Talk:Deep Impact (spacecraft)

Named After The Movie?

Just curious, was the mission named after the movie Deep Impact? I haven't checked the history of the edits on this page, or the movie page, but I figured you guys might be able to tell me with less effort. Karmafist 4 July 2005 21:27 (UTC)

It says right in the article. Deep_Impact_(space_mission)#Before_launch - Omegatron July 5, 2005 01:52 (UTC)

No, oh look, why not look at the actual mission website! http://deepimpact.umd.edu/mission/di-name.shtml

Post Impact

The probe definetly hit the comet, with a pretty massive plume to boot. By my watch it was at about 1:00am CDT. --LouieS 4 July 2005 06:03 (UTC)

Conspiracy

I thought Comet Tempel 1 does not even come close enough to the sun to pose any danger to Earth (perihelion = 1.5 AU). Is this very far fetched theory discussed "on some Internet discussion groups" notable enough to be in here? I would say "No". Awolf002 16:58, 19 Jan 2005 (UTC)

Anyone who knows an iota about orbital mechanics knows that it would be impossible for it to move and hit earth, seriously impossible. A point energy source (which an impact or explosion would be) would have to be so accurate and so massive to move the course of that comet in such a away that it would impact the earth that it boggles the mind to imagine it. We would be talking about a force that would for one destroy the comet, and two have to be triggered at such an exact moment i doubt the technology exsists to do it. "Far fetched" is an understatement, it uneducated garbage. --LouieS 4 July 2005 05:22 (UTC)

Moved pic back, have grand plan

Sorry User:Evil Monkey, I moved the April 25 picture back to the Cruise phase section, just because that's when it was taken and is relevant to that section. I can understand that it introduces white space, but (a) white space isn't really content, and may disappear on other media (say mobile browsers), and (b) this is an article evolving with time, and the white space kind of suggests this.

Grand plan? I guess it would be good to have a pic of launch in the Launch and Commissioning Phase section, and obviously there will be many more paragraphs and pics if everything goes fine on July 4. JamesHoadley 08:12, 16 May 2005 (UTC)

bbc smoking crack or what?

This statement is opposite of what Wikipedia says "The mission is named after the 1998 Hollywood film in which an astronaut attempts to stop a comet hitting the Earth." [1]

All other sources I read say the name match is a coincidence. Somebody at the BBC is making things up? Awolf002 14:57, 10 Jun 2005 (UTC)

The article doesn't say that now - it has "The mission shares a title with the 1998 Hollywood film in which astronauts attempt to stop a comet hitting the Earth."[2] I guess someone corrected them? PaulHammond July 5, 2005 14:26 (UTC)

Reorganized the article layout

I just spend some time reorganizing the article layout, although I don't believe I removed any content. Does it look okay? I also added some sections about the scientific goals of the mission and the pre-launch history of the mission. I highly recommend the June 2005 issue of Sky and Telescope that talks about the mission; it's a good article.--Centurion328 04:20, 12 Jun 2005 (UTC)

July 4

Is it a pure coincidence, or was the date chosen for symbolic reasons? --Ma Baker 18:56, 15 Jun 2005 (UTC)

I think it was chosen intentionally. The "impact" is intended to be a play on the fireworks traditionally produced in the United States on that date. Awolf002 19:16, 15 Jun 2005 (UTC)

I argee with awolf, the amount of fuel used to make the probe hit the comet on June 27th or say July 11th (just pulling that our of a hat, would be minimal. I would guess we would be talking about less that 100lbs of fuel used for the range of those dates, provided it was done early in the flight. --LouieS 4 July 2005 05:17 (UTC)

The date was chosen because the comet was at opposition and at perihelion within a few days of 4 July (one before and the other after, but I forget which was when), so they decided to split the difference. So there were some celestial mechanics involved that were the driving reasons. Adastragrl 18:46, 27 September 2007 (UTC)

Timeline

While arguably useful to have, the average reader will not be interested in a list of times and distances. Would anyone object if we either delete it or move it to a separate page with a "see also" and information on when the mission was planned and so on? Dave (talk) 15:59, Jun 26, 2005 (UTC)

