THE ADVANTAGES OF ICE

I. Background

Study of lunar samples returned by the Apollo missions revealed that the interior of the Moon is essentially devoid of water, so no underground supplies could be used by lunar inhabitants. However, the lunar surface is bombarded with water-rich objects such as comets, and scientists have suspected that some of the water in these objects could migrate to permanently dark areas at the lunar poles, perhaps accumulating to useable quantities.

The discovery of ice on the Moon would have enormous implications for a permanent human return to the Moon. Composed of hydrogen and oxygen, lunar ice could be mined and disassociated into these two elements by means of electrolysis. Electric power could be provided by solar panels deployed in a beam of sunlight that catches a nearby crater rim or by a nuclear generator.

"Some spots on the summits of those mountains are in permanent sun shine. That's an advantage as you can draw solar power all the time," Eugene Shoemaker said. A source of solar energy near a source of water ice has a range of potential applications, he said. "You can let your imagination go a little bit . . . you can see what the possibilities are," he added.

II. Lunar Colony

An abundant supply of water on the Moon would make establishment of a self-sustaining lunar colony much more feasible and less expensive than presently thought. The oxygen generated from the ice could support a permanent facility or outpost on the Moon in the next 50 years. Hydrogen volatiles provide a basis for agriculture and the manufacture of building materials. Anthony Cook of the Griffith Observatory explained. "With water there you could have enclosed areas to grow plants, grow your own food, make your own fuel, make your own air," he said. "You don't have to launch all that stuff from big rockets on the Earth."

"You may be looking at the most valuable piece of real estate in the solar system," ventures Spudis. The discovery of this material, rare on the Moon but so vital to human life and operations in space, will make our expansion into the Solar System easier and reaffirms the immense value of our own Moon as the stepping stone into the universe. "An easily extractable reservoir of water ice can be used not only at a base, but by hydrolyzing water you've got rocket fuel. You could then really think in terms of the moon as a staging area," Shoemaker said.

III. Filling Station/Staging Area

Initial estimates suggest that the volume of a small lake exists, 1 billion cubic meters. For comparison, this amount of water would be equivalent to the fuel (hydrogen and oxygen) used for more than a million launches of the Space Shuttle from Cape Canaveral! Water transformed into rocket fuel can send millions of tons of payload into low-earth orbit, or to Mars and beyond. This hydrogen and oxygen is a prime rocket fuel, giving us the ability to refuel rockets at a lunar "filling station" and making transport to and from the Moon more economical by at least a factor of ten. Ice on the moon saves the enormous expense of having to haul heavy loads of water in spacecraft."

IV. The Debate

John Lewis, professor of planetary sciences and co-director of the Space Engineering Research Center at the University of Arizona at Tucson, was somewhat less convinced of the significance of the discovery. The Clementine data "is extremely tantalizing,' he said, "but whether it can be unambiguously linked to water remains to be seen." Lewis also said any water ice at the moon' south pole "is sort of in the wrong place." Hauling water to more equatorial lunar bases would be expensive and a logistics problem, he said. "I think people are going to have to think really hard about how to use that water [at the lunar south pole]," Lewis said. "My calculations lead me to view that [finding water on the moon] is a rather marginal bonanza," said Lewis, adding that the scientific information about ice at the pole might exceed the economic value.

Again, opinions differ greatly. Philip Chapman, a former NASA astronaut now with the Center for Enterprise in Space of Scottsdale, Ariz., told conference attendees that lunar ice could be worth as much as $9 trillion, when calculating its value for life support, energy storage, agriculture and industry at some future lunar base.

V. Science Data

See Dr. William Feldman discuss how water might have made it to the moon: RealMedia(requires RealPlayer) Quicktime (requires Quicktime Video): 320 x 240 (3.9 Mb) | 160 x 120 (1.46 Mb)

A stable cache of lunar permafrost would be far more valuable than gold to planetary scientists. "For the first time," Spudis explains, "we have a preserved record of the cometary impact rate over time." Probing the polar layers could yield critical insights on how often comets have hit the Earth-Moon system, whether that rate changes with time, and what comets are made of. Like the rings of a tree, the stratigraphy will provide a 2 billion year timeline of the history of each cold trap. It may even allow the age of a cold trap to be determined, which would tell us when the Moon's rotational axis stabilized at its current angle.

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