Talk:Hubble Space Telescope/Archive 2

Archive 1

Archive 2

Orbital inclination?

How about adding the orbital inclination? 82.163.24.100 (talk) 22:23, 21 March 2009 (UTC)

Good idea. It's 28.5 degrees but I can't see how to edit the template:infobox Space telescope to show it. Rod57 (talk) 10:37, 16 April 2010 (UTC)

Deorbited?

The "General Info" section about the Hubble states "Deorbited ~2013-2021." Since it has not yet actually deorbited, this seems to me to be speculative original research, compounded by the use of past tense for a future event that has not yet happened.

I would like to change the wording from "Deorbited" to "Planned Deorbit." Since this is a featured article, I'm posting here first for any input before doing so. Flodded (talk) 07:10, 3 September 2009 (UTC)

I couldn't see how to change the template:Infobox Space telescope to change the wording so I added 'due' before the dates. Rod57 (talk) 10:40, 16 April 2010 (UTC)

OK, exactly where is it?

The article needs to say where the Hubble is. Which longitude does it regularly follow on it's way around the earth. Are there some towns/villages which it regularly passes overhead? Is it always the same height above the earth. Are there some places on earth where it isn't visible.222.152.164.175 (talk) —Preceding undated comment added 02:45, 27 November 2009 (UTC).

It's orbital inclination is about 28.5 degrees. The orbital plane is fixed and the earth spins inside it so there is no fixed longitude. It's in a 'near circular' orbit so the height doesn't vary 'much'. Given its low orbit of only a few hundred km it's probably not visible much further than 30 degrees away from equator. Rod57 (talk) 10:48, 16 April 2010 (UTC)

Serviceability in the introductory section

Currently the talk about Hubble's serviceability eats up almost half of the introductory section. Since the latter is already rather obese and there is a separate section for servicing and service missions as well, I propose that this should be moved from the introduction to be a part of the article body, and shortened to a single sentence reference in the introduction. Of course any relevant material that is not otherwise covered should be moved to the body of the article and trimmed down to avoid undue repetition. Also, if need be, the shortened mention could always be linked to the relevant section further down.

I mean, of course that's something that sets HST apart from earlier work, and enables it to deliver much better over time. But if you had to describe HST anew using a fixed number of words and facing an impatient netizen, *surely* you wouldn't dedicate half of them to try and convince the reader that the damn thing admits spare parts. ;) Decoy (talk) 20:58, 3 February 2010 (UTC)

I see about 1.5 paragraphs in the Lead covering servicing missions. Moving all that text is not appropriate as the Lead should summarize the main text in the article. Shortening the Lead text may be in order, mainly the third paragraph. -Fnlayson (talk) 21:57, 3 February 2010 (UTC)

Shortened. If it should've been moved instead (sorry...), somebody go back in the history & move as needed? TREKphiler ^{any time you're ready, Uhura} 22:09, 3 February 2010 (UTC)

Sounds fine, thanks. For anybody interested, here's the version before the trimming. -Fnlayson (talk) 22:24, 3 February 2010 (UTC)

There were some dangling sentence parts left after the shortening, so I made another pass. Improve as needed, LouScheffer (talk) 22:37, 3 February 2010 (UTC)

A third of the lead to servicing seems about right to me. It factors into all facets of Hubble history (connection to the Shuttle, imaging flaw, mission duration, public debate over safety, uniqueness among space telescopes, public relations, etc.) LouScheffer (talk) 22:45, 3 February 2010 (UTC)

I was trying to save too much of the original. Oops. I took out some of your resto, Lou, trying to say "serviceable" without going into too much detail, which you seemed to (a bit). TREKphiler ^{any time you're ready, Uhura} 22:52, 3 February 2010 (UTC)

The lead should stand alone as a few paragraph description of the subject. So it needs to be self explanatory. The "spirited public debate" was well covered and definitely notable, and should surely be there. But once it is, the lead needs to say why. I'm all for terseness, but removing the 13 words "The fifth was cancelled on safety grounds after the space shuttle Columbia disaster" makes the situation worse. Now instead of reading this phrase, the reader is left to wonder what the "spirited discussion" was about.

If other editors could weigh in here, it would be very helpful. LouScheffer (talk) 00:47, 4 February 2010 (UTC)

I'm not fiercely opposed, but as changed, it left what appears to be a contradiction: there were 5 flights, but the fifth was cancelled? And since IIRC the debate was over whether there should even be a flight, or rather leave HST to wither, the cancellation due to the wreck isn't entirely on-point. If it's to be self-contained, we're back at the length issue, IMO: how much does the lead need to say to canvass the issues? TREKphiler ^{any time you're ready, Uhura} 04:43, 4 February 2010 (UTC)

At least I fixed the 4 vs 5 problem. I also recall debates about whether to proceed with servicing even before the safety issue was raised, but they certainly did not rise to the level of "spirited public debate", with school children and congress critters arguing with NASA. (A google search of 'Hubble mission cancel' shows 2M hits(!), and on at least the first few pages all are about the safety argument). So I think the way it is is OK.

Could be it wasn't as fierce as I recall before the safety issue arose. I just think adding STS safety is an OT issue to HST, even if it played a part in deciding go/no go on the last mission, 'cause HST servicing by then was opposed by NASA regardless. Looking at it now, I'm opposed, but not enough to change it. ;p TREKphiler ^{any time you're ready, Uhura} 06:27 & 06:30, 4 February 2010 (UTC)

Possible error in intro

The introductory paragraph of this article states that Hubble is not the first space telescope, and yet when I google it or search the terms "first space telescope" here, I keep finding sources that seem to say it was the first, and nothing else pops up about what other space telescope could be first. So is Hubble the first or not, and if not what is the first space telescope? 164.107.237.247 (talk) 20:35, 28 February 2010 (UTC)

It does appear to be the first, yes. -RadicalOne•^{Contact Me}•_{Chase My Tail} 20:43, 28 February 2010 (UTC)

It appears to depend on how you define it. Wasn't there a UV telescope? TREKphiler ^{any time you're ready, Uhura} 21:20, 28 February 2010 (UTC)

Not that I can find... -RadicalOne•^{Contact Me}•_{Chase My Tail} 21:23, 28 February 2010 (UTC)

What about OAO? TREKphiler ^{any time you're ready, Uhura} 21:34, 28 February 2010 (UTC)

I never heard of those until now... -RadicalOne•^{Contact Me}•_{Chase My Tail} 21:56, 28 February 2010 (UTC)

Glad to be of service. ;D I also have a vague recollection of an x-ray observatory before HST flew, FWIW. TREKphiler ^{any time you're ready, Uhura} 22:03, 28 February 2010 (UTC)

Now I am embarrassed...tail between the legs...again. -RadicalOne•^{Contact Me}•_{Chase My Tail} 22:45, 28 February 2010 (UTC)

Don't. ;D I've been an SF & space buff since Grade 6, so I've got an edge. ;p TREKphiler ^{any time you're ready, Uhura} 01:48, 1 March 2010 (UTC)

Ah, I help design and build spacecraft, and have been a science enthusiast since I hatched; I should know about these things. -RadicalOne•^{Contact Me}•_{Chase My Tail} 01:54, 1 March 2010 (UTC)

In that case, I'll trade you an embarassed for an envy & call it even. ;D TREKphiler ^{any time you're ready, Uhura} 02:03, 1 March 2010 (UTC)

^_^ -RadicalOne•^{Contact Me}•_{Chase My Tail} 02:06, 1 March 2010 (UTC)

This whole conversation seems very weird to me. The section "Proposals and precursors" lays out all the information discussed here, with detailed references, and it's the very next section of the article. LouScheffer (talk) 13:25, 1 March 2010 (UTC)

Successor section

Seems to need discussion of successor for each of the visible and various UV bands. Rod57 (talk) 16:44, 16 April 2010 (UTC)

Visibility from earth

Has someone more information on the appearance of Hubble Space Telescope on the sky? Which are the exact northmost boundaries of its visbility? —Preceding unsigned comment added by 91.46.223.173 (talk) 14:38, 19 April 2010 (UTC)

See here.

The Hubble Wars

Hello, I am from the russian wiki-editors team, and now we are translating some facts from this article to russian version. There is a fact in the artice: "While Kodak and Itek had each ground back-up mirrors for Hubble, it would have been impossible to replace the mirror in orbit, and too expensive and time-consuming to bring the telescope temporarily back to Earth for a refit." This paragraph has source "Chaisson, Eric (1994) The Hubble Wars; Astrophysics Meets Astropolitics in the Two-Billion-Dollar Struggle Over the Hubble Space Telescope. Harper Collins Publishers, ISBN 0-06-017114-6, p. 184."

Could anybody confirm that this book contains the fact? Alas, I didn´t find free version of the book in the Internet. Thank you. --Dodonov (talk) 16:45, 23 April 2010 (UTC)

Just because copywrited material is not free doesn't make it wrong or unverifiable. Perhaps you could estimate the cost of a replacement mirror and subsequent service mission? It would not be impossible, but nor would it be cheap.--96.244.248.77 (talk) 03:04, 3 March 2011 (UTC)

Kodak developed a backup version of the lens, at cost to the USG. I understand replacment in orbit would not be cheap, yet the article neglects why the alternate was not considered.--74.107.74.39 (talk) 02:44, 6 April 2011 (UTC)

-- Searching Google Books, I did find a version of this quote on page 195 in:

Encyclopaedic Dictionary of Astrophysics,
Edited By S.K. Basu, 2007, 418 pages
Global Vision Publishing House
Printed in India
ISBN 81-8220-220-5
http://globalvisionpub.com/searchBook.aspx
Email: nsingh_2004@vsnl.net
Website: globalvisionpub.com —Preceding unsigned comment added by Alphachapmtl (talk • contribs)

The page cited has support for the first part of the sentence "Although neither the primary nor the secondary mirror could be replaced in orbit, since each is in the nearly inaccessible part of the spacecraft, ...."

