On May 15, 1963, astronaut Gordon Cooper climbed into a tiny Mercury capsule called Faith 7 and launched into space. His mission was to orbit Earth 22 times over 34 hours, making it the longest American spaceflight at the time. For most of the flight, everything went smoothly. Cooper even fell asleep in orbit, becoming the first American to sleep in space. Then, on orbit 19, a green light appeared on his control panel. It meant the capsule thought it was already falling back to Earth. Electrical systems began to fail one by one. The automatic re-entry system stopped working completely. Cooper had to do something no astronaut had done before: fly a spacecraft back through the atmosphere entirely by hand. He used a wristwatch to time his maneuvers and the stars outside his window to stay on course. He drew lines on the window with a grease pencil to track Earth's horizon. His landing was the most precise of any Mercury mission, splashing down just four miles from the recovery ship. Engineers later said the mechanical failure happened because moisture had damaged the electrical circuits during the long flight.