Talk:New Horizons

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Contents 1 Fuel problems 2 Message for Aliens? 3 Solid Rocket 4 Centaur flyby 5 Fastest ever? 6 Launch time 7 Resetting clock and recycling 8 Centaur 9 Mars flyby.... 10 Odd phrasing 11 Jovian radii 12 Propulsion 13 Flyby vs. Orbit 14 Cost of this expedition? 15 Trajectory animation 16 A Second New Horizons Mission? 17 Geocentric vs. heliocentric velocity 18 How long it took 19 New Horizons takes less power than a 100-watt lightbulb 20 New Horizons 21 Second Satellite Launch 22 Ironic 23 Star 48? 24 2002JF56 25 Investigator? 26 Visit to notable planetoids 27 Missing image 28 New Horizons is now no more than 4,200,000,000 kilometers away from 134340 Pluto. 29 "Pluto" vs. "134340 Pluto" 30 Solar escape? 31 First image of Jupiter 32 Magic numbers 32.1 Pre–launch 32.1.1 28°30′36″N, 80°38′51″W 32.1.2 28°34′42″N, 80°35′01″W 32.1.3 28°35′00″N, 80°34′59″W 32.2 Post–launch 32.2.1 Ephemeris revised on January 21, 2006 32.2.2 Ephemeris revised on January 24, 2006 32.2.3 Ephemeris revised on June 13, 2006 32.3 Discussion 33 Why use Template:Jupiter spacecraft? 34 Flyby of Jupiter 35 Uncompressed? 36 No more than 4 billion kilometers away from Pluto 36.1 Sun 36.2 Earth 36.3 Jupiter 36.4 Pluto 37 Name of craft 38 Black&White camera 39 Too risky more than once? 40 Jupiter closest encounter picture 41 "Solar System" vs. "solar system" 42 Context for velocity 43 Ulysses comparison 44 Misleading 45 Rocket propulsion 46 Current status 47 How are the knickknacks secured? 48 This is turning into the lamest of all Edit Wars 49 New Image 50 Fair use rationale for Image:Thermalbattery.jpg 51 Pluto Charon's Barycenter 52 Flyby of Eris and Others?

[edit] Fuel problems

In the Mission Profile section, the article currently says "However, a lack of available plutonium means that the required orbital maneuvers for post-Pluto encounters may not be possible.". Shouldn't that read "a lack of Hydrazine monopropellant"? Or is the plutonium in the radiothermal generator also needed for maneuvering as well as electricity? Ponder 14:45, 2005 Apr 13 (UTC)

lack of plutonium in the radiothermal generators means less operational time, in which they produce enough electicity to keep the spacecraft and its instruments operational. For Pluto flyby there is enough plutonium, but for futher KBO flybys may be not. --Bricktop 15:45, 13 Apr 2005 (UTC)

The comment in the article is at best confusingly phrased, and at worst downright wrong (number of course corrections required won't fix the problem if the problem is lack of power). I've modified the article text to something closer to the meaning of the space.com article cited. --Christopher Thomas 17:31, 29 Apr 2005 (UTC)

Ok, your version is significantly better ;-) --Bricktop 21:55, 29 Apr 2005 (UTC)

It seems that problems with plutonium fuel support were solved, read [1]. Someone should add this to the article (my english is not good enough:-) ). --Bricktop 02:43, 30 Apr 2005 (UTC)

I've updated the paragraph to reflect this development; thanks for the excellent research! --Christopher Thomas 05:11, 30 Apr 2005 (UTC)

[edit] Message for Aliens?

Will New Horizons also have a message for aliens on board as the Voyager Golden Record of the Voyagers?

I haven't heard of any, but I haven't read all material about the probe. Check NASA's pages on the craft, linked from the main article. --Christopher Thomas 19:38, 20 Jun 2005 (UTC)

Also haven't heard of any, although I wrote some parts of this article and nearly all of the german New Horizons article and therefor read large amount of NASA material about the probe. But haven't look specifically for such a "message for aliens" --Bricktop 21:45, 20 Jun 2005 (UTC)

You can add your name to a list that is sent with the spacecraft. That's all, I think. [2] Awolf002 18:05, 16 August 2005 (UTC)

The only message that needs being sent anymore is clearly written in the flight path!   freshgavin TALK    04:35, 20 January 2006 (UTC)

Agreed. Aliens would not understand anything we could put in a message. I never saw the point. Skeletor 0 (talk) 03:02, 4 March 2008 (UTC)

[edit] Solid Rocket

Are there any concerns that this mission will suffer the same fate as CONTOUR? It has a similar solid rocket booster built into the spacecraft: [3] Awolf002 18:05, 16 August 2005 (UTC)

Not quite - NH has a Star48B upper stage, whereas Contour used the upper stage as well as having a Star30 built in - it was the latter that failed. As far as I know, there is no Star30 on New Horizons. Shimgray 18:11, 16 August 2005 (UTC)

also on the contour flight the upper stage did not fire intill it had spent some period of time in orbit in the cold of earths shadow.the accident board I believe cited this as a probable cause of a most likely detonation of the upper stage some days after launch.

[ [user:infocat13 ] ] 24 Jan 2007 --Infocat13 22:27, 24 January 2007 (UTC)

[edit] Centaur flyby

I can't confirm the following sentence beyond an offhand comment on a message forum. I'll therefore remove it for the time being. The Singing Badger 19:39, 10 September 2005 (UTC)

During the cruise to Pluto, New Horizons will perform a distant flyby of a Centaur (an escaped Kuiper Belt Object), (83982) 2002 GO9, in 2010.

I did some calculations and tried to verify this, and the flyby will occur around March 8, 2010 at a distance of 412 million kilometers. — Yaohua2000 14:06, 18 January 2006 (UTC)

Are you sure? My buddies and I came up with March 10th at 390 million kilometers but we're amatures so we just want to know. Skeletor 0 (talk) 23:43, 3 March 2008 (UTC)

[edit] Fastest ever?

According to [4] (who in turn cite NASA as a source), "About the size of a baby grand piano, New Horizons will be the fastest spacecraft ever to depart Earth, according to NASA. It will pass the moon in nine hours and will reach Jupiter in a little more than a year, the space agency says." I always take such statements in the press with a grain of salt, but that does seem quite fast (didn't Apollo take 3 days to get to the moon?). Can anyone provide any details? I didn't see anything obvious on the public web page for NH, but I didn't spend very much time looking. -Dmh 19:15, 16 January 2006 (UTC)

Yes, it is the fastest ever to depart Earth, but not the fastest to leave our solar system, Voyager 2 has multiple gravitational slingshots and leaves faster. You can imagine that Atlas V rocket 551 is really huge and New Horizons is only 480 kg, so the spacecraft will have an extremely high speed. — Yaohua2000 20:27, 16 January 2006 (UTC)

According to a NASA paper (don't have the link any more) NH will leave Earth at a speed of 12,81 km/s if a Jupiter fly-by is achievable and 12,884 km/s if it flies without Jupiter fly-by. --Bricktop 22:27, 16 January 2006 (UTC)

Sorry, these numbers from me were wrong. Spaceflightnow gives the exact speed for yesterday's launch as 10.07 miles per second - 36,256 mph (16,21 km/s) [5]. --Bricktop 06:30, 20 January 2006 (UTC)

