On Aug. 11, 1960, part of the Discoverer 13 satellite became the first human-made object to be recovered from Earth's orbit. The United States Department of Defense launched the mission as part of the C.I.A.'s Corona spy satellite program. They wanted to see if they could return a satellite's instrument package to Earth safely and gently enough to retrieve the object intact. The reentry capsule was a big, bowl-shaped hunk of metal that weighed about 120 pounds and contained only an American flag. After deploying a heat shield and parachute, the capsule splashed down in the Pacific Ocean. A Navy helicopter pulled it out of the water and airlifted it to a ship, which brought it back to Pearl Harbor.President Eisenhower inspects the capsule from Discoverer 13. (Image credit: By Dwight D. Eisenhower Library, Public Domain)Why it matteredThis first paved the way for modern spaceflight. We might take it for granted today as we see rocket stages return to Earth and land with the grace of a rehearsed dance and astronauts go back and forth to the International Space Station. At this point, all variety of capsules and spacecraft have not only gone out into space, but returned. But if we travel back to 1960, this was a groundbreaking feat. Discoverer 13 was a reconnaissance satellite (or what we might call a spy satellite) built by General Electric that launched with no cameras or film on board (subsequent satellites in the series, starting with Discoverer 14, had cameras). Instead, it carried diagnostic instruments and flew 17 times around our planet before reentering our atmosphere, deploying a small parachute and splashing down in the Pacific Ocean where it was retrieved by the U.S. Navy. This momentous milestone proved that it was possible for something to hurtle back through our atmosphere from space, survive the journey and be recovered. With subsequent satellites and missions, cameras and film would allow us further insight into the process, and today we can not only return objects from space with confidence, but we can return humans home to Earth from space. The return journey sends whatever object (or whoever's on board) through our atmosphere at searing speeds and even more searing temperatures. For a spacecraft (or even moreso, spacecraft with humans inside) to get a return right, it has to be built perfectly and the return maneuver has to be executed exactly. Today, this historic milestone might just seem like a satellite falling back into the ocean, but it represents a massive step forward that has allowed us to explore beyond what we once thought was possible.