OK, I'm moving it to the talk page. -- Yaohua2000 17:38, 26 Jun 2005 (UTC)

Magic Numbers

Predict trajectory revised on May 10, 2005 by JPL Horizons Ephemeris System:

• Deep Impact was only 50,000,000 kilometers away from 9P/Tempel 1 at 2005-May-09 23:35:22 UTC.
• Deep Impact was only 40,000,000 kilometers away from 9P/Tempel 1 at 2005-May-20 13:39:11 UTC.
• Deep Impact was only 30,000,000 kilometers away from 9P/Tempel 1 at 2005-May-31 13:23:48 UTC.
• Deep Impact was only 20,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-11 17:58:40 UTC.
• Deep Impact was only 10,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-22 23:52:37 UTC.
• Deep Impact was only 9,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-24 02:52:08 UTC.
• Deep Impact was only 8,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-25 05:52:11 UTC.
• Deep Impact was only 7,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-26 08:51:58 UTC.
• Deep Impact was only 6,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-27 11:51:31 UTC.
• Deep Impact was only 5,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-28 14:50:49 UTC.
• Deep Impact was only 4,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-29 17:49:53 UTC.
• Deep Impact was only 3,000,000 kilometers away from 9P/Tempel 1 at 2005-Jun-30 20:48:45 UTC.
• Deep Impact was only 2,000,000 kilometers away from 9P/Tempel 1 at 2005-Jul-01 23:47:28 UTC.
• Deep Impact was only 1,000,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 02:46:04 UTC.
• Deep Impact was only 900,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 05:27:55 UTC.
• Deep Impact (impactor) was only 800,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 08:09:46 UTC.
• Deep Impact (impactor) was only 700,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 10:51:37 UTC.
• Deep Impact (impactor) was only 600,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 13:33:28 UTC.
• Deep Impact (impactor) was only 500,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 16:15:19 UTC.
• Deep Impact (impactor) was only 400,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 18:57:10 UTC.
• Deep Impact (impactor) was only 300,000 kilometers away from 9P/Tempel 1 at 2005-Jul-03 21:39:01 UTC.
• Deep Impact (impactor) was only 200,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 00:20:52 UTC.
• Deep Impact (impactor) was only 100,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 03:02:43 UTC.
• Deep Impact (impactor) was only 90,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 03:18:54 UTC.
• Deep Impact (impactor) was only 80,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 03:35:05 UTC.
• Deep Impact (impactor) was only 70,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 03:51:16 UTC.
• Deep Impact (impactor) was only 60,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 04:07:27 UTC.
• Deep Impact (impactor) was only 50,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 04:23:39 UTC.
• Deep Impact (impactor) was only 40,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 04:39:50 UTC.
• Deep Impact (impactor) was only 30,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 04:56:01 UTC.
• Deep Impact (impactor) was only 20,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:12:12 UTC.
• Deep Impact (impactor) was only 10,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:28:23 UTC.
• Deep Impact (impactor) was only 9,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:30:00 UTC.
• Deep Impact (impactor) was only 8,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:31:37 UTC.
• Deep Impact (impactor) was only 7,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:33:14 UTC.
• Deep Impact (impactor) was only 6,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:34:51 UTC.
• Deep Impact (impactor) was only 5,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:36:28 UTC.
• Deep Impact (impactor) was only 4,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:38:06 UTC.
• Deep Impact (impactor) was only 3,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:39:43 UTC.
• Deep Impact (impactor) was only 2,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:41:20 UTC.
• Deep Impact (impactor) was only 1,000 kilometers away from 9P/Tempel 1 at 2005-Jul-04 05:42:57 UTC.
• Deep Impact (impactor) has impacted with 9P/Tempel 1 at 2005-Jul-04 05:44:34 UTC.

this might be the end of the world

At first I thought this would be cool but then I started wondering when the probe goes though the the asteroid I think that two things would happed that has to do with the end of the world. First the asteroid will blow up in many pieces or come unstabial and go way of course. ether way it will destroyed are planet or maybe a different one destroying the natural solar systems but still it will effect us one way or the other and if it even comes for us we would not even know and if it blows a hole it would disputing the gravitail pull pulling us into the sun and killing us all like in ratchet and clack 1. The reason I say this is this is just a hypothesis but all sciences is built on it... and I did not what to die with this on my chest if I was right So before you sciencetise but a hole in the asteroid think about this and what cauze it might have, haven't movies though you anything. (sorry about the spelling mistackes) from the monkey man

