article as I last left it right here so that the other wiki editors who have been following this can read and compare without editorials from either of us. ~ 72.199.145.35
It will be interesting to see if you have the courage to leave it alone and allow others to form their own opinion and do their own research. ~ 72.199.145.35

• "As to the references not all being open source on the internet there is not much I can do about that." 72.199.145.35 (talk)

So for your assays, original research, POV and synthesis, WP:Verifiability is not an option. OK, we are done here. Thank you. BatteryIncluded (talk) 19:51, 20 April 2014 (UTC)

There are many references on wikipedia that are to documents that are not open source and they are accepted (references 13 thru 16, and 21 as shown below), why not these? And even though they are not open source, the first page of references 5 and 9 thru 12, are available at the supplied links so that you can get an idea of what they say and what they are about and they are available for purchase. By the way, wikipedia could make all those references open to the world if it would pay for the service from AIAA and SAE. _______________________________________________________________________________________________

## BI, you said you wanted to talk

At the bottom of the lead section you have written:

"Its promoter speculated in 1994 that the skyhook concept could be cost competitive with what is realistically thought to be achievable using a space elevator,[1] but the skyhook is not competitive with other rotating tether concepts.[2] In addition, the rotating skyhook is in fact deemed "not engineeringly feasible using presently available materials".[2][3][4][5][6]"

Regarding: In addition, the rotating skyhook is in fact deemed "not engineeringly feasible using presently available materials"

That statement appears to come from Ref [3] on page 10. The full quote is

"If the mass of the tether alone started to exceed 200 times the mass of the payload, then that was an indication the particular scenario being considered was not engineeringly feasible using presently available materials, although the application might become feasible in the near future as better materials become available with higher tensile strengths at higher operational temperatures."

It then goes on to say

"As we shall see, presently available commercial materials will suffice to make the HASTOL tethers needed. The primary message we want to leave with the Reader is: “We don't need magic materials like ‘Buckminster-Fuller-carbon-nanotubes’ to make the space tether facility for a HASTOL system. Existing materials will do.”"

So it would appear that you misread your reference. The tether mass of 200 times mass of the payload mass is the upper limit to the problem. Systems where the tether mass is less than 200 times the payload mass can be built with "presently available commercial materials."

To further reinforce this the Conclusion to the report states

"The fundamental conclusion of the Phase I HASTOL study effort is that the concept is technically feasible. We have evaluated a number of alternate system configurations that will allow hypersonic air-breathing vehicle technologies to be combined with orbiting, spinning space tether technologies to provide a method of moving payloads from the surface of the Earth into Earth orbit. For more than one HASTOL architecture concept, we have developed a design solution using existing, or near-term technologies. We expect that a number of the other HASTOL architecture concepts will prove similarly technically feasible when subjected to detailed design studies. The systems are completely reusable and have the potential of drastically reducing the cost of Earth-to-orbit space access."

Regarding: "but the skyhook is not competitive with other rotating tether concepts." and

"A 2000 Boeing report on the possibillity of combining skyhooks with hypersonic planes concluded that "In general, the non-spinning tether HyperSkyhook concept does not look competitive with the spinning tether concepts.".[2]"

The full quote is:

"HyperSkyhook

In 1995 Zubrin proposed the “Hypersonic Skyhook” as a solution to the mismatch between the attainable atmospheric speeds of a hypersonic airplane and the orbital speeds of space tethers. Since the orbital speed of the space tether decreases with increasing altitude of the tether system center-of-mass, he proposed the use of very long non-spinning tethers or “skyhooks” reaching down from very high altitudes (thousands of kilometers). His analysis showed that because a hanging tether must be tapered to support its lower end in the gravitational field of the Earth, achieving a HyperSkyhook tether tip rendezvous with a 5.0 km/s (16 kft/s or Mach 16) airplane would require a HyperSkyhook tether mass of 25 times the payload mass. Trying to lower the tether tip speed to 4.0 km/s (13 kft/s or Mach 13) would require a HyperSkyhook tether mass greater than 200 times the payload mass. In general, the non-spinning tether HyperSkyhook concept does not look competitive with the spinning tether concepts. We will, however, revisit this concept in our Phase II studies."

