Why nasa never returned to the Moon?

Space shuttle Atlantis and its six-member crew began an 11-day delivery flight to the International Space Station on Monday with a 2:28 p.m. EST launch from NASA's Kennedy Space Center in Florida. The shuttle will transport spare hardware to the outpost and return a station crew member who spent more than two months in space.

Atlantis is carrying about 30,000 pounds of replacement parts for systems that provide power to the station, keep it from overheating, and maintain a proper orientation in space. The large equipment can best be transported using the shuttle's unique capabilities.