Talk:Atmospheric reentry

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1 Article renamed 2 A better future approach? 3 Culled material re spaceship one 4 Revert 5 RE-entry

Article renamed

Re-entry means "entry back into". I do not believe that re-entry means entry. Nor do I think that re-entry is a technical term which means "entry back into an atmosphere from space" or "entry into an atmosphere from space" except when the subject is implicitly or explicitly known. I think this article should be re-named Atmospheric entry. Paul Beardsell 02:04, 29 Jul 2004 (UTC)

And entry of a spacecraft into Jupiter's atmosphere is entry not re-entry unless it had previously exited that planet's atmosphere. Paul Beardsell 02:04, 29 Jul 2004 (UTC)

Ropers (or someone) should provide references for the usage he is advocating here. Paul Beardsell 02:04, 29 Jul 2004 (UTC)

Hi Paul, the info about not entering the atmosphere again was contributed before I ever worked on this article. From the history: [1] (http://en.wikipedia.org/w/wiki.phtml?title=Reentry&diff=4168054&oldid=3250262). I don't actually know with certainity if this usage is correct — I only did the earlier revert (of "entry" to "reentry") for in-article consistency, assuming the previously submitted info to be correct. As you're questioning whether it really is correct, you might want to ask Patrick who, as I see from the history, submitted that particular bit. The extended usage seems not totally implausible to me though.

In terms of renaming the article, while I wouldn't be all that fussed about it, I personally don't really think it's required: "Atmospheric entry" may be a more technically accurate description, but I do think "reentry" is much more commonly used (and writing an encyclopedia is all about having the info where people expect it). Also, keep in mind that a lot of entry-related considerations will be as regards the Earth for the time being -- and we're definitely talking reentry here, at least until we start building shuttles on the Moon. That said, I'm really not that fussed about this issue. (And I know there's a pattern forming with me being against renaming articles, but there you go ;-)

Ropers 15:27, 29 Jul 2004 (UTC)

Second thought, change of mind: I would probably abstain or even vote for this rename here if there was a vote — but I still think other users (other than Paul and me) should have some kind of chance for input before a rename. What do people think? Any takers? Ropers 15:35, 29 Jul 2004 (UTC)

My contribution just made explicit what I understood from the existing article. I do not know whether that is really the conventional usage, and agree that it is odd. I would prefer Atmospheric entry.--Patrick 21:03, 29 Jul 2004 (UTC)

No other comments so done. You choose your field, there is a re-entry. The reentry page will probably become a disambiguation page eventually but for the time being it just redirects here. Paul Beardsell 22:13, 20 Aug 2004 (UTC)

A better future approach?

The section A better future approach? is plain old speculation, no? It does not seem encyclopaedic is nature. At the very least it requires an external, authoritative reference. Else it must be deleted. Paul Beardsell 23:23, 14 Aug 2004 (UTC)

Actually, perhaps it merely needs a name change. Since the technique's been tested successfully in a real spacecraft, it isn't really a "future approach" anymore. I've preemptively changed it to "shape-changing wings," although there could very well be a better name. --NeuronExMachina 02:15, 15 Aug 2004 (UTC)

What is the real name for this? We are not supposed to be making things up! We are not creating knowledge - we are documenting it. Paul Beardsell 11:46, 15 Aug 2004 (UTC)

Yup. That's me who wrote it. Thanks for the notification, Paul. I also hold that it's very very new (and may or may not see widespread adoption), but it is proven — (for suborbital atmospheric reentry at least) — unless my interpretation of the real-world application is flawed (which I doubt it is). It's perfectly logical once one thinks about it. Stroke of genius by Rutan, I think. IMHO the section rename is probably a good idea but I think the section itself should stay. Just because print encyclopedias are always a few years behind, doesn't mean we have to be. More cutting edge tech is where it's at! ;-) Ropers 03:06, 15 Aug 2004 (UTC)

PS:Ha, ha. "Cutting edge tech." While linking Supercavitation. Gotta love the in-joke. :)