That is the sum total of their analysis of this particular concept. Considering that the two tip speeds they looked at were both for lower tip velocities than all the other references in this wikipedia article, their off the top conclusion is not surprising. Also note that they did plan on revisiting the concept in their phase 2 studies. Also note that no where in this study did they go into an in-depth cost analysis for any of the concepts studied, nor did they investigate the issue of differences in time available for hooking up between the two concepts, so they have not sufficiently examined the concept to form a justifiable conclusion.

Your other comments all have to do with space elevators and I am unsure of the point you are attempting to make with them. Everyone appears to be in agreement that they can not be built with currently available materials.

_____________________________________________________________________________

How do we come to a consensus when you don't say anything here and I have shown that you have misquoted a reference?

So you going to lock me out of the article again? — Preceding unsigned comment added by 72.199.145.35 (talk) 16:53, 19 June 2014 (UTC)

Huntster

I didn't put the POV material in the article. BI put the POV material in the article. I just put the POV sign on it to try to get it resolved. — Preceding unsigned comment added by 72.199.145.35 (talk) 17:02, 19 June 2014 (UTC)

__________________________________________________________________

BI: I am not biased, spamy, incorrect, or defiant. CNTs are not required to build all space tethers - only those that are as long as an Earth surface to geostationary orbit space elevator. There are space tethers in orbit right this very minute that are made with existing materials. Even the Boeing report that you have quoted says they are possible with existing materials. Is there an upper limit to the length that a practical space tether can be built with existing materials? Yes there is. The overall upper length limit for a non-rotating skyhook that is still economically worthwhile is probably around 5,000 km. To the best of my knowledge no one has gone to the trouble of actually determining that upper limit simply because by the time we build one that long there will be better materials that will allow us to build an even longer one.

A good example of this is suspension bridges. About the longest you can build a practical suspension bridge using steel cable is a tad over one mile. They have since made longer ones using carbon fiber cables. But even carbon fiber cables are not strong enough to build a suspension bridge across the Strait of Gibraltar. It is all a matter of degree.

With current materials we can build a non-rotating skyhook up to about 5,000 km in length if we push it. But we don't need to build one that long to make affordable space flight a reality. A 2,200 km long non-rotating skyhook will have a lower endpoint velocity of 80% of orbital velocity for that altitude, and an upper endpoint velocity of 91% of escape velocity for its altitude. Such a skyhook combined with a reusable single stage sub-orbital launch vehicle and the Orion spacecraft would give us affordable access to Earth orbit and all of near Earth space. Space tourism, asteroid mining, satellite solar power stations, and space colonies would all become possible with such a system.

This is the truth. I don't know how to make it any clearer. — Preceding unsigned comment added by 72.199.145.35 (talk) 19:17, 20 June 2014 (UTC)

References

1. ^ Sarmont, E. (October 1994). "How an Earth Orbiting Tether Makes Possible an Affordable Earth-Moon Space Transportation System". SAE 942120.
2. ^ Cite error: The named reference `Boeing.2000` was invoked but never defined (see the help page).
3. ^ Dvorsky, G. (13 February 2013). "Why we'll probably never build a space elevator". io9.com.
4. ^ Feltman, R. (7 March 2013). "Why Don't We Have Space Elevators?". Popular Mechanics.
5. ^ Scharr, Jillian (29 May 2013). "Space Elevators On Hold At Least Until Stronger Materials Are Available, Experts Say". Huffington Post.
6. ^ Templeton, Graham (6 March 2014). "60,000 miles up: Space elevator could be built by 2035, says new study". Extreme Tech. Retrieved 2014-04-19.

## Huntster

NASA says skyhooks are possible. Boeing says skyhooks are possible. Lockheed Martin says skyhooks are possible. JPL says skyhooks are possible. Former astronauts say skyhooks are possible. Rocket scientists and engineers from all over the world say skyhooks are possible.

