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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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djellison
post Jun 29 2006, 01:00 PM
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I'm sure everyone would love a massive long life rover on the surface of Europa....who wouldn't. Every scientist, every engineer would LOVE to have a rover on Europa.

And we'd all like New Horizons to be a Pluto Orbiter, and DAWN to be sample return, and Messenger to be a lander......

But you have to do what is feasable given time, money, and in this case technology. I would wager that if you put MSL on the surface of Europa - it would be dead with a week due to radiation, MC might be able to comment, but I'd think Mastcam would just get quietly fried. 'Shield it' you might say....that would requrie so much shielding the thing would never get off the pad. (because every kg of shielding requires kg's of fuel for landing, and THAT required multiple kg's of payload capacity )

A comparatively simple impactor / hard lander, perhaps with a decent imager, short life etc...that's currently feasable in a sensible time frame and budget and would tell us a hell of a lot about Europa.

MSL will be ( hopefully ) the 7th succesfull landing on Mars. 4 of those were/will be static landers.

If we were talking out 4th Europan lander..I'd be going 'hell yeah - let's go for wheels' - but for our first effort....one needs to be modest in requirements.

As Alan has said w.r.t. NH.....better is the enemy of good enough.

Doug
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Stephen
post Jul 3 2006, 11:20 AM
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QUOTE (djellison @ Jun 29 2006, 01:00 PM) *
I would wager that if you put MSL on the surface of Europa - it would be dead with a week due to radiation, MC might be able to comment, but I'd think Mastcam would just get quietly fried. 'Shield it' you might say....that would requrie so much shielding the thing would never get off the pad. (because every kg of shielding requires kg's of fuel for landing, and THAT required multiple kg's of payload capacity )

Which raises the question of the survivability of any probe sent to Europa to drill down to and release some kind of submarine probe to explore the putative Europan ocean.

Doubtless the drill bot and the sub bot will be safe enough once they have enough ice above and around them to act as a radiation shield, but until they actually start do drilling they will be as exposed to the radiation as any rover or ordinary lander. To prevent getting fried by radiation they will presumably either have to be equipped with shielding or the drilling down into the ice will need to begin almost the moment they land.

It would presumably also limit the kinds of kind of installations left on the surface to keep the lines of communication open with the Earth or with some relay probe outside the radiation zone.

Would it be enough just to leave the antenna on the surface and keep the electronics buried or would it there need to be some degree of electronics that would need to stay above the surface with the antenna? And would it even be practical to even keep the communications electronics buried? (I'm thinking here mainly of all the heat that might be generated by the electronics and what that heat might do to all the ice it's buried in...)

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Guest_Richard Trigaux_*
post Jul 3 2006, 11:44 AM
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QUOTE (Stephen @ Jul 3 2006, 11:20 AM) *
Would it be enough just to leave the antenna on the surface and keep the electronics buried or would it there need to be some degree of electronics that would need to stay above the surface with the antenna? And would it even be practical to even keep the communications electronics buried? (I'm thinking here mainly of all the heat that might be generated by the electronics and what that heat might do to all the ice it's buried in...)

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Stephen


This depends on what antenna.

At first glance, there is no inconvenience to have an antenna to the surface, and eventually 100m of cable down to the buried emitter. But things may be less simple.

-very high frequencies need less cable length, or a waveguide.

-This antenna would need to be omnidirectionnal, so with a low gain, which would require a high emitter power on Europa, and large dishes on Earth to receive. To have a large gain antenna would require some orientation mechanism, which could be more sensitive to radiation. It could work with only mechanical parts, the electronics being buried with the emitter.

About heat, it is not much a problem, I think. It would form a bubble of liquid water around the electronics, so this electronics will soon hang after the antenna cable. The problem becomes more accute if we have a RTG, because RTGs produce much heat, which has to be removed in order to ensure a correct functionning. We can fear that this heat would create a well of liquid water all the way up to the surface, so that the antenna will have to be protected against falling into this well. All this must be tested on Earth into Antarctic ice shield.
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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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