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LRO development
Phil Stooke
post Feb 9 2006, 02:19 PM
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One final point, often not appreciated. The laser would give a lat-long position (you can't see the spot illuminated by the beam). We still need to know the location relative to local features like craters. Since lunar maps still contain many positional inaccuracies, the laser would still leave us uncertain by several km, but it would narrow the search in images.

Phil


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Guest_AlexBlackwell_*
post Feb 9 2006, 06:05 PM
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Kaboom! Ancient impacts scarred moon to its core, may have created 'man in the moon'
The Ohio State University Research News
February 8, 2006

Reference:

Impact-induced mass flow effects on lunar shape and the elevation dependence of nearside maria with longitude
Laramie V. Potts and Ralph R.B. von Frese
Physics of The Earth and Planetary Interiors 153, 165-174 (2005).
Abstract
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Guest_AlexBlackwell_*
post Feb 9 2006, 06:24 PM
Post #33





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QUOTE (Phil Stooke @ Feb 9 2006, 02:46 AM)
Alex, you can't really say that Clementine 'resolved' the Apollo sampling sites - which in effect are only as big as the scoop or the rock which was picked up.

Given your knowledge of the subject, Phil, I wouldn't be surprised if you've read the Blewitt et al. paper. However, for those who haven't, Blewitt et al. have a different definition of "sampling sites."

The authors state, "Apollos 11, 12, and 14 and Lunas 16, 20, and 24 sampled either single points or small areas around the landing site. Individual sampling locations for these missions cannot be reliably separated in the Clementine images. However, the availability of the lunar roving vehicle on the Apollo 'J' missions (15, 16, and 17) greatly extended the range of surface operations. We are thus able to resolve the majority of the sampling stations at these landing sites in images collected by Clementine."

For the Apollo "J" missions, Blewitt et al. further write, "Boxes of 3 X 3 pixels were averaged for most stations. At a few locations where two stations were close together, slightly larger boxes were used to average the two. The data set includes eight stations at Apollo 15, seven at Apollo 16, and 18 (including rover stations) at Apollo 17."

This post has been edited by AlexBlackwell: Feb 9 2006, 07:13 PM
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RNeuhaus
post Feb 9 2006, 07:04 PM
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Very interesting article: Kaboom! Ancient impacts scarred Moon to its core, may have created "Man in the Moon".

I have copied the two last paragraphs:

von Frese said a lunar base would be needed before scientists can more completely answer these questions.

Potts agreed. "Once we have more rock samples and soil samples, we will have a lot more to go on. Nothing is better than having a person on the ground," he said.


Now, the Moon is still a misterious world astro sphere and it must be visited again very soon!

Rodolfo
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Bob Shaw
post Feb 9 2006, 07:42 PM
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QUOTE (Phil Stooke @ Feb 9 2006, 02:23 PM)
It might *just* be possible, Bob, but the tracks will not really have much if any albedo difference - Apollo disturbed soil was only darker near the LM, where the descent engine exhaust brightened the surface and any disturbance exposed darker material again (probably a texture difference rather than true albedo).  LRV tracks far from the LM were not darker. 

Phil
*


Phil:

I didn't realise that the dark tracks were only local to the LM - I always assumed that the spray from the walking astronauts (not to mention the LRV 'rooster tail') was darker than the top of the soil.

Something learned!

Bob Shaw


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dvandorn
post Feb 9 2006, 10:54 PM
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In fact, Bob, the footprints and wheel tracks near the LMs were not at all darker than the general soil at the landing sites. The LM DPS exhaust would sweep the top layer of dust grains from the regolith during landing, resulting in a temporary brightening of the soil around the LMs. "Darkened" footprints and wheel tracks were simply *restoring* the soil's natural albedo within the splash of brightened soil.

There is some question, I guess, as to whether or not the local soil brightening around the LMs still exists. I don't believe any of the Clementine or SMART-1 or Lunar Prospector images were able to answer that question -- though Phil probably knows the answer to that better than I do.