Are you trying to scare us all, or score with WP:BJAODN? Nothing anywhere close to this will happen! Temple 1 has survived many impacts and it will "do just fine" after this one. I just hope the impactor probe does not miss its fast-moving target. Awolf002 30 June 2005 14:30 (UTC)

How could that nonsensical piece of garbage scare anyone? The grammatical structure alone is enough to impede understanding of what is nonetheless an absurd and wholly unfounded 'theory'. It is articles such as this that undermine the usefuless of WIKIPEDIA and do not deserve a respectful reply as yours Awolf002.

Monkeyman, thanks for the joke, I was having a bad day :-)--Karmafist 4 July 2005 21:23 (UTC)

Wikimedia Commons for images

Hi all, I started a Wikimedia Commons page here for image uploads and the like. The whole thing could be fizzer, but if as planned there are impact images returned, I think they should be put there. You just create a Wikimedia Commons account like you would on Wikipedia, upload the file, and stick it in a gallery.

I've added 4 of the shots from Approach phase to this page, I hope you like it. JamesHoadley 2 Jul 2005 UTC+1000

Please note that many of the processed images do indeed have credit lines associated with them that should be included with the images!!! Adastragrl 18:46, 27 September 2007 (UTC)

International and cosmic law

- Did the NASA make sure that the comet has no life whatsoever, including primitive single-cell organisms (genocide) - Did the NASA make sure no other civilization has installations on the comet or claim it as their own, e.g. comet is hollow and is the birth planet of little green men with 3 eyes (attack without declaration of war) - What happens if sheds from the explosion damage some places on the Earth or destroy some other spacecraft (insurance)

The world is really fed up with US aggression. Vietnam, Granada, Panama, Iraq and now Comet Tempel. This comet bombing is the wettest dreams of evil "Star Wars" Teller and Ronnie Raygun come true.

hehehe :-) Dave (talk) July 1, 2005 13:08 (UTC)

PS If you're worried about that sort of thing, see the "controversy" section on the article page.

Well, comets are coated in a tar of fairly complex aminoacids. But um, no, theres no life on it; if there were life on this or any other comet in out solar system, I would start believeing in god because thats the only way it could happen. Hey, at least it's better than the antimatter fantasy. -LouieS 4 July 2005 05:15 (UTC)

Earth-received time vs Spacecraft event time

I've changed all the time in Ground UTC to Orbiter UTC. So the impact time should be 05:44:34 in SCET (One-Way Light Time = 7 minutes 26 seconds). -- Yaohua2000 3 July 2005 08:40 (UTC)

Thanks for clearing that up Yaohua2000. JamesHoadley 3 July 2005 09:30 (UTC)

Remove antimatter controversy

I think calling this a constroversy pays to much tribute to the lonely crackhead that came up with that idea. Similar for any suggestions that the orbit might change dramatically or that the comet would break up.

That's a standard for Wikipedia's NPoV, if there's some wacko view, they deserve to be put in the article, so it goes under the heading Controversy. We could also drown them out. There's also

• The Electric Universe theory reported in SlashDot, home page http://thunderbolts.info/tpod/2005/arch05/00current.htm

• The Exploded Planet Hypothesis (EPH) reported in Usenet, home page http://metaresearch.org/solar%20system/eph/DeepImpact.asp

As a footnote, Controversy sections usually work well in subjects like politics, but in science they're usually cranks. Oh well.

