Wikipedia:Featured article candidates/Galileo project/archive1
Galileo project[edit]
Galileo project (edit | talk | history | links | watch | logs)
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This article is about a robotic space mission to Jupiter. This article is about the mission; there is a separate article about the spacecraft itself. Hawkeye7 (discuss) 20:59, 31 March 2024 (UTC)
UC[edit]
Very much coming in as a non-expert here, but it looks like a cracking article and at least gives me the illusion that I can understand what is going on. UndercoverClassicist T·C 18:29, 1 April 2024 (UTC)
Resolved
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- in reality, the antenna got stuck while in space and didn't open all the way: I know that brevity is important in a caption, but I don't think "got stuck" or a contraction are the right WP:TONE. Suggest "the antenna's motors stalled, preventing it from fully opening", or similar. UndercoverClassicist T·C 10:27, 3 April 2024 (UTC)
- The problem was not with the motors, but with the antenna being stuck, probably vacuum welded in place. Re-worded to address the issue. Hawkeye7 (discuss) 18:48, 3 April 2024 (UTC)
- Not sure about the revised but in reality the antenna could not open all the way: to me, that reads as if it was impossible for the antenna to open fully. UndercoverClassicist T·C 21:07, 3 April 2024 (UTC)
- Simplified the caption to "the antenna could not extend" Hawkeye7 (discuss) 03:18, 4 April 2024 (UTC)
- I still think we have the same problem: it sounds as though the antenna wasn't extendable at all. How about "failed to extend", which makes clear that it should have done so? UndercoverClassicist T·C 06:20, 16 April 2024 (UTC)
- Simplified the caption to "the antenna could not extend" Hawkeye7 (discuss) 03:18, 4 April 2024 (UTC)
Another few:
- pressurized atmospheric entry probe to a vented one: it would be useful to know what these things are: perhaps clearer if we explain it by what the probe would or wouldn't do?
- But the three-stage IUS was itself overweight: It's not a rule, as such, but most style guides would avoid starting a sentence with but. More importantly, if we do use but here, we're setting up some followup in which this additional weight prevented something from taking place, and that never comes, so the paragraph would read better with something like "Furthermore", "Additionally", or indeed nothing at all.
- Changed as suggested. Hawkeye7 (discuss) 03:18, 4 April 2024 (UTC)
- I don't see a change here. UndercoverClassicist T·C 06:20, 16 April 2024 (UTC)
- Hmm. Tried again. Hawkeye7 (discuss) 04:18, 21 April 2024 (UTC)
- All good now. UndercoverClassicist T·C 10:53, 21 April 2024 (UTC)
- Hmm. Tried again. Hawkeye7 (discuss) 04:18, 21 April 2024 (UTC)
- I don't see a change here. UndercoverClassicist T·C 06:20, 16 April 2024 (UTC)
- Changed as suggested. Hawkeye7 (discuss) 03:18, 4 April 2024 (UTC)
- 109 percent of their rated power level: can we explain or link what a rated power level is?
- I will see if I can dig up a source. Hawkeye7 (discuss) 07:01, 16 April 2024 (UTC)
- After digging through various technical documents, I have added a footnote: "The rated power level (RPL) is the power at which an engine can be normally operated. In the case of the Space Shuttle, the specification called for 27,000 seconds operation at 100 percent of the RPL, or 14,000 seconds at 109 percent of the RPL, which was designated full power level (FPL)." Hawkeye7 (discuss) 04:17, 21 April 2024 (UTC)
- Great stuff. UndercoverClassicist T·C 10:53, 21 April 2024 (UTC)
- The second was that despite this, it was also more gentle than the IUS, as it had lower thrust, thereby minimizing the chance of damage to the payload.: grammatically, needs a comma before despite this, but then becomes quite a winding sentence. I would go with something like The second was that it had lower thrust, thereby minimizing the resultant forces on and therefore the chance of damage to the payload.
- David Stockman, the Director of the OMB: per the ever-confusing MOS:PEOPLETITLES, we should decap director here.
- could damage the spacecraft's optics and possibly the spacecraft itself.: the optics are part of the spacecraft, aren't they? Suggest "and possibly other parts of the spacecraft", or even something like "other, more mission-critical parts of the spacecraft", "other parts of the spacecraft, particularly..."
- reads from one memory location disturbed those in adjacent locations: not quite grammatical (what's the antecedent of those: grammatically, it should be reads, but you can't damage a read). The noun "reads" is also a little tricky to parse. Suggest "repeatedly reading data from a single data cell damaged the other data cells around it", or similar.
- Shuttle-Centaur project: needs an endash, I think, as this is really "Shuttle plus Centaur" (compare Lee–Enfield or Mason–Dixon line) (MOS:DASH)
- MOS:ENBETWEEN: Generally, use a hyphen in compounded proper names of single entities. Hawkeye7 (discuss) 07:01, 16 April 2024 (UTC)
- That's not the case here, though, as there's nothing called a "Shuttle-Centaur" (that is, a Centaur that is also a shuttle, as distinct from maybe a "Saucer-Centaur"). This is instead the example given of Wilkes-Barre, a single city named after two people, but Minneapolis–Saint Paul, an area encompassing two cities UndercoverClassicist T·C 08:38, 16 April 2024 (UTC)
- We used a hyphen in the featured article, and it is used in the sources. The form with a solidus is also used in the sources. Hawkeye7 (discuss) 11:07, 25 April 2024 (UTC)
- Reading around, I can see the case for a hyphen: happy with this. UndercoverClassicist T·C 14:37, 25 April 2024 (UTC)
- We used a hyphen in the featured article, and it is used in the sources. The form with a solidus is also used in the sources. Hawkeye7 (discuss) 11:07, 25 April 2024 (UTC)
More to follow.
AG[edit]
Reserving a spot. Artem.G (talk) 19:01, 1 April 2024 (UTC)
First comments:
- Galileo Project managers table looks broken on mobile, I'd also suggest to move it from the lead.
