"The building itself will embody the memory," Calatrava said at a news conference.
It will also shine natural light through dozens of glass panels to the train platforms 60 feet underground. It will feature a large atrium comparable to the city's Grand Central Terminal, and canopied wings that will rise from the station's roof 150 feet in the air and can move to different angles to block the wind.
"We are bringing the light through the building and making the light one of the pillars of the building," said Calatrava, whose designs include the sports complex for the Athens Olympics and train stations in Zurich, Lyon, France and Lisbon, Portugal.
The design was the last of those unveiled in recent weeks to restore the 16-acre trade center site destroyed by the 2001 attack. Architects David Childs and Daniel Libeskind last month presented models of the 1,776-foot Freedom Tower that would replace the trade center. Designers Michael Arad and Peter Walker last week offered drawings for a ground zero memorial.
The price tag for the transit hub is about $2 billion, about $500,000 more than the budget for the Freedom Tower. The federal Transit Administration is providing nearly all the funding for the transit hub, while insurance proceeds from the destroyed towers are expected to pay for the Freedom Tower.
Construction could begin on the new hub by the end of the year; its train service should begin in 2006 and it is expected to be finished in 2009, the same year as the Freedom Tower.
A temporary terminal opened Nov. 23 at the site and is now handling more than 24,000 daily riders. The station had served 67,000 daily passengers before the attacks; the Port Authority of New York and New Jersey, which will operate the terminal, said it is expected to eventually handle more than 80,000 daily rail passengers and 250,000 commuters moving on mechanical walkways to ferries and 14 downtown subway lines.
Calatrava, working with New York's STV Group and DMJM & Harris, had to receive Libeskind's approval for a design that would mesh with the architect's master plan.
Libeskind called Calatrava's design "such a beautiful plan" and said he improved upon his original idea of a Wedge of Light Plaza, designed to be free of shadows every Sept. 11 between the times when the first plane struck and when the second tower fell.
"'Wow' is the first word that's just got to come to your mind," said Mayor Michael Bloomberg. He said the station would be "a building that really appears to take flight just like the neighborhood it serves."
Childs, who designed the Freedom Tower, called it "an emotional, sculptural solution" to relieve mass transit congestion downtown while paying tribute to Sept. 11. "It's not only going to work, it will be an inspiration."
Calatrava, who left the podium during his presentation to draw several pages of sketches so that he could explain "with my hands, more than with my words," said his inspiration for the station was of a child releasing a bird. He said perhaps in the future, birds could be released through the open roof to mark the anniversary.
The winged building would evoke "a new world, life, flight and hope," he said.