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The First Europa Lander, What can be done first, cheapest & best?
nprev
post Dec 31 2005, 12:08 AM
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I think that many people in this forum would agree that somebody's going to have to land on Europa someday before the rather elaborate schemes to penetrate the outer ice layer will ever fly, if for no other reason than to get some relevant ground truth before committing to such an elaborate, expensive, and risky mission.

EO seems to have ruled out any surface science package for that mission (though it would be nice to change their minds! wink.gif ), but I think that there is a valid requirement at some point to directly assess the surface properties of Europa in an inexpensive yet creative way. Some candidate instrument payloads might be:

1. A sonar transducer/receiver set embedded within a penetrometer to determine crust density and examine the uniformity of the ice layer within the operational radius of the instrument (looking for cracks and holes, in other words).

2. A conductivity sensor again embedded inside a penetrometer to measure the native salinity of the surrounding material and possibly derive some constraints on the composition of metallic salts in the European crust (saltiness has a major effect on ice properties, in addition to the obvious need to derive the salt content of any underlying ocean).

3. A seismometer for all sorts of reasons.


How does this sound? Any critiques, additions, or subtractions? I omitted a surface imager not only because of bandwidth/extra complexity considerations but also because it seems desirable to penetrate the crust in order to minimize as much as possible reading any contaminants from Io during surface measurements. The orbiter data could be used to sense and subtract this from the penetrometer readings.


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rasun
post Nov 29 2007, 05:35 PM
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Hi!

Apparently, NASA's Astrobiology, Science and Technology for Exploring Planets program funded the DEPTHX, an autonomous underwater robot.
(See Depthx home here:
http://www.frc.ri.cmu.edu/depthx/
many images here:
http://www.jsg.utexas.edu/news/rels/030807b.html
and here:
http://geology.com/zacaton/
or many links at NASA:
http://astrobiology.arc.nasa.gov/news/expa...ws.cfm?id=10644

DEPTHX and it's follow-up, ENDURANCE are "advertised" as robots that are largely developed so that their next version would be operating in the oceans of Europa, at least that's what I get from the articles. But the Europa Explorer, if approved, will at best fly around 2015, and then a first Europa lander, if approved, probably not before 10 years later; and THEN probably a submarine (but this still sounds very optimistic)

So isn't it too early to start to develop a submarine 20-30 years before it can be launched? Of course it's never too early, and i'm no way against it, but it still sounds strange...? Is this project really seriously meant to have anything to do with Europa?
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JRehling
post Nov 29 2007, 08:36 PM
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QUOTE (rasun @ Nov 29 2007, 09:35 AM) *
So isn't it too early to start to develop a submarine 20-30 years before it can be launched? Of course it's never too early, and i'm no way against it, but it still sounds strange...? Is this project really seriously meant to have anything to do with Europa?


NASA does a lot of low-levels-of-funding exploration of new technologies. I used to work one building over from the robotics building at NASA Ames, and I saw stuff in development over there that doesn't remotely resemble anything that's ever flown, or is scheduled to soon.

Whether or not it actually speeds exploration, it also has public outreach value, encouraging interest in exciting ideas that may one day be put into effect.

I think a real key is that most of this stuff costs almost nothing compared to an actual mission.

One of the interesting things (in a sense, a very uninteresting thing) about a submarine is that remote sensing would be very limited. It would be mainly about analyzing the water immediately in/around the submarine. And maybe the floor, but visual/IR imaging would be limited to meters. There probably wouldn't be much point in wandering horizontally anywhere above the floor.
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DDAVIS
post Dec 3 2007, 11:17 AM
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This discussion is of particular interest to me as I am doing an animation sequence soon of a Europa lander. I have visualized such a thing in the past for the PBS show 'Life Beyond Earth' as a surveyor type lander carrying a probe underneath which would be weighed at the bottom with a plutonium 'lens', with the instruments above this. This probe resembes a blunt version of the Galileo probe entry shell. When released the heat from the lower probe lining melts a hole below it and the probe merrily tunnels its way to the liquid far below.
Any thoughts about this general means to get to the deep ocean with a probe as opposed to other spacecraft schemes being contemplated?

Don
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JRehling
post Dec 3 2007, 07:05 PM
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QUOTE (DDAVIS @ Dec 3 2007, 03:17 AM) *
This discussion is of particular interest to me as I am doing an animation sequence soon of a Europa lander. I have visualized such a thing in the past for the PBS show 'Life Beyond Earth' as a surveyor type lander carrying a probe underneath which would be weighed at the bottom with a plutonium 'lens', with the instruments above this. This probe resembes a blunt version of the Galileo probe entry shell. When released the heat from the lower probe lining melts a hole below it and the probe merrily tunnels its way to the liquid far below.
Any thoughts about this general means to get to the deep ocean with a probe as opposed to other spacecraft schemes being contemplated?