Following the approval of the Voyager missions
- link Voyager programwould cost $634 million (equivalent to $2147 million in 2023)
- $2147 looks strange, IMO 2.147 billion reads better.develop and cost up to $100 million (equivalent to $339 million in 2023.[32][31]
- missing parenthesiswhile the legal challenge was not frivolous
- why frivolous is a red link?It was noted that the name was also that of a spacecraft in the Star Trek television show.
- maybe something like "The name also belongs to a spaceship in the Star Trek series."?a previously unknown radiation belt 31,000 miles (50,000 km)
andat an elevation of 112 miles (180 km) below
- you usually use km before milesScientist Carl Sagan, a strong supporter of the Galileo mission,
- maybe "The astronomer Carl Sagan ..."?- Lunar observations sections lacks any text, did Galileo made any important observations, or maybe the Moon was a test target for its cameras?
- I know that Galileo (spacecraft) exists, but I think a small section about the spacecraft and its instruments can be helpful.
On 26 March 1993, comet-seeking astronomers
- you use both 26 March 1993 and March 26, 1993 date formats in the article- Follow-on missions can be a little bit more verbose, at least for Juno.
More to follow later. Artem.G (talk) 19:34, 1 April 2024 (UTC)
More comments: Artem.G (talk) 18:05, 2 April 2024 (UTC)
and the Space Shuttle main engines (SSME) running at full power—109 percent of their rated power level.[20] Running at this power level necessitated the development of a more elaborate engine cooling system.[28]
- two questions. First: full power should be 100%, so is it correct to say "at full power" here? Maybe smth like "above its full power"? I don't know the right terminology here, so maybe I'm wrong. And second: why more elaborate cooling system was needed? The engines were not designed to work at full power?- 100% refers to the rated power. See RS-25#Upgrades. FPL was 109 percent of rated. Hawkeye7 (discuss) 21:01, 2 April 2024 (UTC)
but NASA hoped to be able to recoup some of this through separate completive bidding on the two.
- I'm not sure I understand what's "separate completive bidding"and the two Voyager spacecraft each carried 80 percent of plutonium
- 80% of Galileo's amount?- Maybe link Detecting Earth from distant star-based systems in Remote detection of life on Earth
the experiment was considered a resounding success and the data acquired will likely be used in the future to design laser downlinks that will send large volumes of data very quickly from spacecraft to Earth. The scheme was studied in 2004 for a data link to a future Mars orbiting spacecraft.[90]
- any updates on that? It's a bit strange to see future tense about data from 1992 experiment.- At the time it was written there was not, but in December 2023, NASA's Deep Space Optical Communications experiment on the Psyche spacecraft used infrared lasers for two-way communication between Earth and the spacecraft. Added this to the article. Hawkeye7 (discuss) 21:01, 2 April 2024 (UTC)
Through the implementation of sophisticated technologies
- what are these technologies? And does it mean that HGA was completely off, unable to transmit anything?a total power of about 10 zeptowatts
- a power of 10 should be more readablea 1980 suggestion that the results of Galileo could be distributed electronically instead of on paper was regarded as ridiculous by geologists
- just curious - it means that previously all data received from spacecraft (ie. Voyager) was printed and not stored on a tape or a computer, right?Its shape was not remarkable for an asteroid of its size.[110]
- what is a 'remarkable shape' for an asteroid?dubbed Dactyl after the legendary Dactyloi; craters on Dactyl were named after individual dactyloi.
- gloss dactyloiDactyl appeared to be an S-type asteroid, and spectrally different from 243 Ida
- type of Ida is not mentionedand telemetry from the spacecraft, travelling at the speed of light, took 37 minutes to reach the JPL
- it reads like the spacecraft itself is travelling at the speed of light. Suggest to change it to "transmitted at the speed of light"and how they had escaped from Jupiter's strong gravitational
- gravitational is a red linkAnother opportunity to observe Io arose during the GEM, when Galileo flew past Io on orbits I24 and I25, and it would revisit Io during the GMM, on orbits I27, I31, I32 and I33.[155]
- what're GEM and GMM? It's explain only in Mission extension, but should be explained at first mention.Occultations by Europa, Io and Jupiter provided data on the atmospheric profiles of Europa, Io and Jupiter
- that's a bit repetitiveClark Chapman argued
- need to be introducedWith more data on hand, in 2003 a team led Kevin Zahle
- "by" Kevin Zahle?Michael Carr, a planetologist from the US Geological Survey, argued that, on the contrary, the surface of Europa was subjected to less impacts than Callisto or Ganymede.[174]
- what was his justification?the Sun, which had only 4 percent of the intensity of Earth
- it reads strangeThe scientific community did not want a repetition of the 1979 Morabito incident
- did they really call it "the Morabito incident"?- I think that File:Shuttle-Centaur with Galileo.jpg is better than File:Model_of_Centaur_G_with_Galileo_probe_(upright).jpg
- I agree with Tercer, the patch looks strange, even though it is from NASA website (and was there since 1996)
- The image in the article is from a NASA site ([7]) and therefore regarded as authoritative.
- In Ganymede and Callisto sections, instead of real photos there are "The internal structure" images. I think real photos would suite the article better, and I'm not sure that internal structures (as pictured) were known during the project.
.jpg){kind=link}
![[7]](https://web.archive.org/web/20171225231937/http://history.nasa.gov/galileo.gif){kind=link}
Hey Hawkeye7, thanks for the great article and for quick fixes! I support the nomination, and it's probably the best article about a spacecraft mission that I've read. Artem.G (talk) 06:40, 3 April 2024 (UTC)
T[edit]
I'm not going to do a review, I'd just like to repeat a comment from my Good Article review three years ago that went unaddressed: the mission patch in the infobox is hideous, and it's not the real one. It's easy to find photos of the real one online [8] [9] and since it's NASA work it should be public domain. Tercer (talk) 08:50, 2 April 2024 (UTC)
- NASA's statement regarding all of its missions emblems is:
Their reproduction in any form other than in news, information and education media is not authorized without approval.
