The explosion jolted the nation, sending shock waves through millions who had watched the disaster on television and horrifying millions of children who had gathered in front of their school's television sets to view the first teacher in space.
And it has brought back to the fore a debate that has surfaced periodically during the 1960s and the 1970s: What is the proper role of humans and machines in space?
Last week, a number of scientists stepped forward to say that the time had come for a re-evaluation, arguing that science had been shortchanged in favor of public relations by NASA's heavy emphasis on the space shuttle. Others maintained that by lacking clear goals for its space program, the United States was misspending billions and limiting the scientific return on its investment.
"Since the mid-1970s, NASA has made a decision to put all of its eggs in the shuttle basket," said Edward Ney, a professor of physics at the University of Minnesota. "That's been wrong. We should be asking ourselves what the 24 shuttle missions have contributed to science and then compare that to what has been accomplished by the unmanned missions such as Voyager 2."
Voyager 2, a small robot craft launched in 1977 and still working, four years beyond its life expectancy, sent back dramatic photos and much valuable scientific information during its pass by Uranus on Jan. 24. The Voyager program cost about $450 million compared with the roughly $14 billion spent on the shuttle endeavor.
The dramatic contrast between the success of the Voyager spacecraft 1.8 billion miles from home and the failure that beset the Challenger has helped heighten the man-versus-machine debate.
