NASA is taking a close look at new concepts to send crews on deep space expeditions near the moon, as a promising next major "stepping stone" for human spaceflight.
The goal of the appraisal is to focus on what can be accomplished cost effectively in the near future, to showcase NASA’s ability to venture beyond low-Earth orbit (LEO).
At the heart of current efforts to explore beyond Earth's orbit is extensive use of the International Space Station, which astronauts can use to prepare for human travel beyond LEO. Moreover, work is underway to find novel ways to reuse existing equipment at the space station.
For instance, leftover components from the station and the now-defunct space shuttle program could be used to house technology demonstration hardware. Indeed, a combo of shuttle/station gear could be re-tasked and put together into a spacecraft for operations beyond LEO, researchers said. [Gallery: NASA's Vision for Deep Space Missions]
Click image for all proposals for deep space stations
Deep space scenarios
One ambitious human voyage on the table is long-duration crewed operations at libration points, gravitationally stable points in space that are also known as the Lagrangian points.
The Lagrange points are space places where the combined gravitational pull of two large masses roughly balance each other out, allowing spacecraft to essentially "park" there.
There are five Lagrange points in near-Earth space. The closest Earth-sun Lagrange points are L1 (between Earth and the sun) and L2 (behind Earth, as viewed from the sun), which are about 930,000 miles (1.5 million kilometers) from the planet. For comparison, the moon is typically about 238,000 miles (382,900 km) from Earth, and represents the farthest point from Earth humans have ever explored.
Space architects contend that Lagrange point travel could sharpen human skills and technologies for even more challenging manned space sojourns.