Talk:Dawn (spacecraft)/Archive 1

new comments
It seems that much of the discussion below, debating the 'anticipated' dates, is moot, unless the historical record is in doubt. Several of the comments are themselves, undated.

orbital mechanics of the mission
It is not mentioned, so I would like to see the very distinctive features of the very low thrust orbital mechanics of this mission addressed/discussed/described. I suspect it is much like the trajectories of light sail spacecraft, in that the thrust is almost tangent to the current orbit, and chosen to drive the craft into 'higher' orbit, nearer the next target body, much more than to 'shoot it at' the target. I also suspect that it takes many (hundreds? of) orbits at 'full power' to lift it from a close (planetary) orbit, to get it to break back into a solar orbit (no longer bound to the previous body). Since it is now ('141229) only a few months from Ceres insertion, is it decelerating to allow capture (and avoid fly-by), or is the insertion a low-delta capture. It sounds like some of the other contributors might have, or have access to, the formulas and details of these trajectories and techniques. Wikidity (talk) 04:53, 31 December 2014 (UTC)

old comments
I'm not sure where to write this as I have just started adding articles to Wikipedia. I'm a JPL engineer that has delivered hardware and is now working ATLO on the DAWN spacecraft. I'd like to add comment to the page but would like to channel the info through the main person running the page. One change is... Technically, L3 Communications (?) Electron Technologies Inc. (L-3 ETI) (formerly a division of Boeing) of Torrance, CA, built the ion thrusters. JPL provides the integration and control of the Ion Propulsion System (IPS), which includes the Thruster Gimbal Assembly (TGA)(this is what I delivered), DCIU, PPU, XFS, and the Ion Thruster. Also, is there a page that shows the phase breakdown of NASA missions and can this article publish the cost profile (and any other info) per phase? I'd like to help, let me know. -gg3369 3 August 2006


 * There isn't any "main person running the page", in fact there's an official policy against that sort of thing (Ownership of articles). If you have an idea for a way to improve the article then by all means just dive right in and make the change. The stuff you mention above looks interesting, though I have insufficient background knowledge to feel comfortable adding it myself. I would suggest, though, that you might want to include some sort of external reference to allow the information you add to be verified by third parties. Doesn't have to be something as rigorous as a journal article, just something to reassure people the information isn't coming out of thin air. Bryan 07:01, 4 August 2006 (UTC)

I'm really curious to know how Ceres might look. I did not know this project (but so many years to reach it...) Please upload images to commons. It is better for all of us. -Pedro 20:00, 26 August 2005 (UTC)
 * Here is one. --Bricktop 20:16, 26 August 2005 (UTC)


 * There are some very, very low-grade images of Ceres currently existing; however, they're good enough that some features can be identified. Image:1 ceres.png. Shimgray 20:21, 26 August 2005 (UTC)


 * thx ppl. I don't like that pic of Ceres. LOL. But at least is something! In the Italian wiki there is a nice artwork on 1 Ceres. But as we know this maybe different from what's out there. -Pedro 00:06, 29 August 2005 (UTC)
 * There are some better ones here:
 * and on page 13 of this pdf file: :.

Postponement
At IAF in Fukuoka last week it was announced that Dawn will be postponed by six to nine months, probably launched early 2007, with no impact on the overall schedule thanks to ion propulsion.Hektor 11:03, 23 October 2005 (UTC)
 * Getting worse, there are now cancellation rumors circulating at NASA.12.163.163.195 00:19, 4 November 2005 (UTC)
 * Seems to take this direction


 * No more rumors, it's over. :( i 7 s 03:51, 3 March 2006 (UTC)
 * Oh no it's not! :-) smyles 19:57, 27 March 2006 (UTC)

Images
I've dropped the one fair-use image, as part of our program of clearing out nonfree images. I notice the Dawn website has some photos of the real craft that would make nice substitutes (already on commons perhaps?) Stan 14:38, 9 December 2005 (UTC)
 * Plz upload pics to commons. :\ It is a very nice pic!!! :) --Pedro 21:31, 9 December 2005 (UTC)

