Updated

Fifty years ago today, a small satellite — the world's first built and launched by humans — rocketed into orbit, beaming down a series of beeps that heralded the coming Space Age to anyone listening on Earth.

The former Soviet Union's successful launch of Sputnik 1, a 23-inch (58-centimeter) wide sphere that resembled a silver beach ball with antennas, on Oct. 4, 1957 marked humanity's first leap into space.

• Click here to view archived Movietone newsreels of the Sputnik launch.

"It is the kind of the kind of thing that does not belong to just one country," said veteran cosmonaut Yuri Malenchenko, who will journey to the International Space Station (ISS) next week with the Expedition 16 crew, of Sputnik's legacy. "It belongs to humanity in general."

Larger and more sophisticated machines followed Sputnik into space, some with creatures aboard and others with science instruments, and it was only a matter of time before humans catapulted themselves into that high frontier above Earth.

• Click here to hear an audio recording of Sputnik's famous beeps.

With the Soviet Union's successful launch of cosmonaut Yuri Gagarin on April 12, 1961, which sparked a race with the United States to send astronauts to the moon and back, humanity firmly established its grasp on spaceflight.

By July 20, 1969, the first humans — Apollo 11 astronauts Neil Armstrong and Buzz Aldrin — were on the moon.

"Here we are, for the first time, leaving our planet," former Apollo astronaut Edgar Mitchell told SPACE.com. "It's the beginning of a whole new epoch in human civilization."

• Click here to visit FOXNews.com's Space Center.

Mitchell was on the winning side of the lunar space race between the U.S. and Soviet Union. He served as lunar module pilot during NASA's Apollo 14 mission — America's third manned moon landing — in 1971.

Sputnik's first flight and the advancements that led to Gagarin's launch and NASA's Apollo landings marked a pivotal point for human exploration, one that has led to a permanent presence for astronauts aboard the ISS, he said.

"It's about as important as when the Phoenicians first started paddling across the Mediterranean and the South Sea islanders first started in their outrigger canoes across the Pacific Ocean," Mitchell said.

From national to international

But human space exploration was initially driven by political pride and technological prowess, not pure science and wonder, former spaceflyers recalled.

"What motivated us ... to go to moon was the advancing nature of the Soviet Union with Sputnik," former Apollo 11 astronaut Buzz Aldrin, the second man to walk on the lunar surface, told SPACE.com.

The Cold War between the two superpowers was well under way by then, he added.

Since Gagarin's first flight, 462 men and women have launched into space, and 21 have lost their lives aboard spacecraft on Earth or in flight.

But it wasn't until July 17, 1975 that two spacecraft from different nations — then-rivals the Soviet Union and the U.S. — met in space for the first time during the Apollo-Soyuz mission.

Three spaceflyers — Russian cosmonauts Fyodor Yurchikhin, Oleg Kotov and U.S. astronaut Clayton Anderson — are living in orbit today aboard the International Space Station, though none of them were even born yet the day Sputnik launched.

"I think it's very important that we work together," Anderson told Russian students this week. "I think the most important thing about the International Space Station is that we're learning to go farther as a world, and not just as independent countries."

Momentum lost

NASA is once more trying to reach out to the moon by retiring its three remaining space shuttles in 2010 and reviving the capsule-based spacecraft concept from its Apollo era to ferry astronauts back to the lunar surface by 2020.

"We had the potential, when we got back from the moon in the Apollo days, to start building the technology ... to get on with it and go to Mars," Apollo 12 lunar module pilot Alan Bean told SPACE.com. "I thought in my lifetime I might see people on Mars; certainly I would see them training and getting ready to go."

But, explained Bean, cultures and countries rarely live up to their potential, due to the shifting nature of interest, funds and priorities between generations.

"I'm not discouraged by it," Bean said, but stressed that NASA will likely need more definite funding if it is to succeed in returning astronauts to the moon by 2020, let alone reaching out beyond lunar exploration.

Continued cooperation among different countries, Malenchenko added, will also be vital to the success of the ISS and future missions to the moon and Mars.

On Oct. 10, Malenchenko — who commanded the ISS in the past — will launch toward the space station aboard a Russian Soyuz spacecraft from Baikonur Cosmodrome in Kazakhstan.

Riding to space with him will be U.S. astronaut Peggy Whitson — the first female spaceflyer to command the ISS — and Sheikh Muszaphar Shukor, Malaysia's first astronaut.

Whitson and Malenchenko, the space station's core crew of Expedition 16, will relieve Yurchikhin and Kotov aboard the orbital laboratory. Anderson will join Expedition 16 for the first leg of the mission.

Astronauts from Europe and Japan are also due to visit or stay aboard the ISS during Expedition 16, and only through such cooperation will research and exploration prosper aboard the station, Malenchenko said.

"That would be the way to go in the future as well," he added.

Copyright © 2007 Imaginova Corp. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.