When people think of American space travel, the first names that come to their minds are usually the likes of Buzz Aldrin, Neil Armstrong and Sally Ride. Like with most massive projects like NASA's, there are a number of people behind the scenes who work tirelessly to get to the point where astronauts can go into space. Those people, however, aren't household names like the folks who blast off on the space shuttles. This series profiles the secret heroes, engineers who helped build the spacecraft and other instruments that have allowed astronauts to launch into space to explore the world beyond what's visible from Earth. The show reveals the stories behind how they created such machines as the Saturn V moon rocket and the Hubble Space Telescope.