Talk:New Horizons

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Power[edit]

Is there any reference regarding the sentence «The RTG will provide about 250 W, 30 V DC at launch, and is predicted to drop approximately 5% every 4 years, decaying to 200 W by the encounter with the Plutonian system in 2015.»?
If the rate of output drop is correct, it appears to me the power in the middle of 2015 will be much higher than the 200W written here:

Year Power (W)
2006 250,0
2010 237,5
2014 225,6
2018 214,3
2022 203,6
2026 193,4
2030 183,8
2034 174,6
2038 165,9

Luca Mauri (talk) 11:06, 7 December 2014 (UTC)

I found a reference for the specs of the RTG over here [1]. On page 4 the authors state that New Horizons needs 237W at launch and 191W at Pluto flyby (minimum). On the bottom of page 3 the authors state that a typical RTG should provide at least 285W at the beginning of mission. On page 6 the authors state that the New Horizons RTG uses plutonium-238, which has a half-life of 87.7 years. In the next scentence they state that the drop in thermal power is only 0.8% per year which corresponds to what I get when I punch my calculation (p = 100 - (100 * (0.5^((1/87.7)*t))) for t = 1 >>> p = 0.787247) in WolframAlpha. That considered the table by Luca Mauri should look like below, considering that the drop in electrical power is the same as the drop in thermal power.

As for the voltage, on page 6 the authors mention a test voltage of 30V. I assume this also goes for the New Horizons probe, so that would be correct. The rest of the power section does not seem to contradict the paper.

Year Power (W)
2006 285
2010 276.131
2014 267.538
2018 259.212

However, this[2] paper (page 41) states a different start power, roughly 245 W and power levels at Pluto (195 ~ 200W), which is not consistent with the power drop 0.8% per year.

Jonathan Juursema (talk) 17:55, 24 January 2015 (UTC)

No where in the "power" section of this wiki article does it say when power level will drop to such an extent that the probe cannot phone home (and thus when and where would the probe be at loss of contact) - this needs to be added.--70.190.111.213 (talk) 14:06, 9 February 2015 (UTC)

References

This paper states that the power will be insufficient to provide energy to the scientific instruments by 2030. [1] 2601:E:CD00:87A:8020:A1B4:10AB:AE3 (talk) 14:33, 27 April 2015 (UTC)

2011 HM102[edit]

I have just redone an edit I made earlier deleting some unsourced claims made here. Supposedly the bandwith to the probe "may" have been limited which is a strange assertion to make - after all the team operating the probe know exactly how much traffic they may send to and from the probe - this is not itself subject to some form of scientific conjecture. In support of that statement we have a reference that does not address the issue at all, which is hardly surprising when it was written five years before even the discovery of the body in question. Nor does it make any reference to any capacity limits on the link to the probe - in short it does nothing to support that claim.

Given that I don't see any reason at all to include it. Speculation about things we know for a fact is not really sound anyway, but when that speculation is essentially a random person editing here rather than attributable to an expert it becomes very difficult to justify. Pink Fluffiness (talk) 20:59, 13 March 2015 (UTC)

I agree, which why I've just re-undone that IP editors revert, this time with a different ref. It still doesn't address the issue at hand but did at least talk about transmission speeds if not limits - the reference still doesn't support the assertion that the reason studies were not done was because there was insufficient data capacity. Without that the calim has no validity. 3142 (talk) 03:02, 14 March 2015 (UTC)
listen i dont know jack about the item in question you are arguing against but Pink Fluffiness's assertion above "that speculation is essentially a random person editing here rather than attributable to an expert" when whomver added it originally added the citation given picked one from someone that is indeed an expert that one being the Principle Investigator for New Horizons, Alan Stern. Thus, to say Alan Stern is not an expert is ludicrous.--70.190.111.213 (talk) 03:37, 14 March 2015 (UTC)
But where did he make that claim? It wasn't in either reference provided so far. You can't say anything you want and then attach a random quote from a qualifying source as evidence to support it: the citation must make the specific point that it is reinforcing. Anything else is original synthesis. 3142 (talk) 03:53, 14 March 2015 (UTC)

NASA-TV (04/14/2015-TwoBriefings@1:00&@2:30pm/edt/usa) - New Horizons spacecraft flyby of Pluto[edit]

FWIW - NASA-TV (Tuesday, 04/14/2015 - Two Briefings => @1:00 & @2:30pm/edt/usa) - panels of experts discuss "New Horizons spacecraft flyby of Pluto".[2] - Enjoy! :) Drbogdan (talk) 12:49, 11 April 2015 (UTC)

References

  1. ^ http://www.boulder.swri.edu/pkb/ssr/ssr-fountain.pdf
  2. ^ Brown, Dwayne; Buckley, Michael (April 9, 2015). "Release M15-057 - NASA Hosts Briefings on Historic Mission to Pluto". NASA. Retrieved April 11, 2015. 

