One of the indelible memories for anyone living through the 1960s was watching CBS newsman Walter Cronkite anchor another televised liftoff from Cape Canaveral, Florida.

Throughout the decade, from Alan Shepard through Neil Armstrong, Cronkite made it clear to his audience that they were taking part in something momentous, something that not only represented the flowering of a great technological achievement but stirred the human soul as well.

This week, the National Aeronautics and Space Administration observes the 50th anniversary of its creation. And make no mistake: There's a lot to celebrate. NASA's achievements write a glorious chapter in human history, one that's nearly impossible to overstate. Is it fair to call NASA the greatest scientific and exploratory agency ever created? It is.

Americans used to appreciate this. Rare was the school in the early '60s that didn't stop the day's activities so student and teacher alike could gather in front of a grainy, often wavy, black-and-white picture of an Atlas booster rising heavenward from the smoke and fire, while Uncle Walter, live from the Cape, told us what it all meant.

It meant a lot. The U.S. space program was a cultural touchstone as much as a scientific or political one. Astronauts were heroes, as revered as any ballplayer or movie star of the time. You'd have to be living in a cave not to know what NASA was, and byproducts of the space program touched almost every corner of American life.

It cost the United States about $40 billion to get to the moon. Even at twice the cost, that's chump change. The human race has been repaid many times over for that investment, as it has for many other NASA projects. So much of what we take for granted today is either directly or indirectly a byproduct of what used to be called space-age technology. Medicine, the military, communications, miniaturization, computerization -- all have benefited because of NASA's work.

The space program also helped to fire an interest in the sciences generally, with all the obvious benefits that accrue to that. And if you believe that reaching for the stars represents a triumph of the human spirit, then those who dedicate their lives to it -- from NASA's astronauts to the Soviet/Russian cosmonauts to all the other spacefarers who have taken up the challenge -- only carry us forward.

And to think it all started, more or less, with the terrifying appearance of a shiny ball measuring a mere 22 inches across.

Sputnik Started It All

It was Oct. 4, 1957 when the Soviet news agency Tass announced to a stunned world that the Soviet Union had successfully placed Elementary Satellite 1, aka "Sputnik," into an elliptical orbit 900 kilometers above the Cold War-wracked planet. The aluminum sphere was the first man-made object to orbit the Earth, and its celestial presence electrified the world and kicked the Space Age into high gear, leading in short order to the formation of NASA.

American scientists were already in a close race with the Russians to launch the first orbiting satellite. But the Americans' Vanguard program, run by the Naval Research Laboratory, was beset by cost overruns and delays. Getting beat by the Russians was a tremendous blow.

The pressure intensified with the successful Russian launch, less than a month later, of the much heavier Sputnik 2 (with the dog Laika aboard). The sting of that was only somewhat mitigated by the Army's successful launch and orbiting of Explorer 1 on Jan. 31, 1958.

It was clear that the United States was losing ground and that its space effort needed a major reorganization. The first step was to reinvigorate the National Advisory Committee for Aeronautics, or NACA, a rather geeky and elitist civilian panel that had been around since 1915. As NACA's charter grew, the decision was made to expand it into a full-fledged government agency.

On July 29, 1958, President Eisenhower signed legislation creating the National Aeronautics and Space Administration. NASA was born.

Space Pioneers

NASA officially became a functioning entity on Oct. 1, 1958, with T. Keith Glennan as its first administrator. There were 8,000 employees, inherited from NACA; three research laboratories -- Langley Aeronautical Laboratory, Ames Aeronautical Laboratory and Lewis Flight Propulsion Laboratory -- and an annual budget of $100 million.

The agency's mission statement will have faint echoes for Star Trek fans: "To improve life here, to extend life there, to find life beyond."

The U.S. and Soviet space programs dueled throughout the decade, launching various satellites (military, communications, environmental) and sending their men (and eventually, women) on increasingly ambitious missions. The Russians were first to hit the moon with a man-made object (1959), first to orbit the moon and photograph its far side (1959), first to send a man into space (Yuri Gagarin, in 1961), first to send a woman into space (Valentina Tereshkova, in 1963), first to have a cosmonaut go EVA, or leave an orbiting spacecraft (Alexei Leonov, in 1965), first to land a probe on the moon and transmit data back to Earth (1966), the first to place a manned space station into orbit (1971).

NASA, though, was no laggard, posting a series of successes throughout the 1960s and eventually overtaking the Russians. The ultimate goal was straightforward, if not simple: Beat the Russians and be first to put a man on the moon.

A manned space program required astronauts, so NASA immediately began screening military and civilian test pilots for suitable candidates. Seven were chosen, and because the project was named Mercury, they became known as the "Mercury Seven": Scott Carpenter, L. Gordon Cooper Jr., John Glenn Jr., Gus Grissom, Walter Schirra Jr., Alan Shepard Jr. and Deke Slayton.

A project of that scope also required massive public support, and NASA cannily touted the Mercury Seven as the mascots of the fledgling space program, turning them into national heroes and rallying the populace behind the agency's lofty goals.

