While the International Space Station provides a testing stage for orbital experiments, it's not the best launching point for, say, a manned deep space mission. Since that's exactly what NASA's looking to do in the near future, the agency is considering building another space station, one "parked" in an area where the Earth and moon's gravitation fields nearly cancel one another out.
These magical little pockets of nearly nullified gravity are know as libration points (or Lagrangian points or L-points), and within them, something like NASA's possible deep space outpost could remain in a fixed position. It'd be a third object orbiting with the moon and Earth around a common center of gravity. There are five L-points around Earth; NASA is looking at Earth-moon libration point 2 (or EML-2), as the best possible site for its next manned outpost, if the agency goes forward with its plan.
EML-2, labeled L2 in the diagram below, is actually beyond the moon:
Whereas the International Space Station lets the U.S. and participating countries play around in orbit, a manned outpost placed at EML-2 would not only provide a valuable staging ground for operations on and around the moon, but also act as a jumping-off point toward Mars, asteroids and beyond.
NASA sees this project as one that would need international support, too, according to Mashable's Stan Schroeder:
The plan also requires "significant international participation" and "U.S. commercial business opportunities to further enhance the space station logistics market." Furthermore, NASA would like to see "multiuse or reusable in-space infrastructure that allows a capability to be developed and reused over time for a variety of exploration destinations."
The agency currently has a team investigating the possibility of an EML-2 outpost, and is supposed to report on the possibility of staging missions there — such as sending out a robotic craft to check the area out — by March 30.
Lagrange diagram credit: David A. Kring/LPI-JSC Center for Lunar Science and Exploration