San Salvador project manager Bruce Heyman shows off one of the working guns that will be used for mock gun battles with other tall ships once the San Salvador sets sail.

Published on April 17, 2012

Retired plumber Roy Libby volunteers four days a week on the San Salvador construction, and has even grown a beard to fit in with the crew.

Published on April 17, 2012

This model shows what the San Salvador replica will look like when competed.

Published on April 17, 2012

The body of the ship will be 95 feet long and be comprised of tens of thousands of pounds of wood.

Published on April 17, 2012

Published on April 17, 2012

Gregory Jaczko, Head of the Nuclear Regulatory Commission, speaking to the media after a visit to the San Onofre nuclear power plant, April 6th, 2012.

Published on April 17, 2012

(left to right) Stuart Bogie, Justin Walter, Elliot Bergman, Matt Lux, Jim Becker, Joe Adamik, Sam Beam, Ben Massarella, Nick Luca, Aida Shahghasemi, Markéta Irglová. Sam Beam, better known as Iron & Wine, leads a 12-piece band through an array of his songs from Iron & Wine’s most recent album, "Kiss Each Other Clean," and other favorites, at a taping at Atlanta's historic Buckhead Theatre on November 10, 2011.

Published on April 17, 2012

(left to right) Joe Adamik, Sam Beam and Ben Massarella from Iron and Wine, performing at Atlanta's historic Buckhead Theatre on November 10, 2011.

Published on April 17, 2012

AMERICA REVEALED host Yul Kwon skydiving.

Published on April 17, 2012

Traffic in Los Angeles. Using aerial footage, high-definition video and real-time satellite data, AMERICA REVEALED traces the movements and communications that miraculously come together to manufacture goods, transport people and materials, grow tons of food and power our increasingly tech-savvy nation.

Published on April 17, 2012

Nightly traffic in Las Vegas. In "Nation On The Move," host Yul Kwon heads out into the wild night in Las Vegas to see how transportation analysts are keeping traffic at bay by revolutionizing the use of one basic tool: the traffic light.

Published on April 17, 2012

Rapid buses have found homes in cities around the world. But they're not finding a place to terminate in downtown San Diego.

Published on April 17, 2012

High angle shot of ship architectural model submerged in water tank.

Published on April 17, 2012

Computerised bridge simulator from NOVA's "Why Ships Sink."

Published on April 17, 2012

Chinook salmon at Dagger Falls.

Published on April 17, 2012

A council of bighorn rams.

Published on April 17, 2012

Otter mom and pup prepare for an afternoon nap.

Published on April 17, 2012

Organic Farming

Published on April 17, 2012

Screen shot of Trayvon Martin Tweet

Published on April 17, 2012

Discovery flies over the Washington Monument

Published on April 17, 2012

Trucks with the natural gas industry, some of the thousands that pass through the area daily, drive through the countryside on January 18, 2012 in Springville, Pennsylvania.

Published on April 17, 2012