JamesHoadley 4 July 2005 10:31 (UTC)

I'm the author of the antimatter bit of the article. It can be removed if the consensus is against it, though I'd prefer to leave it in. I think that: a) since we're lumping the antimatter theorists with "astrologers," it was pretty clear that we aren't taking their theory very seriously, and b) since NASA felt the need to respond to it, it was more than "one lonely crackhead." I figured since Wikipedia isn't paper and it's just a little bit at the end of the article, there was no harm in putting in a discredited theory. Dave (talk) July 4, 2005 14:50 (UTC)

This was my comment originally. I am not a regular writer for wikipedia, so I don't know what the general policy is. I think that in a political topic there is usually some ethnic group that has a different view, as in 5 percent of a population. This is science however, and it is one crackhead against the rest of the world, so it is hardly a NPOV issue. If you would allow this you could add a controversy section to every scientific theory that is otherwise undisputed. I think that in most cases (barring hot topics like evolution) it does not justify the clutter/distraction of an extra paragraph. I am strongly in favor of removal. Cheers, Bas

This view is obviously held by a negligible minority and furthermore is entirely absurd. It is not notable and should be removed. It is NOT policy that any wacko view gets representation in an article and in my opinion that kind of attitude is just a concession and an invitation to the trolls. If this antimatter thing were widespread and covered in the media or whatever, we could note it but at the moment its just wasting article space. The astrologer thing could go under the same category of being irrelevant and unimportant, but maybe that's a bit more notable. --Tothebarricades July 5, 2005 03:40 (UTC)

I wouldn't call it even a minority. Calling it "controversy" makes it appear more important than it really is. I really recommend removing that part, or at least renaming the title, although it is funny in a sad way.--Jyril July 5, 2005 08:01 (UTC)

All right. I know consensus when I see it. I'll remove it. Dave (talk) July 5, 2005 12:43 (UTC)

Flyby spacecraft mass

Do someone know the exact mass of the Deep Impact flyby spacecraft? Because NASA says on some of its pages ([3]) that it weights 650kg, and in its press kits (Launch Press Kit and Encounter Press Kit, PDFs!) 601 kg. --Bricktop 4 July 2005 17:59 (UTC)

Fall back to the sun?

Will the flyby probe fall back to the sun in the future? Or will it orbit the sun? I guess the probe's trajectory is designed to use up most of its kinetic energy at the time of impact so the comet could smash into the impactor from behind. (You switch to the fast lane and let your car gradually slow down. By the time you stopped, you push a button and eject your rear bumper. Some crazt driver moving at 1000000000000000000000000 mph hits your rear bumper and explodes. You take the picture and sell it to NASA.) -- Toytoy July 5, 2005 03:02 (UTC)

The probe will orbit. In general, it is exceedingly hard to make an object "fall back" into the Sun. You need enough rocket power to counteract the kinetic energy that the probe got from the Earth in the first place (30 km/s); otherwise, the probe will miss the sun and will orbit. Currently we don't have any rocket technology that can achieve a 30 km/s delta-v without a whole lotta gravitational slingshots. I'm not sure what you mean by "use up most of its kinetic energy". --P3d0 July 5, 2005 20:45 (UTC)

You mean an elongated elliptic orbit around the sun? What's this probe's orbit? Hohmann transfer orbit? -- Toytoy July 6, 2005 00:36 (UTC)

There needs to be a section for the future, but if I recall correctly, the Flyby spacecraft will encounter Mars in this solar orbit, then come back to Earth's vicinity. It has enough fuel for a retargeting maneuver to another comet, so they are considering options starting very soon, using both fuel and slingshots to retarget.

As for "using up kinetic energy", its orbit brought it to the vicinity of Tempel 1 travelling slightly slower than it*. In fact it was on the same crash course with the comet as the impactor until after it released it. Maybe there should be a better explanation of the orbit mechanics. In any case I'm pretty sure that the only maneuvers it made were slight orbit corrections, and it still has its same basic solar orbit.

(* Slightly slower in solar orbit terms still means a big impact velocity.)JamesHoadley 6 July 2005 15:58 (UTC)

Actually it hit at about 10km/s which is about 20% of solar orbit velocity, so it's not really a slight difference, but I think they achieved the high velocity difference by approaching the comet at an angle, with one Deep Impact's elliptical orbit crossing Tempel's elliptical orbit. JamesHoadley 6 July 2005 16:11 (UTC)

NASA stated repeatedly that the best way to see it is not that the probe hit the comet, but that the comet 'ran over' the probe. If you look at the factsheet (see deepimpact.jpl.nasa.gov) they draw the path of the comet as a circle roughly the size of Mars' orbit and the DI's orbit as an ellipse toughing the comets orbit and earth's orbit, i.e. a Hoffman transfer orbit. The 10 km/sec is thus the DIFFERENCE between the two, which will be much lower than the either the comet's or the probe's velocity. Quick estimate: Orbital speed of Mars (roughly same distance from sun as comet?) is 24 km/sec, so the probe would have probably moved around 14 km/sec at aphelion

http://deepimpact.umd.edu/disczone/challenge_vector.shtml goes into detail about actual and relative velocities!