In its current format, in the trivia section the page says that after a gravity assist from Jupiter, the probe will be the fastest man made object ever at a speed of 47,000mph. Pioneer 11 attained a speed of 108,000 mph at periapsis on its Jupiter swingby according to this NASA page: [6]. Apologies if I am not conforming to the typical format here, but I'm a newbie and didn't know where else to raise this issue, while doing as little damage as possible.--Andrew

(Don't worry Andrew - you are doing great - Welcome to Wikipedia!). I agree we need to get a little more precision into this. I changed the trivia footnote yesterday because the quote in our article was misleading. It is quite possible I still did not get it right. Our old quote said "The New Horizons spacecraft aboard the Atlas V rocket will only take nine hours to reach the Moon's orbit (compared to the three day trip the Project Apollo spacecraft needed to reach the Moon). This will make it the fastest spacecraft ever launched. The record-holder prior to New Horizons was Voyager 1.", but when I looked at Voyager 1, I saw that the Voyager 1 spacecraft is traveling faster than the claimed current speed for New Horizon. Therefore, I surmised (perhaps incorrectly) that the record would not be broken until after New Horizon's gravity assist. I think the first thing to clear up is what do we mean by "fastest"? Do we mean "fastest speed ever achieved for one instant in time"? "Fastest departure from earth's atmosphere"? "Fastest average travel speed"? "Fastest departure from the solar system"? Or do we mean, at the current instant in time, it is the fastest thing, which would mean that other objects could have been faster in the past if they have slowed down in the meantime. Johntex\^talk 15:04, 20 January 2006 (UTC)

I think it is rather ambiguous. Fastest with respect to what? The earth? The sun? The body it is currently orbiting, or whose sphere of gravitational influence it happens to be in at a particular moment? The earth itself has an instantaneous velocity relative to the sun of more than 60,000 miles an hour. So, relative to the earth, Voyager 1 might be moving on the order of 100,000 miles an hour at the right time of year. So I think in that case they mean relative to the earth's mean position, the sun. After thinking about this, New Horizon's own periapsis speed on its Jupiter swingby might even be similar to Pioneer 11's, I haven't seen any published information about that.

The 47,000mph is probably with respect to the sun, relative to which the planets have a mean velocity of zero, but instantaneous velocities that can easily exceed this. A rigorous standard would account for this, and would probably include something about the spacecraft's mean velocity relative to the center of the solar system over a significant period on a planetary orbital timescale being significantly different from zero. Or some such.--Andrew

The number 36,256 mph given as "fastest ever" seems to be relative to the Earth (center), see [7]. Does this make sense to you, as well? Awolf002

• Like you, I have also wondered about "Fastest with respect to what?" I agree it seems the best comparison would be to the sun, but it is difficult to know if that is what other people are referring to when they give measurements unless they either specify it, or unless someone knows of a definite convention that NASA and others in the field stick to. Johntex\^talk 18:45, 20 January 2006 (UTC)

I have rewritten the Trivia section to make it factually correct, while trying to retain as much original wording as possible. You are welcome to fine tune or improve further. 62.245.80.251 02:11, 29 January 2006 (UTC)

Ahhh well let be add further to the confusion then ! Ulysses was reported by aviation space week at the time (1990 ?)to have had the highest hyberbolic access speed from earth orbit.Ulysses and its Star upper stage made it into Jupiter space(some jupiter radii to the left of jupiters "B" plane) and was thrown into a south/north polar solar orbit.But I have no idea as to how this compares to the question at hand.Due to a large error in its trajectory at launch pioneer 11 was fired into a simuler orbit but its orbit was corrected during pioneer 11 TCM-1.the pioneer 11 upper stage however would have made an uncontrolled flyby into a solar polar orbit. [ [ infocat13 ] ]--Infocat13 22:28, 24 January 2007 (UTC)

• Helios 2 Helios 2 Helios 2 Helios 2. Helios 2? Helios 2 Helios 2. Helios 2! --AlexWCovington (talk) 22:14, 20 January 2006 (UTC)

Yup. According to the Guinness World Records, Helios 1 and 2 reached 252 800 km/h and this is the "fastest spacecraft speed". I think they mean "fastest spacecraft speed relative to the Sun". -- Bowlhover 05:36, 21 January 2006 (UTC)

Its funny because in reality, we don't know how fast everything is traveling. For example the speed of the earth? As someone said its about 60,000 miles an hour but then take the solar system at 200 kilometers per second and factor in the speed of the galaxy at 300 km per second and it just becomes immeasurable. We are all traveling at a impossible speed and we don't even notice it! I know that there was not much point to telling that but I just want to make a point Cheers Skeletor 0 (talk) 23:54, 3 March 2008 (UTC)

[edit] Launch time

Someone changed the launch time to 18:14, but are you sure it will launch at 18:14 UTC? (NASA TV coverage just said 1:02 left, but I doubt if this is correct, because the launch window to be open at 18:24 UTC.) — Yaohua2000 17:16, 17 January 2006 (UTC)

There are builtin "holds" in the countdown. Do not use that number to predict when the launch will happen. It is currently planned for 13:24 EST. Awolf002 17:32, 17 January 2006 (UTC)

IT is currently planned for 13:45 EST. --Cyde Weys 2M-VOTE 18:25, 17 January 2006 (UTC)

So, it lauunched at 14:00 EST (1900 UTC). User:Seungwoo

[edit] Resetting clock and recycling

The virtual launch page of NASA says that the clock has been reset to T-4 minutes and holding, but the countdown page says that 'Built-In-Hold' is 40:00. Is the clock at T-4 minutes and holding or is it something else? I guess that the answer to that answers my next question: when the page says 'we will recycle for a 24-hour turnaround' what do they mean by 'recycle'? Do they take out the LO2 and LH2 out of the tanks or is it going to be left there ready for tomorrow's launch attempt? Thanks. DarthVader 23:54, 17 January 2006 (UTC)

During a countdown the clock stops at T-4 minutes and stands for 10 minutes at this point to give the launch team some time to deal with all kind of potentially faults. After that 10 minutes the clock starts again at T-4min and goes on until T-0.

I dont know about kerosine in the main stage, but LOX and LH2 from the main stage and from the Centaur are taken out of the tanks, because of their cryogenic temperatures. --Bricktop 00:37, 18 January 2006 (UTC)

So I am assuming that the LO2 and LH2 are not in the tanks right now. Assuming that this is the case, will the clock start again at say T-120 minutes and counting (or similar) today so that the tanks can be refuelled? Or will the tanks be refuelled at T-4 minutes and holding? DarthVader 07:18, 18 January 2006 (UTC)

Yes LOX and LH2 are now in the ground tanks, not in the rocket. The whole launch procedure of today is the same (or nearly the same) as of yesterday. --Bricktop 12:28, 18 January 2006 (UTC)

[edit] Centaur

What will be the fate of the Centaur stage? Fall back to Earth? Rmhermen 19:38, 19 January 2006 (UTC)

Good question. Acording to the Environmental Impact Statement [8] (pdf), the Aerojet and Atlas stages will separate, break up, and fall into the Atlantic Ocean. The Centaur will accelerate to Earth escape velocity, though, before releasing the spacecraft. It's likely that the Centaur will enter a long solar orbit, though it's not clear to me what velocity it will have when its burn is complete. Potentially it could be leaving the solar system itself, as long as it's going fast enough -- just not going anywhere interesting. --Dhartung | Talk 05:31, 20 January 2006 (UTC)

The centaur is mentioned in a blog/newsletter kept by DR Stern at the new horizens web site as being in a long solar orbit.Perihelion past Mars.

the Star third stage information can be found there to. [ [ infocat13 ] ] 24 Jan 2007

[edit] Mars flyby....