Dawn is back
Source: NASA news release. It should be public domain as a U.S. gov't work, so I'll post it here, and we can work the information into the article. Jonathunder 22:59, 27 March 2006 (UTC) NASA senior management announced a decision Monday to reinstate the Dawn mission, a robotic exploration of two major asteroids. Dawn had been canceled because of technical problems and cost overruns. The mission, named because it was designed to study objects dating from the dawn of the solar system, would travel to Vesta and Ceres, two of the largest asteroids orbiting the sun between Mars and Jupiter. Dawn will use an electric ion propulsion system and orbit multiple objects. The mission originally was approved in December 2001 and was set for launch in June 2006. Technical problems and other difficulties delayed the projected launch date to July 2007 and pushed the cost from its original estimate of $373 million to $446 million. The decision to cancel Dawn was made March 2, 2006, after about $257 million already had been spent. An additional expenditure of about $14 million would have been required to terminate the project. The reinstatement resulted from a review process that is part of new management procedures established by NASA Administrator Michael Griffin. The process is intended to help ensure open debate and thorough evaluation of major decisions regarding space exploration and agency operations. "We revisited a number of technical and financial challenges and the work being done to address them," said NASA Associate Administrator Rex Geveden, who chaired the review panel. "Our review determined the project team has made substantive progress on many of this mission's technical issues, and, in the end, we have confidence the mission will succeed."

Definition of Planet debate...
So.. what do you wanna bet that if Ceres is actually re-declared a planet, Dawn won't have to worry about getting cancelled again? :P --Patteroast 15:45, 16 August 2006 (UTC)

Cracking up
Sorry, but this toggling of the launch date between 20 and 21 June that occurs every couple of weeks in the article is cracking me up. I just had to mention it ;-) Returning to lurk mode. Deuar 22:08, 10 September 2006 (UTC)


 * If you find that sort of thing amusing, check out Lamest edit wars. I doubt in this case it's actually a war, I bet there's just two prominent sources out there that disagree and new people keep coming along and thoughtlessly "fixing" the "mistake" back and forth, but the effect is similar. :) Bryan 23:35, 10 September 2006 (UTC)

No, the person running NASA web site was not up to date with information from the JPL Payload team. Team members who have the schedules in front of them should know the launch of their instruments, don't you think? Amara 19:56, 18 May 2007 (UTC)


 * Just to check, the 20 vs. 21 question wouldn't have been a time zone issue, would it? (And yes, the date does depend on the time zone.) Oh, and as of today, are we all now expecting a launch date and time of 30 June, 21:13-21:33 GMT? (Sdsds - Talk) 20:04, 18 May 2007 (UTC)

slight damage to one of the solar arrays
The slight damage to one of the solar arrays is not slight at all. The structure was damaged and deployment and other mechanical aspects can not be tested anymore. The electrical wireing of the solar panals was damaged. A delay is a decesarry, but not possible.--Stone 16:21, 19 June 2007 (UTC)
 * That seems likely. I wish there were a source to cite that described it that way. (sdsds - talk) 17:37, 19 June 2007 (UTC)
 * The people involved would never make a statment that the mission is in critical conditions because of a technician using a little bit to much force to thighten a screw.--Stone 07:22, 20 June 2007 (UTC)

Satellite of: Vesta and Ceres
I really dislike the notion that Dawn is a "Satellite of: Vesta and Ceres". Strictly speaking that is outright false. After all the probe, as I write these words, is on Earth and is not a satellite. We don't know if it will ever be a satellite as it is possible that it could explode on launch, etc. And if one is going to call it a "satellite" then it is -- if all goes according to plan -- a future satellite of Sun afterwards a satellite of Vesta afterward a satellite of the Sun again and finally a satellite of Ceres. At no time will it be a satellite of both Vesta and Ceres. I really think that this needs to be reworded. Maybe a mission or planned mission to Vesta and Ceres. MichaelSH 00:09, 27 June 2007 (UTC)


