For achievements in civil space exploration, the 1950s certainly stand out. The Soviet Union and United States launched their first Earth-orbiting satellites. The U.S. Congress created NASA, whose leaders selected the first Mercury astronauts. NASA sent the first robotic spacecraft to the vicinity of the Moon and produced the first Mercury space capsules, testing a few models in space in anticipation of human flights to follow. High school students (including myself) formed rocket clubs and launched modest contributions to the national space effort, often unauthorized by school authorities.

Books and magazines offered fantastic images of the unfolding adventure. To a generation of Americans raised on fictional fantasies, the editors at Collier’s magazine announced that humans would “conquer space soon.” To emphasize the point, the editors released an issue whose cover showed a winged space shuttle ascending toward low Earth orbit. Inside, readers viewed a painting of a large wheel-shaped space station serviced by the winged shuttle and an accompanying article by Wernher von Braun, the leading spokesperson for the space exploration movement in the United States.

More magazine articles followed, and von Braun reappeared in a widely viewed trio of television programs on space travel prepared by the Walt Disney Co. When the Disneyland theme park opened in Anaheim, Calif., in 1955, it featured a Rocket to the Moon ride and a one-third scale model atomic rocket designed by von Braun and fellow science writer Willy Ley.

NASA executives adopted elements of the von Braun plan shortly thereafter and von Braun, along with his German rocket team, joined NASA in 1960. The most complete expression of what became known as the “von Braun paradigm” appeared in the 1969 report of the Space Task Group, commissioned by President Richard Nixon. Buoyed by the enthusiasm surrounding the first Moon landings, the report’s authors presented an ambitious plan for the nation’s civil space effort.

If the government maintained the level of commitment to extraterrestrial investigation established during the race to the Moon, the United States could achieve what scarcely two decades earlier had been presented as literary fantasy. Members of the Space Task Group envisioned a three-part Space Transportation System: a winged space shuttle providing easy access to low Earth orbit, a space tug for orbital operations, and a nuclear-powered transfer vehicle to take humans to the Moon and beyond.

Task Group members sketched plans for a large Earth orbiting space station constructed from Skylab-type canisters. In one configuration, designers arranged the canisters like a pinwheel around a central core, providing artificial gravity and room for 100 astronauts. With this infrastructure in place, the United States could establish a lunar base and launch an expedition to Mars – all by 1986.

Preliminary work supporting the report influenced Arthur Clarke as he prepared the screenplay for the classic science fiction movie “2001: A Space Odyssey.” The modern portion of that film opens with a space shuttle docking with a large, rotating space station. Thomas Paine, one of the members of the Space Task Group, repeated its prognostications in the 1986 report of the National Commission on Space, which he chaired. The cover, painted by space artist Robert McCall, showed the ultimate purpose of von Braun’s plan – humans working at a colonial outpost on Mars.

U.S. plans for civil space were not confined to human travel. Von Braun called for a large, automated space telescope – astronauts, he advised, would be stationed nearby to change the film. The Space Task Group proposed an ambitious set of robotic missions – space telescopes, a Grand Tour of the outer solar system, an asteroid belt survey, and spacecraft to Venus and Mars. NASA executives officially maintained the position that humans and robots would explore space together.

In many areas, 50 years of civil space activities have turned fantastic images into scientific reality. In other areas, achievements have lagged behind expectations. The most notable surprises have occurred in the continuing race between human and robotic means.

Taken as a whole, human flight achievements have not matched early hopes and plans. According to the official policies of the U.S. government, NASA should have flown its winged space shuttle between 24 and 50 times each year and replaced the vehicle with a more advanced model 10 years ago. At a cost of $8.8 billion (in 1984 dollars), NASA should have finished construction of a large, Earth-orbiting space station in 1994. Operated by at least six astronauts, the station should have possessed the capability to act as a transfer station for flights to the Moon and beyond. Had the Congress followed the challenge issued by the President George H. W. Bush in 1989, work on a lunar base would be well under way and the United States would be preparing for a 2019 expedition to Mars.

A number of factors contributed to the sluggish pace of human space travel after Project Apollo, most conspicuously its unyielding cost. Fifty years into the advance of aviation, production of the modern jetliner significantly reduced the cost of atmospheric flight. Advocates of extraterrestrial travel envisioned a similar outcome in space. If clever people could cut the cost of flying an airplane, could they not do so for spacecraft? Public officials sought to achieve this goal through the development of NASA’s space shuttle, approved in 1972 and established as a means of reducing the cost of spaceflight by a “factor of 10.”

The U.S. government invested heavily in the development of rockets and spacecraft during the 1950s and 1960s. During the subsequent decades, that investment dwindled. Under the guise of cost improvement, White House budget analysts told NASA engineers to accomplish the impossible – simultaneously cut the expense of space operations while reducing the initial investments in spacecraft design. The inevitable occurred. Paltry investments in launch technology produced spacecraft like the space shuttle that cost more to operate than planned and vehicles like the X-33 that did not fly.

rocket. The planners viewed the space shuttle as a limited-purpose crew transfer and logistics vehicle – a focused approach to shuttle design that might have worked. When government officials shut down the Saturn 5

assembly line – theoretically a cost-saving move – planners by necessity turned to the proposed space shuttle as the means to deliver station components to orbit. This shift in strategy compromised the shuttle design and ensured that the station would consist of a tinker-toy arrangement of small interconnected modules with practically no capacity for rotation or artificial gravity. The space station morphed into a national micro-gravity research laboratory, an orientation far removed from its original purpose.

