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Post by gonetoplaid on Aug 27, 2011 0:06:26 GMT -4
LRO is probably making these maneuvers now because it has already accomplished its primary objectives. Now they can try fun but riskier things. Eventually LRO will strike the lunar surface as it can't carry an infinite supply of station-keeping fuel. The operators will probably reserve some of that fuel for an eventual de-orbit maneuver to a targeted impact site, perhaps another polar location where there's thought to be water. The LRO has dropped down to 20 km to use the Apollo landing sites for calibration purposes. Eventually the plan is to put the LRO into an orbit which is stable for the long term, allowing for an extended mission of another 2 to 3 years.
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Post by gonetoplaid on Aug 26, 2011 23:58:31 GMT -4
Assuming that the lens is not the limiting factor (i.e., it's operating within its diffraction limit), the transverse resolution is set by the pixel spacing. The resolution along the direction of motion is limited by the finite pixel height and/or the exposure time, i.e., how much the spacecraft moves during the exposure, whichever is worse. I don't know the limits of the sensors on LRO, but in this lower orbit it might achieve better transverse than longitudinal resolution for this reason. Quite correct. The LRO NAC camera resolution is limited by the 7 micron pixel size of its CCD sensors. The lower 20 km minimum orbit will allow for approximately 4 times the spatial resolution or twice the resolution along the horizontal and vertical axes. The increased spatial resolution is what will really make the images "snap" with detail.
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Post by gonetoplaid on Jan 30, 2011 14:05:04 GMT -4
That's the smoking section. Outdoor barbecue.
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Post by gonetoplaid on Jan 27, 2011 14:03:42 GMT -4
What causes the ground near Aldrin to be brighter in this picture? Is it a remnant of opposition effect, or is it light reflected from the suit or LM? Or is the ground actually different there? Thanks. The Apollo 11 LM drifted a bit to the left just before touchdown. Thus the terrain immediately around and behind Aldrin was somewhat scoured smoother and more free of very fine dust, leaving both a smoother surface and a somewhat higher percentage of glass beads in the lunar regolith exposed to sunlight. Since the sun was behind and to the right of Aldrin, the result is that the ground now reflects light better towards the down-sun direction where Armstrong with the camera was standing. You might want to check out my analysis of photo AS11-40-5903 on my web site. Here is the link. Just scroll down to the photo. www.mem-tek.com/apollo/ISD.htmlI do have a typo on the page in the above link. The ISD scan was made from their Kodachrome contact duplicate negative of the original Ektachrome transparency film from the mission. My full web site for Apollo stuff is at: apollo.mem-tek.com/
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Post by gonetoplaid on Jan 26, 2011 2:17:17 GMT -4
...I came across an unverified claim that Deke Slayton offered the chance of commanding the first Moon landing to attempt to Borman and then McDivvit, who both refused. True, at least with regards to Borman. Borman turned down Slayton's offer made in the fall of 1968. Slayton had entertained the idea of assigning Borman's crew for the first moon landing, followed by McDivitt's crew for Apollo 12 if Borman failed on the first landing attempt. Slayton's potential shakeup of crew assignments became acedemic when Borman turned down the offer. The above information is from the book A Man On The Moon by Andrew Chaikin, pages 137-138.
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Post by gonetoplaid on Jan 26, 2011 2:00:05 GMT -4
Slayton is no longer with us but, in his book, "Deke" he stated that Gus Grissom would've had a good shot at being the first on the moon. Gonna re-read the book to, once again, review the early crew assignments. I agree. Deke, were he still alive, really is the only one who could answer this question since he was responsible for crew assignments.
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Post by gonetoplaid on Jan 26, 2011 1:52:54 GMT -4
So the Moon's surface can reflect enough light to allow us to read by it here, 250,000 miles away, but not enough to be a suitable fill light to someone actually on the surface? I guess it is unsuitable because moon light is somehow special compared to earth light? Maybe earth light as well is also somehow special compared to sunlight. All I know is that I can read using my nightlight. My nightlight uses a bulb with a tungsten filament. I do know that tungsten light is different than sunlight. Yet sunlight shining down on the Moon is the same sunlight which shines down on the Earth. As I fall to sleep, I find my thoughts drifting away into my mind's twilight. Now I wonder...is twilight before dawn somehow special compared to twilight after sunset?
