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Neptune Orbiter, Another proposed mission
Rob Pinnegar
post Nov 10 2005, 03:51 PM
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This seems like a good place to start off the Uranus and Neptune forum: with the next ice-giants mission.

I will admit to not knowing a whole lot about the Neptune Orbiter With Probes (NOWP), other than the fact that it's in the planning stages, and a few other details I've gathered from Wikipedia and various other Internet sources. Anyone care to get this one going with a bit more information?
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dvandorn
post Dec 5 2005, 07:35 AM
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Does Triton *really* have enough of an atmosphere to allow for efficient aerobraking? At least, without a gazillion passes before you're significantly slowed down?

-the other Doug


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Toma B
post Dec 5 2005, 08:34 AM
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QUOTE (dvandorn @ Dec 5 2005, 10:35 AM)
Does Triton *really* have enough of an atmosphere to allow for efficient aerobraking?  At least, without a gazillion passes before you're significantly slowed down?

-the other Doug
*


NO IT DOES NOT!
The atmospheric pressure at Triton's surface is about 15 microbars , 0.000015 times the sea-level surface pressure on Earth...that's not enough for any kind of aerobraking...
Mars has average presure of 7 milibars, that is why MRO will have to spend many months aerobraking and don't forget that it uses only upper parts of atmosphere where presure is much less than that...
The average pressure on the Earth surface (sea level) is 1000 millibars....
In order to use that little atmosphere on Triton for aerobraking our unlucky spaceprobe would have to fly verry,verry,verry dangerously close to surface...
Edit:
Some approximate calculatins based on these facts:
Mars atmosphere is 143 times less efficient in aerobraking then atmosphere of Earth is...
Triton atmosphere is 467 times worst then Mars... sad.gif
So it would take gazillon passes through it to slow down significantly... sad.gif
Solution : USE ROCKET ENGINES!!! smile.gif


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chris
post Dec 5 2005, 10:49 AM
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QUOTE (Toma B @ Dec 5 2005, 08:34 AM)
Solution : USE ROCKET ENGINES!!! smile.gif
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Which could get exciting if you landed on a patch of methane or nitrogen ice.
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Toma B
post Dec 5 2005, 11:42 AM
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QUOTE (chris @ Dec 5 2005, 01:49 PM)
Which could get exciting if you landed on a patch of methane or nitrogen ice.
*


What did you meen by "exiting" ?
What's exiting about landing on a patch of nitrogen or methane ice?

Edit:
Also what does it have to do with rocket engines?


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chris
post Dec 5 2005, 12:52 PM
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QUOTE (Toma B @ Dec 5 2005, 11:42 AM)
What did you meen by "exiting" ?
What's exiting about landing on a patch of nitrogen or methane ice?

Edit:
Also what does it have to do with rocket engines?
*


If you land on a patch of such ice, and the rocket exhaust is hot enough to vaporise the ice, then you might get an explosive release of gas, which would be dangerous to the lander. The surface of Triton, at -235 Centrigrade, is only 20 degress lower than the freezing point for nitrogen, so it wouldn't be that hard.

Chris
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Toma B
post Dec 5 2005, 01:27 PM
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QUOTE (chris @ Dec 5 2005, 03:52 PM)
If you land on a patch of such ice, and the rocket exhaust is hot enough to vaporise the ice, then you might get an explosive release of gas, which would be dangerous to the lander. The surface of Triton, at -235 Centrigrade, is only 20 degress lower than the freezing point for nitrogen, so it wouldn't be that hard.
*

Question:
Will methane explode without oxygen?
NO IT WILL NOT !!!
...there's not much oxygen on Triton isn't it?
About Nitrogen...
How long would rocket engine work when verry close to surface...2-3 seconds perhaps?
Without any atmospheric presure there might be some sublimation but I'm sure nothing exiting....