The second part "too expensive to bring back to earth" is common sense, but hard to find a reference. One is "Two other scenarios for fixing the focus were briefly considered and quickly discarded. One was to retrieve Hubble, bring it back to Earth, and replace the mirror with a waiting backup, presumably free from flaws. That would have posed enormous technical risks and enormous costs." From Popular Science, October 1990, "The Trouble with Hubble" by Arthur Fisher, p. 100.

Today on Google

In case you aren't aware already, the Google doodle is Hubble, and clicking it leads to search results where this page is near the top, so expect increased traffic for today. There may therefore be more vandalism than usual, but I see no reason why the page should be protected as it appears to be well watched. --RobertG ♬ talk 04:56, 24 April 2010 (UTC)

Indeed. Editors appear to be quite on the ball watching the page today Eedlee (talk) 10:29, 24 April 2010 (UTC)

Hubble 3-m mirror

It should be mentionned that the Hubble telescope was much bigger in it's original design.

Initial design of the Hubble telescope was for a 3-meter mirror Large Orbiting Telescope or Large Space Telescope (LST), with a launch expected for 1979. Funding issues and Shuttle limited dimensions reduced the proposed mirror diameter from 3 m to 2.4 m. I had (but no longer have) references about this in Sky and Telescope magazine.

newly found web reference: http://www.absoluteastronomy.com/topics/Hubble_Space_Telescope —Preceding unsigned comment added by Alphachapmtl (talk • contribs)

The 3 meter diameter is already in this article. See the last paragraph in the Proposals and precursors section (Hubble Space Telescope#Proposals and precursors). -Fnlayson (talk) 18:02, 27 April 2010 (UTC)

The reduction from 3 to 2.4 meters is covered in the 3rd paragraph of the section "Quest for Funding". Also, the reference you cited is a copy of an old version of this very article. LouScheffer (talk) 00:39, 28 April 2010 (UTC)

Added a cite for that I was reading earlier today in Andersen's (great) telescope book. [1] The Hubble chapter is a VG source. Twang (talk) 02:15, 20 May 2010 (UTC)

Hubble video

I have uploaded a video of the HST. I'll leave it up to the editors if they'd like to make use of it in the article. I can also convert to GIF if needed (contact me on my talk page). Cheers. Mahanga^Talk 22:12, 13 May 2010 (UTC)

Discuss changes made on 13/14 of May 2010

There were a batch of changes, all good faith, which did not seem to fit the structure of the article

• The data transmission stuff at the beginning fits better in the data transmission section, not the overview, so I moved it.
• You can easily support the statement that Spitzer lobbied hard for a space telescope. The idea that the Hubble would not exist without Spitzer seems inherently hard to support.
• 'Data is' versus 'data are' goes both ways. I reverted them as part of these other changes, but just because it was easier, not from any principles.

LouScheffer (talk) 11:36, 14 May 2009 (UTC)

Are we speaking strictly in this article? The word "data" is the plural of the singular"datum". —Preceding unsigned comment added by 96.49.224.214 (talk) 22:42, 29 May 2009 (UTC)

See Data#Usage in English for a long discussion of this point. "Data are" is certainly traditional, but "data is", treating data as a collective noun, is common in informal usage, and making its way into formal publications. Some linguistically conservative organizations, such as the IEEE and the New York Times, now specifically allow "data is". I personally think "The data is" is better since it does not call attention to the grammar, but instead lets the sentence flow more naturally to the point it is trying to make. LouScheffer (talk) 23:14, 29 May 2009 (UTC)

With English usage, if what is 'wrong' is not corrected for long enough, it becomes accepted and 'right'. I don't think we're quite at that stage with using 'data' as a singular yet. 'Data is' still sounds horrible to me.--Cavrdg (talk) 06:51, 30 May 2009 (UTC)

I agree with the previous comment. There are two types of changes to linguistic norm: a) optimizations (elimination of asystematic rules and exceptions) and b) acceptance of common mistakes as a new rule. The former makes the language cleaner, the latter.. well, gives us more work to do under item a. We all know that "data is" stems from simple ignorance (not of the participants of this discussion, of course) and we should not give up on correct spelling. It is not a matter of linguistic conservatism, quite the opposite. Let's direct our reformist energy to making good, necessary ans systematic changes to the language that will make it cleaner. LouScheffer, can you please give your position another consideration now that you find yourself in minority on this topic (three users vs. one)? Thank you! Nyq (talk) 14:40, 7 November 2010 (UTC)

I'm afraid this analysis is far too cut and dried, so I'm voting the opposite way - now, there's democracy at work. The issue of preference is a factor; it isn't merely rule based. But consider: "Minister, a number of people is waiting to see you, and a lot of them is very angry." A NUMBER IS (so that's correct), and A LOT IS (that's correct too), as both reflect strictly logical rule adherence, literally, and as both are preceded by the singular "a". But both, in common usage, serve as 'collective' singularities, and the more common usage of "are" is thus justified in that regard. Data too is a collective singularity [of datum] but the same usage sense applies. "Is" is the 3rd person singular present indicative of "be", but these singularities imply their plurality too. So what is literally correct nonetheless looks risible in the examples I have given; indeed, only the present 'PC' pedantry insists on the spurious rule.

The reverse case to number and lot is data. Some insist that data, likewise, in the literal sense of a plurality that is, in usage, handled as a singularity, has to be treated invariably as a plurality when the hearer conceptualises data as a singular entity. The usage and its understood meaning matters more than the theoretical rule. The cases of sloppy misuse, (e.g. you're/your and loose/lose), are indisputable examples of erroneous misuse, but the singularizing of data is surely not such a case.Trevor H. (UK) 19:09, 4 October 2011 (UTC)

Future of HST

I wonder if anyone has looked into adding an ion/electric drive to HST, and sending it out to L2, where astronauts could service it ten years from now?

The recent ascendancy of Sun/Earth L2 and the HLV in our space planning, seem to make such ideas more real, and HST is a serviceable, upgradeable facility observatory, with (I trust) no predetermined limit on its lifetime. This JWST alas is not, due to its lack of provision for on-orbit servicing. Thus it remains in danger of catastrophic failure on deployment, the inevitable rapid obsolescence of its instrumentation, and the eventual degradation and death of critical components. (There is some movement towards ameliorating the JWST issues lately, but it is difficult and very expensive so late in the project.)

Communications and getting HST through the Van Allen belts would probably be the main problems. The ion drive could move it into a space station orbit (around v=3.1 km/s needed) for further work preparatory to the move to L2. A small Centaur stage with ~5000 kg of LH2/LOX, firing for 1000 sec (0.3 g acceleration, another 3 km/s), could get it through the belts quickly, and probably even to L2. Away from Earth, the thermal control issues would be different, but it would not have to move every orbit to avoid looking at the planet, and more of the sky would be observable, more of the time. I think it would continue to be very useful out there, likely for many decades to come.

This seems to me a far better fate for a noble observatory than consigning it to the Air & Space Museum, or (more probably) just dumping it into the Pacific. (Bring it home for the museum in 2100 or so!) Wwheaton (talk) 20:03, 8 August 2010 (UTC)

Why was Hubble still kept alive for so long? Or any manned space program, for that matter. Chaisson's book had a clear quotation from Sen. Barbara Mikulskl (D-MD) why: "It't not about ... science, its about ... Jobs" E.g. its about socialist policies keeping the U.S. space program going, regardless of the value. --74.107.74.39 (talk) 02:50, 6 April 2011 (UTC)

Nationality of Edwin Hubble

It's a constant battle to keep the lede paragraph short and to the point. There is all sorts of stuff that is perfectly true, interesting to some folks, and could be added. However, the lede should contain *only* the points that are most important.

When a reader comes to the Hubble Space Telescope page, what would they want to know about Edwin Hubble, the guy it was named for? Surely, for this page, it is why was the Hubble named after him. This was because of his achievements as an astronomer (discovering the expansion of the universe), not because he was American. (Lots of USA space missions are named after non-Americans). So 'American' is not even the most important fact about Edwin Hubble, much less in the context of the Hubble Telescope. Furthermore, if you want to know the nationality of Hubble, why not check his article? It's just a click away.

Other opinions are of course welcome, LouScheffer (talk) 17:17, 12 October 2010 (UTC)

One word isn't going to adversely affect the opening paragraph. Naming the telescope after an astronomer from the country where the telescope was developed and operated seems appropriate, especially since it takes only 1 word to make this connection. The source of the name is very appropriate bit of info to include here as long as it's brief, which seems to be the case here.--RadioFan (talk) 02:50, 13 October 2010 (UTC)

The hubble telescope is named after an astronomer named Edwin Hubble. —Preceding unsigned comment added by 99.233.220.194 (talk) 22:28, 26 October 2010 (UTC)

However, the lede should contain *only* the points that are most important.

Totally agree. When you arrive at this page, most will know what "space" is and what a "telescope" is, but fewer will know why this one is called "Hubble." And frankly will be more interested in the answer to that question than information on the number of service missions that have been flown to it (which precedes the solution to the naming question, which doesn't even arise in the contents.)

In frustration, since the most important item was "who was this named after," another Google search solved this for me.