Twenty-three days after Gagarin's historic, 108-minute flight, Alan Shepard became the first American into space. It was a quick up-and-back, suborbital affair aboard Freedom 7. Eleven months later, on Feb. 20, 1962, John Glenn completed three orbits aboard Friendship 7 and the space race was officially tied again.

Project Mercury ran its course. It was replaced by Project Gemini in 1965, an intermediate program designed to pave the way for Project Apollo and the final assault on the moon.

To the Moon

Apollo 8 was the first manned spacecraft to enter lunar orbit, circling the moon 10 times before heading home. Apollo 10 amounted to a full dress rehearsal for the actual landing, orbiting the moon 31 times and coming within 50,000 tantalizing feet of the lunar surface.

NASA's supreme moment arrived on July 20, 1969. With the entire world watching -- no exaggeration -- Apollo 11's lunar lander, Eagle, touched down on the powdery surface of the Sea of Tranquility at 4:18 p.m. EDT. The first words spoken from the lunar surface was a simple acknowledgement to mission control: "Houston, Tranquility Base here. The Eagle has landed."

Six-and-a-half hours later, astronaut Neil Armstrong became the first human being to set foot on the moon. Armstrong and Buzz Aldrin spent two-and-half hours on the lunar surface, planting the American flag, placing a plaque ("Here Men From the Planet Earth First Set Foot Upon the Moon. July 1969 A.D. We Came in Peace for All Mankind."), collecting soil samples and setting up scientific instruments.

Astronauts returned to the moon on subsequent Apollo flights to collect additional mineral samples, play a little golf and conduct a slew of scientific experiments.

NASA narrowly averted disaster in April 1970 with Apollo 13, when an oxygen tank ruptured onboard. The mission became a harrowing rescue drama that in some ways was NASA's finest hour. The three-man crew -- James Lovell, John Swigert and Fred Haise Jr. -- abandoned their crippled, oxygen-starved command module and crammed themselves into the lunar lander for an attempted return to Earth. Working with flight controllers on the ground, they swung around the moon, using the lunar gravity to propel them toward Earth. Three days after the explosion, they splashed down safely in the Pacific Ocean.

Although there were five more Apollo missions to come, NASA was already turning its attention to the exploration of deep space, the deployment of an orbiting space station and the development of a reusable craft that it called the space shuttle.

And the race was not without its tragic setbacks.

In January 1967, Gus Grissom, one of the original seven Mercury astronauts, was killed along with two crewmates, Ed White and Roger Chaffee, when their Apollo 1 training capsule caught fire during a test at Cape Canaveral. They were the first fatalities for NASA and the U.S. space program.

Even as they paused to mourn and bury their dead, NASA's engineers and astronauts forged ahead.

Beyond Apollo

On March 2, 1972, NASA launched Pioneer 10, which became the first satellite to pass through the asteroid belt and return close-up images of Jupiter. From there, it sailed on out of the solar system and into deep space, where it continued sending signals until contact was finally lost on Jan. 22, 2003.

NASA launched two more deep-space probes in 1977, Voyager 1 and Voyager 2. Together, the two spacecraft have visited more planets, asteroids, rings and moons, and traveled farther than any other spacecraft. Voyager 1 is now further from Earth than any man-made object.

Closer to Earth, NASA began to "extend life there" by launching its first space station, Skylab, in 1973. Americans were now able to spend extended periods in space, which, among other things, led to more sophisticated studies on the effects of prolonged weightlessness on the human body.

As the cold war thawed, U.S. and Soviet space programs began moving toward a spirit of cooperation, which culminated in the Apollo-Soyuz test project in 1975. The crews performed a few joint scientific experiments, but the real value of this mission was to help the easing of tensions back on Earth, advancing NASA's mission to "improve life here." It also paved the way for future joint U.S.-Russian efforts, like the Shuttle-Mir program.

The centerpiece of NASA's post-Apollo years has been the space shuttle. Designed to carry large payloads in low Earth orbit, the shuttle is the first truly reusable orbital spacecraft. Six shuttles have been built. Five of them -- Columbia, Challenger, Discovery, Atlantis and Endeavour -- were fully operational. The prototype, Enterprise, was not built to fly in space.

Its versatility and durability has made the shuttle NASA's workhorse since STS-1, Columbia's maiden flight in 1981. Shuttles have been used to deploy and recover satellites, to deliver payloads and crews to various space stations, to conduct experiments in the weightlessness of space, and to dispatch crews to repair other space vehicles. In 1990, it was Discovery that deployed another resounding NASA success, the Hubble Space Telescope.

To date there have been 121 shuttle missions. Of those, 119 have ended successfully. The two that didn't remain burned into the national consciousness. The Challenger and Columbia disasters, which cost the lives of 14 astronauts, have dogged the shuttle program since 1986, delaying missions while NASA undertook painstaking investigations.

Recent shuttle missions have centered on keeping the Hubble telescope functioning and ferrying additional components to the International Space Station, a multinational endeavor that has helped NASA strengthen its ties with other national space programs.

Now the shuttle is nearing the end of its operational life. NASA plans to retire the orbiter following STS-133, scheduled for 2010. A new orbiter, Orion, is expected to deploy in the middle of the next decade.

