It started with a simple beep on Oct. 4, 1957. But it was a beep heard around the world. When the Soviet Union launched the 183-pound Sputnik, the tiny satellite ignited a frantic space race between the USSR and the United States.
Milt Heflin was 14 years old when Sputnik launched, and he was already an avid radio enthusiast. He remembers sitting in his backyard in Edmond, Okla., listening to outer space.
"I can still picture myself sitting in the backyard at a card table, with a battery operated radio ... the beep, beep, beep in the head phones. Man, that was really wild," Heflin said. "I came from a little town in Osage County, and word got around that I had heard Sputnik, and people wanted to come to my house to listen to it themselves. No one could believe it."
Heflin's love for radios began when his parents gave him a crystal radio kit for Christmas. By 1957, he had become a licensed ham operator, and when Sputnik was launched he immediately started listening for Sputnik's beep.
Heflin would take that love for radios and his curiosity about Sputnik and space and eventually become a flight director at the Johnson Space Center in Houston, where he witnessed firsthand how far the space program could go with a little motivation.
Sputnik wasn't big. It was about the size of a basketball, took 98 minutes to circle Earth on an elliptical orbit, and its launch changed everything.
National Air and Space Museum curator Roger Launius wrote about the turmoil that erupted the night that Americans learned about Sputnik.
"Two generations after the event, words do not easily convey the American reaction to the Soviet satellite, the only appropriate characterization that begins to capture the mood on Oct. 5 involves the use of the word 'hysteria.'"
The space race was on. The U.S. satellite entry was Explorer 1, which launched from Cape Canaveral at 10:48 p.m., Jan. 31, 1958.
Explorer 1 weighed 30.66 pounds and carried a small scientific payload that eventually discovered the magnetic radiation belts around Earth, named after the principal investigator James Van Allen.
Ret. Air Force Col. Mark Polansky commanded STS 116, and remembers the Cold War very well.
"I got to meet Vladimir Titov, who flew on one of our shuttle missions to the MIR. A long time ago when I was an F15 pilot, he was probably a Soviet fighter pilot and the two of us would not have been on speaking terms back then. And now some of the Russians are really good friends of mine, and we go to each other's houses when we are in town or they are in town. So I think that is a great accomplishment," Polansky said. "We get a lot of international cooperation; just the fact that you go ahead and do something very complicated in a hostile environment, building a space station is not a trivial thing, not to this magnitude."
Since Sputnik, the United States has launched six Mercury flights, 10 Gemini missions, sent six Apollo missions to the moon. The space shuttle, which launches like a rocket and lands like a plane, will have flown for 28 years before it is retired.
The decades since Sputnik have seen more than personal friendships develop between American and Russian engineers and astronauts. Members of the U.S. and Russian space programs are part of the 16-country consortium building the most ambitious construction project ever, the International Space Station.
Pam Melroy will command STS 120, the next shuttle mission headed to the space station. She is very aware of how much she owes to Sputnik.
"I think everybody in the space program is very inspired by the 50th anniversary of Sputnik," Melroy said. "I think one of the greatest things that has come from the last 50 years is that instead of competition, it is about cooperation. That beep sounded very threatening to many American[s], and here we are 50 years later realizing it was a language we can honor and work with."
For Milt Heflin, Sputnik is about the evolution of space technology from the 183-pound satellite launched 50 years ago to the space station orbiting Earth today, which weighs 482,000 pounds.
He says his hope for the next generation is its own beginning.
"I think every kid ought to be able to experience what my generation experienced. Anytime a kid gets to be at the beginning of something, it only happens once. There isn't another beginning, and for those of us back in the days of early radio, and the space program, the first time signals were sent across the Atlantic, what a great thing it was," Heflin said. "Sputnik comes along and people get energized, because they were there at the beginning of this noble enterprise called human spaceflight. What I would tell kids today, is you need to look for another beginning, that you need to watch for, when you see something that interests you, jump on it, and be part of the beginning."