Here's a deal:
Why don't we make a bet and we will see when NASA send that probe in the next 20 to 150 years... smile.gif


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Posts in this topic
- Rob Pinnegar   Neptune Orbiter   Nov 10 2005, 03:51 PM
- - elakdawalla   I don't know much myself about what's poss...   Nov 10 2005, 04:43 PM
|- - tedstryk   I would really like to see a Neptune orbiter with ...   Nov 10 2005, 05:26 PM
|- - Rob Pinnegar   QUOTE (tedstryk @ Nov 10 2005, 11:26 AM)Maybe...   Nov 10 2005, 05:59 PM
|- - elakdawalla   QUOTE (tedstryk @ Nov 10 2005, 10:26 AM)I wou...   Nov 10 2005, 06:20 PM
|- - JRehling   QUOTE (elakdawalla @ Nov 10 2005, 11:20 AM)Ho...   Nov 10 2005, 07:09 PM
||- - tedstryk   If an orbiter is a long way off, I think a Triton ...   Nov 10 2005, 07:13 PM
||- - ljk4-1   QUOTE (tedstryk @ Nov 10 2005, 02:13 PM)If an...   Nov 10 2005, 07:53 PM
||- - Jeff7   QUOTE (tedstryk @ Nov 10 2005, 02:13 PM)If an...   Nov 11 2005, 05:20 PM
|- - hendric   QUOTE (elakdawalla @ Nov 10 2005, 12:20 PM)Ho...   Nov 16 2005, 08:22 AM
|- - Rob Pinnegar   QUOTE (hendric @ Nov 16 2005, 02:22 AM)Accord...   Nov 16 2005, 02:02 PM
|- - tedstryk   It is no doubt battered, but so is Mimas. A possi...   Nov 16 2005, 02:28 PM
|- - Rob Pinnegar   QUOTE (tedstryk @ Nov 16 2005, 08:28 AM)A pos...   Nov 16 2005, 05:09 PM
- - RNeuhaus   The trip to planets beyond than Saturn, I think th...   Nov 10 2005, 07:38 PM
|- - tasp   QUOTE (RNeuhaus @ Nov 10 2005, 01:38 PM)The t...   Nov 10 2005, 09:49 PM
|- - RNeuhaus   QUOTE (tasp @ Nov 10 2005, 04:49 PM)Prometheu...   Nov 10 2005, 10:00 PM
|- - JRehling   QUOTE (tasp @ Nov 10 2005, 02:49 PM)Prometheu...   Nov 10 2005, 10:06 PM
|- - tasp   To revise and extend my remarks, Would a reusable...   Nov 11 2005, 12:59 AM
|- - tasp   Meanwhile, back at Neptune, Has anyone considered...   Nov 11 2005, 01:09 AM
|- - Rob Pinnegar   QUOTE (tasp @ Nov 10 2005, 07:09 PM)Has anyon...   Nov 11 2005, 01:36 AM
|- - tedstryk   QUOTE (Rob Pinnegar @ Nov 11 2005, 01:36 AM)T...   Nov 11 2005, 02:28 AM
|- - Rob Pinnegar   QUOTE (tedstryk @ Nov 10 2005, 08:28 PM)I don...   Nov 11 2005, 06:22 AM
- - Decepticon   There where some ideas for Neptune orbiter in Astr...   Nov 11 2005, 12:42 AM
- - BruceMoomaw   There has actually been quite a lot of work done b...   Nov 11 2005, 04:01 AM
- - tasp   I'll digress to Uranus orbiting briefly. Assu...   Nov 11 2005, 04:11 AM
|- - JRehling   QUOTE (tasp @ Nov 10 2005, 09:11 PM)I'll ...   Nov 11 2005, 02:23 PM
|- - tedstryk   QUOTE (JRehling @ Nov 11 2005, 02:23 PM)Unfor...   Nov 11 2005, 03:01 PM
||- - Rob Pinnegar   QUOTE (tedstryk @ Nov 11 2005, 09:01 AM)That ...   Nov 11 2005, 05:11 PM
|- - tasp   QUOTE (JRehling @ Nov 11 2005, 08:23 AM)If th...   Nov 11 2005, 03:12 PM
|- - JRehling   QUOTE (tasp @ Nov 11 2005, 08:12 AM)Can ...   Nov 11 2005, 04:45 PM
- - BruceMoomaw   I may have something to say on THAT subject in my ...   Nov 11 2005, 04:53 AM
- - BruceMoomaw   That's another reason why, given the likely de...   Nov 11 2005, 10:18 PM