Don


One of the worries is that impurities in the ice would accumulate at the bottom of the hole, eventually creating an obstruction. Even if the fraction of impurity were very low, accumulating one meter of it after ten thousand meters of ice could be a show stopper.

I'm curious about what would happen when you actually hit the water. Would it gush out and rocket your sub into a geyser far above the surface -- which, obviously, would disable it as well as prevent access to the ocean. One of the problems I see with Enceladus is that if what we're seeing are geysers, then it may be pretty well impossible to push into the ocean, since it's trying to get out with considerable force. Which makes sense -- there must be nonzero pressure in water under a shell of ice, whereas the pressure above is the vacuum of space.

Maybe the saving grace would be if the hole re-freezes above the craft, and then when it reached the ocean, there'd be nowhere for it to go up. Somehow, it would have to handle that pressure transition, though, from surface to ocean.

Another issue is how to maintain radio contact. Leaving a chain of repeaters has been mentioned, but that sounds like a lot of mass, not to mention one heck of a lot of failure points.

And once the craft got to the ocean, there'd be a lot more to accomplish. A vertical descent to the rocky mantle would be fascinating, but might entail rather tremendous pressures.

I think realizing this vision is, however, one of the most exciting goals in solar system exploration, and finding the best location (if there is a best location) to make this descent is the real imperative of the next Europa exploration from orbit. Alternately, if a lander were only to sit on/near the surface and analyze the crust, it's still important to pick a good spot.

Good spots Galileo looked at include these:

http://photojournal.jpl.nasa.gov/catalog/PIA01405

http://photojournal.jpl.nasa.gov/catalog/PIA01640

http://photojournal.jpl.nasa.gov/catalog/PIA01177

But given how little of the surface Galileo imaged very well, it's imperative to do a more comprehensive survey.
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Posts in this topic
- nprev   The First Europa Lander   Dec 31 2005, 12:08 AM
- - Steve G   QUOTE (nprev @ Dec 30 2005, 05:08 PM)I think ...   Dec 31 2005, 02:40 AM
- - BruceMoomaw   JPL's study of useful instruments for a small ...   Dec 31 2005, 03:33 AM
|- - JRehling   QUOTE (BruceMoomaw @ Dec 30 2005, 07:33 PM)St...   Dec 31 2005, 04:38 AM
|- - tty   QUOTE (BruceMoomaw @ Dec 31 2005, 05:33 AM)Th...   Jan 1 2006, 11:04 PM
- - edstrick   as Bruce points out.. hit the surface slightly off...   Dec 31 2005, 12:17 PM
|- - Bob Shaw   There are *natural* penetrators as well as man-mad...   Dec 31 2005, 12:40 PM
- - gpurcell   I think it is going to be pretty difficult to argu...   Jan 1 2006, 05:01 PM
|- - nprev   Re the penetrometer descent alignment problem: Wou...   Jan 1 2006, 09:11 PM
|- - RNeuhaus   QUOTE (gpurcell @ Jan 1 2006, 12:01 PM)I thin...   Jan 5 2006, 05:06 PM
- - BruceMoomaw   Uh-uh. An object that short would take weeks -- a...   Jan 1 2006, 09:42 PM
|- - nprev   Hmm. How about a "semi-hard" lander al a...   Jan 1 2006, 10:22 PM
- - ermar   QUOTE Europa has an atmosphere though it is extrem...   Jan 1 2006, 11:52 PM
- - tasp   Perhaps a future mission would drop an impactor at...   Jan 2 2006, 03:42 AM
|- - ljk4-1   QUOTE (tasp @ Jan 1 2006, 10:42 PM)Perhaps a ...   Jan 3 2006, 03:49 PM
- - tty   It's too bad there is no GPS system on Europa....   Jan 3 2006, 06:19 PM
|- - nprev   QUOTE (tty @ Jan 3 2006, 11:19 AM)It's to...   Jan 3 2006, 08:40 PM
- - nprev   AlexBlackwell posted the fact that the 2006 Discov...   Jan 3 2006, 11:59 PM
- - ljk4-1   Tell me this wouldn't be useful for an Europan...   Mar 29 2006, 07:47 PM
- - ljk4-1   Karl Hibbitts describes a proposed hyper-velocity ...   May 1 2006, 06:55 PM
- - PhilHorzempa   It seems that at the November 2005 COMPLEX meeting...   Jun 27 2006, 04:07 AM
|- - Richard Trigaux   Why to limit the life time of a surface lander? if...   Jun 27 2006, 07:16 AM
|- - JRehling   QUOTE (Richard Trigaux @ Jun 27 2006, 12...   Jun 27 2006, 07:04 PM
|- - nprev   QUOTE (JRehling @ Jun 27 2006, 12:04 PM) ...   Jun 28 2006, 01:30 AM
|- - Richard Trigaux   QUOTE (nprev @ Jun 28 2006, 01:30 AM) ......   Jun 28 2006, 07:42 AM
- - RNeuhaus   A panoramic camera plus an astronamic telescope to...   Jun 28 2006, 10:49 PM
|- - JRehling   QUOTE (RNeuhaus @ Jun 28 2006, 03:49 PM) ...   Jun 29 2006, 12:31 AM
|- - djellison   QUOTE (RNeuhaus @ Jun 28 2006, 11:49 PM) ...   Jun 29 2006, 07:23 AM
- - algorimancer   Considering the deliverable mass potential, and ou...   Jun 29 2006, 12:49 PM
- - djellison   I'm sure everyone would love a massive long li...   Jun 29 2006, 01:00 PM
|- - Stephen   QUOTE (djellison @ Jun 29 2006, 01:00 PM)...   Jul 3 2006, 11:20 AM
|- - Richard Trigaux   QUOTE (Stephen @ Jul 3 2006, 11:20 AM) Wo...   Jul 3 2006, 11:44 AM
- - Myran   Yes I agree with djellison and others. To give the...   Jun 29 2006, 03:36 PM
|- - JRehling   I don't think we can bet that a Europa rover w...   Jun 29 2006, 05:51 PM
|- - JRehling   QUOTE (Myran @ Jun 29 2006, 08:36 AM) The...   Jun 29 2006, 05:55 PM
- - RNeuhaus   Now I understand that it is very expensive to send...   Jun 29 2006, 08:14 PM
|- - djellison   QUOTE (RNeuhaus @ Jun 29 2006, 09:14 PM) ...   Jun 29 2006, 09:07 PM
|- - JRehling   QUOTE (RNeuhaus @ Jun 29 2006, 01:14 PM) ...   Jun 30 2006, 05:52 PM
|- - Bob Shaw   QUOTE (JRehling @ Jun 30 2006, 06:52 PM) ...   Jun 30 2006, 07:26 PM
|- - RNeuhaus   QUOTE (Bob Shaw @ Jun 30 2006, 02:26 PM) ...   Jul 1 2006, 02:45 AM
- - nprev   Harkening back to the origin of this thread, I com...   Jun 30 2006, 12:50 PM
- - algorimancer   My rationale behind sending a rover initially is t...   Jun 30 2006, 01:13 PM
|- - Bob Shaw   QUOTE (algorimancer @ Jun 30 2006, 02:13 ...   Jun 30 2006, 01:50 PM
- - djellison   Perhaps the cunning technique that would have been...   Jun 30 2006, 07:35 PM
|- - DDAVIS   QUOTE (djellison @ Jun 30 2006, 07:35 PM)...   Jul 1 2006, 01:16 AM
- - Richard Trigaux   There are three ways to protect electronics from r...   Jul 1 2006, 06:01 AM
|- - Bob Shaw   QUOTE (Richard Trigaux @ Jul 1 2006, 07:0...   Jul 1 2006, 01:55 PM
|- - mchan   QUOTE (Richard Trigaux @ Jun 30 2006, 11...   Jul 3 2006, 12:20 AM