Adastragrl 18:46, 27 September 2007 (UTC)

The original plan

Based on a book published in 2000 (sorry, I forgot the name), this probe was scheduled to be launched during January 2004 and flyby the earth in January 2005 (gravitational slingshot). It was supposed to crash into Temple 1 on July 4, 2005 but with a 500 kg payload. -- Toytoy July 5, 2005 09:47 (UTC)

I think it was exactly the same mission but with a slightly smaller (and cheaper) launch vehicle (maybe Delta 7325 as for Stardust?) --Bricktop 5 July 2005 10:24 (UTC)

That's why you need the slingshot? A smaller and cheaper rocket? We have so many planets, I love slingshots. -- Toytoy July 5, 2005 12:15 (UTC)

You're right with the original 500 kg impactor, read [4]. --Bricktop 7 July 2005 15:05 (UTC)

It really would be amazing if you read the mission website which contains pretty much the answers to alot of the questions and comments posted here... http://deepimpact.umd.edu/mission/di-name.shtml gives a bit of the history of the mission...

Adastragrl 18:46, 27 September 2007 (UTC)

Bright impact

I wonder why photos from the impact showed a bright luminous explosion. There was no detonation or explosion that could have caused this. Or is this another feed for conspiracy theory, igniting a nuclear bomb on Temple 1 in a desperate struggle to move that comet away from its unescapable impact track to earth? (See, that's why they gave Deep impact the same name as the movie Deep Impact, so only insiders know what really is going on. --Abdull 5 July 2005 22:35 (UTC)

All you need for an explosion is a "hot" material that wants to expand. Yes, here on Earth you do this with explosive materials for convenience, but there on the comet, a fast, ca 600 kg heavy block of stuff being decelerated to relative zero speed will create the same thing. Remember: Pressure = Heat. There as a lot of pressure on that copper block during decelaration!! Another way to put it is that all the kinetic energy was converted to heat, and so "boom" :-) Awolf002 6 July 2005 00:21 (UTC)

You really don't want to use any kind of explosive here. Kinetic energy is sufficient. Moreover, they don't want to stuff too much organic materials on the impactor because it will surely pollute the spectrum readings with foreign CO₂, H₂O, NO_x ... molecules. Copper is exotic to the comets so it's easier to disregard copper. I wonder if we could use depleted uranium or else ... -- Toytoy July 6, 2005 00:29 (UTC)

Hi Awolf002, it's hard for me to think about pressure and heat when talking about near-vacuum space. Do you have more information about this process (website etc.)? Thank you, --Abdull 6 July 2005 12:41 (UTC)

Check out these pictures at NASA. It shows the Ames vertical gun range experiment and pictures of simulated impacts. Also... When you hit the surface of a rocky object (like a comet) then you are obviously not talking about "near-vacuum," anymore. Awolf002 6 July 2005 13:27 (UTC)

A relatively small mass pulverised into tiny particles will reflect a lot of sunlight. The same principle works for Saturn's huge ring system (~100,000 km in size), which is estimated to have the same mass as a large comet or small moon (say something 50 km across). I don't think they really knew for sure that it would make a bright explosion, but it's no surprise. JamesHoadley 6 July 2005 16:03 (UTC)

Math?

I don't know if I'm reading this wrong, but it says that the probe hit the comet at 10 km/s, which is equivalent to 6 mph. Is it me or does that not sound right? I'd imagine that 10 km/s is a lot faster than 10mph. I don't know if was meant to be 10 m/s or if the 6.3 miles is the wrong english equivalent to metric 10 km. someone should check that out.