Current status[edit]

I don't think this ever-changing data,

  • As of May 1, 2015, New Horizons was about:
  • 0.59 AU (88,000,000 km; 55,000,000 mi) from Pluto
  • 32.29 AU (4.831×109 km; 3.002×109 mi) from the Sun
  • 31.86 AU (4.766×109 km; 2.962×109 mi) from Earth.
  • Countdown to New Horizons‍‍ '​‍s closest approach: 2 months, 11 days, 5 hours, 58 minutes, 12 seconds

needs to be in an encyclopedia. Bubba73 You talkin' to me? 05:54, 3 May 2015 (UTC)

I definitely agree that the countdown doesn't need to be there, as long as the date of closest approach is mentioned somewhere. The rest of the info, IMO, does help provide some context and sense of scale for the reader though.
That being said, it only works as long as someone keeps updating it periodically....so if that stops or becomes impractical (after the main mission, perhaps), that would be a good point to remove this content. Cheers! Skyraider1 (talk) 10:29, 3 May 2015 (UTC)
@Bubba73: I don't see why you care about that, when there is so much to be improved upon in the article... really. The distances get updated once a month along with the image. Sometimes the distances are updated more frequently (normally by an unregistered editor), but such edits can be reverted, if the "ever-changing data" changes too frequently in your encyclopedic perception. As for the countdown template, where, if not here, is such a template more applicable on wikipedia, than in this particular section? Really, you should first start to care about the removals of all existing countdown-templates on wikipedia (there are several). The template updates itself automatically, and why do you want to deny useful information to the reader in the first place? Why don't you save your encyclopedic energy for July 14, when it needs to be removed from the article for good. Apologies for my rather grumpy tone. -- Cheers, Rfassbind -talk 15:48, 3 May 2015 (UTC)
Speaking of which... Why was the item removed here obsolete? Will the trajectory map no longer be updated? Regards, JoergenB (talk) 06:08, 5 May 2015 (UTC)
@JoergenB: Hi Joergen, thx for not pinning me ;) About two days prior to the edit in question I switched to a new version of the map, showing a sideview instead of a top-down perspective of the trajectory, and I added the text "The map also displays the positions of stars...from the actual perspective, which is slightly above the orbital plane of the planets" However the image got reverted back to the original map, and so it became obsolete (since from a top-down view there's no perspective slightly above the ecliptic) and I removed it (in two steps). In addition, I think I replaced the remaining text item with a more significant observation ("New Horizons resolution better than HST since May, 5"). Hope you had no problems to understand the motivation behind my other 21 edits I did during this period.. otherwise, please feel free to ask. -- Cheers, Rfassbind -talk 01:15, 6 May 2015 (UTC)

This is the only countdown I've seen on Wikipedia. I would be in favor of removing all of them - this is an encyclopedia, after all. An encyclopedia doesn't need to tell the number of seconds to an event. And after closest approach, the countdown may start showing the number of seconds since the closest approach. Bubba73 You talkin' to me? 04:57, 7 May 2015 (UTC)

@Bubba73: After July 14, the template will show "Event time has passed." Please don't speculate about things, that could be tested in no time. I therefore honestly doubt your conviction to do something about the usage of the mentioned templates on wikipedia, since that will definitely require a lot of time. I agree on the "seconds" being not helpful, though. That's why I already posted my suggestions on the talk page of the template, asking for specific amendments to the template in order to allow for a more customized display (i.e. a countdown without displaying the seconds, that is still accurate on the minutes). Thx for leaving the thread and not pinning me. -- Cheers, Rfassbind -talk 17:52, 7 May 2015 (UTC)
If you doubt me, I asked about the policy on village pump yesterday: wp:Village_pump_(policy)#Countdown_clock. Bubba73 You talkin' to me? 17:57, 7 May 2015 (UTC)

It would be nice if someone could reformulate this line: "The spacecraft currently travels at 14.56 km/s (32,600 mph) relative to the Sun and at 13.80 km/s (30,900 mph) relative to Pluto. In astronomical units (AU), this is about 3.1 AU per year, or roughly 0.0084 AU per day."
It isn't clear if the second sentence refers to the speed relative to Pluto or to the Sun. If it were up to me, I'd remove it entirely or do something like 14.56 km/s (32,600 mph) (3.1 AU/y) which is a bit of a hack since Convert unfortunately doesn't support speeds in AU, but I'll let you guys handle it. // 87.67.92.238 (talk) 11:48, 9 May 2015 (UTC)

Go ahead, amend the line. You can do it, I know you can, don't be afraid to come under scrutiny. -- Cheers, Rfassbind -talk 12:20, 9 May 2015 (UTC)
It turns out I just was manipulating Convert badly... Fixed now. // 87.67.92.238 (talk) 13:06, 9 May 2015 (UTC)

VNH0004[edit]

The article now mentions that the NH team a couple of years ago announced that they planned to study in January, 2015. The article VNH0004 itself contains the same claim, in the future tense.

