Astronomers have found about 2,000 planets beyond our solar system. Now, some scientists are expanding the search to look for distant moons, too, in the hunt for signs of life.
When a company named Astrobotic launches a lunar rover in 2017, the MoonArk will be aboard. It's a lightweight, sturdy "portrait of humanity," carrying the work of more than 200 artists and designers.
NK-33 engines, originally destined for a Soviet-era moon shot that never got off the ground and later used in the Antares, are suspect, some scientists say.