-the other Doug


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Phil Stooke
post Feb 10 2006, 03:45 AM
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There are no lunar prospector images! And the others are not detailed enough to resolve tracks. We'll have to wait for LRO.

The sampling site thing is just a different way of looking at it - in effect they are saying what I did, that they identify a pixel or group of pixels containing the sample site (the 'station'). But it can still contain more than one type of surface. For instance at Apollo 14 Station C on the rim of Cone crater the crew sampled soil and rocks. One UVVIS pixel contains lots of soil and quite a few rocks. None of the individual samples are resolved - rocks with different compositions, from different depths maybe, are all averaged in one pixel. I think we're saying the same.

Phil


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Bob Shaw
post Feb 10 2006, 12:00 PM
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QUOTE (dvandorn @ Feb 9 2006, 11:54 PM)
In fact, Bob, the footprints and wheel tracks near the LMs were not at all darker than the general soil at the landing sites.  The LM DPS exhaust would sweep the top layer of dust grains from the regolith during landing, resulting in a temporary brightening of the soil around the LMs.  "Darkened" footprints and wheel tracks were simply *restoring* the soil's natural albedo within the splash of brightened soil.

There is some question, I guess, as to whether or not the local soil brightening around the LMs still exists.  I don't believe any of the Clementine or SMART-1 or Lunar Prospector images were able to answer that question -- though Phil probably knows the answer to that better than I do.

-the other Doug
*


oDoug:

Yes, I had the mechanism 'backwards' - and, taking the DPS plume notion one step further, presumably the ascent engine firing again scoured the surface, as well as blasting bits of foil around the area. Apollo 12 was the dustiest landing site, AIRC, so were any pre-landing vs post-landing vs post-liftoff images taken from the CSM? Over a few hours the shadows wouldn't have changed much for the first two, but there's be quite a change between first and last, and that would obviously mask any effect.

Bob Shaw


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Guest_AlexBlackwell_*
post Feb 10 2006, 05:57 PM
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QUOTE (Phil Stooke @ Feb 10 2006, 03:45 AM)
The sampling site thing is just a different way of looking at it - in effect they are saying what I did, that they identify a pixel or group of pixels containing the sample site (the 'station').  But it can still contain more than one type of surface.  For instance at Apollo 14 Station C on the rim of Cone crater the crew sampled soil and rocks.  One UVVIS pixel contains lots of soil and quite a few rocks. None of the individual samples are resolved - rocks with different compositions, from different depths maybe, are all averaged in one pixel.  I think we're saying the same.

So do I, Phil. I just wanted to make sure no one else understood me to be implying that Clementine UVVIS could resolve individual rocks, soil scoops, etc.
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dvandorn
post Feb 11 2006, 12:36 AM
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QUOTE (Bob Shaw @ Feb 10 2006, 06:00 AM)
...Apollo 12 was the dustiest landing site, AIRC, so were any pre-landing vs post-landing vs post-liftoff images taken from the CSM? Over a few hours the shadows wouldn't have changed much for the first two, but there's be quite a change between first and last, and that would obviously mask any effect.
*

Let's see -- the Apollo 12 CSM didn't have any cameras with enough "throw" to get the kind of resolution you'd need to observe that effect. I think the longest lens they carried for the CSM's Hasselblad was a 250mm. Dick Gordon did try to capture the view through the CSM's optics on his 16mm movie camera, and suceeded in getting an overexposed, washed-out image in which you can sort of recognize Surveyor Crater, but you can't really resolve the actual LM landing point. And the image was so overexposed that any local brightening was washed out.

The only other way to have documented the "bright splash" of the LM's landing site would have been the 16mm movie of the LM liftoff from inside the cabin.... except that the camera malfunctioned and there is no film of the Apollo 12 lunar ascent.