Suggest in fact the issue about what to say about Edwin Hubble be solved at the same time by saying nothing, but giving a link:

The Hubble Space Telescope (HST), named for astronomer Edwin Hubble, is a space telescope that was carried into orbit by a Space Shuttle in 1990.

Hamish.MacEwan (talk) 06:49, 23 September 2011 (UTC)

'Data is' vs. 'Data are'

I will have to disagree that 'data are' is acceptable to the context of the sentence. If you were speaking about 'volumes of data' or some other pluralizing modifier to the word 'data', 'are' would be entirely acceptable. However, in the sentence, "All Hubble data is eventually made available via the archives...", 'data' is mentioned as a singular volume, encompassing all that is, rather than all that are. --Xession (talk) 03:49, 16 January 2011 (UTC)

This has been discussed on this page before several times, including higher on this discussion page. To me the most convincing argument is that you would never say "please send me the datis" even though this would be correct Latin for the dative case. Why don't we say this? Because we are speaking English, not Latin, and hence not bound by Latin endings. This case is made much more rigorously in Data is a singular noun. From a more practical view, rather authoritative sources such as the IEEE and New York Times allow either, so we should use the form that's easiest on the reader. LouScheffer (talk) 04:13, 16 January 2011 (UTC)

The previous debate and the article Data, both fail to address the difference between technical writing usage and general usage. In a technical writing, it is important to impart the difference between the singular datum, and multiple data. However, in general usage, such formalities are not necessary and are not followed by the majority of the population. It is similar to the difference between Legal English and general English. The majority of Wikipedia is certainly not a stage for technical writing, and would be counter the benefit of the general public who reads the encyclopaedia. --Xession (talk) 04:31, 16 January 2011 (UTC)

Even in technical writing, you'll often see sentences such as "The data is consistent with the second hypothesis, with the exception of one outlying data point", where "data point" or "measurement" is used in place of "datum". LouScheffer (talk) 16:12, 16 January 2011 (UTC)

Heh, I know that all too well. I really wish technical papers would be written with a lot more care and precision than they tend to be. Even a lot of older NASA reports, read as if written by uninterested personnel, with few formalities and a bit loose on grammatical rules. The point I was intending to suggest, was that such formalities are usually only intended for technical writing, rather than for articles intended for the general public. I would be a little shocked if even a significant portion of America has heard or would even know how the word "datum" is defined. --Xession (talk) 23:07, 16 January 2011 (UTC)

Needing glasses?

To head off an edit war, let me say: I maintain "optical" isn't limited to "visible spectrum", so even if the main observational areas are outside it, HST still qualifies as "optical", since it's not a radiotelescope (or a dedicated X-ray 'scope). Disagree? TREKphiler ^{any time you're ready, Uhura} 16:00, 2 September 2011 (UTC)

So you say it's optical just because it's not a radio-telescope or an x-ray telescope? Not sure that's good reasoning...

A very common term in the astronomy community for telescopes like Hubble is "UVOIR" (UV-Optical-InfraRed), you'll find plenty of references to this in google. That kind of implies Optical in this sense refers just to the visible part of the spectrum. However you are right that sometimes Optical refers to all these three ranges, IIRC because of the similar detection methods. As a result of this varying in usage I think if Optical is to be used, the sense in which it is being used - to cover UV, visible, and infrared - should be stated clearly. ChiZeroOne (talk) 16:15, 2 September 2011 (UTC)

Then maybe you'd like to look at the infobox where it does say "optical"? Nor am I saying the IR/UV should be deleted. Also, unless my grasp of the etymology is really bad, "optical" means "dealing with light", with no specification on frequency or wavelength... TREKphiler ^{any time you're ready, Uhura} 17:34, 2 September 2011 (UTC)

Perhaps the point you are trying to make is that Hubble is a more or less 'traditional' telescope, a close relative to the ones you see in movies with the astronomer looking through the eyepiece. This captures the difference between Hubble and (for example) a radio or X-ray telescope, and I certainly have some sympathy for this view. However, I think putting 'optical' in the lead is wrong for several reasons. First, as you yourself point out, it's very ambiguous. If you ask 10 different astronomers what wavelengths an 'optical' telescope can see, you'll get (at least) 10 different answers. 'Visible light' is much better defined, but insufficient in this case. The 'near-IR, visible, near-UV' is correct, and already in the very same sentence. Second, it's redundant - the wavelength coverage is specified, more precisely, in the very same sentence. This may seem like a trivial point, but it's crucial to be concise, especially in the lead sentences. (Here's a rough calculation of what an extra word costs, from an earlier discussion. This page is viewed about 70K times per month (see stats). Assuming everyone reads the first paragraph, and they read about 200 words per minute, that's about 2 work-weeks of wasted time per year, or perhaps $1000 US of wasted time per year, per extra word. This calculation is rather inexact, requiring many dubious assumptions, but point remains - we should be concise, especially in the lead...) LouScheffer (talk) 20:03, 2 September 2011 (UTC)

Nobel Prizes in Physics

How many Nobel Prize in Physics has the Hubble's data been used to directly produce? The 2006 and 2011 awards seem like they were to me. Any others? Please consider mentioning them in this article. --Ashawley (talk) 12:50, 4 October 2011 (UTC)

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Root cause of gyro failures identified

Bad claim.

Engineers are confident that they have identified the root causes of the gyro failures, and the new models should be much more reliable.

I was curious, so I checked out the William Harwood citation, which actually states that engineers are confident that they have resolved the root cause of failures of the CU/SDF-A (control unit and science data formatter) and that they are confident the telescope can continue operating with not so many gyros as they would like.

I Googled for "Hubble improved gyros" and all I found was "An improved zero gyro safemode".—MaxEnt 11:35, 24 February 2012 (UTC)

The root cause was corrosion of the fine wires in the gyro, and fixed by purging with nitrogen. This is described in this ESA page on the gyros, which I added to the article. LouScheffer (talk) 00:20, 10 June 2012 (UTC)

Successors, NRO-1

The successors section probably should be updated to reflect this NYT report. SaltyBoatr ^{get wet} 21:03, 4 June 2012 (UTC)

http://www.nytimes.com/2012/06/05/science/space/repurposed-telescope-may-explore-secrets-of-dark-energy.html

Orbit height

In the article: "Orbit height 559 km"

"The Hubble Space Telescope is a joint ESA/NASA project and was launched in 1990 by the Space Shuttle mission STS-31 into a low-Earth orbit 569 km above the ground." http://www.spacetelescope.org/about/general/fact_sheet/ — Preceding unsigned comment added by Dart Raiden (talk • contribs) 01:13, 8 June 2012 (UTC)

There is no single orbital height. It gradually decays, but was boosted by the shuttle repair missions. LouScheffer (talk) 11:54, 8 June 2012 (UTC)

Reference Checking

Endnote 49 is cited in reference to Hubble cost. It directs to the FAQ page for a space agency. At this location, there is no discussion of Hubble cost. This reference was either made in error, or the FAQ page has changed. 199.46.245.231 (talk) 17:53, 4 July 2012 (UTC)

OK, replaced with a more recent NASA document that explicitly refers to life cycle costs (LCC) as of 2010. LouScheffer (talk) 13:48, 4 September 2012 (UTC)

"Ground" vs "figured" ?

The three stages in converting a hunk of glass into a precision astronomical mirror are grinding, polishing, and finally, figuring.

The Allen Commission Report makes it clear that the error in the Hubble main mirror was created during the figuring stage.

The article refers to an error in the grinding six times, and to figuring five times.

I think the references to grinding errors should be changed to figuring errors.

Former ATM and now NitPicker769 (talk) 01:20, 3 October 2012 (UTC)

I agree that if you divide the manufacture into three steps, then the error was in the last step, figuring. However grinding is also the verb used for the whole process, as in the following paragraph from the Space Telescope Science Institute

Newton had given up on trying to grind non-spherical surfaces. He’d tried it in 1666, but the technology of the time wasn’t up to the challenge. A sphere is the easiest shape to grind. Non-spherical shapes are very difficult to grind. In fact, astronomers would have to wait until 1721 for John Hadley to grind the first non-spherical telescope mirror.

or from a book on the Hubble telescope

The HST made a disastrous debut. When first launched in April 1990, it had faulty vision because its primary light-gathering mirror had been inadvertently ground to the wrong shape.

As in these paragraph, especially to non-specialists, grinding refers to the whole process. Figuring, on the other hand, is likely to invoke images of computing with numbers. This has caused confusion before. Readers thought an error in figuring meant that a mathematically wrong prescription was computed, as opposed to the real case where the design was correct and the manufacture was bad. Overall, I'd imagine a large majority of readers are not familiar with the technical meaning of figuring when applied to mirrors.

So overall, I agree the error was in the figuring step. But I think 'ground to the wrong shape' and similar wordings are a better description for the large majority of readers, and so the references to 'ground' should remain. LouScheffer (talk) 13:48, 3 October 2012 (UTC)

I agree with LouScheffer, that was my interpretation too. To the layman the whole procedure is "grinding", and certainly even reliable sources refer to the whole process as grinding when written for a general audience such as the quotes above. That all being said we don't necessarily have to treat the readers like idiots, and considering its importance to the subject perhaps a short statement to explain the process more clearly than presented currently would be useful. ChiZeroOne (talk) 14:06, 3 October 2012 (UTC)

Since this is an encyclopedia (or aspires to be :) ), I'd sooner we call the error a figuring error & link to it. That way we are technically correct, we offer more information for the curious, & we offer an easy explanation for the confused or unfamiliar. (And I count myself among those who've never heard it called a figuring error before.) TREKphiler ^{any time you're ready, Uhura} 15:54, 3 October 2012 (UTC)

I guess I'm too close to the subject (ATM). I would never consider "grinding" as the name for the whole process, but then not everyone has a blacked out basement and a dozen different grades of silicon carbide. I think Trekphiler's suggestion of a link to "figuring" is a good solution. — Preceding unsigned comment added by NitPicker769 (talk • contribs) 17:31, 3 October 2012 (UTC)

The Hubble Failure report does not call it 'figuring', it calls it 'final polishing'. When they use 'figure' as a verb, they refer to the process as a whole, or the specific modification of a sphere to a parabola, which happened during all three stages (since the RvNC accounted for the non-spherical shape). Here are two typical sentences from the report:

The primary mirror was ground and polished to an approximate

shape, about 1 wavelength rms, using the RvNC for the test. This took place at Perkin-Elmer's facility in Wilton, Connecticut. The mirror was then transferred to P-E's Danbury facility, where the RNC was the test instrument for final polishing.