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Post by gonetoplaid on Jan 26, 2011 1:38:01 GMT -4
Aah, yet nobody asks or gives odds for how many followup videos one certain hoax believer individual will produce.
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Post by gonetoplaid on Jan 20, 2011 22:30:10 GMT -4
Hehe. The hoax believers will have a really hard time explaining this article published in 1978 in the Soviet Astronomy Letters, vol. 4, p.302. The following link is a pdf document which is quite interesting reading: articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1978SvAL....4..302N&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdfIn a nutshell, the Soviets used their RATAN-600 radio telescope to do this: "The first experiment for measuring the coordinates with the various sectors of the RATAN-600 is reported. The selenographic coordinates of the ALSEP transmitters deployed on the lunar surface by the Apollo 12 and 14-17 crews have been measured to 1°.0-1°.5 accuracy (or 12-15" in right ascension and declination) with a 1'.5X1° beam." In other words, the Soviets confirmed that radio transmissions coming from the ALSEPS deployed by the Apollo 12, 14, 15, 16 and 17 missions really are coming from the lunar surface, and that they determined the celestial radio sources of those transmissions to a remarkable 12 to 15 arcseconds in both right ascension and declination. That precision translates to a 1°.0-1°.5 accuracy (lunar surface latitude and longitude) on the Moon.
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Post by gonetoplaid on Jan 20, 2011 21:40:42 GMT -4
It sure is possible to determine the distance a photograph was taken from the Earth using spherical trig and photogrammetry. Alternatively, you can simply load a CAD file of the Earth with the Earth's continents and then change your viewpoint and distance until what you see matches the photograph. Or you can simply view Google Earth or the Earth in Celestia and do the same thing -- change your position and distance such that what you see matches the Apollo photograph and then simply note the distance of your point of view from the Earth's surface.
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Post by gonetoplaid on Jan 4, 2011 11:00:30 GMT -4
I concur that Ektachrome was more forgiving compared to Kodachrome regarding exposure errors due to Ektachrome's nonlinear response at both ends of its response curves. As for the regolith albedo properties on the surface of the moon, a similar earth-based example would be to take photographs in a large dew covered grass field. The dew on the grass nicely recreates the Heiligenschein (produced by the tiny glass beads in the lunar regolith) effect seen in Apollo EVA photographs.
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Post by gonetoplaid on Jan 4, 2011 10:42:21 GMT -4
I love it when conspiracy theorists cite the movies 2001 and Capricorn One as "proof" that the moon landings could have been faked. Good Lord, there are so many technical flaws in both movies that any claims that the directors could have used their "expertise" to fake the moon landings is beyond laughable.
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Post by gonetoplaid on Jan 4, 2011 10:36:58 GMT -4
...I think his worst aspect is regarding Apollo where he claims ALL the lunar images are faked, but then claims respect for NASA and the astronauts. Whenever people put to him that because the astronauts say the images are genuine and that they took them, if Jack is correct they must be lying, he shows an absence of fortitude and evades giving a straight answer. The above nicely describes YouTube user hunchbacked. Hunchbacked suffers from identical delusional behavior and believes that all of the Apollo photographs were faked and that the "fakers" deliberately left clues in every faked photo which only hunchbacked (apparently due to his self-perceived brilliance) has found. Hunchbacked, just like a cave man, is incapable of understanding the laws of perspective. I wonder if Jack White has the same difficulty understanding perspective, illumination, and shadows. Jack's mathematical model which "proves" that a fill light was used in photo AS11-40-5866 is utter hogwash. Jack was incapable of understanding that sunlight was reflecting brilliantly off of Armstrong's space suit and that this provided the fill light for the photo sequence of Armstrong descending the Eagle's ladder.
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Post by gonetoplaid on Nov 27, 2010 8:52:52 GMT -4
The visor was also coated with gold to give a color-neutral light reduction. Aluminum, also a good IF reflector, gives a bluish (if I remember - I looked it up a while ago) cast to the light that comes through. Very true -- at least with older coating technologies. For example, older aluminized Mylar solar filters for amateur telescopes yield a very bluish cast when viewing the Sun through them.
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Post by gonetoplaid on Nov 21, 2010 6:11:19 GMT -4
Some assembly required. Your parents put it together. Not my parents. When I was a kid my dad couldn't put together the Big Wheel my brother got for Christmas.
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