- Our use falls under this Fair Use clause, but Commons disagrees.
- I am will to upload a non-free image if that is the consensus here. Hawkeye7 (discuss) 21:01, 2 April 2024 (UTC)
- NASA's statement regarding all of its missions emblems is:
WSC[edit]
Queries by WereSpielChequers. I'm enjoying reading this but not sure I know enough about the topic to do a useful review.
- "Galileo performed close observations of another asteroid, 243 Ida, at 16:52:04 UTC on August 28, 1993, at a range of 2,410 km (1,500 mi). Measurements were taken from Galileo" Was 2,410 the closest approach or the point where they started taking observations? Maybe I'm wrong but my understanding of these flybys is that there is a brief period of time to take observations, and observations start and end at a greater distance than the instance of closest approach.
- "It orbits faster though, with a rotation period of 1.769 days. As a result, rotational and tidal forces are 220 times as great as those on Earth's moon." I thought that the greater mass and maybe proximity of Jupiter to Io as opposed to the Moon to Earth would explain the tidal forces. Though perhaps we are talking about tides on Jupiter as IO also faces Jupiter so the tidal forces would presumably be explained by a bulge.
That's it for now, maybe more later ϢereSpielChequers 12:25, 3 April 2024 (UTC)
"The orbiter was powered by 570-Watt (at launch) radioisotope thermoelectric generators (RTGs)" how many of these 570 watt generators?"The Rogers Commission handed down its report on June 6, 1986.[47] It was critical of NASA's safety protocols and risk management" I'm assuming this was a report on the Challenger disaster, but perhaps we should say so.
RoySmith (Support)[edit]
For now, just some random comments. I don't know if I'll have time for a full review.
- There's many citations to Meltzer 2007. Unfortunately, the PDF accessed by the URL only includes the front matter up to page xvii. Is there a better URL that gets the whole thing?
Background:[edit]
- "They were followed by the more advanced Voyager 1 and Voyager 2 spacecraft, which were launched on 5 September and 20 August 1977 respectively" Is it worth a short explanation here of why Voyager 1 was launched after Voyager 2?
Initiation:[edit]
- "NASA's Scientific Advisory Group (SAG)" the acronym SAG is never used after being defined here, so no reason to have it.
- It seems awkward to say "the JPL". Our own JPL article and https://www.jpl.nasa.gov/ call it just JPL; why not the same here?
- "and the probe would be the first to enter its atmosphere" I would make it "and the first to enter its atmosphere"
- "a Mariner spacecraft like that used for Voyager". I'm not 100% sure what this means. I think you mean "as was used for Voyager". The way it's written now, I could be taken to mean "of similar design".
- "Attitude was determined with reference to the Sun and Canopus" somewhere around here, include a link to star tracker.
- "This allowed it to take high resolution images". Clarify what "this" and "it" refer to. Either or both could be the accelerometer, which I don't think is what you intended. It's also unclear how better attitude control affected the camera resolution, which I assume was only a function of the camera sensor.
- It is easier to take longer exposures images if the camera is held still. Hawkeye7 (discuss) 01:37, 7 April 2024 (UTC)
- Sure, but less camera motion is not the same as higher resolution. On the other hand, now that I've got the full Meltzer PDF (thanks!), I see that it does indeed say "could help maximize photographic resolution". I think that's a bizarre way to say it, but that is what the source says, so who am I to argue with NASA? RoySmith (talk) 02:22, 7 April 2024 (UTC)
- It is easier to take longer exposures images if the camera is held still. Hawkeye7 (discuss) 01:37, 7 April 2024 (UTC)
- "Independent Agencies Appropriations Subcommittee". Many of these subcommittees have a linkable article. Is there one for this?
- "Casani solicited suggestions for a more inspirational name for the project". I had to go hunting a few paragraphs back to figure out who Casani was, so maybe re-introduce him here as "project manager Casani"?
- "from people associated with it, and the most votes went to " this is a long sentence. Maybe instead of the comma, a full-stop or semicolon?
- " Casani officially announced that he had chosen the name", was the choice his alone, or was he just announcing the result of a group decision?
Preparation[edit]
- "a launch on Space Shuttle Columbia on the STS-23 mission" rephrase to avoid the repetition of "on". Maybe "Space Shuttle Columbia's STS-23 mission"?
- "sometime between 2 and 12 January 1982" is inconsistent with {{Use mdy dates}}
- "the Galileo project's engineers decided" I think you can just say "project engineers decided" and trust the reader to understand that you're talking about the Galileo project.
- Changed as suggested
- "To enhance reliability and reduce costs ... This improved reliability and reduced costs" eliminate the redundancy.
- "Another 165 kilograms (364 lb) was added in structural changes to improve reliability" aerospace engineers don't take on 165 kg without a good reason (famous quote: "I’d sell my grandmother for a one-pound reduction!"); is there something more we can say here about what this additional weight was used for?
- "the three-stage IUS was itself overweight" overweight compared to what? It's maximum design capacity? Some assumed weight used in early mission calculations?
- "NASA decided to split Galileo into two separate spacecraft, an atmospheric probe and a Jupiter orbiter". This is confusing. Perhaps this gets cleared up later on, but at this point I'm lost, trying to figure out if we're talking about one spacecraft or two. Here, you talk about two. But in the lead, you say "the Galileo spacecraft consisted of an orbiter and an entry probe. It was delivered into Earth orbit on October 18, 1989" so that's one spacecraft.
- "a signal from Earth takes anything from 35 to 52 minutes to reach Jupiter". A few points here. First, "anything" is kind of informal language. But more importantly, I'd explain the nature of this variation; i.e. it's because the Earth-Jupiter distance varies depending on where they both are in their orbits; readers who are not familiar with how this stuff works might guess it has to do with other factors like varying amounts of power available on the spacecraft, or whatnot. Also, I think these sorts of things are typically cited as round-trip time because that's what really matters if you're trying to do remote control; downlink delay to send telemetry, plus the uplink delay to send a command based on the telemetry you received.