Yes, I would like it to stay as I am (peripherally) aware of the X-prize attempts. But can you post a reference supporting your explanation of what is going on? Wikipedia is not a place for speculation or even for original research. Paul Beardsell 11:46, 15 Aug 2004 (UTC)

I wouldn't actually know any source that currently discusses the issue, but I do think the explanation I gave is just that: a mere plain English explanation of something that's been observed and tested. I don't really see it as original research, but feel free to prove me wrong. (That would likely make me RICH ;-) Maybe there are some sources out there which also/already discuss this, but, honestly, for the moment I'm not too optimistic. I'm glad that most of the media folks got the the 100km bit right. (Equating weightlessness with space, inaccurately converting 100km to 62.5 miles and then converting that back to 100 dot something km, confusing orbital and suborbital spaceflight, confusing feet and kilometers and, yes, confusing 100 and 10,000km were all in the mix.) So I gotta admit: I can't think of any web sources right now — but I am rather confident that any aerodynamics engineer (which I am not, btw.) would easily confirm the validity of the description of SpaceShipOne's workings. Ropers 18:47, 15 Aug 2004 (UTC)

"Prove me wrong": No, I don't have to find a reference showing what you have written to be false, that isn't the way things work. This isn't a scientific journal where new theories are put up to be shot down. You have to support what you write. As you have written it a priori it must go, pending the reference. I will copy it here, to the talk page, so the material is not lost. Paul Beardsell 23:28, 15 Aug 2004 (UTC)

It seems to be discussed a little in an older Popular Science article (http://www.popsci.com/popsci/aviation/article/0,12543,458498-3,00.html). Perhaps "feathered entry," or something similar, is the proper term?--NeuronExMachina 21:56, 15 Aug 2004 (UTC)

Whatever, we just cannot make it up so the term you use must be from an authoritative source. Popular Science, IM(H)0, doesn't quite qualify but if you quote your source others can make their own mind up. It's what they call it not what you call it. Paul Beardsell 23:28, 15 Aug 2004 (UTC)

For whatever it's worth, here's a quote from Rutan itself, mentioned in a few different (http://www.upi.com/view.cfm?StoryID=20040731-012745-6679r) articles (http://dsc.discovery.com/news/briefs/20040802/spacerace.html): "I want to tell you that we do have a way of getting down a lot faster," Rutan commented to Feeney, who participated in the Santa Monica press event. "We can leave SpaceShipOne in feather (a maneuver used during atmospheric reentry that increases drag on the vehicle) all the way down." (note: I'm not sure if Rutan actually said what is in parentheses)

Here's another quote, from an article (http://www.aiaa.org/aerospace/Article.cfm?issuetocid=446&ArchiveIssueID=46) in Aerospace America: SpaceShipOne, the rocket element of Tier One, is designed to reenter like a stable shuttlecock, then glide and land like an airplane. The wings, with an ultralow aspect ratio of 1.7, span 16.4 ft. Their size is based on the requirement to provide enough lift to rotate the vehicle into its ascent attitude after horizontal launch, and to permit conventional gliding approaches and landings. At the top of the climb, the rear part of the wing and the tailbooms—still known collectively as the “feather”—hinge upwards. As the spacecraft starts to reenter the atmosphere, the feather stabilizes it in a flat attitude with the slab-like wings at right angles to the airflow. This creates so much drag in relation to the vehicle’s weight (without fuel) that peak heating is moderate.

As an aside, the Aerospace America article is an interesting find, which I hadn't come across before. There's probably a good bit of information in it which should be integrated into the Tier One wikipedia article. --NeuronExMachina 02:07, 16 Aug 2004 (UTC)

Please don't see this as an insult or attack of any sort, but I would prefer a bit more restraint when deleting material. Being bold is great, but not when there's a difference of perspective (ie. when users have differing views). I see things in a certain way. You see things in a certain way. NeuronExMachina sees things in a certain way. Now, I appreciate that you very clearly think that you're absolutely right (and I think I can even kind of see why that is and where you're coming from). But for you to singlehandedly go ahead and enforce your view — especially when it involves deleting text — well, I think at the very least that's not very democratic. It seems to me that NeuronExMachina is much closer to agreeing with me than with you, so what you have just done is proposed a change, gotten voted down (so far) and then gone ahead and done that change anyway. I think that's not right. At the very least, in a situation like this, I would expect people to try and get a vote — and then all sides should accept what the majority of Wikipedians think.

