ARTICLES MODERN

By WARREN E. LEARY

WASHINGTON — Pending resolution of a potential radiator hose problem, the space shuttle Atlantis is scheduled for launching on Feb. 7 on a twice-delayed mission to the International Space Station, NASA managers said Wednesday.

N. Wayne Hale Jr., director of the space shuttle program, said in a televised news conference that no other technical matters stood and in the way of the 11-day mission that will install the European Space Agency’s Columbus science laboratory at the station. A problem with a backup fuel sensor system that delayed the flight twice in December has been resolved, he said.

After a daylong review of technical questions that could affect the mission, managers decided that the Atlantis and its seven-member crew could take off from the Kennedy Space Center in Florida on Feb. 7 at 2:45 p.m. if the hose problem is settled by this weekend.

The tentative decision to proceed was made on the day two astronauts from the station carried out a tricky six-and-a-half-hour spacewalk to replace a broken motor that hampered the movement of a solar power array.

Peggy A. Whitson, the station commander, and Daniel M. Tani, the flight engineer, each made the sixth spacewalk of their careers by swapping a 250-pound barrel-size motor with a spare that allowed the winglike arrays to begin turning again to receive optimum sunlight.

The operation, carried out when the station was in the Earth’s shadow to reduce the risks of the astronauts’ being shocked by electricity generated by the panels, corrected electrical failures that arose in December in the motor. After the motor swap, ground controllers put the array through two 360-degree test spins and declared it fully operational.

Before ending the spacewalk, the astronauts ventured down the truss holding the arrays to examine another power problem, a large malfunctioning rotary joint that turns all the solar panels on one side of the station. Engineers are looking at ways to repair the joint, which was found in November to be clogged with metal shavings from its inner works.

Mr. Hale said he believed that the radiator hose problem would be resolved to clear the shuttle for launching next week. An inspection this week found that one of four hoses was bent instead of straight when retracted into a storage box, Mr. Hale said.

If the hose in question is functional and not leaking, it should be possible to declare it acceptable for at least one flight as is or, perhaps, if it is manually straightened before launching, he said.

astronauts, NASA, Science, Shuttle Mission Plans, solar power, space shuttle Atlantis