- You need to define USAF the first time you use it.
- "autonomous spacecraft,[35] which was a necessity for deep space probes," There's something odd about the grammar here, but I'm not sure what. Maybe "were a necessity" (or, just "were necessary")?
- " posed little value when observed from a safe distance," I don't think "posed" is the right word here. Maybe "Provided"?
- "Most of the asteroids in the vicinity ... one of the largest of the asteroids" No need to repeat "asteroids"
- As a generic comment, you use "flyby" many times in the article, but never explain what it is. For the benefit of our readers who don't know anything about spaceflight, you should explain what a flyby is the first time it's used in the main body.
- Even more generically, please read through the entire article looking for technical words and consider whether a naive reader would understand them. As an example, you talk about "the orbiter in February 1984 with the probe following". How does an orbiter differ from a probe? Other words that might need explaining include "autonomous", "attitude" (we don't want to be launching any spacecraft in a bad mood!) but those are just a few examples, I'm sure you'll find more.
- Still talking generically, it might be a good idea to give real-life examples of units that a reader might be unfamiliar with. For example, "a lithium–sulfur battery rated at 730 Watt-hours"; it would help the reader understand this better if you said that was about how much energy is in a typical car battery (but please double-check me on that and find a WP:RS)
Spacecraft[edit]
(my apologies for these comments comming in dribs and drabs)
- "general-purpose heat source radioisotope thermoelectric generators (GPHS-RTGs)" WP:SEAOFBLUE. I suggest only linking to GPHS-RTG, and let people drill down from there if they want more details.
- "generated 570 Watts at launch ... rated at 730 Watt-hours." I'm not sure how to handle this better, but it's jarring to have two consecutive sentences talking about power sources using different units (power vs energy). I understand the difference, but I suspect a less technically savvy reader will just be confused and/or come away with the wrong impression that the battery is "bigger" than the RTG, when in fact those values can't be compared in any useful way. I see that you're just giving the data as it's presented in the NASA report, but it would still be nice if there was a better way to present this. Actually, a quick calculation says average of 520 watts x 8 year = 36 MW-Hrs. Upon reflection, this makes sense; the battery only runs the atmopheric probe for the short time it takes to descend and burn up. Hopefully you can find some RS that goes into this sort of analysis so you can present it in the article.
- "Heavy Ion Counter." Why the upper case?
- A holdover from the original version, which used this form. After a change in the MOS (MOS:EXPABBR) in 2017, I and other editors went through the article and removed the uppercasing of abbreviated forms. De-capped. Hawkeye7 (discuss) 21:36, 13 April 2024 (UTC)
Reconsideration[edit]
- "flight tore the spacecraft apart" seems like an unencyclopedic way to phrase that. Maybe something like "Resulted in loss of the vehicle and the deaths of ..."
- "This was only partly due to the NASA management's increased aversion to risk in the wake of the Challenger disaster; NASA management also considered ..." This appears to be based on a p 217 quote from Marty Winkler of General Dynamics commenting on his interpretation of NASA management's decision. So I think this deserves attribution as Winkler's opinion.
- "for a time it looked like its next trip would be to the Smithsonian Institution." That's a cute way to phrase it, but maybe it should be stated a bit more formally. Also, it's an unattributed quote from the source, so that's a problem.
- "southerly declination of −23 degrees" -> "declination of 23 degrees south" Likewise for "northerly one of +18 degrees"
- "Furthermore ... so the main tracking station would be the Canberra Deep Space Communication Complex in Australia". That makes it sound like using Canberra is a problem. Is it? Why?
Nuclear concerns[edit]
- "plutonium in the Galileo's radioisotope thermoelectric generators (RTGs) and General Purpose Heat Source (GPHS) modules" This makes it sound like these are two different things, each with their own plutonium supply. My reading of GPHS-RTG leads me to believe this is a single unit with a single plutonium supply which performs both functions, so this needs to be clarified.
- The overall tone of the first paragraph seems in violation of WP:NPOV. You minimize the risk ("what they perceived as an unacceptable risk") and then state in wiki-voice that "They had been used for years in planetary exploration without mishap", implying that there is indeed no risk.
- " If the Galileo/IUS combination fell free of the orbiter". Missing a word? of -> from, perhaps?
- "an accident might have released up to 11,568 curies (428,000 GBq)." Another example of a unit which is almost certainly unfamiliar to most of our readers. Is that a lot? Are we talking a couple of dental X-ray's worth or another Chernobyl? Likewise with "NASA concluded that the chance of such a disaster was 1 in 2,500". I have no idea if that's a lot compared to all the other risks. NASA must have some standard risk analysis budget. How does this compare with other missions? Also, what does "such a disaster" refer to? In ther previous paragraph you give two different scenarios; which of those is this?
- Chernobyl released between 50 and 185 million curies; three mile island released about 2.5 million curies. I have no figures on the risk assessments of other missions. Part of my job involves carrying out risk assessments, and the low odds and moderate consequences would mean approval. Linked the unite. Deleted "such". Hawkeye7 (discuss) 21:36, 13 April 2024 (UTC)+
Launch[edit]
- "There were fears that the spacecraft might be hijacked by anti-nuclear activists or terrorists". I'm guessing this is due to the plutonium, but please don't make the reader guess. As an aside, I also have to wonder about the risk was of sleep-deprived truck drivers in a high speed convoy over an unfamiliar route at night having a crash. :-)
- Apparently, there is a Nova (American TV program) episode about this, but I haven't seen it. Added that the plutonium was the concern. Hawkeye7 (discuss) 21:36, 13 April 2024 (UTC)
Venus encounter[edit]
- "three hours into the flyby, the tracking station at Goldstone had to be shut down due to high winds" If it was being tracked by Canberra and Madrid, why did it matter what was going on at Goldstone? I'm guessing the answer is that by the time three hours had passed, Goldstone had become the active station, but that should be explained for the benefit of our less technically savvy readers. It also seems odd that you give the time of the flyby down to the second ("05:58:48 UTC") implying it's a discrete moment in time, then later talk about being three hours into it. Maybe just note that 05:58:48 was the time of closest approach?