Now, don't get me wrong. I'm not awfully mad at you, and that's because you did first use the talk page and wait for a reply. It's recently happened to me that another person didn't even do that (and that hurt me and made me livid, but I digress.) I guess what I'm trying to say is: Kudos to you for making a positive effort. Nevertheless, I would still ask you to consider the fact that you're currently only representing 33% of the vote.

(I've not reverted anything for now. Let's first see what can be sorted out.)

NB: You're calling for an authoritative source. Let me put things this way: If I were to write an artice explaining how a steam engine works, would you also expect me to back up such an explanation with links on the web (to "authoritative sources")? I think as Wikipedians we should not be too modest with our own capability for reason and delivering clear explanations for the observable, reproducable and obvious. I thought a major point in this entire project was that we Wikipedians are an authoritative source.

Ropers 02:17, 16 Aug 2004 (UTC)

It is well established and well documented what makes valid material at Wikipedia. You cannot vote to include stuff which is inaccurate! Wikipedia is an authoritative source BECAUSE we are not allowed to make things up - and when we do we destroy the value of Wikipedia. If you write stuff about the steam engine then if it is not correct I will do something about it. I have been doing just that to Stirling Engine recently - an article written by someone who thought he knew all about it but missed the fundamental defining quality of the device! I note that none of your sources say it is lift not drag, which is in the text I have culled. Also, it appears the mechanism is the "feather hinge" and not the various terms being made up for it here. So, now we know. It is not lift; and the moving wings are not what they were called here. Paul Beardsell 07:13, 16 Aug 2004 (UTC)

Culled material re spaceship one

On the other hand, it is assumed that SpaceShipOne's flipping wings (http://www.scaled.com/projects/tierone/photos/images/video/14p_1b.jpg) also start producing lift early, in very thin and high layers of the atmosphere. This would enable the craft to stay in the higher, less friction intensive (and thus less heat-inducing) layers of the atmosphere for longer (ie. until it has slowed down much more than ordinary craft would at that height). Normally, fully inside the atmosphere, a configuration such as SpaceShipOne's flipped wings, where the aft part of the wings (the elevator part) is folded sharply upwards, would result in a stall. However, in a very thin atmosphere (as present near the edge of space), even such a configuration will likely not stall the craft, because of the very low atmospheric density. Instead, it will likely keep the spacecraft oriented at a very high attitude and thus result in producing the maximum lift possible under these exotic aerodynamical conditions. This in turn could help keeping the craft at a higher altitude for longer — and that would allow for maximum deceleration in higher atmospheric layers. This latter aspect itself isn't strictly aerobraking as it is about producing lift (to enable higher altitude aerobraking) — which is why these issues are not discussed in the aerobraking article.

It is assumed that this alternative approach to efficient aerobraking and reentry can be applied to orbital space craft design and may result in a markedly reduced need for strong heat shields in the future. How widely similar solutions will get adopted remains to be seen.

I have cut the above from the article. It may be correct but we cannot have "it is assumed" when that means "it is assumed by a Wikipedian". The article on the craft itself is probably the correct place for the info and such material should be placed there with a reference to it here. Paul Beardsell 23:34, 15 Aug 2004 (UTC)

Revert

I have reinstated the above material.

I understood NeuronExMachina's position to be for keeping the text in the article — see above. (NeuronExMachina: please correct me if I'm wrong and/or your views have changed. If so, I will rest my case.) I was myself also in favour of keeping the material. Paul was the only person who wanted the material removed — and he went ahead and removed it.

