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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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Guest_Richard Trigaux_*
post Jul 1 2006, 06:01 AM
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There are three ways to protect electronics from radiations:

-shielding. An overal shield is out of question, due to its weight. But some crucial parts could be shielded with some very local shields, like power transistors in a DC-CD converter (which can break from a single event, and are critical). A CCD camera chip can also be shielded, classical shield behind, and lead glass optics in front

-short working time. As JRehling and Bob Shaw say, there is no need of a camera working for months, at least not on a static lander.

-hardened electronics. This is about a variety of techniques used to make electronic parts, especially semiconductors, less sensitive to radiations. But this is difficult, and not much can be gained, say one or two orders of magnitude, and that is not enough on Europa. So I suggest to use completelly different methods, such as triodes or electrostatic microrelays, as I already explained on the Venus lander thread.


An alternative to a simple lander would be a very low orbiter. Its orbit could be set to decay little by little, so that it would graze the ground, allowing to send quantities of very high resolution images, showing things like pebbles on large regions. Of course, it would impact the ground sooner or later, with too much speed o survive. But by letting a rope hang to the ground, we could obtain some free braking, before using a rocket to end braking.



Europa ground looks smooth from altitude, but it is likely a kind of ice regolite, with large blocks, pebbles, and much sand. Worse, it seems that there are many equilibrium slopes, so that climbing them would result in avalanches. A rover nightmare!

So, rather than wheels, it would require a kind of large spider, working with some hydraulic system, like scorpio legs. This could make very long legs with a reasonable weight.

But I think that, fortunately, the most interesting regions are the reddish chaotic regions, which formed with breaking and melting of the ice crust. As there was liquid water on the surface, it frozen hard, not in blocks. So, between the small hills if the chaotic regions, there must be flat hard regions, the most interesting place to find chemmicals or biological particules into the ice. The best place to search, and the best place to land...

Three techniques:
-the homing missile, using a high resolution picture to land on a selected place. Variant 1, with a rocket to land at small speed
-same, but variant 2, lands at high speed and buries itself in ice.
-the airbags, which we can expect they will bounce toward a bottom, precisely where we want to go.

Eventually a cluster of small landers with only such crude guidance, have much chances to land, at least one, in the right place. It would be short lived landers, but with analysis tools, microscope, etc. A small chemical heater could melt some ice.


A lander with a long lived seismometre could land in the same way into the same place, where it would find solid ice to operate properly. The variant with a high speed landing is prefered, because it would provide a shielding against radiations.
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Bob Shaw
post Jul 1 2006, 01:55 PM
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QUOTE (Richard Trigaux @ Jul 1 2006, 07:01 AM) *
An alternative to a simple lander would be a very low orbiter. Its orbit could be set to decay little by little, so that it would graze the ground, allowing to send quantities of very high resolution images, showing things like pebbles on large regions. Of course, it would impact the ground sooner or later, with too much speed o survive. But by letting a rope hang to the ground, we could obtain some free braking, before using a rocket to end braking.


Richard:

I quite like the idea of an ACME ™ Space Science Corporation tether being used as a brake - presumably without an anchor at the end, though...

Bob Shaw


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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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