- You might also want to explain that doppler provides a direct measurement of the relative velocity between two bodies (in this case, Galileo and the Earth). Again, this is something our more sophisticated readers will know, but will leave others struggling to understand.
- Doppler is linked. Hawkeye7 (discuss) 21:36, 13 April 2024 (UTC)
- Yeah, but I think it would still be better to provide some explanation here. I suspect most people are familiar with the "train whistle gets lower in pitch as the train passes" demonstration, but I don't think they would necessarily make the leap to "by measuring the change in carrier frequency of the spacecraft's transmission compared to the nominal frequency, you can compute the spacecraft's velocity relative to Earth", and Doppler effect isn't much help for the casual reader trying to figure that out. Likewise, they might have heard of "Doppler radar" in the context of some gizmo the cops use to give you a speeding ticket, but I think it's asking a lot to expect the casual reader to understand the application of that to space navigation. RoySmith (talk) 00:27, 14 April 2024 (UTC)
- "low gain antennae (LGA)" probably should be "LGAs" (plural)
- "DSN's 70 meters (230 ft)", meter (singular)
- "Earth's strong magnetic field causes this to occur ... from its center," it's unclear what "this" and its" refer to. I think you're talking about the Earth's bow shock, and the Earth's center, but clarify.
- "causes the bow wave", I assume "bow wave" and "bow shock" are synonyms, but perhaps reduce confusion by just using the same term in both places.
- Used "bow shock" consistently.
Earth encounters[edit]
- "Galileo made two small course corrections on 9 to 12 April and 11 to 12 May 1990". The source says, "TCM4 was the largest course correction that Galileo would have to perform", which seems at odds with your statement that they were "small".
- "the first time that a deep space probe had returned to Earth from interplanetary space." this is almost word-for-word from the source and is thus a WP:CLOP violation. Either rephrase in your own words or make it a direct quote.
- WP:LIMITED applies here. Hawkeye7 (discuss) 00:13, 14 April 2024 (UTC)
- "The opportunity was taken to conduct a series of experiments." This sentence only makes sense when read in the context of the section heading; it should stand on its own.
- "These included strong absorption of light ... caused by absorption" too many absorptions.
- "These included strong absorption ... of any known natural source" run-on sentence
- "the first ever controls" link to Scientific control
- "another groundbreaking experiment was performed" in who's opinion was it groundbreaking? And since this is "another groundbreaking experiment", what were the other(s)?
- "frequency doubled Nd:YAG laser" SEAOFBLUE, also, link more specifically to Nonlinear optics#Frequency doubling.
- "at a wavelength of 532 nm" I'll admit to not understanding most of Nonlinear optics, but I assume if the frequency doubled, the wavelength is halved, which leads me to wonder if 532 nm is the wavelength before or after the frequency doubling.
- "Cassegrain telescope" link to Cassegrain reflector (I assume that's the right target). I've never heard of using a telescope to transmit an optical beam, but obviously the optics are symmetric, so I assume you put the laser into "eye" end, but it might be worth clarifying that.
- The source says: "coupled to a Cassegrain telescope through a coudé mount arrangement." Hawkeye7 (discuss) 00:13, 14 April 2024 (UTC)
- Add link to Reflecting telescope#Coudé RoySmith (talk) 00:32, 14 April 2024 (UTC)
- "produced images of Earth clearly showing the laser pulses" did they just detect the pulses, or was data actually communicated over this carrier?
High gain antenna problem[edit]
- "Once Galileo headed beyond Earth, it was no longer risky to employ the HGA", HGA was defined several sections earlier; it might be useful to re-introduce where what the acronym means.
- "or 330 seconds if one failed" -> "... if one actuator failed".
- "They would drive a worm gear." Not clear what "they" is; probably "the actuator motors", but this and the previous sentence could be combined and rephrased to make that more clear.
- I assume "graphite-epoxy" means Carbon-fiber reinforced polymer; if so, link.
- ", and when the driver motor started " -> combine with previous sentence with a semicolon, dropping "and".
- "the spacecraft's spin rate had decreased" I assume this was due to the increased moment of rotational inertia? If so, it would be good to explain that (assuming a RS says so).
- "The first suggestion was to re-fold the antenna" who suggested this?
- "so after five deploy and stow operations, the DDA torque was half its original value" This is confusing. Previously you said they didn't try to refold it, and now you're saying they tried five times. Something's amiss here.
- "during the 4.5 years that Galileo spent in storage ... eroded and worn by vibration during the three cross-country journeys by truck" So, did the damage happen during storage or during truck rides?
- "since it transmitted a signal isotropically" this is confusing. Earlier you talk about swinging LGA-1 and LGA-2 to their hard stops, which implies some kind of aiming capability. But now you're talking about isotropic radiation, which to me says it's not aimed in any particular direction. This should be clarified.
- Looks like you have found an error in the source. Corrected. Hawkeye7 (discuss) 00:13, 14 April 2024 (UTC)
- I don't understand what "which transmitted over a one-sixth half-angle" means. One-sixth of a degree? One sixth of the beamwidth of the LGA? Also, in "its bandwidth was significantly less", I'd be specific and say "data bandwidth" or "digital bandwidth", or even better, "data rate" to avoid confusion with Bandwidth (signal processing). RoySmith (talk) 14:39, 14 April 2024 (UTC)
- Also, "The two LGAa were capable of ... but since it transmitted its signal" plural/singular inconsistency. RoySmith (talk) 14:40, 14 April 2024 (UTC)
- And, "but since it transmitted its signal over a cone with a 120-degree half-angle ... its bandwidth was significantly less than that of the HGA," implies that the beamwidth was the only cause of the reduced data rate. In reality other causes were reduced transmit power and (if I'm reading this right) the need to use a smaller aperture receiving antenna on S-band. RoySmith (talk) 14:45, 14 April 2024 (UTC)
- Typo. It should have been "a half-angle of one-sixth of a degree". Corrected. Hawkeye7 (discuss) 21:57, 14 April 2024 (UTC)
- You also should say some more about how they switched to a better compression algorithm. The JPL source says "By programming a software (11,1/2) convolutional code on a Galileo compute". I assume this meant they had the ability to upload new software to the spacecraft, which certainly deserves at least some explanation. RoySmith (talk) 14:50, 14 April 2024 (UTC)
- And, "but since it transmitted its signal over a cone with a 120-degree half-angle ... its bandwidth was significantly less than that of the HGA," implies that the beamwidth was the only cause of the reduced data rate. In reality other causes were reduced transmit power and (if I'm reading this right) the need to use a smaller aperture receiving antenna on S-band. RoySmith (talk) 14:45, 14 April 2024 (UTC)
- Also, "The two LGAa were capable of ... but since it transmitted its signal" plural/singular inconsistency. RoySmith (talk) 14:40, 14 April 2024 (UTC)
- "Conservatism was not restricted to engineers ... putting a wooden ruler up to the screen." This sentence seems out of place for this section.