I see an anonymous has added a Mars flyby to the mission timetable.. although I agree that's the date the probe will pass Mars' orbit, does it actually fly past Mars itself? Tompw 19:57, 19 January 2006 (UTC)

No, it will be very far away from Mars. See my animation, the white one is New Horizons, the red one is Mars. — Yaohua2000 20:13, 19 January 2006 (UTC)

I added that and have corrected the entry per this discussion.

[edit] Odd phrasing

In the intro to the article, Pluto's atmosphere is described as "neutral". What does this mean? I've never heard that word used to describe and atmosphere before.

I added an explanation. Hope this helps. Awolf002 22:37, 19 January 2006 (UTC)

[edit] Jovian radii

Is Jovian radii the right word? Should it just be Jupiter radii? Unless I am wrong my understanding is Jovian mean Saturn, Jupiter, Uranus and Neptune all together not just Jupiter.

n2271 19 January 2006

Jovian means "of Jupiter". Saturn, Jupiter, Uranus and Neptune are Jovian planets because they're "near" and "like" Jupiter. Zocky | picture popups 03:27, 20 January 2006 (UTC)

'Jovian planets' is not general English usage. J, S, U, N are generally referred to collectively as 'gas giants', though there is a general move to distinguish U and N as, perhaps, 'helium giants' or otherwise because they are rather different from J and S.

'Jovian' is indeed 'of Jupiter' and it only refers to multiples of the planet's radius in this case. Tarquin Binary 03:36, 20 January 2006 (UTC)

Therefore, we should not say "Jovian radii of Jupiter"; this is saying the same thing twice over again, which is immediately obvious to anyone :-) I'm removing the "Jupiter" part and I'll link Jovian to the Jupiter article. Michaël 00:32, 21 January 2006 (UTC)

Oops, that didn't make any sense what I just said. I'm not changing anything. Sorry. Michaël 00:34, 21 January 2006 (UTC)

[edit] Propulsion

Surprised the probe doesn't have an ion drive. Any reason why still using hydrazine? especially for such a long range mission. Toby Douglass 17:20, 20 January 2006 (UTC)

For an ion drive you need a big amount of electricity, which is usually generated by solar panels. Unless a nuclear reactor for spacecrafts is developed (Project Prometheus, which was cancelled last year), there is no way to use ion drives beyond the asteroid belt between Mars and Jupiter. --Bricktop 19:09, 20 January 2006 (UTC)

Well... an RTG is always a possibility. But they seemed to have trouble getting enough plutonium for just 120 W. --AlexWCovington (talk) 22:16, 20 January 2006 (UTC)

Yes, but you'll need multiple RTGs. You'll need some kW of power to be consumed by an ion drive. --Bricktop 00:26, 21 January 2006 (UTC)

[edit] Flyby vs. Orbit

What is remarkable to me is that this mission, alone of all the recent planetary missions, will not achieve orbit around the planet that is its primary target, but instead will only fly by. Clearly, you get less science from this approach, so one must wonder why this choice was made. I'm going to assume that it was because it was not possible to carry enough fuel to decelerate into orbit; in other words, NASA was faced with a choice between "get there fast and stay briefly" versus "get there slowly and settle into orbit." I'd love to know more about this; in particular, how long would it have taken to get a spacecraft of simlar capability to Pluto if the goal had been orbital insertion? What other tradeoffs would be involved? Was the chance to do more KB exploration a significant factor, or was it more a matter of "well, we can't stop, we'll be out there, so we might as well look around"? I haven't seen anything addressing this question; I'd be grateful for anything that anyone here can provide. --orbert Fri Jan 22 22:20:03 UTC 2006

A space probe would need MUCH more fuel to go into orbit around Pluto. And it would have to fly on a much slower hohmann transfer route, on which it would take about 30 years to reach Pluto. --Bricktop 00:34, 21 January 2006 (UTC)

It would also have taken more fuel to launch the extra fuel store out of Earth's gravity. Most of the probe's momentum will be given to it by Jupiter, although I don't understand how a probe could escape a planet's gravity with more momentum than it went in with - it would accelerate toward Jupiter, but then slow down as much, shouldn't it? GBC 23:02, 25 September 2006 (UTC)

Excellent question, GBC; see gravitational slingshot for a full explanation. The fast answer is that the probe hooks behind Jupiter in its orbit; Jupiter loses a little kinetic energy to the probe in the encounter. Believe me, Jupiter can spare it. ACW 23:22, 25 September 2006 (UTC)

[edit] Cost of this expedition?

Could someone add something about how much this thing cost to this article? I'd be quite interested in knowing, and I'm sure others would too.

Launch Press Kit says: Approximately $700 million (including spacecraft and instrument development, launch vehicle, mission operations, data analysis, and education/public outreach) over the period 2001–2016. --Bricktop 02:01, 22 January 2006 (UTC)

[edit] Trajectory animation

While I appreciate that a lot of work has gone into making the trajectory animation, I have a few concerns with it:

• The thumbnail version that appears in the article seems to be cropped, as opposed to resized, which results in an image that's very confusing and doesn't really show much.
• Labels on the orbits on the large version would be nice. I can tell what most of them are meant to be, but a new reader might not.
• Per the discussion at Talk:Magnetic resonance imaging regarding the MRI scan animation used there, it might be best to make the basic image static, while having a link in the caption to the full animation for people who want to see the moving version. Perhaps put dots on the orbits in the static version indicating positions at important times, to give some impression of travel time/speed.

Again, thanks for taking the time to produce the animation! --Christopher Thomas 18:58, 3 January 2006 (UTC)

This animation should be longer. It only covers a couple weeks, and thus when it displays in the animation it displays so quickly you can't really make out what's going on. Phaldo 17:41, 17 January 2006 (UTC)

I made this but since no official ephemeris available, I used a gravitation simulator to produce a simulated trajectory, but it is a bit difficult to export the simulated result as GIF animation (I did it manually, but rather take time), the official ephemeris should be available in 2 or 3 hours, so this can be replaced. — Yaohua2000 18:02, 17 January 2006 (UTC)

I also found the animation on the main article page to be annoying and distracting from the reading, without being particularly useful. I like the idea of having the thumbnail be static. Also, how about a link to a "Celestia" presentation? Now that will give a nice orbit plot! — Długosz

The 'Trajectory Aniumation' is not at all clear. It needs more explanation. Can someone supply? Duncan.france 20:38, 18 January 2006 (UTC)

Is there some wrong with that trajectory animation image? In only displays a truncated animation for me, lasting about a full second. -- Pinktulip 05:02, 20 January 2006 (UTC)

doesn't work for me either, I've removed it. optimized gifs don't resize well in my experience. The full size image doesn't work for me either, just a second or so of animation. --Duk 05:42, 20 January 2006 (UTC)

I've updated the trajectory with a svg version, please reload if you cannot see the changes. It seems the svg render engine wikipedia used is very buggy, and due to another wikipedia's bug, the gif animation (800x800) cannot be auto-resized. I'll try to work these problems around if I have time. — Yaohua2000 07:11, 23 January 2006 (UTC)

[edit] A Second New Horizons Mission?

