New NASA Ames Spacecraft to Look for Ice at Lunar South Pole

NASA ^ | 04/10/06 | John Bluck

[KevinDavis]

New NASA Ames Spacecraft to Look for Ice at Lunar South Pole

NASA today announced that a small, 'secondary payload' spacecraft, to be developed by a team at NASA Ames Research Center, Moffett Field, Calif., has been selected to travel to the moon to look for precious water ice at the lunar south pole in October 2008.

The smaller secondary payload spacecraft will travel with the Lunar Reconnaissance Orbiter (LRO) satellite to the moon on the same rocket, the Evolved Expendable Launch Vehicle (EELV), to be launched from Kennedy Space Center, Florida. The NASA Ames team proposed the secondary payload mission, which will be carried out by the Lunar CRater Observation and Sensing Satellite (LCROSS).

[KevinDavis]

[cripplecreek]

Just curious. Have you been keeping up with the new photos from the Mars Reconnaissance Orbiter? So far they're all calibration photos but I think they're going to be good.

http://mpfwww.jpl.nasa.gov/mro/gallery/calibration/index.html

[RightWhale]

Wouldn't it be funny if they hit a chunk of ice a hundred by a hundred yards and a hundred yards deep and sent it all thirty miles up never to be seen again, . . . , and it was the only ice on the moon?

[muawiyah]

This particular crater is reported to have several very special characteristics (besides water).

It is supposedly at the exact dead-center of the Moon's South pole.

It is also supposedly the deepest crater yet found on a planet or a moon in this solar system.

Oh, yes, it also contains water (frozen).

[supercat]

Oh, yes, it also contains water (frozen).

I can understand that the bottom of a crater on the exact south pole of the Moon would never get any sunlight (and would likely be the only such place on the moon, unless there's a crater at the north pole). Given that the rest of the Moon is illuminated by the Sun for half the year, though, I would have expected the average lunar temperature to be somewhat warmish. What is the sublimation temperature for H2O in a vacuum?

[SunkenCiv]

Google

[muawiyah]

It's at the bottom of a very deep hole. Quite possibly the temperature is so low the ice never sublimates.

[RightWhale]

Water ice will remain solid and surprisingly intact until the temperature hits near freezing. If you run the triple point experiment in a vacuum chamber, you will find that the water boils and freezes simultanously until what is left is all frozen, then it stops doing things.

[MikeD]

I can understand that the bottom of a crater on the exact south pole of the Moon would never get any sunlight (and would likely be the only such place on the moon, unless there's a crater at the north pole). Given that the rest of the Moon is illuminated by the Sun for half the year, though, I would have expected the average lunar temperature to be somewhat warmish.

Yes, but the thermal conductivity is rather low, so things in shade tend to stay cold. The craters act as "cold fingers" to trap the evaporated water left on the moon from cometary impacts.

What is the sublimation temperature for H2O in a vacuum?

144 Kelvin, IIRC. I should know that, given my connections to all this stuff...