 * Seems overly pedantic to me. I take that line in the infobox to mean what the intended mission of the probe is, not its current status right at this very moment. As another example, Galileo was intended as a satellite of Jupiter and is listed as such in its infobox even though it has since burned up in Jupiter's atmosphere. Bryan Derksen 07:56, 27 June 2007 (UTC)


 * I modified the infobox to say "Satellite of: Vesta then Ceres" (changing "and" to "then"). Does this resolve the concern about simultaneously orbiting both? Given that past/present/future isn't specified (per Galileo example), can we call this concern "resolved"? (sdsds - talk) 23:58, 3 October 2007 (UTC)

Article rename
I would like to solicit broad input before proceeding with a rename of this article. The current Dawn Mission does not comply with Wikipedia standards for article naming, i.e. WP:CAPS. Becuase multiple renames leave an ugly trail of redirects, rather than simply lowercasing to Dawn mission it makes more sense to determine whether some other name, possibly including the use of parenthesis for disambiguation, makes more sense. How about Dawn (spacecraft)? Dawn (space mission)? Dawn (spaceflight)? Dawn (space exploration)? (sdsds - talk) 19:21, 31 August 2007 (UTC)


 * wel at the moment there isn't much technical information about the spacecraft here, only it's mission. for example what about it's ion engines trust ?? no info about it here.


 * Perhaps then better reorganize it in a larger scale "space missions" with some subs of goals and crafts used


 * Moved to Dawn (spacecraft) for consistency with Galileo (spacecraft), Phoenix (spacecraft), Stardust (spacecraft), etc. Rmhermen 15:32, 27 September 2007 (UTC)

Robotic/Human craft confusion
Hi all - not being familiar with this (and only finding it via the front page), the first paragraph currently says that the mission is to send a robotic space probe, but the following paragraph says that it's a human spacecraft. I'm presuming that no humans are onboard the probe? Could someone with more knowledge possibly clear this up? Or is it just me being stupid :) Richsage 20:44, 30 September 2007 (UTC)


 * Strange wording indeed. Apparently nonhuman constructed spacecraft (built by dolphins or mice?) MAY have visited the asteroids first, but this will be the first spacecraft build by humans. Tom Ruen 20:58, 30 September 2007 (UTC)
 * fixed.Potatoswatter 00:31, 1 October 2007 (UTC)


 * Good catch! Checking back, this error seems to have been inadvertently introduced during this edit by Vedexent. At least it wasn't there too long before being fixed! (sdsds - talk) 23:49, 3 October 2007 (UTC)


 * I'm not convinced it was an error, just weeding out unvoiced assumptions on the basis of the editors. Since some (at least the editors objecting) are apparently easily confused, perhaps it is best left out -- Vedexent (talk) - 17:28, 6 October 2007 (UTC)


 * You are absolutely correct. Editors of this article do make the unvoiced assumption that spacecraft from non-human civilizations are outside the scope of the claims made for Dawn. In fact, anytime in Wikipedia when we write about some event being "the first" of its kind, we mean "the first known" of its kind. We elide mention of the possibility that some other event that we simply don't know about took place first, and we assume our readers understand this. (sdsds - talk) 00:12, 13 October 2007 (UTC)
 * "the first known" didn’t you wont you say 'the first known to you' ? — Preceding unsigned comment added by 99.90.197.87 (talk) 12:04, 21 May 2012 (UTC)

Orbit
The second paragraph states: "Dawn will be the first spacecraft to orbit two planetary bodies other than Earth and the Moon, and the first to visit Ceres and Vesta." This needs to be clarified at the least and probably edited. They Huygens-Cassini probe has been orbiting Saturn for several years now and other probes have also orbited planets. So something about this is either inaccurate or non-specific. Logan 5 19:31, 3 October 2007 (UTC)
 * It is correct: Cassini has only been in orbit around one planet, Saturn. Michaelbusch 20:02, 3 October 2007 (UTC)
 * Ah, didn't catch the distinction. Logan 5 16:04, 5 October 2007 (UTC)

"most massive" vs. "largest"
In the lead sentence, would it be accurate to replace "most massive" with "largest" in describing Ceres and Vesta? I understand large implies volume rather than mass, but a) "largest" is simpler language and b) there isn't some larger but less massive object in the asteroid belt, is there? (sdsds - talk) 23:56, 12 October 2007 (UTC)
 * 2 Pallas is slightly larger than Vesta, but less massive. Deuar 13:00, 13 October 2007 (UTC)

Dawn will be the first ...
In the opening section, it is claimed that:


 * Dawn will be the first spacecraft to orbit two different planetary bodies (other than Earth and the Moon), and the first to visit Ceres or Vesta.