About a year ago, there was talk of launching a second New Horizons spacecraft to Uranus and some other binary KBO. This was before 2003 UB313 was discovered. It so happens to be that a second New Horizons spacecraft could be launched on a Uranus-2003 UB313 mission if launched between 2007-2009. I wonder if mission planners have yet pondered this idea.... J P 18:24, 24 January 2006 (UTC)

See [9] for more. --Bricktop 19:07, 24 January 2006 (UTC)

I've writen about this in the Extrasolar Visions forum [10]. But I read for a Uranus-Pluto flyby, not a Uranus-2003 UB₃₁₃. But seeing UB₃₁₃ would be neat. A Uranus flyby is another cool idea. — Hurricane Devon ( Talk ) 02:47, 25 January 2006 (UTC)

• For instance the mission to Venus from ESA was made from the leftovers of the Mars mission. It would be a good idea, but it would take ages to reach 2003UB313, but launching it to Uranus makes it quite resoanable. Is there any plan from NASA? --Pedro 22:33, 25 January 2006 (UTC)

Venus Express wasn't made from leftovers of Mars Express; the plan was always to use the main bus of Mars Express for future developments, and whilst the instrumentation is mostly redesigned versions of previous ESA instruments, they're not actual spares. However, leftovers do get used - three different probes have used backup hardware from the ill-fated Mars Observer, despite being physically quite different vehicles, for example. Shimgray | talk | 22:46, 26 January 2006 (UTC)

I suppose possible (but doubt it with current budget conditions and our President's emphasis on a human mission to Mars). Anyway, we've already had one Uranus flyby mission - Voyager 2. I would think if we were going to spend the money to go to Uranus, we'd want an orbiter for an extended stay. An orbiter is already planned for Neptune I think, so perhaps it would make more sense to use the spare parts from that.... FelineAvenger 06:32, 26 January 2006 (UTC)

• It is quite possible. Europe's aim is also Humans on Mars around 2030 I guess. A mission to Ceres was also halted, which is an object never visited, and for what I've read, it is interesting. it seems like a new space race... doesn't it? Yes, there's a mission to Neptune and Triton. Is there any European plan to the outer Solar System? I guess not. A mission to UB313 would be nice, mostly because we know nothing about it. -Pedro 01:49, 27 January 2006 (UTC)

[edit] Geocentric vs. heliocentric velocity

Guys, please stop including the statement in the introduction that the Jupiter gravity assist will accelerate the spacecraft from 16 to 21 km/s, or compare the two velocities. This is blatantly incorrect, and such a comparison cannot be done, as the two are very different velocities.

The probe has a geocentric (relative to Earth) velocity of 16 km/s just after launch, but it will slow down (relative to Earth) to about 12-13 km/s before leaving Earth's sphere of influence. At that time, it will have some 43 km/s heliocentric (relative to Sun) velocity, and it will actually slow down on its way to jupiter to some 21 km/s heliocentric.

Stating that the probe travelled 16 km/s at launch, but will travel 21 km/s after Jupiter encounter can lead visitors who don't know much about interplanetary travel to an absurd conclusion that the probe will somehow travel at 16 km/s all the way to Jupiter until Jupiter accelerates it to 21 km/s. That is plainly misleading and false.

The Jupiter encounter and the respective velocity, as well as the effect of its gravity to boost the probe's speed, are already included in the Mission profile section. Please work from there if you want to make improvements or add further information about the probe's speed changes. 62.245.80.251 12:38, 28 January 2006 (UTC)

[edit] How long it took

Passing the moon - 9 hours after launch
Passing Mars - 78 days after launch
Asteroid 2002 JF56 Flyby - 145 days after launch
Closest Approach to Jupiter - 1 year, 39 days after launch
Saturn Orbit Crossing - 2 years, 141 days after launch

[edit] New Horizons takes less power than a 100-watt lightbulb

[edit] New Horizons

Thanks for whoever changed what I wrote. I did use that site for my work but I didn't know how to link the page. I'm still brand new and learning. But it's coming along. :)

[edit] Second Satellite Launch

I live in Florida, and one on of the days when they delayed the launch of NH, there was a satellite launch, which either meant that NASA lied when they talked about a delay, or more plausibly, it was a military satellite launch, which wouldn't be announced the media. I'm not sure whether we should put that in. The Gwai Lo 23:14, 11 February 2006 (UTC)

[edit] Ironic

We're sending a plutonium powered piano to the Plutonian system. LOL — Hurricane Devon ( Talk ) 13:35, 22 February 2006 (UTC)

[edit] Star 48?

What does this comment mean?

"The Star 48 third stage will beat the New Horizons spacecraft to Jupiter. So will two small despin weights, the "yo-yo weights," released from the stage. However, since they will not be in controlled flight, they will not receive the optimal gravity assist, and will pass Pluto after New Horizons."

What's Star 48? Another spacecraft?

It's the upper rocket stage, which boosted New Horizons towards Pluto. Since the upper stage flies with nearly the same speed as the spacecraft, it also will reach Pluto. --Bricktop 21:18, 26 May 2006 (UTC)

and follow the spacecraft out of the solar system.AIAA astrodynamics conference papers from the period of the pioneers and voyagers tell the story of the voyager's star motors also following the spacecraft into a Jupiter flyby and these two objects are heading for the stars.Sadly they do not have onboard any plaques or records--Infocat13 03:38, 25 January 2007 (UTC)

[edit] 2002JF56

In the article it says that it has encountered asteroid 2002 JF56 . However when I go to List of asteroids/112001–113000, there is no asteroid 2002JF56. There is an asteroid 2002 JE56 however (2002JE56) so is it a typo or what ? Hektor 07:18, 16 June 2006 (UTC)

New discovered asteroids are not numbered immediately, this not a typo. Yao Ziyuan 18:15, 18 June 2006 (UTC)

[edit] Investigator?

From the article: >"The mission's principal investigator is S. Alan Stern of the Southwest Research Institute."< Does it really mean investigator, or should it be investor?

Uuhhh... This is a scientific endavour, not a financial one. People who direct the investigation in a major way are given the title principal investigator or PI, yes. Awolf002 16:13, 12 August 2006 (UTC)

[edit] Visit to notable planetoids

Is it possible that the New Horizons will visit, after Pluto, 2005 FY₉, 2003 EL₆₁, Orcus, or other TNOs with the diametre of Mimas or bigger? Is it possible with the power that it has to reach one of these planetoids? That would be cool it would be like the "Voyager 3". Is a "Pluto -> Ixion -> Quaoar" cruise possible?

Permanent Designation	Provisional Designation	Albedo	Equatorial diameter (km)	Semimajor axis (AU)	Date found
	2005 FY9	0.8 ± 0.2	1800 ± 200	45.7	2005
	2003 EL61 "Santa"	0.6 (assumed)	~1500 (1	43.3	2005
(90482) Orcus	2004 DW	0.1 (assumed)	~1500	39.4	2004
(50000) Quaoar	2002 LM60	0.10 ± 0.03	1260 ± 190	43.5	2002
(28978) Ixion	2001 KX76	0.25 – 0.50	400 – 550	39.6	2001
55636	2002 TX300	> 0.19	< 709	43.1	2002
55565	2002 AW197	0.14 – 0.20	650 – 750	47.4	2002
55637	2002 UX25	0.08?	~910	42.5	2002
(20000) Varuna	2000 WR106	0.12 – 0.30	450 – 750	43.0	2000

--Pedro 15:53, 31 August 2006 (UTC)