After the spectacular achievements of the Mercury, Gemini and Apollo flight programs, technical and bureaucratic obstacles combined to frustrate advances in human space travel. Low-cost access to space, artificial gravity, electric power generation and on board flight operations all suffered from a surplus of expectations relative to achievements. As a result, human flight did not advance as rapidly as people standing at the commencement of the space age thought it would.

The reverse proved true for robotic spacecraft. Expectations regarding the progress of robotic flight at the mid-point of the 20th century were modest. Experts believed that space telescopes would capture images on conventional film, that communication satellites would need constant maintenance and repair, and that expeditionary spacecraft far from Earth
would not be able to communicate effectively with the home planet. Such expectations led most experts to conclude that astronauts would be needed practically everywhere that machines traveled.

Advances in robotic technology proved these expectations wrong. In the areas of remote sensing, computing capacity, autonomous operations, miniaturization, imaging, electric power usage and generation, data storage and transmission, and deep space communication, scientists and engineers improved the capabilities of robotic spacecraft well beyond expectations. With their advanced imaging systems, rovers on Mars can “see” just as well as human eyes – and from roughly the same position above the ground. Faint signals from spacecraft in the outer reaches of the solar system reach operators on Earth with remarkable clarity.

Engineers building robotic spacecraft broke transportation barriers in a clever way. Flight engineers typically measure the expensive of space travel in cost per payload pound. When the cost of launch vehicles failed to fall, engineers attacked the second half of the cost per pound equation. Employing miniaturization technologies, they reduced the size and mass of robotic spacecraft to the point that many could be launched on smaller, less expensive launch vehicles. Reductions in the size of the Spitzer Space Telescope, for example, allowed it to be launched on a Delta 7920-H, much less expensive than the burdens incurred in dispatching previous telescopes like the Compton Gamma Ray Observatory on

NASA’s space shuttle. Miniaturization permitted the reductions in launch costs that persistently evaded the efforts of human flight engineers.

In a modern counterpart to Aesop’s fable of the tortoise and the hare, the human space program raced away from the starting line, culminating in the flights to the Moon, then paused to nap. Represented by the tortoise, the slow but steady advance of robotic technologies created a closer contest than people betting on the race initially had imagined.

Many spaceflight advocates want to complete the von Braun paradigm. They want to establish a lunar base and send humans to Mars. In 2004, U.S. President George W. Bush reiterated the U.S. commitment to achieve those goals by authorizing the Vision for Space Exploration.

Perhaps humans will establish a lunar base and send astronauts to Mars. The technology seems within reach and the cost is no more than that of a modern war. Yet technology and culture are moving in a different direction, one that could result in a reformulation of the spacefaring dream.

The original vision of space exploration drew much of its force from an image of the solar system that we no longer believe to be true. Peering through an inadequate telescope at the beginning of the 20th century, Percival Lowell discovered what he thought to be canals on Mars and declared that planet to be “the abode of life.”

In popular literature, writers often portrayed Venus as a primeval place of carboniferous swamps. Arthur Clarke suggested that Lapetus, a moon of Saturn that possesses striking differences in coloration, might be a cosmic beacon whose surface had been altered millions of years ago by extraterrestrials seeking to leave a signal for any earthly creatures smart enough to look. According to the original vision, if life did not exist on places like Mars, then humans could create conditions favorable for its emergence through a process called terriforming.

Investigation of the solar system has revealed a local realm far less hospitable than originally imagined, substantially undercutting the likelihood that humans will move off the Earth to nearby planets in a high-technology version of the western wagon train. With knowledge gained from a few sparsely occupied research stations on the Moon and Mars, humans may come to accept the Earth as the only place in the local solar system where complex life can thrive.

This need not eliminate the spacefaring dream, but it will surely reorient it. Concurrent with revelations about the nature of the local solar system, astronomers have discovered more than 150 extra-solar planets. Inevitably, given advances in detection technology, an Earth-like object will be found, perhaps around a nearby star. Technologies exist for taking spectrographic studies (revealing, for example, the proportions of water vapor and free oxygen in a distant atmosphere) and eventually capturing images with as much detail as pictures of Earth taken from the vicinity of the Moon.

When this happens, public interest in galactic exploration could mushroom in the same manner as the enthusiasm that launched exploration of the local solar system 50 years ago. Yet the new challenge will require exploration methods of a very different kind. Barring the discovery of transportation techniques that evade the current limits imposed by space and time, humans (with their fragile biological frames) are not likely to do the exploring. Nor are robots of the conventional sort, whose activities still remain under the control of flight stations on Earth. The most promising prospects, given advances in artificial intelligence and biotechnology, seem to be robot explorers that are as smart as human beings or humans with exceptionally long life-spans – essentially new species in each case.

This sounds utterly fantastic. Yet remember that scarcely 60 years ago most humans considered space travel to be as fictional as atom-powered aircraft and trains. We have come a long way in 50 years. We can progress much further in the next 50, but judging from the experience of the first half-century, it may be in directions we do not expect to go.

Howard E. McCurdy is a professor in the School of Public Affairs at American University in Washington.

His most recent book Robots in Space, coauthored with Roger Launius, will be issued by Johns Hopkins University Press in December.