16 Shuttle Trips to Put Space Station in Orbit : $10.9-Billion Project Has Less Scientific Use but Gives U.S. Chance to Match Soviets, NASA Says

The United States’ slimmed-down space station approved by President Reagan will be hauled into orbit and assembled in 16 trips by the space shuttle fleet, National Aeronautics and Space Administration officials said Monday.

Preparing to go to Congress to get approval to start contractor selection, NASA officials defended the new design as one giving the United States a chance to match or perhaps surpass the space station technology of the Soviet Union in the next decade, though budget pressures have led the Reagan Administration to make a substantially more modest start.

The compromise design reduces opportunities for scientific experiments aboard the station by eliminating two large booms where extraordinarily sensitive instruments for astronomical and earth observation instruments would have been mounted.

Science Modules Planned

Nevertheless, the linear-shaped $10.9-billion orbiting platform now planned still will carry the science modules to be developed by Japanese and European space organizations, as well as Canadian equipment.

NASA Associate Administrator Andrew Stofan and Thomas Mosher, space station project manager, told reporters at a press conference that, in addition to providing significant scientific and technological return in the near term, the basic station has the potential for expansion into the next century.

They conceded that “enhancement” of the station--the later addition of features originally planned for the basic design--will in the long run cost more than it would have if they had been included in a more elaborate station from the outset.

The space station program was put on hold at the end of last year when a detailed design review concluded that the station, once estimated to cost $8 billion, would in fact cost more than $13 billion.

Reagan Approves

President Reagan gave his approval to the new, less expensive design Friday, clearing the way for NASA to proceed with a detailed plan. The compromise design was worked out among the space agency, the White House Office of Science and Technology Policy, the National Security Council and the Office of Management and Budget.

If Congress accepts the new Administration proposal, Stofan said Monday, NASA hopes to review designs from selected contractors and award contracts for the station before the end of the year.

Current plans call for a launch of the first components in 1994 and for a permanently manned station in 1996, a year later than once anticipated.

Aside from losing the opportunity to mount instruments on two booms, the new design has raised questions from experimenters because it no longer includes advanced solar generators to provide generous supplies of electricity.

Power Held Sufficient

As it is, the station will have about 38 kilowatts less electricity available. But Mosher said the station’s planned 50 kilowatts will be sufficient. About 30 kilowatts will be required for operating the housekeeping, leaving 20 kilowatts to power scientific experiments.

The Challenger accident and the upheaval it caused in the military and civilian space programs prompted the Administration to consider developing a huge, heavy-lift launch vehicle that would be able to put as much as 75 tons into orbit.

Officials had said such a booster could put the space station into orbit with two or three flights. It would also permit more assembly of station components on the ground, reducing the assembly work required of astronauts in space.

But Stofan said Monday that more recent studies had persuaded NASA not to make space station plans contingent on development of a heavy-lift booster.

In its 1987 supplemental appropriations request for its Strategic Defense Initiative, the Administration asked Congress for $250 million for the Air Force to begin development of a large new launch vehicle. The request set off a debate in Congress over whether the assignment properly belonged to the military or to NASA.