Neither body is planetary (or at least both are not - a case can be made for dwarf planet Ceres) so this isn't accurate.

If one claims it is the first to orbit two celestial bodies, then one has to add "(other than the Earth, Moon, and Sun)". This gets a bit awkward.

You can't say the first to visit more than one celestial body; the Voyager program has a whole laundry list of visited moons and planets.

As it doesn't seem to be very distinctive for orbiting, or visiting, celestial bodies - it really is only the first to reach one, stop, start up again, and go somewhere else, as opposed to he Voyager probes which only flew by non-stop. Maybe the mention that it is the first spacecraft to Vesta and Ceres can be incorporated into the first paragraph, and this second paragraph should be struck entirely. -- Vedexent (talk) - 13:49, 13 October 2007 (UTC)


 * What do you think of my edit? Also keep in mind Hayabusa visited Itokawa and left, so that probe was also probably capable of performing a similar mission, and indeed performed the "interplanetary" feat of arriving and leaving. Potatoswatter 01:27, 14 October 2007 (UTC)


 * Sorry, but I don't think it is immediately obvious to readers that you consider the Sun a "domestic" (as opposed to foreign) celestial body ... and the phrase is a bit cumbersome. I took another crack at it. My version is more long winded, unfortunately, but I think it is clearer. -- Vedexent (talk) - 18:22, 14 October 2007 (UTC)
 * Oh, actually I completely forgot that all interplanetary probes have a solar orbit phase before "orbit insertion." Anyway, it's better not to be so glib. Cool. Potatoswatter 18:27, 14 October 2007 (UTC)

FC first light
I saw the first pictures of some stars and a nebula. Very impressing! I hope the second camera works also as good. --Stone (talk) 20:41, 8 January 2008 (UTC)
 * Found the pictures. NASA Dawn Framing Camera Gallery--Stone (talk) 08:22, 6 June 2008 (UTC)

Mars gravity assist 2009
During the swing at 27 minutes passed midnight on the 18th of February 2009 the closeesed approach is scheduled to be 565km. The Framing Cameras will take pictures of a several 100 km broad stripe of Mars running between Tharsis vulcano and Olympus Mons. The Cameras of the Mars express spacecraft will make pictures of the same region later to calibrate the cameras and to compare the two cameras. Dawn: Kursänderung am Nachbarplaneten Mars--Stone (talk) 12:22, 16 February 2009 (UTC)
 * Sorry no pictures yet, due to problems.--Stone (talk) 20:17, 18 February 2009 (UTC)

Type of camera
I may have missed it, but where in the article does it talk about the kinds of cameras in the spacecraft? What kind of resolution is available? What kind of graphics format is being used? There was a link that indicated somebody was trying to build a camera for it, but there didn't seem to be any hard information as to what he had come up with? Were there any compromises as to what was desired, and what the actual result was? How many bits of color information are associated with the pixels, or bits of data? If an infrared camera is being included, how is the data being merged (if it is merged at all) with the regular data? Is raw data being transmitted back to earth, or is there some kind of redundancy and correction involved before it is transmitted? How many CCDs are being used? Does the camera have a shutter? If there is a shutter, how much power is required to open it? Is the spacecraft currently flying with the shutter closed, to protect the lens from micrometeors? 216.99.198.176 (talk) 04:53, 17 August 2009 (UTC)


 * I just added some more info on the instrument suite that addresses several of your questions. You can also look at the references listed above. IntrplnetSarah (talk) 15:54, 14 April 2011 (UTC)

