What is the NASA used for?

NASA is responsible for the nation's public space program. NASA has led U.S. efforts for space exploration ever since, resulting in the Apollo missions to the Moon, the Skylab space station, and later the Space Shuttle. Currently NASA is supporting the International Space Station and developing new Ares I and V launch vehicles. (Wikipedia)
For the source and more detailed information concerning your request, click on the related links section (Wikipedia) indicated directly below this answer section.