BI, a biologist, says they are not. Who are you going to listen to? — Preceding unsigned comment added by 72.199.145.35 (talk) 20:28, 21 June 2014 (UTC)

You have been asked, multiple times, to SIGN YOUR POSTS. You seem incapable of following even the most basic of instructions, or are you doing this on purpose? -- 79.67.248.110 (talk) 05:13, 22 June 2014 (UTC)
BI: Always the misdirection and the bad manners. First it is one issue, then another, and never a straight answer to any. You dish it out then get upset and indignant when it doesn't work. Sweetheart, among other things I am a former ship's officer, U.S. Navy, 2 years home from the Gulf. I have seen it all. You are mildly entertaining but other than that you aren't even a blip on the radar. You want manners and respect? Try showing some. I have tried being polite with you and all I get from you is attitude. If that is the way you want to play it that is fine with me, just don't start whining to others about it when you get like in return. So now that you are finally talking how about we stick with the issue: you say skyhooks can't be built with existing materials - NASA, Boeing, Lockheed Martin, JPL, a former astronaut, and a host of others say they can. Why won't you accept that? It is not even your field of study; so why are you so hard over on this one? 72.199.145.35 — Preceding unsigned comment added by 72.199.145.35 (talk) 05:58, 22 June 2014 (UTC)

## WP:3O request declined

A request was made at WP:3O regarding the previous two sections (#BI, you said you wanted to talk and #Huntster). But WP:3O is exclusively for discussions where two editors can't progress -- never more than two. BatteryIncluded, Huntster and two IPs makes four, so WP:3O is not available. You may want to try other methods, such as the Dispute Resolution Noticeboard.

, @Huntster: I'm quite surprised to see two such experienced editors, and one of you an admin, arguing by edit summary, where you tell the IP to come to the talk page, and when he comes to the talk page, you ignore him here. I don't know and don't care about the technical details, but this is good faith editing, not vandalism, and I think you are both being unfair to do that. You also appear indistinguishable from a tag team.--Stfg (talk) 18:05, 22 June 2014 (UTC)

I have already entertained this fanatical single-purpose user for months. He is all yours. Cheers, BatteryIncluded (talk) 18:16, 22 June 2014 (UTC)
Declined. WP:NPOVN is thataway. Cheers, --Stfg (talk) 18:25, 22 June 2014 (UTC)
Same. Someone else can deal with this SPA BS. This is not good faith editing by the IP, and should not be treated as such; it is pushing an agenda. Just not worth the effort. Huntster (t @ c) 19:43, 22 June 2014 (UTC)

Stfg. Thank you for your time and your comments. I will go to the Dispute Resolution Noticeboard. 72.199.145.35 — Preceding unsigned comment added by 72.199.145.35 (talk) 19:15, 22 June 2014 (UTC)

