The four astronauts on next month's fifth space shuttle flight, its first operational venture, plan to land the 100-ton Columbia one minute before sunrise with their hands off the controls to demonstrate the spaceliner's versatility.
"These are big steps in this program," flight director Tommy Holloway said yesterday at a news conference at Houston's Johnson Space Center. "We're still asking ourselves whether to make the autopilot landing on this flight, but as of today that's our objective . . . ."
On landings after the first four test flights, astronauts took over the controls from onboard computers at altitudes of between 2,500 and 5,200 feet because they wanted to demonstrate pilot landings while checking out the automatic landing system.
That system uses a complex method of bouncing microwave signals from the shuttle to antennas on the landing strip and back to the shuttle.
None of the first four flights demanded a landing so near darkness. The crew of the next flight, scheduled Nov. 11, is to land Columbia on the lake-bed runway at California's Edwards Air Force Base one minute before sunrise to show that it can be done.
The crew of the eighth shuttle flight next year is to take off from Florida's Kennedy Space Center at night and land at night on Kennedy's concrete runway, again to show that it can be done.
Not only does NASA want to demonstrate the shuttle's ability to take off and land in the dark under hurried or emergency conditions, the Air Force also wants a demonstration of night takeoffs and landings in case it needs the shuttle under such conditions.
For example, if war were to break out suddenly, as in the Falkland Islands this year, the Air Force might want to orbit a new spy satellite from the shuttle and position it to observe the fighting.
Next month's flight will carry the largest number of crewmen who have flown on the same mission.
Two of the astronauts are to don spacesuits and make the first walk in space by a shuttle astronaut.
Civilian astronauts Joe Allen and Bill Lenoir plan to open the cargo-bay hatch behind the crew cabin and move along the starboard and port sides of the 50-foot-long bay to see how space walking is best done outside Columbia, which is the size of a DC9 airplane.
The two will be hooked to wires by 50-foot-long tethers that are supposed to pull them back if they drift into space.
The other crew members are civilian commander Vance Brand and Marine Col. William Overmeyer, the copilot.
"It's a little bit like walking a dog on a leash," flight planner Terry Neal said yesterday.
"Our major objectives on the space walk will be to check out their suits, their tethers, the slide wires, their handholds, their radios and their lights, which will be on their helmets like coal miners wear."
This first operational flight is to involve the orbiting of two communications satellites for Satellite Business Systems of McLean and Telesat of Canada.
The satellites' owners paid $30 million apiece for the satellites and are paying the space agency $10 million apiece for the launch. Each satellite is insured for $65 million against loss on the flight.
This will be the first time astronauts have ferried commercial satellites into space.
At Cape Canaveral late yesterday, workers began pumping 27,000 gallons of volatile fuel aboard Columbia, and took special precautions to avoid a repeat of the fuel spill that delayed the shuttle's second launch.
Protective bibs and buckets were installed to prevent the toxic propellants from spewing down the shuttle's sides.