NASA broke ground Tuesday for an assembly building for the proposed space station Freedom, an orbiting laboratory that the agency hopes to start building within five years.

NASA unveiled its plans for a smaller, cheaper station last week."There are a lot of people who thought we weren't going to make it to this ceremony today, and I'm glad that we're here," station director Richard Kohrs said at an outdoor ceremony.

"It would be hard to overestimate this. This is real," said William Lenoir, head of NASA's space flight program.

The $56 million building is the largest construction project undertaken at Kennedy Space Center since the Apollo era of moon launchings. About 1,000 people will work at the three-story structure, where components of the space station are to be assembled before being carried into orbit by the shuttle.