Meanwhile, NASA is currently lavishing a lot of attention on our nearest planetary neighbor, Mars. Although NASA rovers have pretty well discounted the possibility of the existence of little green men, the red planet's geological history is being intensely studied. NASA's recent declaration that water ice is present on Mars holds out the hope that some form of life did, or does, exist.

The Next 50 Years

Challenges lie ahead as NASA moves into its second half-century. Funding remains a chronic problem, especially in the age of the shrinking government purse. NASA, like other agencies, has to fight for its place at the budget trough.

Public perception has also changed over the years. A new generation, one that has grown up taking space flight for granted, doesn't understand why the seemingly routine should be so costly. What they fail to realize, perhaps, is that none of this is routine, and never will be.

Maybe this glib miscalculation is also what spurs on that new breed of space explorer, the private entrepreneur. The idea that a few wealthy space enthusiasts could somehow supplant NASA and come anywhere near matching its achievements -- ever -- is laughable, or would be if it weren't given so much credence in certain corners of the popular consciousness.

Not to belittle the accomplishment, of course, but getting a pilot to the edge of space in an experimental aircraft is so ... 1956.

Laughable or not, however, NASA is watching this new generation of space entrepreneurs. That much is clear.

And as the first decade of the 21st century comes to a close, NASA can look back on a half century of real achievement. There have been failures and disappointments, but considering the size of the omelet it was inevitable that a few eggs would get broken along the way. Nobody understood that better than the 17 astronauts who lost their lives in service.

By any measuring stick, the American space program, kick-started by a tiny Russian satellite in 1957, stands as both a towering scientific success and a triumph of the human spirit. We are privileged to be along for the ride.

"Form follows function." Nowhere is that dictum more inflexible than in the hostile reaches of outer space. So nothing hews to that dictum more closely than the space suit. Even as it has evolved over NASA's 50 years to adapt to increasingly sophisticated missions and changing spacecraft technology, the space suit's central purpose -- to maintain a human environment where none exists -- remains constant.

From the Mercury suit worn by John Glenn during his historic three-orbit flight in 1962 to today's shuttle and space station rigs, the basic requirements for the space suit have not changed, but the designs have. Here's a look back at the last piece of technology standing between NASA's astronauts and oblivion.

An astronaut is fitted into his space suit. Because suits are recycled among astronauts, they need to be constantly resized to maintain adequate pressure. This is accomplished using a sizing device developed for NASA by Hubert C. Vykukal.

Enos the chimp, restrained by wrist tethers and still wearing his space suit, after returning from orbit aboard Mercury Atlas 5 in November 1961. He beat John Glenn into space by two months.

John Glenn in his Project Mercury pressure suit, which he wore when he became the first American to orbit the Earth. Glenn is also the only astronaut to go into space wearing both Mercury and space shuttle suits.

Neil Armstrong, pictured here, would be the first human being to set foot on the moon. But not in this suit. Here, he models a Project Gemini G-2C training suit, designed to be flexible when pressurized.

On June 3, 1965, astronaut Ed White became the first American to walk in space. He's wearing a modified Gemini space suit and is tethered by a lifeline to his Gemini IV capsule.

Engineer Bill Peterson fits test pilot Bob Smyth into an Apollo space suit with a lunar excursion module restraint harness during testing in 1968. Project Apollo put astronauts on the moon, so the suit had to be designed for both lunar conditions and maximum flexibility.

America's first man into space, Alan Shepard, walked on the moon a decade later as commander of Apollo 14. This was the suit he wore, minus helmet and gloves, when he played his famous round of lunar golf.

The iconic shot: Astronaut Buzz Aldrin is photographed by Apollo 11 commander Neil Armstrong in the Sea of Tranquility. Armstrong is just visible in Aldrin's face shield.

When the first shuttle flight, STS-1, lifted off on April 12, 1981, astronauts John Young and Robert Crippen wore the ejection escape suit shown here. It's a modified version of the Air Force's high-altitude pressure suit.

This is the familiar orange launch and entry suit worn by current shuttle crews, nicknamed, appropriately enough, the "pumpkin suit." This is an all-purpose suit designed to cover most contingencies: It includes a helmet with built-in communications gear, a parachute pack and harness, a life raft and life-preserver unit, an oxygen manifold and valves, and survival gear.

In February 1984, shuttle astronaut Bruce McCandless became the first astronaut to float in space completely untethered to his spacecraft. A jetpack known as the manned maneuvering unit kept McCandless within hailing distance. NASA has since ditched the MMU and are once again secured to the spacecraft, although they do wear a similar device in case of an emergency.

An artist's conception of the future launch and entry suit, left, and a spacewalk suit. Although NASA plans to retire the shuttle in 2010, there are plans to replace it with another vehicle, Orion, by mid-decade, and to return to the moon by 2020.

Adrian Emry, 7, of Moses Lake, Washington, gives a thumbs-up to NASA engineer Bill Welch, who wears a lunar spacesuit concept for use in Project Constellation, the planned U.S. return to the moon.