Human space flight is technically remarkable and emotionally uplifting, but the fundamental reason for venturing into space is for science. The Columbia tragedy of February 2003 reopened the wounds initially inflicted by the Challenger explosion. Do the risks of sending humans into space justify the ends? Is it time to de-emphasize astronaut science, and to concentrate instead on unmanned missions into space?
|In the last 30 years, humans have strayed no farther than 300 miles above the Earths surface, the distance from Portland, Maine, to New York City.|
The June launching of three unmanned missions to Mars (the European Beagle 2 and NASAs $800-million twin rovers) has rekindled interest in unmanned space exploration.
Neil Armstrong took his giant leap for all mankind on July 20, 1969, with Apollo 11. The success of the Mercury and Gemini missions paved the way for the lunar landings, largely because they captured the worlds attention and opened the publics purse. Several of my graduate school faculty mentors actively trained lunar astronauts. I fondly recall one petrology professor who emphasized the differences not only between basalt and anorthosite, but also between spatter cones and arrowheads.
In December, 1972, geologist Harrison Jack Schmitt and Eugene Cernan, became the 11th and 12th the last two men to walk on the surface of an extraterrestrial world (Apollo 17). The decade of the Apollo Project remains unmatched in excitement and imagination. Those dreams and that commitment have since been set aside. Space exploration has been replaced by space flight. In the last 30 years, humans have strayed no farther than 300 miles above the Earths surface, the distance from Portland, Maine, to New York City!
Many describe the science generated by the shuttle program as modest, unexciting and (most importantly) incapable of igniting the publics imagination and support. In the Feb. 9 New York Times, reporter George Johnson rather cruelly suggested that the most significant science to come out of Columbias last mission may be a final theory on why it crashed. Harshly trivializing the experiments conducted during the final mission (soil dynamics under pressure; the effect of dust storms on global warming), he described Columbias last mission as a flop, before it became a disaster.
The costs of human space flight are enormous. The shuttle was projected to cost a mere $10 million per week with weekly roundtrips planned. The shuttle has actually flown an average of just five times per year, with each trip costing $500 million. NASAs budget for the whole shuttle and space station program annually is $5 billion. This exceeds the National Science Foundations annual budget which funds 20,000 research grants, resulting in tens of thousands of papers.
We should not abandon space exploration. However, a careful, critical reexamination of who and what we send into space is in order. How can we best unlock the secrets of the universe and expand human knowledge? As geologists, we wish to better understand the origin and evolution of the solar system, the terrestrial and jovian planets, and our atmosphere, hydrosphere and biosphere. This goal must drive the program, not the development of military technologies, practical technical spinoffs, such as Velcro, or even national prestige and morale.
How can the additional data best be acquired? NASA has a number of impressive missions slated for the next decade-and-a-half. Some target the terrestrial environment: CloudSat 2004 will examine clouds on a global basis; Aura 2004 will look at the ozone layer; and Aquarius 2006-2007 will look at ocean salinity and heat budget. Other missions are planned for beyond Earth, for example, the exploration of the martian surface in 2009 with the Smart Lander and Long-range Rover, and the Far Infrared Space Telescope in 2015, which will examine deep space.
Could we do more? Certainly. Should we? Without question. Unmanned, solar-powered probes capable of collecting soil samples from terrestrial planets and asteroids are one approach. Seismic exploration of planetary interiors requires instruments, but not seismologists, on extraterrestrial ground. Planetary orbiters could tell us much about jovian planetary atmospheres and climates. Space-based telescopes would reveal far more about our own and other galaxies than anything from the shuttle. (High-resolution cameras could certainly pick out that inevitable Starbucks stand on some distant planet as well as any astronaut!) Instruments weigh less than astronauts, do not breathe, require no feeding, produce no waste and need not be brought back.
Obviously, additional information on long-term human responses to weightlessness must be acquired if we decide to return humans to space. New approaches are probably in order. Some have suggested second-generation launching systems that consist of powerful conventional rockets capable of ferrying materials and crew to orbital stations from which smaller, less expensive vehicles could be launched. Another intriguing proposal from HighLift Systems in Seattle is the space elevator, which would slide up and down a 22,300-kilometer cable, one end attached to Earth and the other to an orbiting station located at a fixed point above the ground.
Other, arguably higher purposes might compel us to venture into space again. The Apollo missions tangibly demonstrated the fragility of our planet. Earths citizens were momentarily closer together. An unmanned lunar lander might have provided as much data, but its landing imprint pales next to those bootprints! Many believe it is these higher purposes that transform space exploration from a mere scientific endeavor to a mission. Pragmatic financial grounds may be the tiebreaker. A recent USA Today piece quoted a well-known phrase from Tom Wolfes The Right Stuff. Its more effective, when reversed from the original: No Buck Rogers, no bucks.