- - tasp   Alex Blackwell has a post in the Uranus Orbiter th...   Nov 12 2005, 02:26 PM
|- - tedstryk   Here is an approach sequence of Proteus. All colo...   Nov 15 2005, 11:59 PM
|- - Rob Pinnegar   QUOTE (tedstryk @ Nov 15 2005, 05:59 PM)It is...   Nov 16 2005, 06:25 AM
- - tasp   And even Miranda is somewhat oblongish. Would I b...   Nov 16 2005, 06:31 PM
|- - David   QUOTE (tasp @ Nov 16 2005, 06:31 PM)And even ...   Nov 17 2005, 03:11 AM
- - tasp   I suspect the 'lumpiness' of Iapetus is a ...   Nov 17 2005, 04:46 AM
|- - Bob Shaw   QUOTE (tasp @ Nov 17 2005, 05:46 AM)I suspect...   Nov 17 2005, 08:01 PM
- - tasp   With a greater understanding or how orbital tours ...   Nov 26 2005, 02:55 PM
- - Decepticon   A simple Google search reveled this!? What P...   Nov 26 2005, 03:41 PM
- - BruceMoomaw   That's the nuclear-electric version of Neptune...   Nov 27 2005, 02:43 AM
- - Decepticon   I hate anything that Unfurls. When Galileo...   Nov 27 2005, 12:31 PM
- - BruceMoomaw   Just keep in mind that Galileo's antenna was e...   Nov 27 2005, 01:32 PM
|- - vjkane2000   QUOTE (BruceMoomaw @ Nov 27 2005, 06:32 AM)Ju...   Nov 28 2005, 03:38 AM
|- - mchan   QUOTE (BruceMoomaw @ Nov 27 2005, 05:32 AM)Ju...   Nov 29 2005, 07:51 AM
- - edstrick   In a conversation some 10? years ago, maybe at the...   Nov 28 2005, 06:06 AM
- - edstrick   Deployments have ALWAYS been one of the big missio...   Nov 29 2005, 08:44 AM
- - tasp   Just in case NASA/JPL finds themselves looking for...   Dec 5 2005, 05:23 AM
- - dvandorn   Does Triton *really* have enough of an atmosphere ...   Dec 5 2005, 07:35 AM
|- - Toma B   QUOTE (dvandorn @ Dec 5 2005, 10:35 AM)Does T...   Dec 5 2005, 08:34 AM
|- - chris   QUOTE (Toma B @ Dec 5 2005, 08:34 AM)Solution...   Dec 5 2005, 10:49 AM
||- - Toma B   QUOTE (chris @ Dec 5 2005, 01:49 PM)Which cou...   Dec 5 2005, 11:42 AM
||- - chris   QUOTE (Toma B @ Dec 5 2005, 11:42 AM)What did...   Dec 5 2005, 12:52 PM
||- - Toma B   QUOTE (chris @ Dec 5 2005, 03:52 PM)If you la...   Dec 5 2005, 01:27 PM
||- - paxdan   QUOTE (Toma B @ Dec 5 2005, 01:27 PM)Question...   Dec 5 2005, 01:47 PM
|||- - ljk4-1   Drop a probe right into one of the Triton geysers....   Dec 5 2005, 02:57 PM
||- - chris   QUOTE (Toma B @ Dec 5 2005, 01:27 PM)Question...   Dec 5 2005, 03:07 PM
||- - Toma B   QUOTE (chris @ Dec 5 2005, 06:07 PM)I wasn...   Dec 6 2005, 08:48 AM
||- - chris   QUOTE (Toma B @ Dec 6 2005, 08:48 AM)All righ...   Dec 6 2005, 10:41 AM
|- - helvick   QUOTE (Toma B @ Dec 5 2005, 09:34 AM)Mars atm...   Dec 5 2005, 12:02 PM
|- - JRehling   QUOTE (Toma B @ Dec 5 2005, 12:34 AM)Mars atm...   Dec 5 2005, 04:23 PM
- - edstrick   Note that the surface of Triton may be very rough ...   Dec 5 2005, 11:07 AM
- - tasp   Check out the last half of the Uranus orbiter thre...   Dec 5 2005, 03:05 PM
- - ermar   As a long-time lurker, sorry for spamming links, b...   Dec 10 2005, 02:23 AM
|- - Toma B   QUOTE (ermar @ Dec 10 2005, 05:23 AM)As a lon...   Dec 10 2005, 06:56 AM
- - BruceMoomaw   They definitely won't fly the nuclear-propelle...   Dec 10 2005, 06:42 AM