Removed the word 'so' before 'vital' in the sentence: 'Because the framing camera is so vital for both science and navigation, the payload has two identical and physically separate cameras (FC1 & FC2) for redundancy, each with its own optics, electronics, and structure.' Something is either vital or not. — Preceding unsigned comment added by 130.123.104.22 (talk) 23:09, 1 August 2011 (UTC)

Multi-mission claim
I just marked the last sentence of the lead as needing a citation and as being dubious. for reference: Dawn is innovative in that it will be the first spacecraft to enter into orbit around a celestial body, study it, and then re-embark under powered flight to proceed to a second target. All previous multi-target study missions—such as the Voyager program—have involved rapid planetary flybys. What about Cassini-Huygens? If there is some press release or newspaper reporting that is making this claim, then we should repeat it here regardless. However, If that's the case then this sentence needs a citation. Claims of fact such as this should be cited regardless though, which is why I've added the citation needed tag in addition to the dubious tag. — V = IR (Talk&thinsp;•&thinsp;Contribs) 03:45, 16 July 2011 (UTC)
 * Cassini only went into orbit around Saturn. From memory it got a gravity assist from Jupiter but did not enter orbit.  It's orbit around Saturn is intentionally irregular so that it is brought into close proximity to other nearby targets but it remain at all times in orbit around Saturn. However, the current phrasing is overly inclusive - it would cover the Apoolo missions to the Moon for example.  http://dawn.jpl.nasa.gov/mission/Dawn_overview.pdf is careful with its assertion:  "Dawn will be the first mission to orbit a main belt asteroid and the first to orbit two extraterrestrial (and nonsolar) bodies."  I may get around to citing this if no one else does first but right now I'm already running late for something else so need to dash. Crispmuncher (talk) 14:48, 16 July 2011 (UTC).
 * Now done. Crispmuncher (talk) 18:38, 16 July 2011 (UTC)
 * Excellent, thank you Crispmuncher. I knew that the assertion must have come from NASA somewhere, but it seemed oddly inexact. I see now that it was merely a poorly crafted paraphrase (still, kudos to whoever actually added it for making one hell of a good effort). It's a bit of (basically) OR on my part, but since this is a talk page... I understand what you're saying about Cassini, but it's changed it's orbit fairly continuously since it arrived at Saturn. I'd have to find (or create) a diagram of it's trajectory to really make a definitive statement about it, but something tells me that it's "orbited" at least one of Saturn's moons at some point. Course, that probably depends on how strict of a definition to an "orbit" is used. Oh well, the statement that JPL made asserting Dawn being "the first to..." is perfectly accurate, regardless (and it kinda doesn't matter anyway, since everyone is saying that it's "the first to orbit two bodies"). — V = IR  (Talk&thinsp;&bull;&thinsp;Contribs) 22:40, 16 July 2011 (UTC)


 * Has Cassini's potential+kinetic energy ever been negative with respect to a moon? —Tamfang (talk) 23:54, 28 August 2011 (UTC)

Cassini hasn't orbited any moons. That would be like saying Cruithne is a satellite of the Earth. They were all flybys. It's never been captured by the gravitational field of a moon, and then broken free.

I've put the statement back in the lead. It's a key demonstration of the ion drive, which is the real purpose of the mission. (Or at least the purpose that got the funding.) It's therefore a key aspect of the mission. — kwami (talk) 02:46, 29 August 2011 (UTC)

Use of italics on its name
Any particular reason why Dawn is witten with italics in the article's name and throughout the article? Cheers, BatteryIncluded (talk) 00:18, 29 August 2011 (UTC)


 * It's a ship. —Tamfang (talk) 18:09, 21 May 2012 (UTC)

revelant pix ?
in the following section irrelevant explanation to relevant obfuscation. 

Microchip
Dawn carries a computer chip bearing the names of more than 360,000 space enthusiasts. The names were submitted online as part of a public outreach effort between September 2005 and November 4, 2006. The microchip (about the size of a United States nickel coin) was installed on 17 May 2007 above the forward ion thruster, underneath the spacecraft's high-gain antenna. More than one microchip was made, with a back-up copy on display at the 2007 Open House at the Jet Propulsion Laboratory in Pasadena, California.