|- - Richard Trigaux   QUOTE (mchan @ Jul 3 2006, 12:20 AM) Besi...   Jul 3 2006, 09:52 AM
- - edstrick   In the outer solar system, we have tended to find ...   Jul 1 2006, 08:50 AM
- - Myran   Just offhand and without checking I dont think any...   Jul 1 2006, 02:26 PM
- - djellison   Pushbroom? Doug   Jul 3 2006, 07:36 AM
- - nprev   Richard, that sounds good for a long-lived stand-a...   Jul 4 2006, 01:09 AM
- - Roly   March 26 2006 Powerpoint on various Europa Lander ...   Sep 3 2006, 07:07 AM
|- - angel1801   Has anyone thought of putting an Europa Lander at ...   Sep 3 2006, 04:27 PM
|- - ugordan   I would think the landing site will be determined ...   Sep 3 2006, 06:37 PM
|- - JRehling   QUOTE (angel1801 @ Sep 3 2006, 09:27 AM) ...   Sep 4 2006, 05:15 PM
- - Roly   Any chance that the launch vehicle for the Europa ...   Sep 4 2006, 03:01 AM
- - edstrick   The radiation is not FROM Jupiter. The radiation ...   Sep 4 2006, 11:07 AM
- - Julius   Being modest,I'd still say that 3 days lifetim...   Sep 5 2006, 08:03 PM
- - nprev   I still think a hard-lander, a penetrometer, or so...   Sep 6 2006, 01:43 AM
- - algorimancer   Something like the MER's autonomous navigation...   Sep 6 2006, 12:55 PM
|- - ugordan   Still, the biggest problem is soft landing via pow...   Sep 6 2006, 01:27 PM
- - algorimancer   I just had one of those Aha! moments and came ...   Sep 9 2006, 09:24 PM
- - Myran   Thats a wild idea algorimancer. But regardless ho...   Sep 10 2006, 07:42 AM
|- - algorimancer   QUOTE (Myran @ Sep 10 2006, 02:42 AM) Tha...   Sep 10 2006, 01:05 PM
- - nprev   Hmm. Given that the Galileo data was a bit limited...   Sep 10 2006, 09:00 PM
- - Drkskywxlt   I think any such impact with the surface of Europa...   Sep 11 2006, 01:32 PM
|- - AndyG   The (admittedly ill-fated) penetrators of Deep Spa...   Sep 11 2006, 03:34 PM
- - remcook   Most importantly IMO is the whole uncertainty of t...   Sep 11 2006, 04:12 PM
|- - algorimancer   QUOTE (remcook @ Sep 11 2006, 11:12 AM) ....   Sep 11 2006, 05:47 PM
- - Julius   Main objective should be to get a Europa lander sa...   Sep 12 2006, 07:37 PM
- - rasun   Hi! Apparently, NASA's Astrobiology, Scie...   Nov 29 2007, 05:35 PM
|- - JRehling   QUOTE (rasun @ Nov 29 2007, 09:35 AM) So ...   Nov 29 2007, 08:36 PM
|- - DDAVIS   This discussion is of particular interest to me as...   Dec 3 2007, 11:17 AM
|- - JRehling   QUOTE (DDAVIS @ Dec 3 2007, 03:17 AM) Thi...   Dec 3 2007, 07:05 PM
- - nprev   Wow. Don, only thing I can think of is that th...   Dec 3 2007, 12:46 PM
- - dvandorn   I would say that not only is it imperative that a ...   Dec 4 2007, 07:54 AM
|- - JRehling   QUOTE (dvandorn @ Dec 3 2007, 11:54 PM) T...   Dec 4 2007, 03:02 PM
|- - hendric   QUOTE (JRehling @ Dec 4 2007, 09:02 AM) U...   Dec 4 2007, 04:55 PM
- - nprev   Nihilistic, but IMHO painstakingly plausible, oDou...   Dec 4 2007, 12:19 PM
- - Cugel   Why would you go all the way down to the liquid wa...   Dec 4 2007, 01:06 PM
|- - JRehling   QUOTE (Cugel @ Dec 4 2007, 05:06 AM) Why ...   Dec 4 2007, 03:06 PM
|- - centsworth_II   QUOTE (JRehling @ Dec 4 2007, 10:06 AM) I...   Dec 4 2007, 03:55 PM
||- - marsbug   I dont know about squid but there are many studies...   Dec 4 2007, 04:35 PM
|- - Cugel   QUOTE (JRehling @ Dec 4 2007, 04:06 PM) I...   Dec 4 2007, 07:30 PM
||- - nprev   QUOTE (Cugel @ Dec 4 2007, 11:30 AM) At l...   Dec 5 2007, 01:45 AM
|- - tty   QUOTE (JRehling @ Dec 4 2007, 04:06 PM) I...   Dec 4 2007, 07:42 PM
- - centsworth_II   I think it's safe to say that the first Europa...   Dec 4 2007, 05:58 PM
- - dvandorn   I don't think I'd be good with just openin...   Dec 4 2007, 07:12 PM
- - charborob   A probe melting its way all through Europa's i...   Dec 4 2007, 08:03 PM
- - dvandorn   My thoughts exactly -- it's going to be a very...   Dec 4 2007, 08:58 PM
- - hendric   Well, RTGs actually put out quite a bit of heat, a...   Dec 5 2007, 01:41 AM
- - DDAVIS   Wow, this discussion is great! I am imaginin...   Dec 5 2007, 07:10 PM
- - tty   Let's do some order-of-magnitude calculations ...   Dec 5 2007, 07:23 PM
|- - hendric   QUOTE (tty @ Dec 5 2007, 01:23 PM) Let...   Dec 6 2007, 05:47 PM
- - mchan   QUOTE (dvandorn @ Dec 4 2007, 11:12 AM) A...   Dec 6 2007, 04:20 AM
- - nprev   Gotta say that I'm pretty sold on the pristin...   Dec 6 2007, 07:14 AM
- - edstrick   Both from a science and an engineering perspective...   Dec 6 2007, 09:39 AM
- - centsworth_II   At the least, a first Europa mission should map th...   Dec 6 2007, 05:02 PM
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