Debate Intensifies Over Risks of Manned Space Exploration

It has been an extraordinary week of triumph and tragedy for the nation’s space program with the spectacular success of an unmanned mission to Uranus coming at the same time as the loss of seven lives aboard the Challenger.

Voyager 2, a small robot, still working nearly perfectly four years beyond its life expectancy, sent back dramatic photographs and a warehouse full of scientific data about a planetary system 1.8 billion miles away. The contrasts between its triumph and the tragedy of Challenger has stimulated a longstanding debate that centers on one question: Why risk human lives in space exploration when so much can be done with unmanned probes?

Critics of manned space flight have long argued that the cost in dollars as well as lives will prove too great, but experts in the field doubt that Tuesday’s disaster will shift the nation’s space program away from manned ventures.

“I think it’s going to continue to be a mix of both,” said Stanford University economist Roger Noll, a staunch critic of the shuttle program.

Noll, like many others, believes the space program has become so identified with heroic astronauts doing the seemingly impossible in space that it is not likely to turn back.

‘Dramatic Soap Opera’

“It’s a tremendously dramatic soap opera,” Noll said. “The tragedy actually brings back the excitement and the sense of risk.”

Walter A. McDougall, a University of California, Berkeley, historian who is a highly regarded expert on space, said the crash may lead to a reduction in the number of shuttle flights, “but we’re not going to do away with manned flight.”

He said it is likely that “the use of people on a lot of these flights is going to come under a lot of criticism that is going to be hard to answer.”

McDougall said it isn’t necessary to put people in space in order to launch satellites, and the disaster may well give new clout to private corporations that have been wanting to get into the launch business but could not compete with the National Aeronautics and Space Administration.

But that doesn’t mean that the human element is likely to diminish significantly in the coming years.

“That’s what makes the space program sexy,” McDougall said. “That’s not to say that the wonderful unmanned missions haven’t been exciting, but those pretty pictures are fun to look at and then you put them on the coffee table. But the manned program is a winner in terms of public acceptance.”

Space Telescope

Some have suggested that the acceptance by the public is just further proof that NASA is good at public relations, but some projects on the immediate horizon could not be done without manned space vehicles. Space Telescope, which has been described as one of the most important scientific instruments ever built, is supposed to be placed in orbit by the space shuttle this fall. With a manned space program, it will be possible to update and service the instrument many times during the 20 or so years that it is expected to be in service.

The loss of one orbiter means that NASA will have to pick from competing demands, and science missions may prove the most vulnerable. Several unmanned space probes are due to be launched from the shuttle in the near future, but they most likely will have to take a back seat to cargo with a higher priority.

“The Defense Department has the first claim on shuttle launches,” said Stanford’s Noll. “Their number of launches will stay constant. That means you have a decline in the number of launches for civilian purposes.

“And we’re either going to lose the satellite business to the Europeans or we’re going to use the shuttle to launch satellites. That doesn’t leave much for science,” Noll said.

More Variety Possible

It could be that one result of all this will be greater variety in the nation’s launch arsenal. The Air Force climbed aboard the shuttle bandwagon only when ordered to by Congress, and the continuing problems with the shuttle could lead to a new generation of expendable launch vehicles that carry payloads, but not crews, into space.

“They’re going to increase their pressure to return to at least standby use of expendable launch vehicles,” McDougall said.

Unmanned launch vehicles could also provide alternatives for launching commercial satellites. The European space program, which has suffered a number of failures with its unmanned rockets, has nonetheless attracted considerable business from U.S. corporations that could not book time aboard the shuttle.

That would not solve the problems confronting U.S. and European scientists who already have space probes waiting to be launched. Two probes that were to have been launched in May--one to study Jupiter and the other to study the polar regions of the sun--were built specifically to be launched from the shuttle and they cannot be launched with conventional rockets.

UNMANNED SPACECRAFT ACHIEVEMENTS

Saturn’s rings as seen in 1981 by Voyager 2 spacecraft. Satellites and terrestrial probes have measured and poked into near and deep space for 25 years, sending back loads of scientific information on biology, geology, communications, radiation and inter-planetary magnetic fields, among other things. Among the achievements of unmanned space flights:

Moon exploration. After a fly-by by the U.S.S.R.’s Luna 1 satellite in 1958, the U.S. launched the Pioneer and Ranger series spacecrafts. After several failures, the Soviets landed Luna 9 on the moon’s surface in 1966, providing the first televised pictures of the moon’s surface. That experiment, and the U.S. Surveyor 1 that followed, demonstrated that soft landings were possible. U.S. and Soviet satellites in the Orbiter and Luna series orbited the moon, giving a detailed look at the surface, paving the way for man’s walk on the moon in 1969. The later flights allowed scientists to remotely examine geological samples.

Planetary flights. In 1961, the Soviets aimed a Venera craft at Venus, coming within 62,000 miles. The first U.S. attempt at Venus failed, but Mariner craft swept by Venus (within 22,000 miles) in 1962 and by Mars (within 6,100 miles) in 1964 and made extensive reconnaissances of Mars in 1969 and 1971. The Soviets landed a Venera probe on Venus in 1970 and received the first radioed reports from another planet’s surface. The U.S. Mariner and Viking series probes collected information from Mars that changed the popular view of that planet. U.S. Pioneer craft measured the atmosphere of Jupiter in 1973; a later craft carried a message in symbols to tell any other living beings about humans. Mariner 10 traveled to within 500 miles of Mercury in 1974, and what we know about Saturn and Uranus results largely from the U.S. Voyager spacecraft.