 * There does not have to be an image for absolutely every component, especially a non-mission-critical component like that microchip. A random, undersized image of an 8GB memory chip adds little to the article. Michaelmas1957 (talk) 18:12, 21 May 2012 (UTC)
 * Explain why you feel it was "a random, undersized image"? — Preceding unsigned comment added by 99.90.197.87 (talk) 05:22, 22 May 2012 (UTC)
 * Is Dawn fitted with a 2008-model SanDisk memory card, lying on top of a 1950s-era magnetic memory, as the image shows? I'm pretty sure anyone visiting an article about a NASA space probe knows what a microchip is; do we really need an image to illustrate? The other images are either of its mission-critical instruments (highly unusual devices outside of space travel) or of Vesta; they are clearly relevant to the article. Michaelmas1957 05:27, 22 May 2012 (UTC)
 * If you are so sure which chip was used can you cite its serial number? Every one flash drive contain unique serial number which you can read eg by dumping device by dd. in sources serial information is not clear on the device image only its size is clear. /// Unfortunately you did not answer the question to you previous remarks so is prone address(debug) the last one. But if you reconsider the discussion may productively continue. — Preceding unsigned comment added by 99.90.197.87 (talk) 05:40, 22 May 2012 (UTC)


 * If you have to include an image of a microchip, at least find an image of the actual Dawn chip. Just using a stock image would be like using an image of an ordinary handheld camera for the Dawn cameras - "A camera, similar in nature but utterly dissimilar in design to the Dawn cameras". Michaelmas1957 05:30, 22 May 2012 (UTC)
 * A microchip identical to the Dawn one would be fine, regardless of serial number. If Dawn actually used a SanDisk chip, then go ahead and use the image, but make sure to cite a source for it. Michaelmas1957 05:45, 22 May 2012 (UTC)
 * IMO, the microchip is worth mentioning, but not inserting an image of it. Cheers, BatteryIncluded (talk) 15:14, 11 September 2012 (UTC)

No longer orbiting vesta
Dawn has apparently departed for Ceres:

http://news.yahoo.com/dawn-craft-depart-asteroid-dwarf-planet-090107827.html

As the wikibox is somewhat unique, any suggestions on how to format the orbital information. Is it more appropriate to say Vesta (former) or should we put a time range that it was orbiting Vesta? In the latter case, does anyone know of a source that gives more exact arrival and departure times than the Yahoo article? - Sangrolu (talk) 12:50, 5 September 2012 (UTC)
 * Update - This article has exact dates of entering and exiting Vesta orbit; I'm going to have a go at adding the dates to the article. - Sangrolu (talk) 13:32, 6 September 2012 (UTC)
 * It is rather a fuzzy concept, not really very appropriate for precise description. Closer to Vesta than ~500,000 km it might orbit stably (if its velocity is not too high), about twice that far and it is in orbit around the Sun; in between, "it depends".  Probably they are quoting the time when its velocity is high enough that it will definitely escape from Vesta into solar orbit, even if the ion drive should shut off. (But then, who really cares?) Wwheaton (talk) 15:29, 6 September 2012 (UTC)


 * In other words, when its energy with respect to Vesta (kinetic minus grav.potential) is positive; that's what I'd use. —Tamfang (talk) 19:29, 6 September 2012 (UTC)

What after 3 months at 375km Ceres orbit
What might happen after 3 months at 375km Ceres orbit ? Will it go lower ? Rod57 (talk) 11:57, 3 December 2014 (UTC)

needed?
Does this: "while images taken of Pluto by New Horizons will exceed the resolution of the Hubble telescope by approximately May 5, 2015" serve any purpose in the article? Bubba73 You talkin' to me? 07:10, 4 February 2015 (UTC)
 * Not in my view. --Njardarlogar (talk) 20:17, 4 February 2015 (UTC)


 * Of course, I agree. Bubba73 You talkin' to me? 00:25, 5 February 2015 (UTC)