That course is certainly open to you, but I sense that it won't be very productive. Having read a lot more of this talk page, and of the article history, I'm still able to assume good faith on your part, but I can't say much for your ability to make your case. Wikipedia works by developing consensus, and you have probably actually pushed consensus away from you by the repeated, frankly tendentious insertions of your material into the article while you neglect basic Wikipedia competences like signing your posts, getting the right number of newlines between paragraphs so as not to create malformatted text, and treating your co-editors with enough respect not to suggest that your four degrees trump someone else's biological expertise (for just one example). Whether you can now overcome the negative vibes of all this, I don't know (and I don't even care about the technical issues), but I do think that a visit to WP:DRN just now will prove to be just digging a deeper hole. In the most friendly way I can, I recommend you to get a named account, develop Wikipedia competence and a record of good editing, and only then return to this issue. Hope this helps. --Stfg (talk) 22:51, 22 June 2014 (UTC)
Stfg. Again thank you for your time and your thoughtful comments. Yes the problem has a long history. I went through the articles of creation process for an article called Orbiting skyhooks. It was a lot of work to do that. It was then suggested that it be merged with this one and shows up here as item 9 on this Talk page. At that point, and from my point of view, the article was cut to pieces, twisted, warped, and made into a complete lie, full of gross technical inaccuracies, and untruths. I attempted to discuss it with the group of editors who were doing it (of which BI was the apparent leader) but was ignored and/or patronized just as occurred in items 20 and 21 of this Talk page and in the edit summaries on the view history page. Some of those comments still exist on the Orbiting skyhooks Talk page. There were even a number of rude messages left on my user page (I was Skyhook1). Again, from my point of view, the article was eventually so completely distorted that it became a complete lie in regards to the technology, the physics, and the very reason for the article to be written in the first place. At that point I gave up and declared the article original work and reverted the article back to the way it was before I started. About a month after that I glanced at the Skyhook (structure) and saw that some of my work had been incorrectly reincorporated into the article. That lead me to attempt another go at it with the same result. Except that time, since I didn't have anything to lose and since I had lost all respect for the people I was interacting with here due to their lies and BS, I pushed it to the limit in the hopes of finding both the reason for their actions and to see if there was a voice of sanity and reason at wikipedia or if BI and her gang were it. I suspect it is my pushing things to the limit that you are calling tendentious. At the end of that I was locked out of the article. That was about 2 months ago. Somewhere along in all of this I stopped signing in so that I didn't have to put up with the rude comments on my user page and in an attempt to force them to communicate with me on the Talk page where it would be out in the open. Anyway, a lot of water under the bridge for an article on Skyhooks. If I knew then what I know now when I first got the idea of writing the Orbiting skyhooks article I never would have started.

So what brought me back? A week or two ago I was doing a google search on something (I forget what at this point), but in one of the hits for the search there was a picture of skyhook that was from a NASA presentation that I gave back in the 90's (not a picture from Skyhook (structure)). That surprised me so I clicked on it and it lead me to the Skyhook (structure) article. Again I saw that BI had incorrectly reincorporated some of my work into the article again, and again I attempted to correct it. As a scientist, as an engineer, as a test pilot, and as a ship's officer, I have learned a certain intolerance for half truths, inaccuracies, and lies. Quite simply they can be very expensive in time, money, equipment, and lives. So that is the story from my perspective. Where now? You appear to be a voice of reason, what do you suggest? 72.199.145.35 — Preceding unsigned comment added by 72.199.145.35 (talk) 03:44, 23 June 2014 (UTC)

I see. Well, you said, "If I knew then what I know now when I first got the idea of writing the Orbiting skyhooks article I never would have started." That suggests to me that your best course might be simply to drop the stick and back slowly away from the horse carcass. What you've written above shows that you're thinking of the article as yours -- that's a problem described at Wikipedia:Ownership of articles. You can't, for example, write something and then withdraw it and expect it to stay withdrawn. As I said, I'm not going to look at the technicalities of this, so I can't say whether you're right or wrong about the content. But if you enter into a fight with Wikipedia editors, you'll eventually be shown the door anyway. If you still want to progress this, I stand by what I suggested yesterday. It will take time and patience. Best wishes, --Stfg (talk) 07:38, 23 June 2014 (UTC)

Stfg. I remember reading someplace in the instructions for editors that editors are not supposed to change the meaning of an article in their editing. Is that not true? It was the wholesale violation of that rule that led to my regret about starting the project. You can see it very clearly in the difference between the article after it was first approved, after it was merged with this one prior to BI and company jumping in, and what it had become when I declared it original material. My goal in starting the project was a complete and accurate article about skyhooks that would be fun to read, a source for technical papers on the subject via the references, and worthy of feature article status. I would still like to see that happen and I would enjoy working with experienced editors who support those goals. If that is not possible as you appear to be suggesting, then why would anyone want to write an article of substance for wikipedia if no one at wikipedia has any concern for truth and accuracy? 72.199.145.35 — Preceding unsigned comment added by 72.199.145.35 (talk) 18:18, 23 June 2014 (UTC)