Does anybody know whether or not such a study indeed was made in January (possibly with the negative but not quite uninteresting result that no satellite was found, or even that the object was not detected where the calculated orbit suggested that it would be), or instead the idea to make such a study was abandoned? JoergenB (talk) 06:25, 5 May 2015 (UTC)

I would assume VNH0004's proposal reached the same fate as that of 2011 HM102. exoplanetaryscience (talk) 21:48, 7 May 2015 (UTC)
It is standard to assess targets of opportunity as the mission progresses. Once the probe is there, it can estimate its relative path to the object and proceed with a go/no-go depending on the fuel to spare. I would not suffer in this article every object considered along the decade of this mission. Cheers, BatteryIncluded (talk) 21:53, 8 May 2015 (UTC)
Anyhow, it was not enough to edit just the first part from a future "will be" tense to a conditional "would be" tense, but retain the indicative future tense for the second and third observations. If (as Exoplanetaryscience suspects) the study of VNH0004 was cancelled, then the claim "A second object will be observed in June 2015, and a third in September, after the flyby" simply is wrong; even if that June observation is performed according to the 2012 plan, it then will be the first, not the second such observation. Therefore, I changed the tenses.
The resulting text is a bit stiff; but I guess that it would anyhow be rewritten later, when the outcome of any June study is clear, and when there are updated plans for the "transplutonian" part of the mission. (However, I mainly hope for and expect new information about and pictures from the Pluto system in June, and I suspect that secondary targets then will not be of a priority.) Regards, JoergenB (talk) 19:00, 12 May 2015 (UTC)

Resolution exceeding Hubble[edit]

On what date did/will New Horizons' resolution exceed that of Hubble? The "Current status" section says May 5 but the "Mission timeline" and "Future mission timeline" sections say May 15. All three dates used to say May 5, but two have been changed in the past few days. Thanks. DH85868993 (talk) 06:06, 7 May 2015 (UTC)

The New Horizons website says "May-June 2015" - you might not be able to pin down an exact second. Bubba73 You talkin' to me? 06:10, 7 May 2015 (UTC)
http://www.seeplutonow.com/ (which is the ref for the "May 15" date in the "Future mission timeline" section) has a "Countdown to Better than Ever Imaging" which currently sits at about 8 days, which would tie in with the date of May 15. I presume "Better than Ever Imaging" is a reference to better-than-Hubble resolution (but I couldn't find anywhere that explicitly said that). I'm not really fussed which date the article says, but I would prefer the article to be internally consistent, and use the correct tense for exceeeded/will exceed. DH85868993 (talk) 06:40, 7 May 2015 (UTC)
The "May 5" has now been changed to just "May", so the article is now internally consistent (and the tenses are correct). Thanks. DH85868993 (talk) 21:43, 7 May 2015 (UTC)

Please see http://i0.wp.com/www.universetoday.com/wp-content/uploads/2015/04/nh-weaver_5.jpg — Preceding unsigned comment added by 112.215.36.142 (talk) 14:58, 8 May 2015 (UTC)

Countdown template being discussed[edit]

The template that shows the countdown in the "Current status" section of this page has been nominated for deletion. Your feedback is welcome on that page. – Jonesey95 (talk) 03:04, 11 May 2015 (UTC)

Bad wording on page[edit]

"Estimates for the *sizes* of these bodies (assuming albedo 0.35) are Hydra 60 km, Nix 45 km, Kerberos 13 km, Styx 10 km." I believe it should be "diameter", no ? Can somebody confirm and correct ? 177.133.126.114 (talk) 12:26, 27 May 2015 (UTC)

Updated with the current estimates of diameter in both kilometers and miles, minimum to maximum, since there's a wide variation, and the numbers used here were the minima. Also recalculated the resolution for each using the pixels per kilometer given in the beginning of the paragraph and the minimum size for each. P Aculeius (talk) 12:54, 27 May 2015 (UTC)

unclear sentence[edit]

"Long-range imaging will include 40 km (25 mi) mapping of Pluto and Charon 3.2 days out." Is that trying to say that starting 3.2 days before the closest encounter, it will start mapping Pluto and Charon to 40 km resolution? Bubba73 You talkin' to me? 15:57, 27 May 2015 (UTC)

It would appear so. exoplanetaryscience (talk) 17:35, 27 May 2015 (UTC)

NASA-Audio (06/03/2015@1pm/edt/usa) - Moons of Pluto - "Surprising" Finds.[edit]

NASA-Audio (Wednesday, June 3, 2015@1pm/edt/usa) - Panel of experts to discuss latest "surprising" findings by the Hubble Space Telescope of the Moons of Pluto.[1] - Enjoy! :) Drbogdan (talk) 12:08, 29 May 2015 (UTC)

References

  1. ^ Chou, Felicia; Villard, Ray (May 28, 2015). "M15-085 - NASA to Hold Media Call to Discuss Surprising Observations of Pluto’s Moons". NASA. Retrieved May 29, 2015.