To remove the spherical aberration from this system, we need to figure, or

shape, the spherical mirror into a parabolic (aspheric) surface. To make the marginal rays cross the optical axis at the same focal point as the paraxial rays, the surface is figured into a parabola by removing material from the outer surfaces of the mirror, Figure C-l(b).

By this definition, 'figuring' happened during all of grinding, polishing, and final polishing phases. And this definition of 'figuring' is not technically correct, either, since in the Hubble they were trying to make the mirror a hyperboloid, not a paraboloid.

So if even the solidest of references is not clear on what 'figuring' is, perhaps we should follow the reference and state that the error happened in the 'final polishing phase'. LouScheffer (talk) 18:43, 3 October 2012 (UTC)

OK, tried the re-write, with link. See what you think and modify as you see fit... LouScheffer (talk) 19:01, 3 October 2012 (UTC)

As it now stands, you're very close to what I'd want. Just two issues: the number of null correctors in the first steps could be clearer (one each? two each? two total?), & the wording. (I'd use "final step (figuring") Otherwise, good to go. TREKphiler ^{any time you're ready, Uhura} 19:19, 3 October 2012 (UTC)

Looks fine to me, too.

On another note, could any reader think that the "edge of the mirror" means the part running from the front to the back? Would something like "from the face of the mirror near the edge" be clearer? Or am I just living up to my handle? NitPicker769 (talk) 21:00, 3 October 2012 (UTC)

♠No, you might have a valid point, there. Best make it clear what is & isn't being figured. Maybe add a note in a caption where the mounted mirror hides the back-to-front edge? Something like, "The finished mirror with figuring complete"?

♠Aside: I haven't read the whole page in awhile, so, is the reason they didn't test more carefully mentioned? As I understood it, they were trying to save money because NASA was penny-pinching... TREKphiler ^{any time you're ready, Uhura} 22:30, 3 October 2012 (UTC)

I changed the text to "the perimeter was too flat" which seems less ambiguous to me. Other opinions are welcome. (Also 'final polishing' to 'final polishing step', per suggestion above. LouScheffer (talk) 02:44, 4 October 2012 (UTC)

One more tiny quibble, now, I'm afraid. :( Was the error bang on the perimeter, or just toward the outer rim? As phrased, you may be leaving a misleading impression. (Yeah, this is getting really technifinicky...) TREKphiler ^{any time you're ready, Uhura} 02:52, 4 October 2012 (UTC)

Magdalena Ridge - did it use a mirror ground for Hubble?

From one reference: Bakker, E.J. and Westpfahl, D. and Loos, G. (2008). "Magdalena Ridge Observatory: the start-up of a new observatory" (PDF). Astronomical Telescopes and Instrumentation: Synergies Between Ground and Space. pp. 701615--701615. {{cite conference}}: Unknown parameter |booktitle= ignored (|book-title= suggested) (help); Unknown parameter |organization= ignored (help)CS1 maint: multiple names: authors list (link)

In the 1970s several classified research projects in the US developed zero-gravity mirrors for space based applications. Among these was a 2.4meter (7.9-foot) mirror developed by ITEK Corp. of Lexington, MA (Fig. 5). This mirror was never launched into space and was later found to be in storage at the PERKIN ELMER facility in Danbury, CT. At that point in time the AFRL was the legal owner of the mirror and was paying a monthly fee to PERKIN ELMER for its storage there. Since there was no planned use for the mirror, AFRL was interested in the possibility of other possible uses or users for it.

Since the Hubble was never classified, and never owned by the Air Force Research lab, this supports a military program. Also, the Hubble switched to a 2.4 meter mirror precisely because the tooling already existed, so the same mirror size is not very strong evidence.

and from Gordon J. Pentland, Kerry Gonzales, Kevin Harris, Eileen V. Ryan, Elwood C. Downey (May 2006). "The Magdalena Ridge Observatory 2.4 m Telescope". Proc. SPIE 6267, Ground-based and Airborne Telescopes. doi:10.1117/12.669795. Retrieved 19 Jan 2013. {{cite conference}}: Unknown parameter |booktitle= ignored (|book-title= suggested) (help)CS1 maint: multiple names: authors list (link)

This telescope utilizes a high quality primary mirror and cell from a now decommissioned military application.

On the other hand, the reference that was used to derive the Hubble origin is no longer accessible, and a web search of the title could not find it either.

Also, the Hubble failure report mentions a backup Kodak mirror, but not an Itek one. A NY Times article states that Kodak and Itek made a combined bid for mirror construction, but it was rejected.

So overall, it seems to me the mirror is not from a Hubble program. But of course there could be other sources and evidence... LouScheffer (talk) 21:35, 21 January 2013 (UTC)

You are right; I jumped the gun a bit there—the new source I cited (your first above) is insufficient on its own. I was relying on my still-fresh memory of the source I cited last year (the one which had since become a deadlink) to close the gap, and I shouldn't have. However, I did finally relocate that old source:

Magdalena Ridge Observatory (01 January 2008). 2.4m Observatory Technical Note (PDF) (Technical report). 1.6. p. 2. Retrieved January 21, 2013. {{cite tech report}}: Check date values in: |date= (help)

The primary mirror was built by Itek in the 80's as one of three to compete for the Hubble Space Telescope.

I would prefer more than once source, but this seems a sufficiently reliable one to establish its origin in relation to Hubble. That being said, perhaps it's merely a trivial mention in the scope of this article. Thoughts? Maralia (talk) 22:11, 21 January 2013 (UTC)

There's another line of evidence that this is not a Hubble mirror. The Magdelena Ridge telescope has a primary that is specified as f/2.03, where the Hubble mirror is f/2.3. So the mirrors are different shapes, and it could not have been a backup mirror for the Hubble. Also, the Magdelena Ridge total optical system is f/8.8, where Hubble is f/24, so they have (very) different secondaries as well. Of course, they could still have been part of the same development program, even if different mirrors. Also, the "One of three" comments seems odd, since both the NYT and the failure report say there was 1 backup mirror. Overall, I suspect the other two sources are more accurate. LouScheffer (talk) 23:14, 21 January 2013 (UTC)

Here's another source that says "one of three for Hubble", but also states the primary is f/2.03, which is not the Hubble specification. NESSI: the New Mexico Tech Extrasolar Spectroscopic Survey Instrument LouScheffer (talk) 23:22, 21 January 2013 (UTC)

One other point. The first paper has a picture of the Magdalena mirror. Both the Hubble mirror (and the backup) have large mounting bolts at 120 degree intervals around the circumference. The Magdalena mirror does not appear to have them. LouScheffer (talk) 03:30, 22 January 2013 (UTC)

I sent an email to Dr. Eileen Ryan, director of the observatory, asking the origin of the mirror. Let's see if she responds, and if so what she says... LouScheffer (talk) 04:16, 22 January 2013 (UTC)

Thanks—appreciate your following up on this. Maralia (talk) 05:35, 22 January 2013 (UTC)

Dr. Ryan cheerfully replied as follows: The mirror *was* originally part of a competition for the Hubble contract, even though it is not the same optically as the Hubble mirror (different prescription); after Itek was not picked for the Hubble, it became part of a classified Air Force project; when the Air Force project in turn was discontinued, it became available for MRO. She says that according to the Itek folks she worked with (they helped adapt the zero g mirror to ground use) they could not use their (classified) military expertise to bid for the Hubble mirror. They built this one as an unclassified example, though it supposedly looks a lot like the spy satellite mirrors. This makes sense since the specs (2.4m, f/8.9) are a better match for looking through the atmosphere than for use in an orbiting telescope, where the PE/Kodak numbers (2.4m, f/24) make more sense. LouScheffer (talk) 03:38, 23 January 2013 (UTC)

Fantastic to get such a quick and helpful response from her. Thanks again for taking the initiative. Maralia (talk) 15:59, 23 January 2013 (UTC)

So which is it?

In the introductory section, penultimate sentence of last paragraph:

"The telescope is now expected to function until at least 2013."

In the last sentence of Servicing Mission 4 section:

"The work accomplished during SM4 is expected to render the telescope fully functioning at least into the year 2014, and perhaps longer."

67.60.251.74 (talk) 10:53, 23 March 2013 (UTC)

Quality?