It's extremely unlikely that NH will be able to alter its course enough to fly by any of the objects you've plotted orbits for. It'll pass by Pluto at about 13.8 km/s. Pluto's escape velocity is about 1.2 km/s. This means any course change resulting from a Pluto flyby would only be a slight deflection in an almost-straight hyperbolic course. Total maneuvering delta-v of NH itself is only 0.3 km/s. So the only additional objects NH can visit are those that are within a cone somewhere on the order of +/- 5 degrees from its present path (or lower; this is an upper bound estimate). --Christopher Thomas 16:50, 31 August 2006 (UTC)

• | Not good then. because something smaller than 400 km will be just ice for a drink. At lest, there's Pluto and Charon to show-off. As it won't cross another planetoids in the path the best would to orbit Pluto, but I've heard that's not achievable. --Pedro 22:38, 31 August 2006 (UTC)

If New Horizons had enough fuel to orbit pluto it'd probably be able to visit Eris as well, which is the real one everyone'd want to see... Orbiting a planet is hard work... There is lots of things that can be gained by visiting a smaller body, look at the comet missions, NEA missions. None of those objects were very big, but they did return some interesting results. Tuvas 20:03, 26 September 2006 (UTC)

Tuvas ! good to see you here.I have been looking through old and new space craft missions looking for the odd item such as where are they now? you know the history of science.have not even got to the mars wiki pages yet.editing very amall parts of voyager and pioneer so far.I can see potential here.......................images of soviet landers here on wiki hahaha--Infocat13 03:48, 25 January 2007 (UTC)

[edit] Missing image

The image in the info box does not exist. Did someone forget to upload it? Will 19:31, 10 September 2006 (UTC)

[edit] New Horizons is now no more than 4,200,000,000 kilometers away from 134340 Pluto.

2006-09-24 06:29:27.205 UTC

Object	Range (km)	Range-rate (km/s)	Velocity (km/s)!
134340 Pluto	4,200,000,000	-21.260	22.392
Jupiter	256,896,937	-19.738	19.738
Sun	549,876,822	19.509	22.626
Earth	647,963,355	37.241	52.264

[edit] "Pluto" vs. "134340 Pluto"

Definitely not trying to start a "Pluto is a planet" fight here... not my interest at all... but I do think that there is some merit to the complaint about the use of "134340" - albeit for a very different reason than what the poster intended. There's really no need to list it as "134340 Pluto" just because it is catalogued as such. The common name (for the dwarf planet, just reaffirming that this isn't some desperate plea for Pluto's planethood) is Pluto, and using the full term -- especially in a casual reference such as this -- is akin to referring to a friend by his or her full name every time you speak to them. Just my two cents. --Ckatz^chat_spy 08:22, 26 September 2006 (UTC)

I do agree, the use of the 134340 Pluto is a bit overkill, but I don't see any reason to remove such a reference from a talk page, and certainly not for removing posts that were made between the times. Personally, when I'm talking about an astroid, I wouldn't use the number either, but, there are times where it can be useful. Tuvas 20:00, 26 September 2006 (UTC)

Agree with you 100% about the editing of the post, and the other deletions - that was completely uncalled for. The editor in question should have started a dialogue instead. --Ckatz^chat_spy 20:38, 26 September 2006 (UTC)

[edit] Solar escape?

Will NH escape the Sun's gravity, or will it (eventually) end up orbiting back? I assume the former... either way, I think the "is a satellite of" field needs a note in it.

Problem solved - if there's no text on the line (I removed the "N/A"), then the field doesn't appear at all. Good catch! --Ckatz^chat_spy 22:15, 26 September 2006 (UTC)

Also, could someone who knows how archive the older content of this page? Tompw 21:36, 26 September 2006 (UTC)

[edit] First image of Jupiter

You can find it here: http://pluto.jhuapl.edu/news_center/news/092606.html NH started working. In the image one can also see Europa and Io and their respective eclipses on Jupiter. --Pedro 23:54, 26 September 2006 (UTC)

The article says the plan is to "fly within 10,000 km (6,213.7 mi) of Pluto". The translation to miles seems overly precise here.

[edit] Magic numbers

[edit] Pre–launch

[edit] 28°30′36″N, 80°38′51″W

[edit] 28°34′42″N, 80°35′01″W

[edit] 28°35′00″N, 80°34′59″W

[edit] Post–launch

[edit] Ephemeris revised on January 21, 2006

*******************************************************************************
 Revised: Jan 21, 2006         New Horizons Spacecraft                      -98
                          http://pluto.jhuapl.edu/index.php

 Schedule:
  2006-Jan-19... launch (Atlas V551 1st stage, Centaur 2nd, STAR 48B 3rd
  2007-Feb   ... Jupiter gravity assist
  2015-Jul   ... Pluto Charon encounter
  2016+      ... Kuiper Belt object encounters

 Mission Objectives:
  * Map surface composition of Pluto and Charon
  * Characterize geology and morphology of Pluto and Charon
  * Characterize the neutral atmosphere of Pluto and its escape rate
  * Search for an atmosphere around Charon
  * Map surface temperatures on Pluto and Charon
  * Search for rings and additional satellites around Pluto
  * Conduct similar investigations of one or more Kuiper Belt Objects

 Spacecraft:
  1025 lbs (465 kg), 8 feet wide (2.5 m), RTG powered

 Post-launch trajectory:
   98_pred_20060119_20060125_od003             (released 2006-Jan-20)
*******************************************************************************

[edit] Ephemeris revised on January 24, 2006

Full text: Ephemeris revised on January 24, 2006

Note: The data assumes no leap seconds in 2006–2015.

*******************************************************************************
 Revised: Jan 24, 2006         New Horizons Spacecraft                      -98
                          http://pluto.jhuapl.edu/index.php

 Schedule:
  2006-Jan-19... launch (Atlas V551 1st stage, Centaur 2nd, STAR 48B 3rd
  2007-Feb   ... Jupiter gravity assist
  2015-Jul   ... Pluto Charon encounter
  2016+      ... Kuiper Belt object encounters

 Mission Objectives:
  * Map surface composition of Pluto and Charon
  * Characterize geology and morphology of Pluto and Charon
  * Characterize the neutral atmosphere of Pluto and its escape rate
  * Search for an atmosphere around Charon
  * Map surface temperatures on Pluto and Charon
  * Search for rings and additional satellites around Pluto
  * Conduct similar investigations of one or more Kuiper Belt Objects

 Spacecraft:
  1025 lbs (465 kg), 8 feet wide (2.5 m), RTG powered

 Post-launch REFERENCE trajectory from APL:
  nh_ref_20060119_20150727_v01   (released 2006-Jan-24, predicted thereafter)
*******************************************************************************

Full text: Ephemeris revised on January 24, 2006

Note: The data assumes no leap seconds in 2006–2015.

[edit] Ephemeris revised on June 13, 2006

Full text: Ephemeris revised on June 13, 2006

Note: The data assumes no leap seconds in 2006–2015.

Revised: Jun 13, 2006        New Horizons Spacecraft                      -98
                         http://pluto.jhuapl.edu/index.php

Schedule:
 2006-Jan-19... launch (Atlas V551 1st stage, Centaur 2nd, STAR 48B 3rd
 2006-Jun-13... Approaches 2002 JF56 to within 102,000 km at 04:06 CT
 2007-Feb   ... Jupiter gravity assist
 2015-Jul   ... Pluto Charon encounter
 2016+      ... Kuiper Belt object encounters

Mission Objectives:
 * Map surface composition of Pluto and Charon
 * Characterize geology and morphology of Pluto and Charon
 * Characterize the neutral atmosphere of Pluto and its escape rate
 * Search for an atmosphere around Charon
 * Map surface temperatures on Pluto and Charon
 * Search for rings and additional satellites around Pluto
 * Conduct similar investigations of one or more Kuiper Belt Objects

Spacecraft:
 1025 lbs (465 kg), 8 feet wide (2.5 m), RTG powered

Post-launch REFERENCE trajectory from APL:
 nh_ref_20060119_20150727_v02 (released 2006-Jun-13, predicted thereafter)

Full text: Ephemeris revised on June 13, 2006

Note: The data assumes no leap seconds in 2006–2015.