I have a problem with this:

If there is a discussion about whether or not to delete text from an article and more people speak up in favour of keeping the contested material, then a single person simply cannot overrule the majority and delete the text anyway. That's undemocratic.
(I also personally perceived the tone of Paul's comments as rather harsh and impolite, if not bordering on the vindictive.)

I have no desire to see this escalating any further, but I would like to say this to Paul:

Maybe you are right and maybe I am wrong. But you absolutely cannot overrule a majority no matter how much you think you are right. Most people are rather convinced of their own convictions. (Obviously.) No matter how strong your views are, it still doesn't make your voice count as two or three. One man, one vote. That's the way things work.

I understood that you said there wasn't any need for a vote because it's a matter of Wikipedia rules. However, it should be obvious that I would not have included the material if I thought it was against the Wikipedia rules. (Very few contributers would do that and they're known as trolls.) So your reference to Wikipedia rules runs down to again different views about what those rules really say. It's again a matter of opinion. And again we're on an even field: Your voice is only as powerful as mine or any other person's. Think about it this way: If you really are so right and correct in what you say, then you should have no problems convincing others to support you.

If NeuronExMachina were to announce support for Paul's position (with no other people siding with me), then I will readily yield and be happy to have the material removed from the article again.

Failing that, if Paul were to otherwise demonstrate a majority for the deletion of the said text, I will also be more than happy to accept that.

I will not however accept anything less than living up to these democratic standards. Get a majority, then delete. Why the haste? Without being vengeful or impolite, I would like to say that continued deletions of the text before achieving Wikipedia community consent will promt me to send this issue down the slippery slope of RfC, mediation and (failing everything) arbitration. That doesn't have to happen. Paul, I found your handling of the atmospheric reentry renaming issue exemplary: First a discussion which established the majority view, then you waited a quite substantial amount of time for further input, then you renamed. That was well done. I would hope this issue can be resolved equally gracefully. Ropers 19:03, 21 Aug 2004 (UTC)

To further complicate matters, I think my own view is somewhat in-between. The various quotes and such absolutely support that the feathered approach increases drag at high altitudes, thus decreasing peak heat. More controversial is the claim that it also increases high-altitude lift a significant amount, and that this lift plays an important role during reentry. I haven't found any sources to support it, and I don't know enough (i.e. nothing at all) about aeronautics, so I have no idea if it's safe to state this in the article. Perhaps it would be wise to get more opinions on this, preferably from those familiar with the field? --NeuronExMachina 00:02, 22 Aug 2004 (UTC)

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My position agrees entirely with that of NeuronExMachina and I am sorry if that destroys any wish of his to remain in the middle in this discussion. Wikipedia is not the place for made up material. Should Ropers find the references to support his text and it can stay. Otherwise it cannot. Ropers has the the onus entirely the wrong way around. Why the haste to delete? he asks. Why the haste to insert unsubstatiated speculation is what I ask. The text has been challenged, so now references to support it must be found. Ropers is free to ask for review etc, we all know what the outcome will be: This is an encyclopedia. And I am not being anti-democratic, there has been no vote, whatever Ropers says. All Ropers needs to do is supply the reference. I am not trying to personalise this issue, it is unfortunate that Ropers has taken offence but he has done so without just cause. I regret he has done so but that does not mean that unsubstantiated speculation can be allowed to stay. Ropers says he would not have introduced his speculation if he thought it was against the rules. I am sure that that is the case but now he understands that speculation (especially that of the Wikipedian contributing the material) is not worthy of inclusion in our encyclopedia. So I call on him to desist from doing just that. Paul Beardsell 01:50, 22 Aug 2004 (UTC)

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I have copied the following from my Talk page for completeness and am submitting this to RfC. I would have been ready to yield and close off this issue after NeuronExMachina's last comment, but seeing Paul's latest two messages, my frustration, hurt and general Wikistress is just too high. I would like to invite the community to comment. Ropers 04:43, 22 Aug 2004 (UTC) Copied text follows:

