IPB

Welcome Guest ( Log In | Register )

3 Pages V  < 1 2 3  
Reply to this topicStart new topic
Mercury Landers
tasp
post Nov 26 2005, 06:14 PM
Post #31


Member
***

Group: Members
Posts: 903
Joined: 30-January 05
Member No.: 162



Just throwing out some ideas, may be helpful in the long run.

The amazing trajectory Messenger is taking to Mercury would be reversible, wouldn't it? I'm thinking an orbiter/lander could be sent to Mercury (granted this part is going to be heavy) to study the planet, and the lander could collect some surface samples and put them into orbit around Mercury.

A retreiver craft could be sent to collect the samples and then return to earth via a reversed version of the Messenger flight plan.

The key to making this work is that you set it up so that as much of the delta v as possible is provided by gravity assists from Earth, Venus, and Mercury for all the spacecraft involved in the mission.



Also,

To expand on some of the ideas posted in this thread, could a kevlar net orbiting Mercury (tethered to a shielded orbiter) 'snag' debris from a plume generated from an impactor craft?

This might be a 'cheap and dirty' way of retrieving materials from the surface of Mercury as part of mission to return them to earth.
Go to the top of the page
 
+Quote Post
Bob Shaw
post Nov 26 2005, 06:30 PM
Post #32


Senior Member
****

Group: Members
Posts: 2488
Joined: 17-April 05
From: Glasgow, Scotland, UK
Member No.: 239



QUOTE (tasp @ Nov 26 2005, 07:14 PM)
Just throwing out some ideas, may be helpful in the long run.

The amazing trajectory Messenger is taking to Mercury would be reversible, wouldn't it?  I'm thinking an orbiter/lander could be sent to Mercury (granted this part is going to be heavy) to study the planet, and the lander could collect some surface samples and put them into orbit around Mercury. 

A retreiver craft could be sent to collect the samples and then return to earth via a reversed version of the Messenger flight plan.

The key to making this work is that you set it  up so that as much of the delta v as possible is provided by gravity assists from Earth, Venus, and Mercury for all the spacecraft involved in the mission.
Also,

To expand on some of the ideas posted in this thread, could a kevlar net orbiting Mercury (tethered to a shielded orbiter) 'snag' debris from a plume generated from an impactor craft?

This might be a 'cheap and dirty' way of retrieving materials from the surface of Mercury as part of mission to return them to earth.
*




The killer with Mercury landings - not counting the interplanetary stuff, where perhaps there might be *reverse* slingshots to be had with some clever planning - is that as it's an airless body you're limited to rocket-based descents. Add the cost of transporting your fuel for ascent and there are some quite rapid diminishing returns! Of course, if there's ice at the poles, in-situ fuel might be an option - otherwise, the 'smash and grab' mission seems about the only game in town!

Bob Shaw


--------------------
Remember: Time Flies like the wind - but Fruit Flies like bananas!
Go to the top of the page
 
+Quote Post
Guest_BruceMoomaw_*
post Nov 26 2005, 09:13 PM
Post #33





Guests






There was, I've heard (though I haven't confirmed it), a smash-and-grab Mercury sampling mission once proposed for Discovery. Meanwhile, the ESA has actually done the preliminary design for a full-fledged Mercury landing and sample return -- although they also did so for Venus, which may give you some idea of how politically realistic the plan is. I'm convinced that, given their cost, it will be a long time before we see a landing and sample-return mission from any large world that doesn't have possible biological evidence -- that is, Mars and (in the longer run, if previous landers turn up something interesting) Europa.
Go to the top of the page
 
+Quote Post
tty
post Nov 27 2005, 04:42 PM
Post #34


Member
***

Group: Members
Posts: 688
Joined: 20-April 05
From: Sweden
Member No.: 273



QUOTE (Bob Shaw @ Nov 26 2005, 08:30 PM)
The killer with Mercury landings - not counting the interplanetary stuff, where perhaps there might be *reverse* slingshots to be had with some clever planning - is that as it's an airless body you're limited to rocket-based descents. Add the cost of transporting your fuel for ascent and there are some quite rapid diminishing returns!  Of course, if there's ice at the poles, in-situ fuel might be an option - otherwise, the 'smash and grab' mission seems about the only game in town!

