Engine Dies on Liftoff but Shuttle Is in Orbit : Emergency Landing Averted; Crew May Make Full 7-Day Flight Despite Craft’s Low Altitude

One of the space shuttle Challenger’s engines suddenly died after liftoff Monday but the spacecraft was able to achieve a low orbit, and space agency officials made a preliminary decision to keep the crew aloft for the planned stay of seven days. It was the first time in 19 shuttle missions that an engine had failed after liftoff.

Jesse M. Moore, director of the shuttle program, said at a press conference after the launching, “We are safely in orbit. The crew is doing fine. We are pretty optimistic about achieving essentially all the objectives of the mission.”

Orbit 70 Miles Low

Because of the lost engine, Moore said, the craft had achieved an orbit about 70 miles lower than planned and probably would remain there throughout the mission.

The engine was shut down by an on-board computer about three minutes before its scheduled burnout. The speed of the craft and the remaining two main engines carried the Challenger into orbit.

The engine that failed has no further purpose during the flight and would not have been used again in any case, according to officials at the National Aeronautics and Space Administration. The shuttle uses two smaller engines for maneuvers in orbit and during its return to earth.

Challenger, carrying $78 million in scientific instruments had rocketed into space at exactly 2 p.m. PDT, 97 minutes past its scheduled liftoff.

An earlier effort had aborted on the launching pad on July 12. In that incident, a computer sensed an engine valve failure and halted the launching three seconds before liftoff. Failure to lift off Monday would have forced NASA to cancel the flight for up to a year because of a crowded shuttle schedule.

Although officials later painted a picture of a mission only slightly handicapped, the first few moments after the engine shut-down were harried at Kennedy.

In the control center “there was a buzz,” said Thomas Utsman, shuttle director at Kennedy. “Everyone was feeling good about getting that beast out of town, and then it happened.”

Should the failure have occured slightly earlier in the flight, the shuttle would have been forced to make an emergency landing at one of several designated sites in Europe or the United States.

As it was, Utsman said, the control center took several minutes to assess the situation. “We were getting ready to send people to Edwards,” said Utsman, referring to the landing site at Edwards Air Force Base in California. Minutes later, he said, NASA realized that the shuttle had achieved an orbit high enough to stay aloft.

Moore later denied at the press conference that the agency ever considered bringing the winged spaceship back to earth immediately. The sequence of events was such, he said, that the flight’s duration was never in jeopardy.

Overheating Indicated

According to Moore, a computer controlling the shuttle’s main engines began to indicate overheating in the pump feeding hydrogen fuel to one of the craft’s engines about five minutes after liftoff. The computer then switched to an alternative channel to check the initial reading.

The second channel also registered overheating, and the engine was automatically shut down at 5 minutes, 45 seconds into the flight.

The shuttle’s main engines are arranged in a triangle pattern at the rear of the craft and burn liquid fuel. The shuttle’s two huge booster rockets, which provide most of the thrust for ascent, fired successfully.

To ensure that the spacecraft achieved a stable orbit, the remaining two engines were burned almost a minute longer than planned, and some of the shuttle’s reserve fuel was jettisoned.

The smaller orbit-maneuvering engines were later fired briefly to stabilize the orbit, which ranged from 115 to 241 miles above Earth.

May Be Instrument Failure

Late Monday, NASA officials said that they still were not certain whether the fault lay in a true failure of the fuel pump or whether the instruments registered incorrectly. The answer probably will not be found until the shuttle returns, they said.

Monday’s launching was delayed initially beyond its scheduled time of 3:23 p.m. by a problem with one of the three gyroscopes that are situated in each of two solid-fuel rocket boosters that help give the shuttle the thrust needed to reach orbit. The problem was fixed and the countdown was resumed.

Dr. Daniel Spicer, chief scientist for the mission, said that most of the scientific experiments scheduled for the weeklong tour probably would still be carried out. But he said that this assessment was “preliminary.”

Challenger is carrying an array of instruments and the crew includes five scientists who will work in two 12-hour shifts to conduct experiments around the clock.

Eager to Test Device

The equipment, mounted on three pallets attached to the cargo bay, includes a $60-million German-made Instrument Pointing System designed to point telescopes precisely. NASA scientists are eager to test this system so it will be ready for another mission in March, when scientists hope to get a good look at Halley’s comet.

Other experiments will study the sun, the gas surrounding Earth, cosmic rays, infrared radiation, bone demineralization and mineral balance during space flight.

NASA officials said that they were still assessing whether the latest problems with the shuttle would result in more delays for later flights.

Several flights scheduled for later this year already have been postponed because of the Challenger’s failure to lift off earlier this month. Moore said that the current problem may have no impact on the schedule. “We are hopeful,” he said at the press conference.

The crew of the Challenger includes Air Force Col. Gordon Fullerton, the mission commander, and Col. Roy D. Bridges Jr., the pilot. Scientists aboard are F. Story Musgrave, a NASA medical researcher, Anthony England, a NASA geophysicist, Karl Henize, a NASA astronomer, John-David Bartoe, an astrophysicist with the Naval Research Laboratory, and Loren W. Acton, an astronomer with Lockheed Corp.