The last sentence of the 4th paragraph of the introduction: "The telescope was restored to its intended quality by a servicing mission in 1993." is extremely biased. Correction of the optical distortion does not return the telescope to the "quality" intended. Since when does a patched repair job restore quality? The quality was never there to be "restored" nor does "intended quality" have a clear meaning. I suggest that if the claim is: "The telescope's capabilities were corrected to design specification by repairs and additional equipment during a servicing mission in 1993." to use that or something similar.173.189.72.242 (talk) 16:19, 13 April 2013 (UTC)

The confusion, I think, is whether it is talking about the quality of the telescope (an abstract quantity with no clear measurement, as in "the Hubble is an mediocre/satisfactory/excellent telescope) or the quality of the images. The quality of the images are what is meant. These did indeed have an intended quality (90% of all collected light within 0.1 arcsec, IIRC.), and were "restored" in the sense that they had an intended quality, then did not, then did again. In principal these two meanings of quality could be different - you could have a bad quality telescope that hardly ever works, even if takes high quality images on the rare occasions it works correctly. However, the Hubble has high quality by almost any metric (it works well AND takes high quality pictures) so the sentence (in my opinion) is not misleading, especially since the details are explained later in the article. LouScheffer (talk) 01:18, 14 April 2013 (UTC)

Proposed automatic updating of orbital elements

I've proposed that this article be included in a trial involving using a bot to update orbital elements automatically on a fortnightly basis. I've started a discussion at WikiProject Spaceflight regarding this article and nine others, and would welcome some input from the users involved in maintaining the pages in question. --W. D. Graham 21:00, 24 July 2013 (UTC)

Fun "fact" about HST's orbit

I just realized:

• Hubble was released during STS-32. That mission had to retrieve the Long Duration Exposure Facility (LDEF). So the orbit of the LDEF determined the initial orbit of HST.
• LDEF in turn was released during STS-41-C. That mission had to service the "Solar Maximum Mission" (SolarMax) satellite. So the orbit of the LDEF (which lacked orbital manoeuvring capabilities) was determined by the orbit of the SolarMax satellite.

So the orbit of the broken SolarMax satellite (plus orbital decay of the LDEF) determined the initial orbit of HST.

(Though the initial orbit of the HST and the orbit of the retrieved LDEF were not identical, as the Shuttle released the HST into a different orbit. Similarly the LDEF was released into a different orbit than the captured SolarMax. Hence I write determined and not identical.)

(And BTW, this is not a well researched fact, and I may be wrong – but I thought I shared this in case anybody was interested to follow this up.) Tony Mach (talk) 10:36, 27 November 2013 (UTC)

Without research, I suspect this is a case of correlation and not causation. All three are in the highest-altitude orbit accessible to the shuttle, obtained by launching due east to get the greatest gain from earth rotation. Probably all three wanted the highest orbit they could get. LouScheffer (talk) 13:37, 27 November 2013 (UTC)

I was aware that the inclination of 28.5 is favourable for launches from Cape Canaveral and the Kennedy Space Center. However, there is more to orbital parameters than inclination (and height) – if an spacecraft is to rendezvous with another object in space, the orbital planes have to match at the time of launch. From Orbital plane (astronomy): "A launch vehicle's launch window is usually determined by the times when the target orbital plane intersects the launch site." Moving the orbital plane is very fuel intensive and practically feasible only for small corrections. So yes, the launch site in Florida determined the inclination (and yes, the Shuttle determined the height), but I am still convinced that it is factual to state that the orbital plane (at the time of release) – and hence "the orbit" – was determined by the chain stated above, as the planes had to be chosen to coincide. The problem is that this is at the moment original research by (and not very good at that). So, if anybody can back that up with proper sources, it would be a nice (but not very important) addition, IMHO. Tony Mach (talk) 14:09, 27 November 2013 (UTC)

Hubble Space Telescope captures shattering asteroid

Headine-1: Hubble Space Telescope captures shattering asteroid, at least 10 pieces seen in photos.

• http://www.foxnews.com/science/2014/03/07/hubble-captures-shattering-asteroid/?intcmp=features

QUOTE: “ The Hubble Space Telescope has captured the first pictures of a disintegrating asteroid. Asteroid P/2013 R3 was detected in September in the asteroid belt between the orbits of Mars and Jupiter. It appeared as a fuzzy object. Further observations by ground telescopes revealed three bodies. The Hubble telescope uncovered 10 objects, each with dusty tails. The four largest fragments are up to 656 feet across. Scientists say the asteroid began coming apart early last year. They theorize sunlight is slowing pulling the asteroid apart by increasing its rotation. A planetary scientist at the University of California, Los Angeles, David Jewitt, led the investigation. He says seeing the rock fall apart before our eyes is pretty amazing.The pictures were released Thursday.” — [Amazing picture], FYI, Charles Edwin Shipp (talk) 22:59, 7 March 2014 (UTC)

 Done — Seems to be in the article here already; nicely done; great series of pictures. (Search for P/2013). — Charles Edwin Shipp (talk) 23:09, 7 March 2014 (UTC)

Mirror error

I remember reading at the time that when the mirror was finished at PE, an old time telescope maker tested it, and said, hey, it is off..Is this true, and if so is there an authoritative source ? — Preceding unsigned comment added by 50.195.10.169 (talk) 21:56, 2 May 2014 (UTC)

Answered? -- Charles Edwin Shipp (talk) 10:47, 14 November 2014 (UTC)

The mirror type used in Hubble (Ritchey–Chrétien telescope) cannot be tested by any of the really old-time techniques that a skilled amateur, or professional from the 1930s or so, might use. This is precisely why the Palomar telescope, from the 1940s and 50s, does not have the wide-field performance of later telescopes. They were very worried about schedule and cost, and did not want to try any "new" technology, and so used a parabolic (not hyperbolic) mirror which could be easily verified by techniques from the previous century. Now for the Hubble mirror, there was also an "old" null corrector technology, decades old, using lenses. Perkin Elmer was worried this was not good enough, and therefore built a theoretically better mirror based corrector. And it's true the "old" technology said the mirror was off, despite the new technology saying it was OK, but they chose the believe the new. But it's not like there is some simple test an old telescope maker could have run to see the error - the last telescope that had a mirror type where this was possible was the Palomar mirror. The disagreement between the older and newer measurement techniques is covered in the article and may be the source of the story. LouScheffer (talk) 14:44, 14 November 2014 (UTC)

Which shuttle

It's a constant battle to keep the lede paragraph short and to the point. There is all sorts of stuff that is perfectly true, interesting to some folks, and could be added. However, the lede should contain *only* the points that are most important to the topic at hand, which is the Hubble space telescope.

Exactly which shuttle carried the Hubble into orbit is not particularly relevant to the telescope. A good test is "What would have changed had it been a different shuttle?" Very little, as far as I know. So it's perfectly fine to put in the article, but not in the lead paragraphs and particularly not in the first sentence.

As always, other opinions are welcome. LouScheffer (talk) 12:56, 19 November 2010 (UTC)

Somewhat similar rationale applies here as does Edwin Hubble's nationality in the previous talk section. Which Orbiter is not critical to summarizing what the HST is in the Lead. But it does not matter too much to me. -fnlayson (talk) 13:40, 19 November 2010 (UTC)

This is not a big deal in the article - indeed, one of the main charms of Wikipedia is that fanatics of all stripes add all sorts of interesting detail to topics you never heard of. However, the lead paragraph in particular should be a concise overview of the topic. From The Elements of Style#The Third Edition (1979) LouScheffer (talk) 14:05, 19 November 2010 (UTC)

“ Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. ”

I find it a bit ridiculous, IMO, to war over a single word that in no way dtracts from the article, but if you are going to remove the name of the shuttle, it is more precise (and concise) to change the sentence to a space shuttle rather than the space shuttle. The common phrase "The space shuttle" is a holdover from when the Columbia was the only space shuttle. Since there are multiple space shuttles, it is not appropriate to use wording implying there is only one. One would not say the cargo was brought over on the ship, they would either include the name of the ship, or change the sentence to the cago was brought over on a ship. Just my two bits ... LonelyBeacon (talk) 15:50, 19 November 2010 (UTC)

You are absolutely correct. That's how it used to read, and how it reads now. Thanks, LouScheffer (talk) 20:28, 19 November 2010 (UTC)

The argument about this is absolutely ludicrous. It is completely relevant which space shuttle and mission carried the most well-known space telescope in all of human history to where it is. This information should absolutely be in the opening paragraph. But I'm not going to argue with editors who are on a power-trip to be dictators on Wikipedia. G90025 (talk) 13:40, 14 December 2013 (UTC)

Here's a crude calculation of what an extra word costs. This page is viewed about 70K times per month (see stats). Assuming everyone reads the first sentence, and they read about 200 words per minute, that's about 2 work-weeks of wasted time per year, or perhaps $1000 US of wasted time. This calculation is rather inexact, requiring many dubious assumptions, but point remains - we should be concise, especially in the lead... LouScheffer (talk) 20:41, 19 November 2010 (UTC)

I would never argue against having a concise leadin for many reasons (ranging from consensus and policy to aesthetics). Bringing up the economic argument might equally play into the reason it should be there: when people read the leadin, they expect something like that to be there, and now need to go look for it. I personally think it belongs, but if I was asked to defend it with policy or guideline, I would be hard pressed to find something. There are other things in the leadin that I would take out as not being necessary for a fundamental understanding of what the HST is, rather than the name of the shuttle that carried it into orbit ... but I must acknowledge that as an opinion, and nothing more than that. LonelyBeacon (talk) 03:20, 20 November 2010 (UTC)

Spurious stat - the time all the world's 6.8 billion people take over their daily dump accrues to centuries a day... but so what, it doesn't for EACH! We might as well all try to breathe a few times less each minute, "because it takes time we could be using for something else." Like, erm, taking a dump perhaps? Trevor H. (UK) 19:18, 4 October 2011 (UTC) — Preceding unsigned comment added by Trevor H. (talk • contribs)