10 km/s = 36,000 km/h = 22,500 mph. (It's unsafe at any speed, afterall, it crashed into something miserably. These NASA's drunken drivers could't even steer it away. They hit a small small dirty snowball in such a big big space.)

If you do it on earth, you'll get a ticket no matter where you are. -- Toytoy July 6, 2005 06:41 (UTC)

The text says mps (miles per second). God, it's a six-month-long red-eye flight and they're counting it by the second. -- Toytoy July 6, 2005 06:45 (UTC)

That trip was a bore. Whoever onboard that probe must have been sorry for taking the ride. The Voyagers carried a lousy sound track. The Pioneers had some sort of abstract pornography on them. Passengers on that trip, whoever they were, got not even a small packet of peanuts. By any standards, it's the death of economy class in-flight service. No movies! No food! No free soda! -- Toytoy July 6, 2005 07:02 (UTC)

Well, the passengers had a rather long list of names to read over during the trip. ;) -- KTC 18:18, 22 January 2006 (UTC)

"Contraversy"?

Is it really necessary to have that astrologer story under the heading "Contraversy"? I saw the heading "Contraversy", and figured that there was some bonafide contraversy about the mission, like there was with the Cassini mission to Saturn. Instead, I saw that story that reads more like an article out of The Onion... --Bletch 6 July 2005 21:35 (UTC)

I think the section should be removed. Does it really matter what astrologers think about this? Methinks not. And calling it a "controversy" is almost comical. If it stays, it should be renamed "Astrologers' objections to the mission" with a brief summary and an external link. --Tothebarricades July 8, 2005 07:54 (UTC)

I changed the heading to "Lawsuit by Astrologer"; I have to admit I did get a chuckle or two out of the story, and it would be nice to leave it in given nowhere else to put the thing. --Bletch 8 July 2005 13:06 (UTC)

I don't care how you call the section, as long it is removed. I don't mind keeping it in for some time, but I think it should go in the long run. IMHO an encyclopedia should be a concice source or information, with all the possible details to be found in the references. This means that not every fart that is being produced should be included. Compared to the 100s of millions it costed, the great engineering, the dramatic impact and hopefully some good science, the acts of a single crackhead in Russia will be a total non-event when you would look back in one year. Bas

I think this is an interesting fact worthy of WP. Even if you disagree with that crackhead (as I do), it was well published in the news and a Russian court is dealing with it (besides laughing all the way to the bench, I suspect). Awolf002 15:06, 13 July 2005 (UTC)

I see nothing wrong with this section. It's just an amusing sidelight. Harmless and worth keeping since collecting trivia is one of the reasons WP exists. Plus it has media coverage so that makes it notable. 23skidoo 15:11, 13 July 2005 (UTC)

That's what I mean, it has media coverage now, so leave it in now. In one year however, that is forgotten and it is no longer worth mentioning. Bas

Well, it's been more then a year since impact, so unless anyone objects in the next week, this section will be removed.--Planetary 01:24, 10 July 2006 (UTC)

Alright, it's gone now.--Planetary 22:20, 17 July 2006 (UTC)

Disambiguation page?

Whe someone types in "Deep impact, they proabaly want this article. But they have to go through a disambiguation page in order to get here. I mean, does anyone still care abbout the movie? My idea: work things a bit so that "Deep Impact" leads to the article rather than the disambiguation page; and have a link there at the start of the article. Comments?

I'm tempted to agree with this user - anyone strongly disagree? The Singing Badger 23:05, 17 September 2005 (UTC)

Yeah, I agree, it's like with the old planets disambiguation pages, seriously, if someone is looking for the Greek god Saturn they're unlikely to be surprised that the page lands on the planet Saturn. JamesHoadley 23:17, 19 September 2005 (UTC)

Sounds good to me, too Awolf002 23:36, 19 September 2005 (UTC)

Before you make the change, you should put the same suggestion on the Deep Impact (movie) talk page and see what people there think. You might get a different point of view from movie buffs than you do from astronomy buffs. Care to guess which category is larger? --Blainster 23:01, 20 September 2005 (UTC)

Change "Principle Goals"

http://www.newscientistspace.com/article.ns?id=dn8670

The goal "Are cometary nuclei highly cohesive and tightly-packed, or porous conglomerates?" has been proven; should someone add something in there? I would recomment a strikethrough, and a link to this article.