 * the sentence states that two similar programs are running concurrently - seems appropriate to me--70.190.111.213 (talk) 18:13, 16 February 2015 (UTC)

Inter-trajectorial editing problems between Vesta and Ceres
This could have very well spilled over into an edit war. An anonymous user has apparently gone rampant again, but this time the edits seem constructive and I copyedited them. However, the user is insistent on their style of formatting and has reverted even my rollbacking, clearly unaware that having direct quotations "paraphrased and properly cited" is not enough for an article – close paraphrasing, like I saw with their version, is unacceptable. What should be done? I can deduce from the talk page that said anonymous editor steadfastly refuses to accept others' viewpoints. Parcly  Taxel  07:04, 17 February 2015 (UTC)
 * I've left a stern message. Maybe that will help. If it doesn't, go to the edit war noticeboard. --I dream of horses (T) @ 07:37, 17 February 2015 (UTC)
 * all "close" paraphrasing has been removed - any changes further than this would become just original research or crystal ball.--70.190.111.213 (talk) 06:46, 22 February 2015 (UTC)

Pallas flyby
So, no possibility of a Pallas flyby in 2018 or so? Maybe we could mention that? — kwami (talk) 00:55, 26 February 2015 (UTC)
 * There's no fuel to fly past Pallas. See the mission conclusion section of the article. Jonathunder (talk) 01:01, 26 February 2015 (UTC)
 * I see no benefit of listing the objects the spacecraft will not investigate. Cheers, BatteryIncluded (talk)
 * Well, not every object it won't investigate, obviously, but if Pallas was initially a potential target, it's appropriate to say why it isn't any longer possible. Jonathunder (talk) 01:15, 26 February 2015 (UTC)
 * Pallas was mentioned in early press releases as a possibility for an extended mission. Even those who didn't see those press releases at the time might come across them.
 * I expanded the mission-concl section after posting here and then investigating further. This is something I've been interested in since before Dawn was even launched, and I assume others may feel the same way.  Also, if anything I think I've discovered turns out to be wrong, it will hopefully be corrected in this article so I and others can learn about it.  — kwami (talk) 19:55, 27 February 2015 (UTC)


 * The "Pallas flyby was a possibility until the reaction wheels broke" article text seems to be someone's vague memory of a press release, and is contradicted by the official Dawn mission journal. I think we should revert to the old version Ttwaring (talk) 01:59, 8 March 2015 (UTC)


 * It's not contradicted. He says it was not never entertained as a "serious" possibility.  But there was enough interest to propose at least two flyby dates, and the relative chances of achieving them.  — kwami (talk) 05:09, 8 March 2015 (UTC)


 * I might be missing something here (if so, my apologies), but where is the info on Pallas coming from? There's no info on dates or chances in the missions journal link above...is there a record of a press release somewhere? If the info is to stay in the article, it needs a source per WP:V. Cheers, Skyraider1 (talk) 12:26, 8 March 2015 (UTC)


 * There was sporadic talk of this before launch. I can't find anything now, though something is probably archived.  I found a 2008 mention in a blog that "the possible post-main mission rendezvous with Pallas hasn't been mentioned for a while".  I'll keep looking.  — kwami (talk) 19:50, 9 March 2015 (UTC)
 * A pre-launch paper on Dawn says that Pallas is difficult to reach, and "although measurements at Pallas are highly desirable, exploring Vesta and Ceres may be sufficient to bracket the properties of large 'minor' planets." — kwami (talk) 20:00, 9 March 2015 (UTC)

Here are another two mission journal references. As per the mission team: "Pallas was never part of our plan. Indeed, we have never even taken a serious look at it. I don’t know quite how the story originated. It may have been a desire by some people, but no meaningful mission analysis ever supported it. " Ttwaring (talk) 14:57, 10 March 2015 (UTC)


 * It might have been someone on the team speculating about what would be possible, rather than a formal proposal. We should follow what your refs say unless we can dig up the original speculation/proposal.  I would suggest, however, that we do keep some mention of this, to answer future readers who may have the same question.  — kwami (talk) 20:26, 10 March 2015 (UTC)


