"What we're looking at is polar locations—both the north pole and south pole," she said.
The moon's poles are believed to be bathed in near constant sunlight, which should allow for solar power generation.
In addition, polar temperatures are relatively moderate. Other lunar regions tend to fluctuate between extreme heat and cold.
Furthermore, the poles contain craters whose slopes may be permanently in the shadows—an indication that water ice and other potentially useful chemicals may be available.
"It's also interesting to note that we know very little about the poles on the moon. In fact, we know more about Mars," said Scott Horowitz, associate administrator for NASA's Exploration Systems Missions Directorate.
Doug Cooke, deputy associate administrator for the directorate, said one potential location is at the edge of Shackleton Crater. Located at the south pole, the crater is sunlit 75 to 80 percent of the time.
"And it is adjacent to a permanently dark region where there are potentially volatiles"—substances such as water ice, which would likely evaporate if exposed to much sunlight—"that we can extract and use," he said.
The potential site, he added, is about the size of the Washington Mall, which measures about 0.9 square mile (2.4 square kilometers).
NASA envisions using an all-purpose lander that maximizes the amount of cargo that can be shipped to the moon in a single trip, Cooke said.
Horowitz likened the lander, which is in the preliminary design stages, to a pickup truck.
"You can put whatever you want in the bed. You take it to wherever you want, and so you can deliver cargo, crew [and] do it robotically [or] do it with humans onboard. These are the types of things we are looking for," he said.
"What you can put on the surface allows you to develop a capability much more quickly. The more you can land, the better it is."
The current plan envisions incremental base construction beginning in 2020 with four-person crews making seven-day visits to the moon until their basic necessities are in place.
"It will probably take several years—probably into the 2024 timeframe—before you see a fully functional base where you could have a continual presence with rotating crews like we have on the International Space Station today," Horowitz said.
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