No it is completely untrue that "editors are not supposed to change the meaning of an article in their editing". That would be ridiculous, since it implies that once an article is created, its meaning cannot be changed, however absurd it is. I'm not saying that it's impossible to do those things you say you want; I'm saying that you're going the wrong way about it. And if you think that this situation implies that "no one at wikipedia has any concern for truth and accuracy", then I think such a sweeping statement is ridiculous. It's like saying you're in step and the whole rest of the regiment is out of step. You're setting yourself above other editors and marking out a battleground, and you'll get nowhere like that.
And please, sign your posts by typing ~~~~, not by typing out your IP address. You know how to, because you were doing it as Skyhook1. Just typing the IP address is disruptive, because a bot comes along and signs it for you, and its edit summary means that yours no longer appears in people's watch lists. --Stfg (talk) 20:31, 23 June 2014 (UTC)

Stfg. I have no interest in arguing so I will give an exact example.

Is it ok for an editor to change this: "If the mass of the tether alone started to exceed 200 times the mass of the payload, then that was an indication the particular scenario being considered was not engineeringly feasible using presently available materials, although the application might become feasible in the near future as better materials become available with higher tensile strengths at higher operational temperatures."

and this

"As we shall see, presently available commercial materials will suffice to make the HASTOL tethers needed. The primary message we want to leave with the Reader is: “We don't need magic materials like ‘Buckminster-Fuller-carbon-nanotubes’ to make the space tether facility for a HASTOL system. Existing materials will do.”

into this: "In addition, the rotating skyhook is in fact deemed "not engineeringly feasible using presently available materials".

?

It is changes such as this that I am referring to. Skyhook1 (talk) 22:52, 23 June 2014 (UTC)

@Skyhook1: thanks for using your account and for signing. There's no Wikipedia rule to say that such a change is inherently OK or not OK. It depends entirely on what reliable sources say. As I haven't looked at the technical issues, and wouldn't be able to evaluate them if I did, I can't comment on the issue of feasibility using current materials. All I can offer you is what I have already offered you, and there's nothing more for me to say. Goodbye, and kind regards, --Stfg (talk) 07:18, 24 June 2014 (UTC)
Stfg. Thank you very much for your time and your comments. Skyhook1 (talk) 18:48, 24 June 2014 (UTC)
Skyhook1, thank you for saying so. Good luck. --Stfg (talk) 19:46, 24 June 2014 (UTC)

## Fake reviews

The user Skyhook1 has been on a months-long edit war adding fake positive reviews of the Skyhook. I took a vacation from his BS, and am back. Specifically, he uses the Boeing report on space tethers [10] that reviews 6 different tether systems: Skyhook, Rotovator, CardioRotovator, CASTether/LIFTether, Tillotson Two-Tier Tether, and HARGSTOL. The Boeing study concludes that: "Unless a major breakthrough occurs in high strength tether materials, such as the commercial development of carbon nanotube fibers, it does not seem possible to push the non-rotating tether HyperSkyhook concept down to speeds of 3100 m/s (Mach 10)." and "In general, the non-spinning tether HyperSkyhook concept does not look competitive with the spinning tether concepts." He then proceeds to quote the positive reviews of the HARGSTOL/HASTOL systems as if they were written for the Skyhook. That is a very dishonest and disrupting attitude from this single-purpose user. Faking reports makes him a liability to Wikipedia. BatteryIncluded (talk) 22:31, 9 August 2014 (UTC)

It is interesting to see how you distort the truth. You were the one who was distorting the comments in the HASTOL study. It is all documented above on this Talk page. Regarding: "Unless a major breakthrough occurs in high strength tether materials, such as the commercial development of carbon nanotube fibers, it does not seem possible to push the non-rotating tether HyperSkyhook concept down to speeds of 3100 m/s (Mach 10)." I have no disagreement with this statement. None of the skyhook studies referenced in the article are for skyhooks with a lower endpoint velocity this slow. None of them, rotating or non-rotating, come anywhere close to that slow of a lower endpoint velocity. The positive reviews for skyhooks in the HASTOL study that are included in this article are all for skyhooks with faster lower endpoint velocities.