[edit] Discussion

Ummm... what exactrly are these? Tompw 17:34, 5 January 2006 (UTC)

These are the instantaneous distances between New Horizons and Pluto. — Yaohua2000 19:22, 5 January 2006 (UTC)

OK... but why three tables for different lattitudes and longitudes? And what's the difference between "range rate" and velocity?

The spacecraft to be transported twice during this peroid. The range rate is the rate of range, range is the position difference between New Horizons and Pluto, while velocity is New Horizons' speed with respect to Pluto. They are different. — Yaohua2000 01:44, 6 January 2006 (UTC)

Sorry, I'm still not getting it. Firstly, from what you said, the range is the distance form New Horizons to Pluto, so the "range rate" is the rate at which the range changes... which is exactly the speed relative to Pluto! Secondly, could you explain in a bit more detail abotu the different lat/longs?

Range-rate does not equal to the speed, because the spacecraft does not fly toward its target directly. For the first lat/long, it is Payload Hazardous Servicing Facility at Kennedy Space Center, where the assembly hall at, for the second lat/long, which is Vertical Integration Facility at Launch Complex 41, about 1800 feet south to the launch pad, the third lat/long is the launch pad. — Yaohua2000 20:34, 19 January 2006 (UTC)

Range-rate is the same as pluto-relative velocity (as long as we're treating velocities as scalars now...). "Velocity" on the chart is, I assume, sol-relative? - JustinWick 03:24, 21 January 2006 (UTC)

Velocity is pluto-relative velocity, range-rate is the rate range changes, they do not equal because the probe does not travel toward Pluto directly. — Yaohua2000 12:36, 22 January 2006 (UTC)

New ephemeris available at JPL Horizons, data above should be updated soon. Yao Ziyuan 18:08, 18 June 2006 (UTC)

Data updated. Yao Ziyuan 06:53, 30 September 2006 (UTC)

[edit] Why use Template:Jupiter spacecraft?

New Horizons will only pass Jupiter. It is not intended to be real target. The craft will do observations, but only because it will be passing though. Will (Talk - contribs) 19:30, 4 October 2006 (UTC)

• you are incorrect, it is also a Jupiter spacecraft as it will flyby Jupiter, in the same way as voyager or pioneer. Don't confuse it with newer kind of missions like Galileo and Cassini.--Pedro 19:38, 4 October 2006 (UTC)
  • yes, I put the template there because this mission has a planned Jupiter encounter. Just passing through is no real argument, as it will also just pass throught Pluto... Ricnun 21:34, 4 October 2006 (UTC)

• Then there should be a "spacecraft to Pluto" template there, too. While it's only the first to Pluto, I think it's safe to say more Plutonian spacecraft are going to be flying in the future.

What's the use of having a template with one item?! Pluto is very faraway... Maybe just the template of Jupiter seems rather stupid, but no other craft reached Pluto or will reach it in the near future. Wait, there are cancelled missions:

• Pluto Fast Flyby (USA, 2010) - cancelled
• Pluto Express (USA, 2012) - cancelled

--Pedro 11:10, 7 October 2006 (UTC)

The Jupiter template is used for all the missions that had Jupiter as one of it's targets. This is the case. As for a Pluto template, it makes as much sense as a Neptune one... Perhaps a "outer planets" template that would list Uranus, Neptune, Pluto, KBOs, etc? This would have more than one spacecraft on it. (unsigned)

Jupiter template does not seem out of line. New Horizons will apparently return more data from Jupiter than it will of Pluto! FelineAvenger 03:10, 8 October 2006 (UTC)

I have added the Pluto template, after having seen that Uranus an Neptune have such templates. -- BIL 20:17, 6 March 2007 (UTC)

My impression was the the template was for craft that had Jupiter has a primary target. New Horizons will do science there, but its instruments were calibrated for Pluto. My impression was Jupiter was being used to test the instruments more than actually attempting to do useful science that could not be done another way. Will (Talk - contribs) 03:27, 8 October 2006 (UTC)

The template also lists Cassini-Huygens which flew by Jupiter, but whose primary target was Saturn FelineAvenger 04:31, 8 October 2006 (UTC)

[edit] Flyby of Jupiter

I restored the "Jupiter" mention after it was deleted a few moments ago, but then reverted myself to rethink. Obviously, the journey includes Jupiter for the speed boost. However, is the mission a flyby of Pluto etc.", or a flyby of "Jupiter, Pluto, etc."? Is NASA planning to do any scientific work at Jupiter? Thoughts? --Ckatz^chat_spy 00:15, 9 December 2006 (UTC)

• Jupiter is a fly-by gravity assist, the probe was built for Pluto. That alone makes Pluto the priority and and a Plutonaian spacecraft.Something14 00:30, 9 December 2006 (UTC)

[edit] Uncompressed?

Initial, highly-compressed images will be transmitted within days. The science team will select the best images for public release. Uncompressed images will take about nine months to transmit

This must be incorrect. There is no conceivable way New Horizons will be wasting bandwidth transmitting uncompressed anything beyond simple telemetry. I think this should read 'highly-lossy' and 'lossless' images, although I can't speak to it; it is possible that all compression used for the mission is lossy to different degrees. Allenc28 19:50, 21 January 2007 (UTC)

[edit] No more than 4 billion kilometers away from Pluto

2454120.284880148 = A.D. 2007-Jan-19 18:50:13.6448 (CT)

[edit] Sun

• Range: 738,866,580 km (4.939018 AU)
• Range-rate: 17,846.202 m/s
• Velocity: 19,774.088 m/s

[edit] Earth

• Range: 833,230,977 km (5.569805 AU)
• Range-rate: -2,844.746 m/s
• Velocity: 27,101.859 m/s

[edit] Jupiter

• Range: 64,081,751 km (0.428360 AU)
• Range-rate: -18,599.807 m/s
• Velocity: 18,614.977 m/s

[edit] Pluto

• Range: 4,000,000,000 km (26.738348 AU)
• Range-rate: -18,417.111 m/s
• Velocity: 19,276.503 m/s

222.130.193.31 19:04, 19 January 2007 (UTC)

[edit] Name of craft

Did I miss how the craft got its name? And the even more interesting question of how it got a name that sucks so badly? Why don't we just call it Applegate Enterprises? Even New Nifty Gizmo would say more about what it is and does, than what they got. No historical reference, even. The technical writer in me wishes to protest. SBHarris 01:07, 20 January 2007 (UTC)

Here's how New Horizons was named: [11]

It's from May 2005, so no wonder you missed it!--Planetary 06:36, 28 February 2007 (UTC)

[edit] Black&White camera

Why is the main telescope camera black and white ? Looks somewhat boring. Probably because it allows higher resolution? There seems to be a colour camera onboard also (PERSI). Are there photos of Jupiter with it? -- 217.209.225.140 19:51, 6 March 2007 (UTC)

The data is still being downloaded from the probe. Expect color images in a few months. For now, just some sample images were transmitted, to check that everything is well with the spaceprobe.Ricnun 00:21, 7 March 2007 (UTC)

[edit] Too risky more than once?