In fact, though, the Apollo 12 landing site probably wasn't all that much dustier than any of the other mare landing sites. Pete brought his LM down by curving along the north rim of the Surveyor Crater, and dropped pretty much straight down from about 200 feet directly over the northwest rim. Crater rims on the Moon seem to display less consolidation in their regolith -- the slope keeps the surficial layer from "firming up" as much as it does on more level ground. At least, all of the Apollo moonwalkers reported that the dust on relatively "flat" ground let them sink in less than an inch, but that crater rims were "soft" and that they sank in several inches on most crater rims. This was pretty ubiquitous at all of the landing sites, as I recall.

So, Pete's Intrepid blew up so much dust because 1) it kept blowing over the same spot for the final 200 feet of descent, and 2) it was blowing down on a crater rim that, by its nature, was composed of looser and less consolidated dust than they would have encountered on the adjacent plains.

To back this up, I'll point out that the second dustiest landing was Apollo 15's, during which the LM made a near-vertical final descent from about 150 feet, with the engine plume impinging directly on the rim of a 10-meter shallow crater. (The engine bell even got whacked by this small crater's rim, since the LM landed directly astride its western rim.) So, dustiness of landing seems to have been controlled by whether or not the exhaust was plowing up a crater rim during an extended near-vertical descent.

-the other Doug


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ljk4-1
post Feb 11 2006, 04:42 AM
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If this is any help, Lunar Orbiter 3 was able to image Surveyor 1. In magnified views, you could even see the lander projecting its shadow across the lunar surface.

http://history.nasa.gov/SP-168/section2b.htm#96

http://nssdc.gsfc.nasa.gov/imgcat/html/obj...lo3_h194_1.html

http://www.astrosurf.com/lunascan/Surveyor1.htm


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"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

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Guest_BruceMoomaw_*
post Feb 11 2006, 05:31 AM
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On Apollo 12 , Dick Gordon -- from lunar orbit -- saw not only the LM but the Surveyor clearly through the CSM's navigation telescope.
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dvandorn
post Feb 11 2006, 06:27 AM
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Gordon saw both the LM and Surveyor with his eye, yes. They didn't really show up in the 16mm film frames, was my point.

-the other Doug


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ljk4-1
post Feb 17 2006, 04:08 PM
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Dolores Beasley
Headquarters, Washington
Phone: (202) 358-1753

Nancy Neal Jones
Goddard Space Flight Center, Greenbelt, Md.
Phone: (301) 286-0039

Feb. 17, 2006

RELEASE: 06-065

NASA'S Lunar Orbiter Team Passes Preliminary Design Review

NASA's Lunar Reconnaissance Orbiter team recently passed its Preliminary Design Review heralding the start of the mission confirmation process.

The first in a series of robotic missions to the moon, the lunar orbiter is scheduled for launch in October 2008. It will carry six science instruments and a technology demonstration. The mission goal is to develop new approaches and technologies to support human space exploration to Mars and other destinations.

The preliminary design review concluded Feb. 9. The results of the review, on-going assessments of project cost and schedule will support a confirmation review this spring.

The confirmation review represents NASA's formal decision for authorizing additional work and will set the project's cost estimate. The mission's Critical Design Review is scheduled for fall. It will represent the completion of detailed system design, the transition to assembly and integration of the mission elements.

For information about NASA's Exploration Systems Mission Directorate on the Web, visit:
http://www.nasa.gov/exploration

For information about NASA and agency programs on the Web, visit:

http://www.nasa.gov/home

This Article URL:

http://www.nasa.gov/home/hqnews/2006/feb/H...ar_orbiter.html


--------------------
"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

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PhilHorzempa
post Apr 3 2006, 07:01 PM
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[size=2]Does anyone have recent info on the RLEP-2 unmanned lunar lander?
From what I can make out, APL was awarded the contract to design a Lunar
Lander System a few months ago, with launch planned for January 2011. However,
I haven't found a written or visual description of what might be planned for this
lander.

The LRO is RLEP-1, but it appears that the RLEP-2 lander doesn't have
a spacecraft name. How about calling it Surveyor 8? Do we want to start a
separate thread for this mission?
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