BI, if you seriously believe all the BS you have been writing then you need to take a course in reading comprehension and maybe a few engineering courses and then re-read the referenced reports. But I also seriously doubt that this is the source of our disagreement, after all it was you who added the porn site links onto a number of the references used in this article and that is not editing in good faith or discussing a disagreement like an adult.Skyhook1 (talk) 00:32, 10 August 2014 (UTC)

## Really? Non rotating tidally stabilised tethers?

So how many times per orbit doesn't a tidally stabilised tether rotate?

None.

It rotates at least once per orbit.

There's something very funny about an article where the people writing it haven't understood that all potentially practical 'skyhook' tethers rotate.

Can I ask where rotating tethers are covered? You know, the ones that could perhaps be practically built?GliderMaven (talk) 00:29, 10 August 2014 (UTC)

The Moon rotates around the Earth and always shows the same face to the Earth. Most people see that and say it does not rotate. Yes it rotates exactly once per orbit and it is called being tidally stabilized. The same applies to non-rotating skyhooks. They rotate exactly once per orbit and always keep the same endpoint at the bottom and always maintain a vertical orientation. They are called non-rotating skyhooks in order to distinguish them from rotating skyhooks that rotate more than once per orbit.

Non-rotating skyhooks are covered in section 2 of the article. Rotating skyhooks are covered in section 3. Skyhook1 (talk) 00:47, 10 August 2014 (UTC)

## Building on sourced version

This version looks to be adequately sourced without the blatant OR issues present in this version. Material can be added in if it has proper and relevant references. The article isn't supposed to read like someone's personal justification of the concept. --NeilN talk to me 15:01, 10 August 2014 (UTC)

Yes, that (and the subsequent copyedits by Diannaa and betafive) appear to remove the immediate problematic OR issues. A great improvement, thank you. Agree also with your other comments. 05:32, 11 August 2014 (UTC)
I agree. Thank you. I will start reviewing the removed material in order to bring back any information that is supported by references. Thank you. BatteryIncluded (talk) 17:04, 11 August 2014 (UTC)

## Scope of the article and the term “skyhook”

I've read the 2000 Bogar/Boeing report, and noticed a difference compared to this article which might be a source of some confusion.

Our article covers a variety of both spinning and non-spinning tether launch systems with no a priori restriction on such details as the length of the tether or the altitude, eccentricity, or other parameters of its orbit. Here, we use the term “skyhook” in a generic sense to cover all of those, with references to dates of 1990 or earlier.

The Boeing report addresses multiple specific designs of tether launch systems, both spinning and non-spinning. It seems that the entire scope of the Boeing study fits within the scope of our article, and all of the various designs they analyzed can, in our terms, be called “skyhooks”. But that's not how Bogar et al. use the term.

One of the specific designs addressed by the Boeing study has the proper name “HyperSkyhook”. The HyperSkyhook

• was proposed in 1995
• is strictly non-spinning
• has a specific orbit, much higher than the orbits of other proposed launch tethers
• has a specific length, much longer than the lengths of other proposed launch tethers

So while the HyperSkyhook may be one specific example of our generic term “skyhook”, it doesn't represent all of the variations.

That distinction is important in evaluating the results of the Boeing study. For the general concept, and therefore for the topic of our Wikipedia article, Boeing concluded that

“we have identified a baseline HASTOL architecture that works” (p. 4)

and

“We don't need magic materials like ‘Buckminster-Fuller-carbon-nanotubes’ to make the space tether facility for a HASTOL system. Existing materials will do.” (p. 10)

But for the specific design of the (non-spinning) HyperSkyhook, Boeing concluded that

“the non-spinning tether HyperSkyhook concept does not look competitive with the spinning tether concepts” (p. 20)

Bottom line: Boeing's conclusions are favorable for the general concept of a space tether orbital launch system, our “skyhook”, but unfavorable for the specific design of the HyperSkyhook.