David Souther

More results

Here is a mission update with some useful graphs and information. I'd add it too the objectives section but I'm going to be away in reality for a few days. If anyone reads this till then add the things in. --Planetary 23:51, 18 August 2006 (UTC)

GA nomination

I nominated this article for GA. Please check and see if there are any errors that I may have missed on the aritcle before it gets reviewed. Thanks to everybody that helped to contribute to the article. --Nehrams2020 04:23, 25 June 2007 (UTC)

GA review comments

Hi, You have a very impressive article here. It is well referenced. It has excellent images. It gives great and complete coverage. However, presently it is B category in rating. It definitely deserves to be GA after the comments are addressed. Please consider them as room for improvement en route to peer review and FA.

• The opening sentance foxes the reader - is it ongoing or yet to reach its objective of meeting Tempel1 mission? Better to begin with -

Deep Impact is an ongoing NASA space probe launched on 12 Jan 2005 for studying...<general purpose of the mission>. The highlight of the mission to date has been <encounter with Comet Tempel & main outcome>. <...your other sentances summarising the rest of the articles followed with the mention of the public interest and ending with the future mission.>.

Done I reworded this somewhat, mainly just adding the "ongoing".

• I suggest that the sections be rearranged as follows to give a more logical sequence of events based on the likely expectation of the reader for information:-
  • Scientific goals of the mission.
  • Spacecraft construction and design.
  • Mission profile.
  • Mission events.
  • Future activities.
  • Public interest.

Done I moved the mission profile down, but believe that the future activities should be the last section in the article as there has been no notable public interest on the future activities.

• The scientific goals could do with an expansion beyond a single sentence . You may like to give the goals first and the researchers later.

Done Added a few more sentences and moved the researcher section below it.

• Two questions arise in a layman's mind from reading section 'Mission profile'. Something needs to be done about that.
  • Firstly, has the dust not settled as yet showing the impact crater. Will it be possible to get a look at the impact crater after this? Or will it remain unanswered?

Modified the wording.

• • Secondly - has the ESA found out the composition of the comet as yet.

I included information about the composition in the results section.

• This text leaves a person thinking that Deep Impact flyby was reprogrammed to another (unnamed) comet after its mission retargetting to Comet Boethin -

After this flyby of Tempel 1, Deep Impact was retargeted to comet Boethin. On 20 July 2005, a trajectory correction maneuver was performed to place the spacecraft on a trajectory to carry it to the Earth and use a gravitational slingshot to target another comet and the follow-on mission was approved 31 October 2006.

The sentences can be combined and resplit along different lines to read better.

I don't understand where it says another comet. The statement currently states "...where it would use a gravitational slingshot to reach the new target.", with information about the new comet in the sentence before it.

It already appears to have been done. The text above was the original wording at the time of review.

• Complete this sentence by adding a clause -

If the impactor was loaded with other materials such as explosives, it would create a significant amount of organic vapor... which would have <the following consequence>.

A layman may not understand what is the significance of the organic vapour.

Removed the statement, couldn't find any further information on it.

• The sentence about the origin of the name with reference to the film can be delinked from preceding text and put in a separate para. The previous text deals with the mission history and the name origin fact suddenly seems jarring as you encounter it.

Done Moved the information to the Spacecraft design and instrumentation section.

• This sentence should be in past tense as the event is over and since the next sentance is also in past tense :-

The approach phase extends from 60 days before encounter (May 5) until five days before encounter.

Done

• A subsection on post-impact manouvreing or action taken after impact to disengage would add completeness to the 'Mission Events' even if it just one or two lines giving the gist . Maybe the first sentance of future activities or something from last sentances of the mission profile belongs here...

Done

• There appears to be a contradiction, maybe these facts are unconnected, but if I make a mistaken assumption, then others could too. There may be need for some kind of text modification...
  • The proposed $500,000 extended mission...
  • the mission would provide about half of the information as the collision of Tempel 1 but at a tenth of the cost.

Done Switched to a fraction of the cost. It appears that he is going off of a different figure.