- Storage was expensive in the 1980s. The organization I worked for abandoned plans to put five years data online in favour of just 12 months because each month required a disk that cost $20,000 at the time, so that saved nearly a million dollars. A decade later, I bought the 48 disks for $200 each on my corporate Amex card. Hawkeye7 (discuss) 21:57, 14 April 2024 (UTC)
Asteroid encounters[edit]
- link asteroid belt
- S-type asteroid 951 Gaspra SEAOFBLUE
- False titles are allowed in American English, but re-worded. Hawkeye7 (discuss) 21:57, 14 April 2024 (UTC)
- "passing ... to a distance" to -> at? Or maybe "within"?
- "In all, 57 images of Gaspra were taken", drop "In all"
- "Perhaps the most surprising feature was several relatively flat planar areas" Who is making the editorial judgement about how surprising this is? "According to Joe Scientist, the most surprising feature was..."
- "Galileo suddenly abandoned the program and resumed its cruise configuration." Unclear what that means. What is "the program"? Does resuming it's cruise configuration mean it attempted to undo the course correction, or powered down the instruments it was going to use for observing, or something else maybe? Also, "suddenly" sounds like editorializing, so attribute: "Fred Flight Controller said the configuration change happened suddenly".
- "Measurements were taken from Galileo using SSI and NIMS" Drop "from Galileo". Of course they were taken from Galileo; there's no other possible place they could have been taken from.
- "The requirement to use the LGA resulted in a transmission rate of 40 bits per second." You've said this already in a previous subsection, so no need to repeat. Or maybe something like: "At this time, the LGA was still only running at the 40 bps data rate available during the Gaspra flyby", which gives the reader some context about where they were in the ongoing efforts to increase the data rate.
Voyage to Jupiter[edit]
- "A tiny Doppler shift in the signal of the order of a few centimeters per second" This seems like a weird mixing of units. Doppler shift is a change in frequency. From that you can compute a velocity. So, "A velocity change of a few centimeters per second, as measured by Doppler shift".
- "it was fired for the first time" Perhaps I'm picking nits here, but was it ever test fired on Earth? If so, "fired for the first time in XX years", or "after completing its manufacturing tests", or whatever. It's certainly possible this was its first firing ever; some engines are never test fired before a mission, but some are.
- "it would perform as a communications relay": maybe "perform" -> "act" ?
- " The Galileo probe's project manager ... this role could be performed by LGA-1" This sentence is awkwardly placed. The previous sentence talks about firing the engine, and the next sentence talks about how that firing changed the velocity, but this sentence has nothing to do with the engine.
- The "Isbel, Douglas; Wilson, James H. "Galileo Flying Through Intense Dust Storm" (Press release). NASA/Jet Propulsion Laboratory. 95-147. Retrieved November 16, 2020. URL can't be reached.
Jupiter[edit]
- "when it was still 15 million kilometers (9.3 million miles) from Jupiter", drop "still"
- "The bow shock was not stationary, but moved to and fro in responses to solar wind gusts" "not stationary" is redundant with "moved". Also, responses -> response
- "by which time it was 9 million kilometers" unclear what "it" refers to.
- " Most robotic spacecraft respond to failures by entering safe mode ... not possible for Galileo.[136]" You've already discussed the need for autonomous operation in Preparation; no need to go over that again here.
- "The descent probe awoke in response to an alarm" the word "alarm" sounds like there was some kind of failure that it was responding to. Maybe "timer" wou;d be a better word?
- "encountered a previously undiscovered belt of radiation ... Before the atmospheric entry, the probe detected a previously unknown radiation belt". Is this two different belts? Needs to be clarified one way or the other.
- You use "bars" as a unit. I'm pretty sure it's not supposed to be pluralized, i.e. "1.5 to 2 bar". I also don't see the point of {{convert}} here; that's useful for metric-english conversions, but bar -> kPa doesn't add anything of value.
- "The probe slowed to subsonic speed" It's not clear what "subsonic" means in this context. I assume we're talking about below the speed of sound in the local Jovian atmosphere? If so, clarify that, and give a number for what Mach 1 is in those conditions.
- "which would then take days to arrive using the LGA" maybe "to be transmitted" instead of "to arrive"?
- "a pressure of 22.7 standard atmospheres" earlier you used "bar"; why the switch to "standard atmosphere" here?
- "completely destroying it" How does "completely destroying" differ from just plain "destroying"?
- "more winds than expected" -> "stronger winds than expected"
- "The atmosphere was more turbulent and the winds a lot stronger than expected." largely duplicates the previous sentence.
- "it entered a 198-day parking orbit" link Parking orbit. Also, it's not clear what 198 days refers to. Is that how long it was in orbit, or how long a single orbit took?
- Orbital period - added explanation. Hawkeye7 (discuss) 20:32, 15 April 2024 (UTC)
- "Most of its initial 7-month long orbit", we already know it's 198 days, no need to convert that to months.