Why not multiple Jupiter dives? Multiple gravity assists could shorten the trip time to Pluto. 82.131.210.162 09:30, 13 March 2007 (UTC)

No it's not like that. The ship only passed by at a very shallow angle - not slingshotting all the way around jupiter. Basically, as NH passes by Jupiter, the planet drags the ship in it's wake, so Jupiter looses some momentum giving it to the probe. This image shows what's going on: Joelholdsworth 10:23, 13 March 2007 (UTC)

 

I could have been possible to do it again if passing Saturn or Uranus. Now the position of these planets is not such that it is possible. In the 1980-ies it was possible during a period to do this, since the planets had the correct positions, and it was done by Voyager 1 (Jupiter and Saturn) and Voyager 2 (Jupiter, Saturn, Uranus, Neptune). To repeat the Voyager 2 journey is not possible until about year 2150. -- BIL 15:23, 13 March 2007 (UTC)

There's also something to be said for sending the ship too quickly. When it arrives at Pluto, it won't be braking or going into orbit: it will be flying by as Voyager and other probes before it. If the craft were going too fast, it wouldn't have much time to snap pictures and take other readings. There had to be a balance between speed and usability.
—ZorkFox (ষTalk) 03:42, 18 April 2007 (UTC)

[edit] Jupiter closest encounter picture

I was trying to replace the current picture with one from http://pluto.jhuapl.edu/mission/passingplanets/passingPlanets_current.php at a more accurate time, but I can't find the upload link on the Commons picture. Can someone help? Rdl381 22:05, 15 March 2007 (UTC)

[edit] "Solar System" vs. "solar system"

I disagree with Ckatz's edit comment that "solar system" should be capitalized because "there is only one (ours)". If there were no other planets around other stars, I could consider this a valid reason. But I maintain that "solar system" is not a proper noun, and ours is certainly not the only one, and therefore should be lower-case. See this end note on the Solar System article: Solar_System#endnote_Anone. After all, one only capitalizes "Captain" when referring to the master of a vessel when citing a formal title (Captain Jack Sparrow) or when directly addressing a person with that rank: "Aye, Captain." (As opposed to: "The captain scanned the horizon.")

Unless there is an outcry or other form of consensus, backed up by reasoned argument, I am going to reinstate my edits.
—ZorkFox (ষTalk) 03:38, 18 April 2007 (UTC)

This issue comes up occasionally in the astronomy articles, and it is a common misconception that "solar system" refers to any star-and-planet system. However, as outlined in the Solar System article, and in several related discussions, "Solar System" refers only to the Sun and the associated objects orbiting it. There is also an IAU guideline for English spelling of astronomical objects, which uses as an example "the Solar System". With that in mind, it's not a question of what you maintain, it is instead about what the accepted standard is on Wikipedia - and that would be "Solar System". --Ckatz^chat_spy 05:17, 18 April 2007 (UTC)

Please note, as well, that the citation you used (from the Solar System article) does not support your assertion that "solar system" is a generic term. Here is the relevant text:

"Capitalization of the name varies. The IAU, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects (Solar System). However, the name is commonly rendered in lower case (solar system) including in the Oxford English Dictionary, Merriam-Webster's 11th Collegiate Dictionary, and Encyclopædia Britannica."

As you can see, it does not address the generic issue at all, only covering the capitalization. Further it outlines how - while some sources use lower case - the "authoritative body regarding astronomical nomenclature" specifies using capitals. --Ckatz^chat_spy 05:25, 18 April 2007 (UTC)

Thank you very much for the clarification and the education.  :)
—ZorkFox (ষTalk) 06:18, 25 April 2007 (UTC)

Glad to be of assistance. I've had many people help me out in the time I've been here, so it's good to "pay it forward" (so to speak). Cheers. --Ckatz^chat_spy 06:26, 25 April 2007 (UTC)

It doesn't matter anyway. "solar system" is not the name of our system. The true proper noun is the Sol System (our sun is named Sol) Cheers! Skeletor 0 (talk) 01:33, 4 March 2008 (UTC)

[edit] Context for velocity

I was thinking about how we describe NH as the fastest probe, and was impressed with the "nine hours to the moon versus three days for Apollo" comparison given. In a similar vein, the time taken to get to Jupiter (just over a year) could be compared to, say Voyager (18 months?), or Cassini (crossing Jovian orbit, I have no idea?) or Galileo at six years(!). It may not be a fair comparison as the routes and relative planetary positions, but may provide some context to rather abstract numbers. I, for one, have no concept of 21km/s, but seeing something relative may help. If there are no useful comparisons, then just ignore my rambling. LeeG 23:28, 2 May 2007 (UTC)

Your point is a good one, and it raises interesting ideas about other ways to improve or expand the article in addition to your suggestion of comparing time taken to reach Jovian orbit. From an orbital mechanics perspective, the easy value to compare two spacecraft trajectories is the Characteristic energy, C₃, but that totally lacks meaning for most readers. Whereas time to cross Jovian orbit is quite intuitive. By the way, it is fair to compare Jovian orbit crossing times! The tradeoff for probes that have taken more circuitous routes using gravity slingshots is exactly that: a tradeoff of time en-route versus launch cost. It might be a reasonable question to ask (and for the article to answer): why did the New Horizons mission planners see a need to get there so quickly? Why did they spend money on such a powerful launch vehicle? (Sdsds - Talk) 00:18, 3 May 2007 (UTC)

[edit] Ulysses comparison

Ulysses was not technically launched directly toward Jupiter. It first reached Earth orbit on the space shuttle. See the article for details. Someone should clarify this comparison. 71.102.134.129 03:07, 12 May 2007 (UTC)

[edit] Misleading

It is misleading to compare New Horizon's travel time to the Moon and that of Apollo 11. Apollo 11 would have gotten there much faster if it didn't have to take time to slow down to actually land on the Moon.--Pharos 23:49, 21 May 2007 (UTC)

You make a good point. What the article needs in this spot (or somewhere) when discussing the New Horizons' velocity is a sense of "How fast is that really?" A better comparison would be to some other spacecraft that left the vicinity of Earth. For example, how fast was Voyager 1 travelling when it crossed the orbit of the Moon? Sadly, we don't seem to know the answer to that. So to give a sense that New Horizons is going faster than other spacecraft, what else can we do but compare with Apollo? (Sdsds - Talk) 00:31, 22 May 2007 (UTC)

I think we should only compare it to Voyager and other outer planets probes. Of course earlier flyby/impact missions to the Moon also got there considerably faster than Apollo 11. Luna 2 hit the the Moon dead-on in 33 1/2 hours in 1959! I think I remember the Apollo 11 comparison was first put out in a press release at the time, and I couldn't help thinking it was highly irresponsible of NASA to hype themselves in this manner.--Pharos 02:30, 22 May 2007 (UTC)

OK, I've removed the Apollo 11 comparison. If someone has a more meaningful comparison on the Earth-Moon trip time, feel free to add it.--Pharos 01:08, 28 May 2007 (UTC)

Again, it serves no purpose to compare velocities in space. For my reasoning see above section called "Fastest Ever?" Skeletor 0 (talk) 01:44, 4 March 2008 (UTC)

[edit] Rocket propulsion

This is just a layman's POV, but in missions like this one where you're taking 10 years to get all the way to Pluto, I've never understood why they can't just strap a massive fuel tank and rocket on it, and continue accelerating to a few 100,000MPH. That'd cut down the flight time a lot, obviously. Any ideas why this isn't done? --=== Jez === 22:58, 29 May 2007 (UTC)