• • The total cost of developing the spacecraft and completing its mission reached $US300 million.
• BTW your link to CNN.com places the cost at 330 million dollars, not 300 million dollars, appears to be a typo.

That was because I switched one source that said 300, to CNN which sounded more reliable, but forgot to change the number.

• The wikilink of HRI camera goes to an article on HiRISE camera of the Mars Reconnaissance Orbiter. Have I missed something? The wikilink does not mention that this camera has been placed on Deep Impact though the manufacturer is same. In case of Space Missions, arent each of the instruments custom-made? If HRI is different from HiRISE it may be more appropriate to place HiRISE in the wikilinks of 'See also' below.

Done I removed the wikilink, as there is no article on the HRI. I checked some links through Google seeing if HiRISE was connected with Deep Impact and couldn't find anything, so I just removed the wikilink.

• The Impact Targetting System and MRI deserve to be wikilinked and stubs made if necessary. These kinds of instruments would be common to other spacecraft too, just as hi res imaging cameras were fixed on Deep Impact as well as the Mars Reconnaissance Orbiter. Some other terms in that section such as infrared spectroscopy, and imaging could also do with wikilinking. A quick check for this aspect over the complete article would'nt hurt either.

Done I added a couple of more wikilinks. Since I removed the wikilink for the HRI, the other ones probably don't need one either. If they are ever made into articles, I'll be sure to wikilink to them.

• In the Results section, the first para doesnt really give a good representation of the results. It requires rework. It gives a negative note in the beginning. Was'nt the mission successful? It achieved the collision, problems with instruments were overcome with ingenuity, navigation was near-perfect. A large plume was created. Here there should be some text describing something of significance in all this. The test is - can the Results section give lucid and succint overview to someone who cannot be bothered to read the rest of the article. Perhaps, this link will help develop it?

I added some positive quotes, and information about the questions of the scientific goals. Let me know if you want further information.

• Wikimedia Commons has many Deep Impact instrument images which can be placed in a gallery under Spacecraft construction.

I added some images from the Commons page, but for different sections. The article already has sufficient images for the construction, and the link at the bottom of the page can direct the readers to more of the images.

• Lastly, NPOV. Negative events such as the Russian court case have been discussed in the talk and kept out by consensus as per your talk page. But, if GA is to be aspired for, NPOV has to be assured. There should be a reference in the text - albeit a brief one. Playing devil's advocate, are a rock concert and Chinese press release more relevant than a court case to the extent that they are mentioned but not even a single line is permitted for the (I agree) crank case? Remember NPOV is a quickfail criteria for GA, much less FA, which this article deserves to be developed into.

I'll get to this as well, wasn't even aware of it. NPOV is always my priority, so I'll get in there once I fix everything else.

Done Made mention of it in the Media coverage section. I'm still searching for a NASA reaction to the lawsuit.

Regards, AshLin 12:10, 2 July 2007 (UTC)

My personal congratulations to Nehrams2020 and all other contributors to this aricle for its reaching GA.AshLin 11:27, 7 July 2007 (UTC)

Deep Impact spacecraft's earth flyby - incorrect date?

In the second paragraph of the article it says the following:

The spacecraft will fly by Earth on December 31, 2007 as it heads to a new mission to study extrasolar planets and comet 85P/Boethin.

What is the source for this information? I have studied NASA's page showing Deep Impact's trajectory, which you can find here (note it's Java and takes a while to load):

[5]

Skip to December 31, 2007 and then continue forward. You'll see that Deep Impact's Earth fly-by is due for January 30, 2008 (distance from Earth will be 0.0131 AU) as opposed to December 31, 2007. Now I know that there's a disclaimer at the head of the page, stating that the data should not be used for determining accurate long-term trajectories, but.. could it really be that inaccurate? One whole month out? I am not convinced.

I would be glad to look at the data again and I'd ultimately like to know what the source was for the December 31 fly by. If no source is provided I will edit the article.

Kahotep 10:53, 15 October 2007 (UTC)

• Perhaps the date was changed since the article was updated with the Dec. 31 date? If you've got a solid source like NASA's own webpage giving a different date, I don't think you need to wait - go ahead and change it. 23skidoo 17:53, 15 October 2007 (UTC)