Shuttle Problem Nearly Forces Emergency Landing

KENNEDY SPACE CENTER, Fla. â€”  The space shuttle Atlantis almost had to make an emergency landing Saturday when its huge cargo bay doors would not open in orbit and allow heat to radiate from the shuttle.

Flight director Jeff Bantle said 10 more minutes and he would have ordered Atlantis and its five-person crew to return to Earth--fast. However, the two doors finally swung open and the shuttle was able to remain safely in orbit for another day.

NASA had tried to bring Atlantis down twice on Saturday, but both landings were postponed because of cloudy skies over Kennedy Space Center.

The mission, during which astronaut Shannon Lucid was left on the Russian space station Mir for a five-month stay, already had been troubled by a leaky steering system that forced NASA to cut short the flight by a day.

The crisis with the cargo doors began shortly after NASA passed on the landing attempts at the shuttle landing strip in Florida.

Within minutes, the astronauts began reversing their landing procedures, which required reopening the 60-foot cargo bay doors.

The doors must be open while the shuttle is in orbit to allow radiators in the cargo bay to dispel heat collected from shuttle electronics. They are closed several hours before landing.

Had the cargo bay doors remained shut, Bantle said, Atlantis could have stayed in orbit for only another four hours before the heat would have begun damaging the shuttle’s electrical systems.

The process of opening the doors was halted when two switches indicated that four of the 16 center-line door latches had not opened. Mission Control told the astronauts to look out their windows to see if they could tell whether the latches were indeed closed.

As astronaut Linda Godwin rushed to a mini-laboratory in the cargo bay for a better view, commander Kevin Chilton and pilot Richard Searfoss began turning off as much equipment as possible in the crew cabin to reduce the amount of heat being generated.

When three of the astronauts made a visual check and agreed that all the latches were open, the crew was ordered to override the automatic system and proceed with the opening. About 30 minutes after the trouble began, both doors swung open.

Flight controllers eventually traced the problem to two frozen, malfunctioning microswitches. Such a dual failure had never happened before.

When the doors swung open, Atlantis’ astronauts were just 25 minutes from having to begin making an emergency landing at Edwards Air Force Base in California.

This morning’s scheduled landing could be either at Kennedy or Edwards, depending on the weather. The first attempt was scheduled for 4 a.m. PST.