Space Program to Be Affected Until the 1990s

The loss of the space shuttle Challenger will make it “extremely difficult” for the United States to carry out even its least ambitious plans for scientific, military and commercial uses of space for years to come, according to National Aeronautics and Space Administration documents and shuttle experts.

And, if pending investigations establish that Tuesday’s tragic explosion stemmed from a major flaw in the shuttle system, American space activity could be virtually shut down through the end of this decade.

Reliance on Shuttle

Those assessments, standing in stark contrast with the shuttle’s popular image as a dramatic but under-used space trolley, stem from the fact that U.S. policy makers made an all-our-eggs-in-one-basket decision a decade ago to rely almost entirely on the shuttle for lifting into space everything from scientific probes of the solar system and commercial communications satellites to the spy satellites that are vital to national security.

“We are pretty much dependent on the space shuttle for access to space over the next few years,” Robert Cooper, a former assistant defense secretary and former head of the Goddard Space Flight Center, said Wednesday. “There is no alternative. It would certainly take several years to provide the country with an alternative.”

In earlier days, much of this equipment could be carried into orbit by smaller unmanned rockets. But, today, experts agree, virtually all such space equipment has become so large and heavy--and development of newer rockets has lagged so much--that the shuttle is the only vehicle powerful enough to lift the devices.

And, even if the problem that destroyed Challenger proves to be relatively simple to fix, its loss leaves the United States with only three shuttles--too few to handle the civilian and military payloads already scheduled. Moreover, under NASA’s most optimistic scenario, a replacement for the destroyed orbiter could not be built until the early 1990s.

Titans Being Updated

Although work was already under way to update Titan missiles for satellite launchings, they are not expected to be put in service before the late 1980s. Experts said it is highly unlikely that the new Titans could be conveniently adapted to manned space flights or many other projects for which the shuttle is believed to be vital.

“The feeling, though we never were really able to quantify it down to mathematical certainty, was that the shuttle probably had a 1-in-1,000 reliability,” one former Pentagon expert said.

Cooper and others agreed that the odds of finding construction or design problems are very low, given the shuttle’s record of 24 successful launchings before Tuesday’s mid-air explosion. But, even a quick return to regular missions would leave the nation with only 75% of its normal space fleet at a time when the shuttles’ cargo bays have become crammed to overflowing with satellites, military payloads and scientific experiments.

Some federal and private experts said that Congress, in a wave of sympathy for the space program, may well approve the construction of a replacement for Challenger. But that project would take years, cost billions and sap much of NASA’s space exploration budget.

Replacement Costs

According to a master plan for shuttle operations through 1995, prepared last July by NASA and the Defense Department, a replacement for the lost Challenger orbiter and its rockets would cost up to $2.2 billion and take as long as six years to complete.

The plan said that a new shuttle could be finished in 1993 if Congress authorized construction by this October and that construction time could be shaved by 18 to 24 months if the orbiter were built largely from spare parts.

During the construction period, the remaining three orbiters would be able to make a maximum of 18 flights a year, compared to the 24 projected under pre-disaster schedules.

“Should a major structural element of an orbiter be damaged, placing the orbiter out of service for even the minimum estimated time, it would be extremely difficult to support even the base line master plan” for shuttle operations, the document stated.

Because the shuttle is the country’s only practical vehicle for lofting payloads into space, the impact of even a brief delay or lessening in spaceship flights could be dramatic.

Could Use Delta Rockets

The United States could use some aging Delta rockets for small payloads, but most modern commercial and military satellites are too heavy for those vehicles. Some payloads, such as deep-space probes, can be launched only from the shuttle.

The Air Force, long unhappy with the shuttle program’s dual military-civilian role, is readying an improved model of the workhorse Titan missile for launching military satellites. But only limited numbers of the missiles will be available, none until the late 1980s.

“It’s certainly true that the military has launches to make that are very important and which are committed to the shuttle now,” said Lou Allen, director of the Jet Propulsion Laboratory in Pasadena. Commercial satellite sponsors “are in the same boat,” he said.

In the long run, the shuttle is regarded as essential to American space ambitions in the mid-1990s and beyond. Parts for a proposed multibillion-dollar space station, now scheduled for construction in the mid-1990s, could be ferried up by Titan rockets, but they could not be assembled without shuttle-borne construction workers.

The space station, in turn, is vital to the only major manned space project now envisioned by planners--a 21st-Century trip to Mars.

Fresh Look Urged

Rep. George E. Brown Jr. (D-Colton), a veteran legislator on the House committee that oversees NASA, called Wednesday for a fresh look at the nation’s space goals in the aftermath of the Challenger disaster. Although he said he believes a replacement for Challenger is necessary, he added that Congress should not act in haste.

“I think it’s proper to subject this whole thing to intense scrutiny at this point,” he said. “This may be a decision point for the whole future of space, and we don’t want to do something that will come back and haunt us.”