Bob Shaw
*


The best and fastest way to acquire Mercury samples is almost certainly to search for meteorites here on Earth.
I'm reminded of an old saying in paleontological circles: "The best place to find unknown fossil species is in museum drawers". smile.gif

tty
Go to the top of the page
 
+Quote Post
edstrick
post Nov 27 2005, 08:43 PM
Post #35


Senior Member
****

Group: Members
Posts: 1870
Joined: 20-February 05
Member No.: 174



Two or three years ago, there was some reporting on an odd meteorite that had distinctive isotope patterns and chemistry. There was some speculation it was Mercury ejecta, but that interpretation didn't seem strongly favored. I don't recall it's name/designation. I've heard no further discussion of it, and have wondered what the status on it is. Meteoritical Society meeting abstracts may have contained something but I haven't broused them extensively.
Go to the top of the page
 
+Quote Post
DEChengst
post Nov 27 2005, 09:20 PM
Post #36


Member
***

Group: Members
Posts: 270
Joined: 29-December 04
From: NLA0:
Member No.: 133



QUOTE (tty @ Nov 27 2005, 05:42 PM)
The best and fastest way to acquire Mercury samples is almost certainly to search for meteorites here on Earth.
*


But that wouldn't be as interesting. The great thing about a sample return mission is that you can select the rocks that you'll be researching. There are a lot of Martian meteorites, but we would learn at lot more if we could get our hands on some Meridiani Planum sedimentary rocks.


--------------------
PDP, VAX and Alpha fanatic ; HP-Compaq is the Satan! ; Let us pray daily while facing Maynard! ; Life starts at 150 km/h ;
Go to the top of the page
 
+Quote Post
JRehling
post Nov 28 2005, 01:55 AM
Post #37


Senior Member
****

Group: Members
Posts: 2530
Joined: 20-April 05
Member No.: 321



I can't find the reference to the Mercury smash-and-grab sample return either, although I had found it on the web a couple of years ago. It was a real "outsider" proposal, conceived from someone not really working in space exploration, IIRC, and I don't know if it was an official Discovery proposal or not -- yet it is a solid idea. Certainly this kind of sample return is not as useful scientifically as having a rover move around and delicately select a geologist's wishlist, but what this kind of mission lacks in benefit, it makes up for in cost savings.

NWA 011 is the name of the meteorite that was speculated upon as being mercurean in origin. Here are some discussions of the item's origin, however, that don't even mention the word "Mercury", FWIW:

http://web.utk.edu/~lataylor/pub-list/Floss-1153.pdf
http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1094.pdf
http://aaa.wustl.edu/Work/pub_files/northwestafrica011.html

There can only be so many rocky parent bodies in our solar system's past/present that were large enough to exhibit major radiogenic heating, and Mercury is one of them. Perhaps we'll end up with an exhaustive list one day and identify the Mercury meteorites by elimination. But we're not close to that day...

A smash-and-grab sample return would not only have its own value, but would also possibly clinch the identification of Mercury meteorites in our possession. In terms of delta-v, we more or less need a solar orbit that has aphelion at 1 AU and perihelion at 0.48 AU -- that is more delta-v than a Venus/Mars lander, but then the craft would essentially be an Earth lander without instruments. It would be highly desirable to perform remote sensing of the impact site, a la Deep Impact -- the instruments should perhaps be mainly contained on the impactor, since instruments on the return craft wouldn't have any use after the impact while flying back to Earth.
Go to the top of the page
 
+Quote Post
Guest_BruceMoomaw_*
post Nov 28 2005, 02:11 AM
Post #38





Guests






Keep in mind that this thing will fly past Mercury at damn high speed, and thus its sample grains may be largely melted. However, since a comparably high-speed flyby of Europa is considered scientifically worthwhile, I presume one of Mercury is too.
Go to the top of the page
 
+Quote Post
ljk4-1
post May 30 2006, 06:15 PM
Post #39


Senior Member
****

Group: Members
Posts: 2454
Joined: 8-July 05
From: NGC 5907
Member No.: 430



In this 1971 book, Beyond the Moon: Future Explorations in Interplanetary Space
by C. B. Colby, there is a chart of then future planetary missions:

http://sun3.lib.uci.edu/~jsisson/beyond.htm

For Mercury, they indicate an orbiter for 1982. Was there ever an actual plan
to orbit Mercury in the early 1980s?

Of course the chart also declares a manned lunar base in 1978 and manned
expeditions to Venus and Mars in 1982 and 1981, respectively.


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

Go to the top of the page
 
+Quote Post
Guest_BruceMoomaw_*
post May 31 2006, 05:45 AM
Post #40





Guests






NASA never -- and I mean never -- put any Mercury orbiter anywhere in even the also-ran listings of its desired future planetary missions, until Chen-Wan Yen, in the late 1980s, came up with the complex but workable kind of multiple gravity-assist flyby setup that Messenger is now using. Until then it was thought to be far too expensive and complex for what (to quote Ken Croswell in 1991) "isn't a sexy planet." Indeed, I didn't hear a peep about Mercury as a possible high-priority target until the Discovery Program AOs started.
Go to the top of the page
 
+Quote Post

3 Pages V  < 1 2 3
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 29th March 2024 - 11:53 PM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and 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.