Shuttle Returns to Florida After Satellite Mission : Space: Columbia touches down to criticism that an unmanned rocket could have done same task. NASA director defends flight.

After flying 4 million miles as unnoticed as a stealth bomber, the space shuttle Columbia glided to a bull’s-eye landing at Florida’s Kennedy Space Center Sunday, concluding its 13th orbital mission.

The flagship of the National Aeronautics and Space Administration’s shuttle fleet touched down at 6:05 a.m. PST, after a steep descent across the Gulf of Mexico and a thunderous crossing of the Florida peninsula.

Kennedy Space Center Director Robert Crippen praised the six-member crew for a “super job” in carrying out what he described as a “chock full” schedule throughout their 10 days in space. He brushed aside observations that the most conspicuous accomplishment of the flight--the launch of a 900-pound satellite--could have been carried out equally well by an expendable rocket.

Acknowledging that planners “took some hits from people who consider themselves experts on manifesting,” Crippen maintained that assignments in addition to the satellite release had kept the astronauts “working hard all the time.”

After the 1986 Challenger disaster, NASA moved to limit the manned shuttle to roles that cannot be carried out by expendable rockets.

But the LAGEOS II satellite launch on the flight’s second day had been planned before the Challenger accident, and so the mission, undertaken in collaboration with the Italian space agency, remained assigned to the shuttle.

Reporters and technicians who witnessed Sunday’s landing got no glimpse of the astronauts after they touched down.

Shortly after the orbiter rolled to a stop on the space center’s concrete runway, all six moved directly into a van at the shuttle’s hatch. The van took them to crew quarters several miles from the runway.

Crippen said that the astronauts elected to remain inside so that technicians could continue to collect data for medical and physiological studies that were part of the mission.

All were reported fit.

Some two hours after the landing, the spacecraft was towed back to the center’s Orbiter Processing Facility to begin preparations for its next flight in 1993.

Launch operations director Robert Sieck said that the spacecraft had returned without any technical problems of concern. An early inspection found only one of the tiles on its protective skin damaged sufficiently to require replacement.

Sunday’s landing marked completion of the seventh successful U.S. spaceflight in 1992. The year’s last, a military mission to be carried out by the shuttle Discovery, is scheduled for launch Dec. 2. After releasing the LAGEOS II geodesic satellite on Oct. 23, crew members spent much of their time on medical and physiological experiments and working in a Canadian laboratory filled with 10 experiments.

The 11 payloads in Columbia’s cargo bay also included a new materials processing laboratory, which was operated remotely by scientists and technicians in a control center at NASA’s Marshall Space Flight Center in Huntsville, Ala. After release from the shuttle, the LAGEOS satellite was boosted from an altitude of about 185 miles to 3,665 miles by a small Italian-built rocket motor.

Covered with some 426 prisms, it is to be used by tracking stations around the world to reflect laser beams and enable scientists to measure the minute movement of the Earth’s crust, which is responsible for earthquakes.

As is now the case with most shuttle flights, much of the astronauts’ work addressed problems relevant to the construction and operation of the planned Space Station Freedom.

The mission was commanded by Navy Cmdr. James D. Weatherbee. Other crew members were shuttle pilot Michael A. Baker and mission specialists Charles L. Veach, William M. Shepard, Tamara E. Jernigan and Steven MacLean. MacLean is a Canadian making his first spaceflight.