The word negligible comes to mind. That aside, if we took up that position then nothing would ever get written. Fortunately we aren't paying per word and Wikipedia is not paper. For balance, please could you provide an estimate of the time wasted by people who do want to know which Shuttle it was launched by having to search for that information, and the time wasted compiling these statistics. --W. D. Graham 18:33, 25 June 2014 (UTC)

In a speed reading comprehension test, you just know that if the shuttle is named, it will be asked, making it the slowest word in the sentence. In other contexts, a boring specificity is barely observed. The first time I read LoTR as a 12 year old (this was before Star Wars) I made it through all three volumes in short order without being firm in my mind that Sauron and Saruman were two different characters. No, I wasn't reading Arabic shorn of the vowel markings, but I might as well have been in my rush to find out what happens. In this instance, as for which shuttle, that's the kind of thing a military aircraft buff simply can't live without, while the rest of us barely perceive the significance. People read by metaphor far more than they realize: if you say "delivered by the Reading Railroad" you don't have to specify the locomotive. The Space Shuttle was, after all, a kind of abstract rail line. I think the real reason everyone stuck to the "the" shuttle is that the stairway to heaven was single occupancy. For the same reason we refer to "the tennis ball" as if those conspicuous auxiliary bulges in the tennis tights are anatomical. The cute ball girl hands the tennis stud "a ball" and then he pounds "the ball" over the net. When does it change? Badminton does not have shuttle girls, so I guess it's best as changed.—MaxEnt 12:28, 24 February 2012 (UTC)

I'd say that is is more to do with the fact that there were only five Shuttles (six including Enterprise), whereas there are many trains in the world. A case of the extraordinary rather than the mundane. --W. D. Graham 20:26, 25 June 2014 (UTC)

Every satellite/probe that has been launched aboard a Space Shuttle and has its own page on Wikipedia mentions which Shuttle it was launched from in its opening paragraph(s) with the exception of Magellan (See: 1, 2, 3. 4, 5, 6, 7, 8, and 9). If that information is relevant enough for those machines, I don't see how should be different for Hubble. -Martinman (talk) 20:44, 24 June 2014 (UTC)

I can see absolutely no reason not to put the Shuttle name in the lead. The argument of brevity is nonsensical since the change won't even increase the word count of the lead ("a Space Shuttle" to "Space Shuttle Discovery") - and if he's so concerned about time wasted then we can save a few milliseconds on the load time by taking out the ridiculous footnote that has been inserted to explain this. --W. D. Graham 18:33, 25 June 2014 (UTC)

Mentioned in the Lead is fine, but not in the first sentence. That would just make the first sentence overly long, imo. -Fnlayson (talk) 18:45, 25 June 2014 (UTC)

For getting it out of the first sentence, how about "The Hubble Space Telescope (HST) is a space telescope that was launched in 1990 and remains in operation. A 2.4-meter (7.9 ft) aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared spectra. The telescope, which is named after the astronomer Edwin Hubble, was deployed by the Space Shuttle Discovery during the STS-31 mission and has since been serviced by five other missions." (changes in bold)? --W. D. Graham 18:51, 25 June 2014 (UTC)

• I was looking at putting the launch info in a 2nd sentence like "The Hubble Space Telescope (HST) is a space telescope that has been in operation since 1990. It was carried into orbit by Space Shuttle Discovery on April 24, 1990." Your version seems better and fits in with existing text. And that footnote can be removed with a change like these. ;) -Fnlayson (talk) 19:24, 25 June 2014 (UTC)

Hubble "lessons learned"

There is probably a lot that could be written here. I will start off. Something that Hubble mission should have considered was an INDEPENDENT evaluation of the mirror and assembly. I mean FULLY independent, including new instrumentation to measure the optical quality of both the mirrors and the subsequent assembly. I do not subscribe to the argument that such requirements are untestable. I invite the readership to comment. --96.244.248.77 (talk) 03:08, 3 March 2011 (UTC)

While true, Congress denied NASA the money to make it possible. The failure to test was an effort to cut costs, & it bit them. TREKphiler ^{any time you're ready, Uhura} 03:30, 3 March 2011 (UTC)

Kodak and Itek proposed that each would make a mirror set, then each would test the other's mirrors. Their bid was more expensive, and rejected. This is covered in the article. LouScheffer (talk) 18:28, 3 March 2011 (UTC)

Yes, but the bid was much less expensive then the money PE got after all cost overruns they did. Further I read somewhere that the US Air Force offered NASA an end to end test of the complete telescope for free. NASA declined the offer. Some suspect that the mirror error was known but kept secret to give the shuttle a PR stunt. Want a nightmare lesson? Orion needs a mission and could reach JWST at L2 to repair it! — Preceding unsigned comment added by 84.172.177.13 (talk) 07:59, 27 May 2011 (UTC)

I visited PE while the mirror was being polished and was shown it. I was also shown a large vacuum chamber in the same area that was to house the complete assembly to test it. I was told by my host that NASA had not approved (or withdrew the money) to test the assembly, and PE was out the money to construct the chamber. More than anything else I am concerned that this fact does not seem to be in the record (that I have seen anyway.) I also saw the first casting at corning, it was cracked. It was in a stairway mounted on the wall above a landing. hope you can use this information.Ianhenderson007 (talk) 15:35, 26 September 2012 (UTC)

There is also another, indeed bigger "lessons learned" on HST - the total life cycle cost of keeping the mission going from the time the initial flaw(s) was (were) detected. Perhaps a new telescope might have been a cheaper than trying to keep both HST and the shuttle program going? The main article does not discuss the totality of HST failure. Sure there were benefits, but at what cost?? I know this is controversial, but I'm asking for some real money figures to be presented - show us the cost/benefit. Life cycle costs don't end quickly - HST is still flying at the present time! 71.10.145.225 (talk) 02:42, 13 December 2014 (UTC)

Needs section on UV capabilities and results

Very hard to locate Hubbles relevance to UV astronomy. Could we have a section to summarise Hubbles UV capabilites, past and current, maybe for IR too. - Rod57 (talk) 09:58, 1 June 2012 (UTC)

• Looks like just the STIS 115–1030 nm and WFC3 200-1700 nm. But what results ?
• Intro says near-UV but according to Ultraviolet#Subtypes WFC3 also covers Middle-UV and STIS even covers some of Far-UV (to 115nm). - Rod57 (talk) 14:16, 28 June 2014 (UTC)

I would add that HST (and other NASA) imagery is often presented highly "colorized". HST does not process human eye spectrum the same - thus colorized. NASA is ripe with presenting both colorized and "artist conception" imagery. Beware that this is not scientific and also biased. NASA does not usually indicate that images are often "doctored".--71.10.145.225 (talk) 03:07, 13 December 2014 (UTC)

Hubble images usually document fairly well what went into their creation, though you sometimes have to read between the lines (for example, it may only indicate which wavelengths were combined to render a final product, but that should tell you that the image has been manipulated). Images from the various Mars rovers normally get very specific about modifications made and whether or not an image represents Earth or Mars lighting. If NASA limited their images to what the human eye could see, we'd be left with quite a bit of dull imagry. I can't begin to understand how you can say these images are "not scientific and also biased" when those same images represent data used by researchers in their studies. I have to believe you're trolling here. — Huntster (t @ c) 09:25, 14 December 2014 (UTC)

Ignored error?

P. 512 of the Dunar article does not quite say or imply the company just ignored the error. It does say something like they believed the results "were less accurate than the primary device which reported that the mirror was perfectly figured". It also says on p. 513 that PE didn't use the required expertise and they failed to verify their results. Myrvin (talk) 20:39, 26 November 2014 (UTC)

I've had a go at clarifying this. Myrvin (talk) 20:58, 26 November 2014 (UTC)

Agree that "dismissed" is more accurate than "ignored". But while quotes are often helpful, but this one seems to take 3 lines to say they did not believe the 2 null correctors, since they thought the reflective one was better. So I think it's better to say just that. LouScheffer (talk) 03:58, 27 November 2014 (UTC)

Vandalism

When I searched for hst 5 the page came up but the description of this page was:

"Hubble Space Telescope (redirect from Hubble Space Telescope (HST)) can't find ma berries buttt i found this *lick The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990, and 116 KB (13,167 words) - 05:17, January 8, 2015"

This is vandalism that was reversed by a bot, but somebody should either go into the search metadata and correct the listing, or mark this page for recrawl. (I do not know how to do this or where to report it, or how ofetn the whole system undergoes recrawl but somebody reading this does). TeigeRyan (talk) 20:31, 8 January 2015 (UTC)

TeigeRyan, it is impossible for editors to affect the search metadata themselves. It is just a matter of waiting for the system to recrawl, which should be fairly soon. — Huntster (t @ c) 20:53, 8 January 2015 (UTC)

Images 'beamed' to earth in black & white, each captured in red, green and blue

In the "Hubble data" / "Transmission to Earth" section we find the following sentence : "Images from Hubble are beamed to Earth in black & white, with each image being captured with red, green, and blue filters. Then these images are combined into one image by a Hubble imaging team, using a "Technicolor process".[131]".

This ranges from being misleading to false:

- The data captured by cameras on the HST is not "black & white" in any meaningful sense. Each exposure captures the intensity of light within particular bands of the electromagnetic spectrum, none of which the human eye and brain would perceive as "black & white". I find it misleading.

- While the filter wheels include (roughly) red, green and blue filters, it is rare for all three of those filters to be used for one observation. There are many other filters in use, near infrared or "hydrogen" filters being favourites. Much of the observations are not even performed through more than one or two filters.