 * Done! I will also update the Pallas article. Ttwaring (talk) 20:42, 10 March 2015 (UTC)

Going over those announcements, I was reminded that all the hoopla about Dawn visiting a DP is incidental: the intent was to study the large bodies (protoplanets) of the belt, and if Pallas wasn't feasible, Vesta + Ceres would hopefully be enough to "bracket the properties of large minor planets". (There was similar hoopla about Vesta being a "real world" when it was visited.) That particular paper was all about comparing these three bodies, and Hubble time was devoted to Pallas to provide info on the missing member of the trio, so I changed the lead to say Dawn is visiting two of the three (known) protoplanets in the belt. Also, the mission was only able to get funding because of the return from developing a new form of propulsion. We tend to overlook the drive now, but that really belongs in the lead, as part of a dual mission. — kwami (talk) 23:24, 10 March 2015 (UTC)

DAWN will orbit CERES
To quote: (CNN) NASA's tractor-trailer sized Dawn spacecraft will snuggle up to Ceres on Friday, getting close enough to be pulled into orbit and to complete the first mission to a dwarf planet. "I'm just delighted that Dawn is now on the doorstep of Ceres," Jim Green, director of NASA's planetary science division said in a news conference on Monday. Ceres was discovered in 1801 (Pluto wasn't found until 1930) and was the first object found in our solar system's main asteroid belt between Mars and Jupiter. ... ... ... [As you all know, right?] Headline-1: NASA spacecraft nearing mysterious dwarf planet Ceres QUOTE: "Ceres was demoted to an asteroid because 19th century astronomers couldn't be sure it was round. But it was bumped up to a dwarf planet when that category was created in 2006." -- AstroU (talk) 13:32, 3 March 2015 (UTC) -- PS: FYI for future editing.
 * http://edition.cnn.com/2015/03/02/us/dawn-spacecraft-ceres/index.html?icid=maing-grid7%7Cmain5%7Cdl1%7Csec3_lnk3%26pLid%3D621681


 * Nope. Had nothing to do with it being round, but that it appeared to be a fragment of a planet that had broken up.  We now know that to be untrue, but it finds its modern parallel in the idea of clearing its orbit.  Not coincidentally, I might add:  There is an intentional parallel between the 2006 reconception of the Kuiper Belt and the 19th-century reconception of the Asteroid Belt.  — kwami (talk) 06:19, 6 March 2015 (UTC)

Where do you watch?
I believe the 'SLOOH' observatory community will have a 'live' broadcast and commentary tomorrow, Friday 3-6-2015. Are there alternative websites for the Ceres event? It starts at 10am tomorrow (Friday): http://live.slooh.com/stadium/live/dawn-to-arrive-for-ceres -- AstroU (talk) 02:08, 6 March 2015 (UTC) -- PS: Maybe it will be just commentary at 'SLOOTH.com'

Entering Ceres orbit
Will Dawn have to fire its engines to enter orbit of Ceres, or will Ceres' gravity capture it? Bubba73 You talkin' to me? 02:42, 6 March 2015 (UTC)


 * Apparently the latter, given the quote in the thread above and several others like it. — kwami (talk) 06:20, 6 March 2015 (UTC)

A very interesting and informative article in an Aviation Week news flash --  Read the reader comments also. -- AstroU (talk) 16:31, 6 March 2015 (UTC)


 * This 3min video at Space.com verifies that JPL will fly it in (with solar propulsion) This is done very, very well and is most informative! -- AstroU (talk) 16:39, 6 March 2015 (UTC)

However, gravity also had a role. Gravity and spaceship propulsion (forces) were balanced. Spaceship propulsion was controlled from JPL to counterbalance Ceres gravity. -- Charles Edwin Shipp (talk) 19:49, 7 March 2015 (UTC) -- PS: Thanks for the link at space.com (just above) that explains with computer animation, "JPL gracefully approached into orbit", to loosely quote.

Assessment comment
Substituted at 14:38, 1 May 2016 (UTC)