Test pilots and engineers embark on the first flight of the largest airplane ever built: the Stratolaunch, a one-of-a-kind aircraft designed to transport rockets, spacecraft and experimental hypersonic planes into the stratosphere.

Engineers in China are constructing the largest and most ambitious water transfer project in human history, defying nature to move vast quantities of water from the south to the dry north in Beijing, all without the use of pumping stations.

Explore three battlefield behemoths that command land, sea and air.

Inside access shows how an engineering marvel lifts boats to new heights.