By Howard McCurdy
Sunday, July 19, 2009
Our old heroes from space lore were men and women, real or fictional and (mostly) human -- Neil Armstrong, Buzz Aldrin, Christa McAuliffe, James T. Kirk, Spock. But a new age is upon us, and a new lineup of heroes awaits our adulation. There's Hubble, the space telescope. Sojourner, the Mars rover. And Huygens, the atmospheric probe. Call it the rise of the machines.
I offer that statement as an observation, not a preference. I am as much of a space cadet as anyone else. I helped form a rocket club in high school, watched the original "Star Trek" series, saw "2001: A Space Odyssey" a half-dozen times and pored over Carl Sagan's books. I get depressed when forced to confront the possibility that humans might be stuck on this single planet until the last of us dies. But none of that changes reality.
When it comes to space, we've outsourced the jobs to machines. In his famous 1945 article anticipating communications satellites, Arthur C. Clarke opined that humans would need to operate the orbital switching stations. Wernher von Braun, who proposed a large space telescope, was sure that astronauts would be stationed nearby. For nearly every outpost in space, from spaceships and space stations to lunar colonies and Martian research bases, we thought humans would be there. We were wrong.
We did not anticipate the incredible advances in machine technology that the second half of the 20th century would bring. Technologies such as remote sensing, digital imaging, solid-state electronics, electric power generation, space communication and computer capacity reduced the costs and improved the capabilities of robotic spacecraft dramatically. We don't need technicians to change the film in space telescopes -- the telescopes don't use film -- and we don't need astronauts to maintain communications satellites. Meanwhile, human spaceflight efforts have stalled.
Advocates of manned spaceflight promised that they could build a fleet of reusable shuttles that would cut the cost of putting people into orbit by a factor of 10. They bet that they could build a low-cost, permanently occupied space station that would serve as a staging point for expeditions beyond. They tinkered with propulsion systems, claiming that a nuclear-powered rocket could get someone to Mars in three months instead of seven and slash the round trip from 2 1/2 years to as little as nine months. They planned to develop electric power generating systems that would not require huge solar arrays. Any of these achievements would have advanced the cause of human spaceflight considerably. But they never happened.
Instead, for most activities in space, from military reconnaissance to commercial applications, we now rely on machines. The Space Foundation reports that humans worldwide spent $257 billion on space and related activities in 2008. Less than 8 percent was devoted to human flight.
For really complex tasks, humans are still more capable. Before the recent shuttle mission to the Hubble Space Telescope, NASA officials considered using a machine to make the repairs. The leading candidate was Dextre, a robot currently working on the international space station. In a head-to-head analysis of abilities, a special committee of the National Research Council concluded that "the planned NASA robotic mission is less capable." But if recent trends persist, Dextre or a descendant might take some future astronaut's job.
At the beginning of our space program, we wanted humans to explore the inner solar system in part because the visionaries of spaceflight thought that people could settle there someday. We believed we were on our way to establishing settlements on Mars (and even Venus). Writers primed the public with reports that the first explorers would find life forms on the Martian surface. Life magazine informed its readers in 1944 that "the vast regions on Mars that change from green to brown in seasonal cycles are covered by vegetation."
Exploration has revealed Mars to be much less hospitable than imagined, and Venus even worse. This is the great revelation of the first phase of space travel -- scientists call it the "rare Earth" hypothesis -- and robots, such as Sojourner, discovered it. And if the Mars of our imaginations exists somewhere, chances are that a machine will find it.
Closer to home, machines will continue to be the heavy lifters. They already monitor the Earth's ozone hole and take the temperature of the seas. They have landed on asteroids and returned samples from comets. Huygens settled down on the Saturn moon Titan, and the Galileo probe descended through the Jovian atmosphere. Hubble helped us refine estimates of the age of the universe and understand more about the dark energy that causes the universe to expand at an ever-increasing rate. Robots are roaming Mars while our plans to personally visit the Red Planet are a long way off.
Advocates of human space travel want people to participate in this work, not from a distance, but by traveling in rockets. For now at least, the space race belongs to the machines.
Howard McCurdy is a professor of public affairs at American University and the author of "Space and the American Imagination."