- - BruceMoomaw   Sure: http://www.lpi.usra.edu/opag/jun_05_meetin.....   Dec 10 2005, 08:46 AM
|- - tedstryk   QUOTE (BruceMoomaw @ Dec 10 2005, 08:46 AM)Th...   Dec 10 2005, 01:29 PM
- - AlexBlackwell   I apologize for reviving a dead thread; however, F...   Jul 17 2006, 07:51 PM
|- - Rob Pinnegar   QUOTE (AlexBlackwell @ Jul 17 2006, 01:51...   Jul 18 2006, 03:36 PM
|- - JRehling   I would think that at some point the weight of the...   Jul 18 2006, 03:38 PM
|- - Chmee   QUOTE (JRehling @ Jul 18 2006, 11:38 AM) ...   Jul 18 2006, 03:47 PM
|- - AlexBlackwell   QUOTE (Chmee @ Jul 18 2006, 05:47 AM) By ...   Jul 18 2006, 04:42 PM
- - ljk4-1   I wonder if a very large solar sail could be desig...   Jul 18 2006, 05:34 PM
- - Analyst   Before the "nuclear problem" comes the m...   Jul 20 2006, 10:54 AM
|- - antoniseb   QUOTE (Analyst @ Jul 20 2006, 04:54 AM) B...   Jul 21 2006, 11:52 PM
|- - Stephen   QUOTE (antoniseb @ Jul 21 2006, 11:52 PM)...   Jul 25 2006, 04:35 AM
|- - Greg Hullender   But surely at the distance of Neptune the force ap...   Jul 25 2006, 05:01 AM
|- - helvick   QUOTE (Greg Hullender @ Jul 25 2006, 06:0...   Jul 25 2006, 05:34 AM
- - ljk4-1   Would a Neptune orbiter be able to utilize the pla...   Jul 25 2006, 02:58 PM
|- - TritonAntares   QUOTE (ljk4-1 @ Jul 25 2006, 03:58 P...   Jul 25 2006, 11:17 PM
- - qraal   Hi All Solar concentrators are such a cool concep...   Jul 26 2006, 01:40 PM
- - mimile   There have been many good answers to the question ...   Feb 11 2007, 11:38 AM
- - Rob Pinnegar   Those are good points, but it may be worth keeping...   Feb 11 2007, 05:04 PM
- - nprev   Nereid: 27.6 deg with respect to Neptune's equ...   Feb 11 2007, 05:37 PM
|- - JRehling   It's odd that people brought the topic of Nere...   Feb 12 2007, 01:42 AM
- - nprev   Good point, JR. In fact, Nereid spins pretty fast:...   Feb 12 2007, 04:13 AM
- - tasp   OK, I am not smart enough to visualize this in my ...   Feb 12 2007, 06:24 AM
- - mchan   Possibly that the node crossings of the two orbits...   Feb 12 2007, 08:05 AM
- - tasp   Wikipedia has stats on Nereid and reports its...   Feb 12 2007, 03:14 PM
|- - JRehling   QUOTE (tasp @ Feb 12 2007, 07:14 AM) Wiki...   Feb 12 2007, 04:12 PM
- - tasp   Thanx, appreciate the clarification very much. So...   Feb 13 2007, 03:43 AM
- - Rob Pinnegar   The orbits will certainly precess -- but at that d...   Feb 14 2007, 01:57 AM
|- - TritonAntares   Hi, any ideas for an illustration, report, paper, ...   Feb 17 2007, 09:16 PM
|- - TritonAntares   Hi again, here a link to a french website dealing ...   Feb 18 2007, 02:10 PM
|- - tedstryk   It also has some of the strangest seasons, due to ...   Feb 22 2007, 02:13 PM
- - mchan   There is a graph in "The New Solar System...   Feb 17 2007, 11:42 PM
- - Rob Pinnegar   Yeah, looking at some of the references cited abov...   Mar 1 2007, 02:30 PM
- - tasp   Just throwing out some ideas here: Modify a follo...   Mar 2 2007, 05:30 AM
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