Another reentry

Is that your text I want to delete? See the talk page. Paul Beardsell 23:26, 14 Aug 2004 (UTC)

It is indeed. I have replied here. Ropers 03:10, 15 Aug 2004 (UTC)

"Vindictive" is just inappropriate. Vindictive is what you call an unwarranted action in revenge for something. I had certainly not taken personal offence at your text. I notified you above I was going to delete it. Eight(!) days later you have still not bothered to provide a reference to support it but you have found time to criticise the text's deletion. NeuronExMachina says he cannot find a reference to support your speculation re "lift". Neither can I: That together with your claims re the craft's aerodynamic "stall" I also cannot find anywhere. Put up or shut up. You are wrong to personalise this. There is no need for ad hominem attack: Just support your text with an authoritative reference. Paul Beardsell 02:49, 22 Aug 2004 (UTC)

You quoted that single word out of context. I wrote (in parentheses):

       (I also personally perceived the tone of Paul's comments as 
       rather harsh and impolite, if not bordering on the vindictive.)

Princeton's WordNet 2.0 returns two definitions for "vindictive". Their second definition is:

    2: showing malicious ill will and a desire to hurt; motivated
       by spite; "a despiteful fiend"; "a truly spiteful child";
       "a vindictive man will look for occasions for resentment"
       [syn: despiteful, spiteful]

I believe that I have a right to communicate my feelings in the way I have done. I do not believe that my sentence was an ad hominem attack. I also believe that telling me to "put up or shut up" in response to my concerns shows that my concerns may have been perfectly warranted.

Ropers 03:55, 22 Aug 2004 (UTC)

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Well, it seems that Roper's use of "vindictive" is even more critical of me than I thought. Why he thinks me "vindictive" is pointless to ask, I suppose: If he cannot or will not give a reference for the material he is making up then I'm sure he can't support this either. By the definitions quoted it seems that the vindictiveness is the other way around from what Ropers supposes: He will not support his speculation with a reference; I point this out; he vindictively attacks me. Paul Beardsell 20:42, 22 Aug 2004 (UTC)

If only the same energy were expended by Ropers looking for a reference for the questionable material re "lift" and "stall". Paul Beardsell 20:46, 22 Aug 2004 (UTC)

Dude, you guys should both just chill out and relax. We all just want to make this article better -- let's not let this get personal. I propose we leave the paragraphs on the talk page for now, until we can either get a reference to support the lift claim, or someone else knowledgeable about aeronautics who supports that the claim is "common sense." The second paragraph (which doesn't make specific reference to the lift claim) might be integrated into the article in the meantime, perhaps with some rewording to show that it's speculation. It's possible something similar could even be done for the first paragraph.

This brings up a related question -- is speculation, if clearly marked as such, permissible in a Wikipedia article? I can't seem to find any clear answer from the community portal pages. --NeuronExMachina 21:33, 22 Aug 2004 (UTC)

Speculation: My understanding is that speculation in Wikipedia is allowed when the speculator has standing and not otherwise. An example of allowable speculation is: "Einstein speculated about quantum mechanics that ..." An example of speculation which is not allowed is when a Wikipedian documents his own unsubstantiated musings. This is the case even when the text is annotated as speculation but certainly when it is presented as fact when it is not! Paul Beardsell 23:08, 22 Aug 2004 (UTC)

If references can be found for the speculation, then yeah, lets have it in the article... if not, then not. The section looks pretty good to me at the moment. Iain 12:33, 1 Sep 2004 (UTC)

RE-entry

The introductory paragraph reads (in part):

By extension the term is used to refer to the transition from the vacuum of space to the atmosphere of any planet or other celestial body, even if not entering again

I dispute this. I cannot find any reference to the word "reentry" yet being used for our spacecraft entering the atmospheres of any other planet or moon. As a re-entry of any other-wordly atmosphere has not yet been achieved or even attempted I am not surprised. Entry? Yes. Re-entry? No. Paul Beardsell 19:24, 10 Sep 2004 (UTC)