Here's the confusion: One sentence in the Boeing report notes that the HyperSkyhook is an example taken from a larger class of “skyhooks”, all of which are non-spinning, very long, and in very high orbits. That very specific use clashes with our use of “skyhook” as a generic term, and the clash has introduced errors in our article. For example, in our section 1.2 “Types of skyhooks”/“Rotating”, about spinning tether systems, we quote p. 20 of the Boeing paper on the non-spinning HyperSkyhook, and we claim that the Boeing paper's conclusion is that presently-available materials are not adequate for a spinning design, even though that paper vigorously asserts the opposite, that presently-available materials are adequate for a spinning design (and even identifies those materials by name). Oops.

Our use of the term “skyhook” is clearly at odds with Boeing's. In the bigger picture, is Boeing's usage unique, or is it universal? Is there some consistent vocabulary across most reliable sources? If there is, it might be best for us to follow that precedent in our own article, rather than risk it causing further errors in our content. In that case, we might find ourselves updating the name of the article again.

20:51, 12 August 2014 (UTC)

Maybe you can create a referenced section dealing with the name and terminology? That may be critical for the article improvement, as there is historical baggage in the name: [11] Thanks. BatteryIncluded (talk) 17:38, 13 August 2014 (UTC)
A 1983 report online, great, thank you. The closer we can get to the origins the better, and the article doesn't cite online versions of the sources from 1966 and 1975. (The Science paper may have a login-required online version.) 01:03, 14 August 2014 (UTC)

## BatteryIncluded

My team and I are using this as part of our NASA space settlement contest proposal. We have checked with our physics prof., our math teacher, our science teacher, and the profs at SDSU who are helping us. They all say that your version is wrong and the one by Skyhook is right. We have also seen how you and your gang have jacked this and we think you are full of it. Even Unician says you are wrong. Since wikipedia is supposed to work on consensus, we are the new consensus so go away. Athena99 (talk) 17:25, 13 August 2014 (UTC)

@Athena99: Please host your research and study materials elsewhere. --NeilN talk to me 17:32, 13 August 2014 (UTC)
@Athena99:, Please get started at WP:Tutorial and pay close attention to Help:Referencing for beginners, abstain of introducing WP:Original Research. Also, please read WP:Conflict of interest and WP:Wikipedia is not here to tell the world about your noble cause. The article has a lot of room for improvement. Your call. Cheers, BatteryIncluded (talk) 17:41, 13 August 2014 (UTC)
I was going to thank the young Ms. Athena99 for her kind words in granting me some vague aura of authority when she wrote “even Unician says you are wrong”, however incorrect her statement was. But, alas, it was not to be, for she was just yarn with button eyes (and a gang tattoo), and our differences would always have come between us. (Differences like arrogance, manipulation, deception, misrepresentation, sockpuppetry, gang mentality, and gaming the system are a bit much to overlook.) 22:57, 13 August 2014 (UTC)

## Protected for a month

Hopefully now Skyhook1, Athena99, and Flash500 (who are, let's face it, almost certainly the same editor) can discuss how their version passes WP:N, WP:V and WP:RS. Black Kite (talk) 17:48, 13 August 2014 (UTC)

should it not be semi-protected? As now only admins can edit the article. And I do not think we are all admins, that have wanted to further the article? NathanWubs (talk) 18:51, 13 August 2014 (UTC)
Probably, as only new editors were being disruptive. Pinging Black Kite. --NeilN talk to me 19:03, 13 August 2014 (UTC)
All three users have been checkusered and blocked. If Black Kite doesn't see this request to reduce protection I'll make a formal request at WP:RFPP in a few hours. --NeilN talk to me 19:51, 13 August 2014 (UTC)
Yep, done (incidentally, the reason I didn't semi-protect was because Skyhook1 was auto-confirmed). Black Kite (talk) 10:17, 14 August 2014 (UTC)
Thank you. --NeilN talk to me 13:54, 14 August 2014 (UTC)
Maybe a one month full protection is needed for user Skyhook1's adrenaline to subside. BatteryIncluded (talk) 14:39, 15 August 2014 (UTC)
Skyhook1 has been indefinitely blocked. --NeilN talk to me 15:16, 15 August 2014 (UTC)
@NeilN: Yes, and came back today as Sucmybut. --BatteryIncluded (talk) 15:24, 15 August 2014 (UTC)
We should be okay, there's now 48 people watching the page. -- Diannaa (talk) 16:45, 15 August 2014 (UTC)