(note to self: next up, Io)
Io[edit]
- "radius of 1,821.3 kilometers" -> mean radius
- Link orbital resonance here, since it's the first use (and unlink under Europa)
- Link "Tidally locked" to Tidal locking
- Link "Earth's moon".
- "to melt rock and create volcanoes and lava flows." rephrase to avoid repeating "and"
- " Only the fields and particles instruments were allowed to collect data, as these required the tape recorder to run at slow speeds, and it was believed that it could handle this, whereas the SSI camera required it to operate a high speed, with abrupt stops and starts." This is almost word-for-word from the source. See WP:CLOP.
- "When Galileo next approached Io on I25 at 20:40 Pacific Time" I get that the source you're citing uses Pacific Time, but you're using UTC everywhere else, so convert to UTC.
- "Galileo flew past Io on arrival day" explain what "arrival day" is, probably under the "Arrival" section above. There's a bunch of possible days that could be called that (arrival at the bow shock, closest point of approach to Jupiter, entering orbit, etc)
- "As a consequence, three quarters of the observations were taken over a period of just three hours." I don't understand why this is a consequence of there being an Earth-Sun conjunction.
- Galileo cannot be received when the line of sight is blocked. Hawkeye7 (discuss) 04:49, 16 April 2024 (UTC)
- Yeah, but that only affects transmitting data to Earth. Observations can still happen and record the data on tape, so I still don't see how one is a consequence of the other. RoySmith (talk) 17:47, 16 April 2024 (UTC)
- Link to Solar conjunction
- "The I24, I25 and I27 encounters had been on equatorial orbits, which made it difficult to determine whether Io had its own magnetic field, or one induced by Jupiter" why does being in equitorial orbit make this difficult? And, are we talking about Jupiter's equator or Io's equator?
- "but data transmission was hindered by a Solar occultation" link to Occultation
- A likely source was brine below the ice crust" link brine
(up to Ganymede)
Ganymede[edit]
- "with a diameter of 5,270 kilometres" you describe the other moons by their radii. Pick one and use it consistently. Also, be consistent about kilometres vs kilometers.
- "strength of about 750 nanoteslas (0.0075 G)" Tesla and Gauss are both SI units; no need to show both. But it would be useful to compare this to the strength of Earth's magnetic field, since most readers will have no clue how big a Tesla is.
- Link "inclination" to Orbital inclination.
- "This discovery led naturally to questions about its origin." "This" and "its" both refer back to the previous paragraph. Maybe just combine the two paragraphs.
- "the scientist in charge of the magnetometer experiment" needs a comma after.
- Not sure if "Arbela Sulcus" needs to be capitalized.
Callisto[edit]
- "allowed them to operate as a gigantic array" link to Aperture synthesis
- "enabling a higher bit rate despite the spacecraft's long distance from Earth", Drop the "despite ...." clause; the larger aperture allowed for a higher bit rate regardless of all other factors. The biggest problem here was that the HGA was inoperative; the transmission distance was exactly what was expected during mission planning.
- "40 percent ice." clarify what you mean by "ice" Do you mean specifically frozen H2O, or the more general sense i.e. Volatile (astrogeology)#Planetary science.
Amalthea[edit]
- "long axis towards Jupiter at all times ... pointed in relative to Galileo at all times." rephrase to avoid the repetition of "at all times'.
- "weighed 2.08×1018 kilograms" -> "had a mass of ..."
- "debris ejected from Amalthea and form a tenuous, and perhaps temporary, ring.[220]" A ring around Jupiter or around Amalthea?
Star scanner[edit]
- "predominantly >2 MeV (0.32 pJ) electrons" Is there any reason to convert to J? I would think MeV would be the universally used unit of measurement here.
- They are, but... MOS:CONVERSIONS: "For units of measure that are ... not part of the SI or US customary systems... supply a parenthetical conversion into at least SI units." Electron volts are Non-SI units mentioned in the SI, hence a conversion is supplied. Hawkeye7 (discuss) 20:13, 16 April 2024 (UTC)
- "second magnitude star Delta Velorum" link to Magnitude (astronomy)
[edit]
- The Tomayko, James E. (March 1988) URL 404's
End of mission and deorbit[edit]
- "Galileo impacted Jupiter in darkness just south of the equator" What does it mean to "impact" something made of gas?
- The sources consistent use the term, and we have a whole article on impact events on Jupiter that does not define it. But at some point it gets so dense that it is like hitting a solid surface.
- "Galileo had not been sterilized prior to launch and could have carried bacteria from Earth." link sterilized and bacteria.
OK, finally got to the end. So much for "just some random comments" :-) I'm going to give this a rest for a bit then come back and see how things look overall.
Second pass[edit]
- The orbiter would be in orbit around Jupiter when the probe arrived, allowing it to perform its role as a relay." It's unclear what "it" refers to: the orbiter or the probe.
- "required a second Space Shuttle mission and a second carrier to be built for the probe" What is the carrier? I'm guessing it's some mounting adapter that lets you install the probe into the shuttle cargo bay, but clarify.
- "NASA hoped to be able to recoup some of this through competitive bidding." You put that in just for comic relief, right?
- "President pro tempore of the Senate" I don't think I've ever seen this spelled out in full, it's always just "president pro tem", so that's probably what we should use here.
General comments[edit]
- All images need MOS:ALT text. Some images (for example, File:Galileo atmospheric probe.jpg) include extensive amounts of text, so pay close attention to MOS:TEXTASIMAGES.
