Neptune Orbiter, Another proposed mission |
Neptune Orbiter, Another proposed mission |
 Nov 10 2005, 03:51 PM
Post
#1
|
|
|
Member  Group: Members Posts: 509 Joined: 2-July 05 From: Calgary, Alberta Member No.: 426  |
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? |
 |
 
|
 |
|
Dec 5 2005, 07:35 AM
Post
#2
|
|
 Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
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 -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
|
|
|
|
|
Dec 5 2005, 08:34 AM
Post
#3
|
|
 Member Group: Members Posts: 648 Joined: 9-May 05 From: Subotica Member No.: 384 |
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...  So it would take gazillon passes through it to slow down significantly... Solution : USE ROCKET ENGINES!!! 
-------------------- The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
Jules H. Poincare My "Astrophotos" gallery on flickr... |
|
|
|
|
Dec 5 2005, 10:49 AM
Post
#4
|
|
 Member Group: Members Posts: 255 Joined: 4-January 05 Member No.: 135 |
QUOTE (Toma B @ Dec 5 2005, 08:34 AM) Solution : USE ROCKET ENGINES!!! Which could get exciting if you landed on a patch of methane or nitrogen ice. |
|
|
|
|
Dec 5 2005, 11:42 AM
Post
#5
|
|
|
Member Group: Members Posts: 648 Joined: 9-May 05 From: Subotica Member No.: 384 |
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? -------------------- The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
Jules H. Poincare My "Astrophotos" gallery on flickr... |
|
|
|
|
Dec 5 2005, 12:52 PM
Post
#6
|
|
|
Member Group: Members Posts: 255 Joined: 4-January 05 Member No.: 135 |
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 |
|
|
|
|
Dec 5 2005, 01:27 PM
Post
#7
|
|
|
Member Group: Members Posts: 648 Joined: 9-May 05 From: Subotica Member No.: 384 |
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...
-------------------- The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.
Jules H. Poincare My "Astrophotos" gallery on flickr... |
|
|
|
|
Dec 5 2005, 03:07 PM
Post
#8
|
|
|
Member Group: Members Posts: 255 Joined: 4-January 05 Member No.: 135 |
QUOTE (Toma B @ Dec 5 2005, 01:27 PM) 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.... Toma, I wasn't talking about combustion. The explosion I am postulating would be purely mechanical, driven by gas pressure. Imagine if the exhaust warmed some water ice with pockets of nitrogen gas in it. Secondly, remember the geysers on triton - small in temperature lead to some pretty dramatic effects - from Wikipedia: "It is thought that the surface of Triton probably consists of a semi-transparent layer of frozen nitrogen, which creates a kind of greenhouse effect, heating the frozen material beneath it until it breaks the surface in an eruption. A temperature increase of just 4 K above the ambient surface temperature of 38 K could drive eruptions to the heights observed." (That height being 8Km!) Chris Edit: added Wikipedia info |
|
|
|
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 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 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 |
|
Lo-Fi Version | Time is now: 10th November 2024 - 06:09 PM |
|
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |
|