## Thank you for the hard work!

Just wanted to thank all the people that have been busy the last few days, cleaning up the article and others things. Including the what links here section. I had done some minor cleaning and was going to return today to it for some more. However, it seems that someone or multiply people have beat me to it. So thank you for that. NathanWubs (talk) 18:54, 13 August 2014 (UTC)

## Definition of skyhook

@Johnmoor:, @Skyway: Hello. Having reached stability and page protection, I now feel it is an appropriate time for me to request a favor from you two, who seem quite familiar with space tethers and space elevators. The record in this talk page shows that there has been -and remains- a lack of an appropriate definition —or brief description— of what is a skyhook. I am kindly requesting that -if you have the time- please review and incorporate an updated paragraph of what is currently understood by the term "skyhook" in the context of an orbital tether system. Any other addition or correction to the current version will also be appreciated. Thank you, --BatteryIncluded (talk) 20:05, 15 August 2014 (UTC)

I personally wouldn't be suited to try to define them, but I think that's not our place anyway because it would be OR. I think anyone could search the literature for secondary sources that might try to define it. If reliable non-POV secondary sources can't be found, that could be a problem. It might mean that the synthesis of everything in the article under the idea of "Skyhook" is all OR. But I don't know, I haven't been much of a follower of the article.
Skyway (talk) 01:57, 18 August 2014 (UTC)

I see there was a fairly substantial dispute over the contents of this article that wound down last August. Since then, there’s been very little progress in improving the article.

Unfortunately, there are still many serious problems here, including many statements that are plainly false and contradicted by the referenced sources.

The article's introduction would be more useful to visitors if it made the following points in a clear and easily understood way. Many of these points are already made in the article, and all of them are well supported by the existing sources.

1) The term "skyhook" has been applied to both rotating and non-rotating tethers in orbit around the Earth or other bodies such as the Moon and Mars. It is rarely used to refer to tethers that are anchored to the surface of the body, which are generally known as space elevators. Note that the term "rotating" describes the motion of the skyhook with respect to a fixed reference point on the body; even a so-called non-rotating skyhook still rotates once in each orbit.

2) A skyhook can be used to transfer energy and momentum between the skyhook itself and objects such as satellites and space vehicles that attach temporarily to it. A skyhook can operate as an electrodynamic tether to gather energy gradually and release it into attached objects more rapidly.

3) The specific strength of the tether material imposes a limit on the mass, mass distribution, length, and rotational velocity of a skyhook.

4) Although no available material is known to have sufficient specific strength for a space elevator on Earth, skyhooks can be made and have been deployed in orbit using various synthetic fibers.

And then the sections on non-rotating and rotating skyhooks should make these points clearly:

5) A non-rotating skyhook can maintain a vertical orientation through gravity-gradient stabilization. This type of skyhook orbits at an angular velocity related to the altitude of its center of mass, which means that the lower tip of the skyhook is traveling at a lower linear velocity than a satellite normally would at the same altitude. This means that a launch vehicle needs less energy to reach the skyhook than it would to reach orbit. The vehicle could then gain energy by climbing the tether. The specific strength of the tether material for a non-rotating skyhooks is defined by (equation). (And give an example.)

6) A rotating skyhook can be designed so that one or both tips become momentarily stationary with respect to the ground. A sub-orbital launch vehicle with a vertical trajectory could rendezvous with the skyhook at this point and connect to it. As the skyhook rotates, it will add energy to the vehicle, which can disconnect again at a different point in the rotation to enter orbit around the body, follow a ballistic trajectory to a different point on the body, or escape the body’s gravitational field entirely. Similarly, a vehicle approaching a body could use the skyhook to slow its motion relative to the body, making it easier for the vehicle to land on the body. The specific strength of the tether material for a rotating skyhooks is defined by (equation). (And give an example.)

I’m not going to get an account here, so someone else will have to make the necessary edits. 71.197.166.72 (talk) 22:28, 5 April 2015 (UTC)