- Much of the data is not combined into color pictures at all. When it is, I most definitively would not describe the process as having anything to do with "Technicolor", which is a trademark referring to very specific processes that have little to do with all the digital processing done for astronomic pictures and is probably not even a remotely familiar term to most people anymore.

I'm erasing that sentence, it would not be particularly relevant to that section if it was correct, anyway. 82.231.41.7 (talk) 20:22, 3 December 2013 (UTC)

The point that the Hubble takes monochrome images through different filters, which are combined to make color images, seems important enough to mention. I made it more technically correct; it's an open question where it should go, but I left it here for now. LouScheffer (talk) 04:13, 4 December 2013 (UTC)

"Hubble data" seemed like the right section, so I added a sub-section "color images". LouScheffer (talk) 04:22, 4 December 2013 (UTC)

-March 23,2015: A video describing the process by which Hubble made images are colorized by the Imaging team lead. It may be useful as a reference. http://video.nationalgeographic.com/video/magazine/150315-ngm-hubble Jcardazzi (talk) 12:19, 23 March 2015 (UTC)jcardazzi

Viewing the Hubble

The Hubble Space Telescope is clearly visible to the naked eye if you know where to look, similar to the Space Station - although the Hubble is not as bright due to its height and smaller size. Web sites such as Heavens-Above provide predictions of where and when it will be visible. Can anybody see a reason not to mention this briefly?--Gronk Oz (talk) 14:05, 14 March 2015 (UTC)

I think ISS viewing is included only because it gets mentioned by NASA and the media quite often, which implies a certain notability in the activity. I don't see how Hubble viewing has any relative notability, or why there's any real reason to include it in an already long article. Perhaps the addition of a section on satellite/spacecraft viewing at amateur astronomy would be warranted? — Huntster (t @ c) 20:41, 14 March 2015 (UTC)

Thanks for that response, Huntster - that makes sense. I don't know why it is taking so long for me to think in terms of notability...--Gronk Oz (talk) 04:23, 16 March 2015 (UTC)

‎Reverting for no reason

When you undo someone's edit, you get a little message saying "If you are undoing an edit that is not vandalism, explain the reason in the edit summary." "Restore general link on accuracy and precision and text" is not an explanation. It's just a statement of what you've done. Here is why I've remade the change.

• The use of brackets was wrong. Parentheses are for additional information or asides, and you can check if they are correctly used by reading the sentence with the parenthesis omitted. In this case, that yields "This device was assembled incorrectly, resulting in an extremely precise shape for the mirror", which is clearly absurd.
• The manual of style says that links should be made to form "relevant connections to the subject of another article that will help readers understand the article more fully", and that you should "make sure that the reader knows what to expect when clicking on a link". It is not at all clear what to expect when the text "precise (but wrong)" is linked. The most logical thing to expect would be an article about the shape of the Hubble mirror. A general article about terminology related to systematic and random errors goes against the principle of least astonishment. The link is therefore unhelpful, as I said in my edit summary.

200.86.119.126 (talk) 00:25, 18 April 2015 (UTC)

Two editors have ignored the talk page and simply re-reverted my changes. Their edit summaries were:

• Agree about parens, but many people get confused about how something can be precise but not accurate. So the link is helpful.

This is not the place to educate them. Indeed, the link only served to confuse. The wording in the article is "precise but wrong". A link from that text has no intuitive destination. I changed the text to make it clearer, with no need to link to an article with marginal relevance.

• adjust link to avoid confusion about what's being linked (easter egg)

Linking to accuracy and precision from "precise but wrong" is confusing. Linking just from "precise" is even more confusing and inaccurate.

Now if there is really a need to discuss straightforward improvements on the talk page, how about doing that, instead of just trying to force your preferred version back in for no clear reason? 200.86.119.126 (talk) 03:51, 18 April 2015 (UTC)

• These were clearly not simple reverts as you're implying. Changes were made to address the issues you pointed out. The accuracy and precision link was the relevant link for precise there. I don't get how that can be confusing. Now are there any remaining issues with the text itself? -Fnlayson (talk) 19:41, 18 April 2015 (UTC)

I am happy with the text. Are you? You did simply revert the majority of the edit I made, leaving an uninformative edit summary and then ignoring the talk page until now. Please do in future explain why you are reverting people's work, if you really need to revert it; spending time considering how to make an article better only to find that someone's undone your work without any explanation is exasperating. 200.86.119.126 (talk) 22:59, 19 April 2015 (UTC)

Changed the title of the section to be more factually accurate. Most of the changes were not reverts (which means to go back to the original), but good faith attempts to converge on content and wording acceptable to all. Also, they were not for "no reason", but for reasons they explained in the edit summary, but you did not agree with. In most cases, if your change can easily be explained in one sentence, it's pretty standard practice to simply make the change and summarize in the edit summary (after all, Wikipedia says "Be bold!"), partially because the edit summary is much easier to view than the tail end of the talk page. If after several rounds of changes there is no convergence on a text acceptable to all, *then* it's time to use the talk page. This may seem a little brusque, especially to an editor who sees their obviously correct edit changed (or reverted) by someone with a different opinion, but in general this two step process (a few rounds of changes with edit summaries, then move to talk if no convergence) works pretty well, and minimizes editor effort in the normal case (at least for technical articles) where concensus is achieved fairly quickly. LouScheffer (talk) 03:46, 20 April 2015 (UTC)

How dare you change my words to imply that I said something I didn't, and that is false? I'm disgusted that you'd think that's an OK way to behave. Never edit or move someone's comment to change its meaning (bold from original). Are you trying to be provocative? Fnlayson reverted my changes. Fnlayson did not explain anything in the edit summary. Fnlayson and you ignored the talk page - I said "see talk" in an edit summary two days ago but you both carried on editing the article without bothering to read what I wrote here. When you finally do appear on the talk page, it's not to discuss any content but to tamper with my words and to pretend that you don't understand the situation. What exactly is your intention here? 200.86.119.126 (talk) 12:07, 20 April 2015 (UTC)

• Section headings/labels are not considered part of someone's post. They can be modified per WP:TPO. -Fnlayson (talk) 14:11, 20 April 2015 (UTC)

Looks like you're more into provoking people than building an encyclopaedia. Do not change my words to make it look like I said something I didn't. It's disgusting behaviour and you should apologise for it. 200.86.119.126 (talk) 20:09, 20 April 2015 (UTC)

• Wikipedia's relevant policy (WP:Talk page guidelines) says: "Section headings: Because threads are shared by multiple editors (regardless how many have posted so far), no one, including the original poster, "owns" a talk page discussion or its heading." -Fnlayson (talk) 20:41, 20 April 2015 (UTC)

I must respectfully disagree. An IP complained about some edits. If those who made them feel they are justified, a simple and calm explanation is all that is needed. Changing the section title to re-characterize the complaint in an argumentative way is not civil behavior. WP:CIVIL is a core policy of Wikipedia. Furthermore, adding the words "Others are changing my changes" suggests they were written by the complainer and they were not. Also see WP:BITE. Really, enough.--agr (talk) 21:26, 20 April 2015 (UTC)

Thank you very much, agr, for your intervention. BITE doesn't really apply because I've been editing for many years. But I can tell you that this kind of behaviour - reverts for no reason followed by tag team baiting and bullying - is the norm when you edit anonymously. It seems that for many people, baiting anyone they don't recognise is much more fun than building an encyclopaedia. It's vanishingly rare that any registered editor calls it out so I really appreciate it when they do. Thanks again. I await an apology from LouScheffer and Fnlayson for reverting for no reason, for refusing to discuss anything on the talk page, and for disgustingly changing the section title to make it look like I said something I didn't. 200.86.119.126 (talk) 01:22, 22 April 2015 (UTC)

You're welcome, but if you've been here for a while you should realize that editors are sometimes more abrupt than one might like and positions tend to harden. Often the best approach is to let slights slide and focus on the task of improving the encyclopedia. As far as I can tell everyone in this discussion is trying to get the article right and that is the important thing.--agr (talk) 00:37, 23 April 2015 (UTC)

Favorite Images

Is this item of any interest in this article? Top 10 Images Taken by the Hubble Space Telescope, scientists who have worked on the project chose their favorite pictures- Scientific American by Nature http://www.scientificamerican.com/slideshow/top-10-images-taken-by-the-hubble-space-telescope Jcardazzi (talk) 00:10, 24 April 2015 (UTC)jcardazzi

It's too highly subjective to really have any value in the article, IMO. — Huntster (t @ c) 01:29, 24 April 2015 (UTC)

Is this item of any interest for the article? I understand it is subjective per the scientists opinions but it seems valuable as thoughts on Hubble history, or maybe as link in a further reading section? http://www.scientificamerican.com/article/hubble-top-moments-25th-annivesary Jcardazzi (talk) 14:53, 24 April 2015 (UTC)jcardazzi

I've merged this with the previous section as it is about the same topic. — Huntster (t @ c) 16:11, 24 April 2015 (UTC)

Add a Videos Section?