- At this point, the lack of ALT text is the only thing holding me back from supporting this. RoySmith (talk) 12:07, 19 April 2024 (UTC)
- The ALT for File:Galileo atmospheric probe.jpg got cut off (I assume there should be a number at the end), but that won't keep me from supporting. Overall, an interesting article. Thank you for submitting it, and for putting up with my nit-picking. RoySmith (talk) 17:19, 25 April 2024 (UTC)
- At this point, the lack of ALT text is the only thing holding me back from supporting this. RoySmith (talk) 12:07, 19 April 2024 (UTC)
Image and source review[edit]
File:Artwork Galileo-Io-Jupiter.JPG, File:Galileo Preparations - GPN-2000-000672.jpg, File:Galileo probe deployed (large).jpg, File:The Moon from Galileo - GPN-2000-000473.jpg, File:Ganymede diagram.svg, File:Galileo Amalthea artwork.jpg, File:Galileo End.jpg and File:Galileo mission patch.png have broken source links. File:Astronauts John Fabian and Dave Walker pose in front of a model of the Shuttle-Centaur.jpg should have a non-direct image link, especially as it seems to have come from a different website. Is there no source link for File:Galileo in 1983.jpg? File:Descent Module.jpeg and File:Jupiter's clouds.jpg need more information. File:Galileo Probe - AC81-0174.jpg has a broken link, which also seems to be a direct link. Not a comment on images, but the follow-up missions sections seem to be pretty spartan. ALT text ought to get consistent capitalization. Also, Artwork Galileo-Io-Jupiter.JPG probably needs a more detailed ALT text, since it describes the apparel of Galileo. Ditto File:Descent Module.jpeg. File:243 ida.jpg'ALT is talking about the wrong moon. Image:Galileo atmospheric probe.jpg'ALT doesn't have the pressure. File:Plate Tectonics on Europa.jpg's ALT probably wants to say "cryolavas"; "cryolarvae" is an interesting concept though.
.jpg){kind=link}
- File:Artwork Galileo-Io-Jupiter.JPG, File:Galileo mission patch.png: secondary links still work.
- File:Galileo Preparations - GPN-2000-000672.jpg, File:The Moon from Galileo - GPN-2000-000473.jpg], File:Ganymede diagram.svg, File:Galileo Amalthea artwork.jpg, : Added archive URLs.
- File:Galileo probe deployed (large).jpg: not broken.
- The second and third link are, and the first doesn't show the image. Jo-Jo Eumerus (talk) 08:20, 26 April 2024 (UTC)
- File:Galileo in 1983.jpg: Added source.
- File:Astronauts John Fabian and Dave Walker pose in front of a model of the Shuttle-Centaur.jpg Link is fine. Requests for direct links will not be honoured. Hawkeye7 (discuss) 17:30, 25 April 2024 (UTC)
- Sorry, meant "non-direct" link. As in, a link to the webpage where you found the image, not a link to the image itself. Such direct links can be hard to repair when they break, and the information the link is there for (e.g copyright statements) isn't on the file page. Jo-Jo Eumerus (talk) 08:20, 26 April 2024 (UTC)
Source review-wise, I am checking this version; spot-check upon request. #44, #71, #75, #150, #175, #204 are broken. #177 can probably get a better source information than a raw URL. What makes #224 and #225 a reliable source? I am wondering about spaceflightnow.com too, since they don't give much information on themselves. I presume the differences between various sources with respect to identifiers are b/c some of them have identifiers and others don't? That needs doublechecking as e.g Cowen 2001 doesn't have the doi 10.2307/3981750 shown. Jo-Jo Eumerus (talk) 13:01, 25 April 2024 (UTC)
- #44, #71, #75, #150, #175, #204 have the archive URL added.
- #177
- Deleted #225
- Spaceflightnow.com is considered reliable (Wikipedia:Reliable sources/Noticeboard/Archive 40)
- Hmm? The only mention of Spaceflightnow.com is when it is compared to a different source. Jo-Jo Eumerus (talk) 08:20, 26 April 2024 (UTC)
- I consider Spaceflightnow.com a reliable source for Spaceflight news. We can ask at the WP:RSN. Hawkeye7 (discuss) 12:47, 26 April 2024 (UTC)
- It's not clear to me what editorial oversight Spaceflight Now provides, and that's what determines if it's a RS or not. They have a "Member Content" section (https://spaceflightnow.com/category/members/); I'd be wary of using anything from there (not that you have). Looking at the four citations to Spaceflight Now, two ("Galileo to fly over source of recent polar eruption on Io" and "Galileo data recorder still not working") are NASA/JPL NEWS RELEASE, so clearly no problem with those as far as RS goes, but the citations are wonky; they should have NASA/JPL as the publisher and Spaceflight Now noted as the content deliverer using the "via" attribute (or find the originals on a NASA site). "Galileo spacecraft crashes into Jupiter" is by Peter Bond who has published several books through reputable publishers (https://peterbondspace.com/) so I'm inclined to accept him as a RS based on WP:EXPERTSPS. "The Galileo trials" by Ben Evans I'm less sure about. He's described as "a schoolteacher and freelance astronomy and space exploration writer", so I'll need some more convincing to accept him as an expert. RoySmith (talk) 16:42, 27 April 2024 (UTC)
- I consider Spaceflightnow.com a reliable source for Spaceflight news. We can ask at the WP:RSN. Hawkeye7 (discuss) 12:47, 26 April 2024 (UTC)
- Hmm? The only mention of Spaceflightnow.com is when it is compared to a different source. Jo-Jo Eumerus (talk) 08:20, 26 April 2024 (UTC)
- Cowen (2001) doi looks okay to me. Hawkeye7 (discuss) 17:30, 25 April 2024 (UTC)
- Now that it's added, yes. I just wonder if there are other sources that could have DOIs added. Jo-Jo Eumerus (talk) 08:20, 26 April 2024 (UTC)
- I added the doi in December 2020 ([11]). Are we talking about the same link? Usually I rely on the citation bot to add them. Hawkeye7 (discuss) 12:47, 26 April 2024 (UTC)
- Nevermind that, I have no idea what I was seeing there. Jo-Jo Eumerus (talk) 13:57, 26 April 2024 (UTC)
- I added the doi in December 2020 ([11]). Are we talking about the same link? Usually I rely on the citation bot to add them. Hawkeye7 (discuss) 12:47, 26 April 2024 (UTC)
- Now that it's added, yes. I just wonder if there are other sources that could have DOIs added. Jo-Jo Eumerus (talk) 08:20, 26 April 2024 (UTC)