Credit: Courtesy of NASA
After only a few more flights into low Earth orbit, the venerable shuttle program of the National Aeronautics and Space Administration will be brought to an end in May 2010, and the ungainly vehicles that have represented many successes and two dramatic failures will be grounded permanently. Then, after five years, if all goes according to schedule, a new design for manned flight will make its debut.
Known as the Ares vehicles, these rockets will be capable of traveling far beyond Earth orbit. The first test flight of the Ares I-X is scheduled for launch in April 2009, and NASA has announced that astronauts will take Ares I on missions to the International Space Station no later than 2015. Ares I and Ares V Moon missions are scheduled to start no later than 2020.
But the future is not assured for the Ares program. One of the more terrestrial problems is money. NASA's budget for the fiscal year 2009 is $17.6 billion, but according to Tennessee Democratic congressman Bart Gordon, chair of the House Committee on Science and Technology, NASA's budget is not enough for what it's asked to do.
A bigger question has arisen in recent years about whether men and women in space are more an expensive, risky luxury than a necessity. Former Republican congressman Nick Smith, at one time chairman of the Research Subcommittee of the House Science Committee, wrote, "These [manned] projects have provided relatively little scientific discovery compared to the cost benefit of unmanned missions."
Not so, says Chris Culbert, chief of robotics systems at NASA's Johnson Space Center, in Houston, Texas, who argues that robonauts should supplement, not replace, the work of humans, whose depth and breadth of performance is beyond current robotics capability.
As the bots-versus-bods debate rages, forty-five space-exploration experts met at Stanford University in February 2008 for a two-day conference called Examining the Vision: Balancing Science and Exploration. The conference participants concluded that NASA's program for human exploration must lead to Mars and beyond, and that future administrations must fund NASA adequately to sustain its science programs and encourage international collaboration. And, yes, robots will play a role in those journeys.
Houston, We Have a Birthday
As NASA turns fifty, its golden anniversary offers a chance for both reflection on what has been accomplished and planning for what constitutes future success. The first half-century of space exploration has taken us from Earth to the Moon, and has put shuttle crews into orbit so often that launches rarely make the news.
Though some of astronomy's most astonishing discoveries have been made by unmanned vehicles like the Hubble telescope and hardy robot travelers such as Voyager and the Mars Exploration Rover, supporters of manned exploration say the lessons learned by prolonged human habitation aboard the Russian Mir space station and the International Space Station form crucial research for establishing a base on the Moon or making a manned trip to Mars. This information matters because NASA is developing powerful new rockets, to be used on the Ares I and Ares V, that can take crews at least as far as the Red Planet.
A parallel program of robotic missions, such as Messenger, which sent back to NASA close-up photographs of Mercury in January 2008, will pave the way for humans by making scouting trips ahead of manned missions. (For flights to places too distant for human exploration, robot-operated crafts are the only option.)
"The development of the Orion/Ares I/Ares V transportation system is being done in a way that provides a substantial capability for subsequent Mars expeditions," NASA administrator Michael Griffin said last year. Griffin estimates that the first landing on Mars could be around 2020, though predictions that far out have to be considered highly speculative.
The hope for a long-range future in space is fueled as much by optimism as by rocket fuel. At a recent symposium on the agency's next fifty years, John M. Horack, manager of science and mission systems at NASA's Marshall Space Flight Center, emphasized how inseparable space transportation systems are from the science they enable. "Spacecraft have always made possible our ability to learn about the universe," Horack said, "and NASA must continue to extract the full measure of value from the spacecraft they develop by creating the most positive knowledge outcomes."
Horack recalled that the launch of the first U.S. satellite -- Explorer I on January 31, 1958, months after Russia's Sputnik -- resulted in the significant discovery of the Van Allen radiation belts around Earth.
Mars, or Bust?
Given the technologies foreseeable in the next twenty-five to fifty years, the vast distances just within the solar system, and the limits of human physiology, Mars will likely be the ultimate goal for manned flight. With President Bush's urging, the Moon, says Barbara Cohen, the Marshall Space Flight Center's lead lunar scientist, will also be explored "for its own merits."
Exploration has always been a large part of the romance of human history, so though robots will be counted among the Marco Polos, Amerigo Vespuccis, James Cooks, and Ferdinand Magellans of the coming age of space, men and women will still be making daring voyages of discovery. According to Larry Capps, CEO of the U.S. Space and Rocket Center, in Huntsville, Alabama, it's important to provide space camps and other opportunities for teachers and students, because someone sitting in a school science class today may be the first to put human footprints on the red dust of Mars. We can only hope.