Could a Videos section be added near the bottom of the article? Reason: I have seen Hubble videos that add explanations to the Hubble mission which include interviews, videos and graphics which I think are educational for readers, which are not easily captured in text. Thank you, Jcardazzi (talk) 17:16, 26 April 2015 (UTC)jcardazzi

• Could this link to the public video be posted in the article for readers?

http://video.pbs.org/video/2365472415/ Public Broadcasting System(PBS) Show: NOVA Title: Invisible Universe Revealed Aired: 04/22/2015 Lenght 53:30 Rating: TV-G Jcardazzi (talk) 20:34, 1 May 2015 (UTC)jcardazzi

Again, articles do not exist as a place to dump links to any and all media resources. — Huntster (t @ c) 22:38, 1 May 2015 (UTC)

This PBS public Television NOVA video specifically is a 25 year history of Hubble with explanations from NASA & scientists & repair astronauts explaining the Hubble history and scientific contributions.Jcardazzi (talk) 23:59, 1 May 2015 (UTC)jcardazzi

And? Given it is Hubble and it is the 25th anniversary, I'm sure there are any number of documentaries that have or will be made about its history. Doesn't change anything. — Huntster (t @ c) 03:57, 2 May 2015 (UTC)

And.. I think the PBS NOVA Hubble documentary is valuable to inform readers interested in getting knowledge not available in a text article format. There may be many 25 year documentaries, (there is 1 on the NASA website) I suggested one I thought valuable to readers.Jcardazzi (talk) 12:19, 3 May 2015 (UTC)jcardazzi

25th Anniversary

Is there a wikipedia way to include a link to video articles created for the 25th Anniversary? Like a history section? For example: http://www.nature.com/news/hubble25-1.17298#/Anniversary-special in which there is a video where 5 scientists discuss their top discoveries, which seems valuable historically. Thank you, Jcardazzi (talk) 20:10, 27 April 2015 (UTC)jcardazzi

Just as we don't include links to any news article or website we come across, we don't do that with videos. Limit external links to citations and the most critical external links. I would suggest you find consensus before adding more links of any kind to the article. — Huntster (t @ c) 04:32, 28 April 2015 (UTC)

Top right box website http://hubble.nasa.gov is no longer updated

Can http://www.nasa.gov/hubble be added to the box, and http://hubble.nasa.gov/ be marked as an archive?

The website in the top right box http://hubble.nasa.gov/ states "This website is kept for archival purposes only and is no longer updated", the bottom of the website states: "For the latest news on Hubble, visit http://www.nasa.gov/hubble." Jcardazzi (talk) 00:13, 30 April 2015 (UTC)jcardazzi

 Done — Huntster (t @ c) 04:47, 30 April 2015 (UTC)

Term "heavens" inappropriate in a scientific article

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

i feel the term 'the heavens' in the last passage of the article - "furthermore, space telescopes can study the heavens across the entire electromagnetic spectrum, most of which is blocked by Earth's atmosphere" is not appropriate in a scientific article. Anilrchn (talk) 09:07, 4 April 2016 (UTC)

Use of 'heavens' in a scientific context is not unusual, and is taken to mean the skies above and not the religious meaning. See this Nature article or this satellite tracking software. But if it bugs you you can change it... LouScheffer (talk) 13:12, 4 April 2016 (UTC)

بسم الله الرحمن الرحيم وقل ربي زدني علما صدق الله العظيم — Preceding unsigned comment added by 197.166.130.184 (talk) 14:11, 25 April 2016 (UTC)

Google translates this as "In the name of God the Merciful and say to my Lord Simply the great truth of God" (I can't read it myself, and was curious what it said.) LouScheffer (talk) 14:57, 25 April 2016 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

I propose to delete the above two comments (not the first 2), unless anyone objects. - Rod57 (talk) 18:32, 14 October 2018 (UTC)

• I've added close discussion templates (Template:Discussion top & Template:Discussion bottom) above. Deleting the later posts is fine with me. -Fnlayson (talk) 01:09, 15 October 2018 (UTC)

I would mildly object (on principle) to removing any comment that's on-point to the article, but not make a fuss if it was deleted. TREKphiler ^{any time you're ready, Uhura} 18:29, 15 October 2018 (UTC)

• The Arabic text and translation seems mostly off topic to Hubble imo but not a big deal. -Fnlayson (talk) 18:50, 15 October 2018 (UTC)

Information out of date - cost per citation

I read the following passage under the heading "Impact on astronomy":

"Although the HST has clearly helped astronomical research, its financial cost has been large. A study on the relative astronomical benefits of different sizes of telescopes found that while papers based on HST data generate 15 times as many citations as a 4 m (13 ft) ground-based telescope such as the William Herschel Telescope, the HST costs about 100 times as much to build and maintain.[144]"

The work cited dates to 2000. Is there more recent information on the cost-effectiveness of the Hubble?

26 August 2016‎ RandyMRingen

First extra-solar visitor not photographed?

why hasn't hubble photographed Object 1L/2017 u1 ? the thing appears to be ten times longer than it is wide and is from outside our solarsystem. nearly a kilometer long and only a few dozen LD from earth?

what gives?

please respond to info @ the ubie . com 72.94.230.198 (talk) 16:28, 28 November 2017 (UTC)

A kilometre-wide object even at 1I/2017 U1's closest approach to the Earth (0.16 au) would subtend about 0.009 arcseconds). This would be unresolved with the Hubble Space Telescope. There would be little point in interrupting HST's busy observing schedule to image a point source. TowardsTheLight (talk) 19:22, 28 November 2017 (UTC)

HST might have given us lower noise light curves (over time), and also a light curve in the UV (if that had any value). - Rod57 (talk) 18:39, 14 October 2018 (UTC)

How complete was the prototype and what happened to it

Article mentions the prototype was better tested than the launched mirror/craft. Not sure it refers to just a mirror or more than that. Would be interesting to see more detail on the development process including the prototype. - Rod57 (talk) 18:22, 14 October 2018 (UTC)

Costs - which years dollars

Costs are mentioned briefly but its not clear which years dollar values they relate to. It would be nice to see a breakdown of the project costs, and maybe a history of how cost estimates changed during the development process. Could then compare to the cost of the first servicing mission. - Rod57 (talk) 18:28, 14 October 2018 (UTC)

'Soft Capture and Rendezvous System' changed to 'Soft Capture Mechanism' as thing installed on Hubble

Article previously said 'Soft Capture and Rendezvous System' had been installed on the Hubble. The source [2] says that the SRCS consists of the SCM on the Hubble, and the 'Relative Navigation System (RNS)' fitted on the Shuttle (not the Hubble). I have also added in info about the 'Soft Capture and Rendezvous System', partly because Soft Capture and Rendezvous System presently redirects to Hubble Space Telescope, so it is useful to have a mention of Soft Capture and Rendezvous System in this article. FrankSier (talk) 12:17, 24 October 2018 (UTC)

More classic Wiki sexism?

Herein lies no mention of Nancy Roman . In some circles she's regarded the "Mother of Hubble".

GenacGenac (talk) 22:22, 11 December 2018 (UTC)

"Photoshop'ed Imagery criticism

While I like to see images from HST, NASA does TOO MUCH with image enhancements or "artist rendition" imagery for promotional purposes. And not enough to say what image processing was done. This greatly diminishes both scientific accuracy and credibility of the material presented. Please stop popularizing your evidence since it no longer becomes science. It diminishes all sources that present it, including Wikipedia. --2600:6C48:7006:200:D84D:5A80:173:901D (talk) 04:55, 15 March 2018 (UTC)

And the Reliable Source(s) that you have that backs up what you stated is ____ ? — Preceding unsigned comment added by 50.111.47.191 (talk) 16:22, 9 December 2019 (UTC)

Naked Gun

Really minor point, but Naked Gun 2 1/2 does not show the RMS Titanic but the RMS Lusitania. The source is mistaken, but I cannot offer an alternative. (Removing the claim altogether would be an option.) Here are links to show that it is the Lusitania, though:

• what appears to be the image used in the movie
• Lusitania plans
• drawing of the RMS Titanic sinking, showing the differences in aft layout. Aragorn2 (talk) 21:07, 19 February 2021 (UTC)

OTA abbreviation

OTA actually stands for Optical Tube Assembly, not Optical Telescope Assembly. The OTA is just one part of a telescope. See, for example, on these telescope manufacturer's sites; https://uk.telescope.com/Telescopes/Telescope-Optical-Tube-Assemblies/pc/1306/1323.uts https://www.rothervalleyoptics.co.uk/skywatcher-optical-tube-assemblies.html https://optcorp.com/collections/optical-tube-assemblies-ota https://www.firstlightoptics.com/optical-tube-assemblies.html https://www.celestron.com/collections/optical-tubes Point of Presencetalk 08:02, 7 September 2021 (UTC)

but in at least some NASA glossaries (eg 1992 HSP user guide), OTA stands for Optical Telescope Assembly. - Rod57 (talk) 01:45, 11 October 2021 (UTC)

Changes to the instrument bar graphic timeline at Servicing missions and new instruments

Regarding the instrument bar graphic at Servicing missions and new instruments. It's very helpful, so helpful it would be nice to repeat it, or something similar, further up the article at List of Hubble instruments. :

• since the graph is rendered each time the article is viewed, is it ok to copy the code and repeat the rendering ?
  • or put in a template ? (would still render each time & place) - eg see {{Include timeline}}
• how shift "WFPC" left to not overlap the next bar (centre in bar rather than start in centre) - (done with align:left/anchor:from/shift)
  • (try align:centre anchor:centre)
• where is the syntax documented for this type of graphic (timeline) ?
  • (Wikipedia:Timeline & examples from Category:Graphical_timelines)
  • syntax, see Help:EasyTimeline syntax - noted as #comment in the timeline script
• could we indicate other periods of degraded operation (eg gyros just prior to SM 3A),
• can we note on STIS bar the period it is non-functional (2004-2009) - (done)
  • could maybe do similar with NICMOS & ACS (need a better way than just shorter bars - overlap ?)
• can we add a title to the graphic - eg "Instruments installed in the radial and 4 axial bays" (done with "textdata")
• maybe add pointers below the time axis to show the SM1..4
• - Rod57 (talk) 02:30, 11 October 2021 (UTC)