That's a fair question; one reasonable answer might be "cost". Ask: how much would it cost to launch that massive fuel tank? Even if the fuel tank weighed only as much as the probe itself, the launch costs would be double! Also ask: what's the hurry? (Sdsds - Talk) 04:06, 30 May 2007 (UTC)

Another reason is that if you got to 100,000 MPH, you now have the problem of decelerating to some reasonable speed such that you can enter the orbit of the body you are exploring. This requires even more fuel. Often times, you want to use the minimum fuel allowed so that you can allow for more margin in building your science instrumentation/payload. Wikipedia brown 02:55, 19 June 2007 (UTC)

Yet another consideration is the fact that rockets cause a lot of vibration, and some of the instruments need to be perfectly still to operate correctly. The dust counter is the best example of this. Unlike the other instruments, it's operating almost non-stop all the way to Pluto, but its sensitive detectors are triggered by even the slightest vibration. If a rocket were burning during the entire voyage, the dust counter would be overwhelmed and unable to collect any real data. 205.175.225.22 00:05, 15 November 2007 (UTC)

[edit] Current status

The "Current status" section isn't really current status - it's more of a history of what's happened so far (stopping in November 2006), and thus overlaps significantly with the "mission profile" information immediately preceding it. Is there any reason why this shouldn't all be merged into one narrative? Or was the intention that "current status" should be a more detailed version of what's already been said? If so then at minimum the heading needs changing. Matt 23:54, 29 June 2007 (UTC)

...and later on in the article there's more overlap, since the Jupiter flyby is mentioned for a third time under "Science objectives and observation plan". I think two treatments - a mission summary and a mission detail - should be enough, no? And at the end, "Mission notes" seems a kind of miscellany, most of which could be integrated into the earlier text to improve organisation.

Overall, I think this article could do with a reorganisation. I did just make a few organisational changes actually, but I'm reluctant to take the thing apart any more in case I am missing some overarching principle. Thoughts? Matt 00:09, 30 June 2007 (UTC)

[edit] How are the knickknacks secured?

The "cultural artifacts" description here fills my head with amusing images of loose objects getting out of control... Pluto's discoverer's ashes getting in the mirrors and camera, the compact disc revolving unpredictably every time the gyroscope is applied, and so on. I'm sure all these things must be very well secured - how? 70.15.116.59 18:33, 27 October 2007 (UTC)

[edit] This is turning into the lamest of all Edit Wars

I am talking on whether Pluto was a Greek or a Roman god. He was both. But since he was a Greek god before he became a Roman god it is proper to call him a Greek rather than a Roman god. It is not that the Greeks called the god of the underworld Hades and the Romans Pluto, it was the ancient Greeks first called him Pluto and the Romans adopted the name. This is not the case of Venus that we can properly call a Roman godess since her Greek name was Aphrodite, other than that we are talking about the same god (the Romans simply adapted the Greek Pantheon and gave them Roman names, if they did) in this case we have the same name. While in Homer he is only called Hades, since Aeschylus (at the latest) he is also called Pluto and, as Plato said:

τὸ δὲ Πλούτωνος, τοῦτο μὲν κατὰ τὴν τοῦ πλούτου δόσιν, ὅτι ἐκ τῆς γῆς κάτωθεν ἀνίεται ὁ πλοῦτος, ἐπωνομάσθη: ὁ δὲ “Ἅιδης,” οἱ πολλοὶ μέν μοι δοκοῦσιν ὑπολαμβάνειν τὸ ἀιδὲς προσειρῆσθαι τῷ ὀνόματι τούτῳ, καὶ φοβούμενοι τὸ ὄνομα “Πλούτωνα” καλοῦσιν αὐτόν.

As for Pluto, he was so named as the giver of wealth (πλοῦτος), because wealth comes up from below out of the earth. And Hades--I fancy most people think that this is a name of the Invisible (ἀειδής), so they are afraid and call him Pluto. (Plato, Cratylus 6 403, translation by Fowler 1921 Loeb edition from Perseus)

While modern mythographers disagree with Plato this is direct proof that Pluto is also the Greek name of the god. BTW the references that I have added are from Greek sources calling the god Pluto, they are not telling which is Pluto relation with Hydra and Nix, as is implied by having the ref at the end, the ref goes at Greek not Pluto. One of the guidelines of Wikipedia is 'do not remove sourced material unless you want to get into trouble'.

If this edit is removed without citing a hard source why he should be called a Roman rather than a Greek god, I will take this to WikiProject:Mythology for arbitration. about.com is less reliable than Plato My reluctance to get bogged in a new edit war while I am busy is why until now edited this page anonymously. Ikokki (talk) 16:23, 24 January 2008 (UTC)

Who cares anyway? This article is about a spacecraft, not about mythology. I simply replaced "the Greek god Pluto" with "the mythological Pluto" and now all is well. Go and fight about it somewhere else. Cop 663 (talk) 17:05, 24 January 2008 (UTC)

Agreed, Cop 663, it's an irrelevant point here, fair compromise. (We could even go with "the classical god Pluto" too if we wanted.) Ikokki, I agree it's a lame edit war. Thanks for starting it (and perpetuating it). Also, thanks for finally using the article talk page. BTW, please learn how to use the citation templates. That's why they're there. Thanks in advance.  :-) --Bark (talk) 19:51, 24 January 2008 (UTC)

[edit] New Image

Image of Pluto taken in negative:

Serendi^podous 22:14, 25 January 2008 (UTC)

[edit] Fair use rationale for Image:Thermalbattery.jpg

Image:Thermalbattery.jpg is being used on this article. I notice the image page specifies that the image is being used under fair use but there is no explanation or rationale as to why its use in this Wikipedia article constitutes fair use. In addition to the boilerplate fair use template, you must also write out on the image description page a specific explanation or rationale for why using this image in each article is consistent with fair use.

Please go to the image description page and edit it to include a fair use rationale. Using one of the templates at Wikipedia:Fair use rationale guideline is an easy way to insure that your image is in compliance with Wikipedia policy, but remember that you must complete the template. Do not simply insert a blank template on an image page.

If there is other fair use media, consider checking that you have specified the fair use rationale on the other images used on this page. Note that any fair use images lacking such an explanation can be deleted one week after being tagged, as described on criteria for speedy deletion. If you have any questions please ask them at the Media copyright questions page. Thank you.

BetacommandBot (talk) 02:26, 12 February 2008 (UTC)

[edit] Pluto Charon's Barycenter

During New Horizons encounter with Pluto in 2015 will its NASA handlers investigate the "Barycenter" or center at which Pluto and Charon orbit each other (which just happens to be above Pluto's surface). Is a "Barycenter" simaliar to a "Libration Point"? Will there be small moons found there? The Earth/Moon "Barycenter" is located below Earth's surface (not at it's center) this causes the Earth to "wobble", does it also help keep the Earth's interior molten? Jalanp (talk) 17:08, 3 May 2008 (UTC)

[edit] Flyby of Eris and Others?

I am wondering if in the part where it says that by 2016-2020: Kuiper Belt, does anyone have info on whether NASA is planning to get New Horizons to pass Eris' orbit, as it is just as mysterious(probably more). As well, why is there such a broad date on the Kuiper Belt, is there not a definite date for entering the Kuiper Belt?

Laisinteresting 22:58, 25 May 2008 (ET)