Local Engineers to Keep an Eye on Endeavour : Aerospace: Assembly practice runs scheduled for the mission will help McDonnell Douglas in Huntington Beach with work on space station.

The nation’s newest space shuttle, Endeavour, is scheduled to lift off Thursday on its maiden voyage and one of the most challenging missions in the 11-year history of the shuttle program.

If things go as planned, Endeavour’s seven-day flight will include a record three spacewalks, the delicate and potentially dangerous rescue and relaunch of a $150-million communications satellite, and a practice run at assembling parts of the planned Space Station Freedom 200 nautical miles above the Earth.

In addition, the six men and one woman aboard will flight-test the latest bells and whistles that the National Aeronautics and Space Administration has devised for its four-shuttle fleet.

With Endeavour’s launch coming as Congress renews the debate over the future of America’s manned space program, “The general theme of this mission seems to be the human role in space,” said John E. Pike, director of the space policy project for the American Federation of Scientists. “To demonstrate or evaluate just what you can do with people that you can’t do some other way, I think that’s what this . . . is all about.”

Endeavour’s mission, the 47th shuttle flight since the Columbia was launched in 1981, is of particular interest in Orange County.

In Huntington Beach, engineers at McDonnell Douglas Space Systems Co., which is building a major portion of the planned, $30-billion space station, are relying on the assembly practice sessions to help them evaluate assembly procedures and complete final, detailed design work.

“There are so many things that we’re getting out of it,” said Bob Overmyer, McDonnell Douglas’ director of operations and robotics for the space station project.

Named after the 18th-Century ship that was the first command of Capt. James Cook, the British explorer, the $2-billion Endeavour replaces space shuttle Challenger, which exploded in 1986, killing seven astronauts and stalling NASA’s manned space program for more than two years.

Completed a year ago by workers at Rockwell International in Palmdale, the Endeavour includes a host of new features intended to improve navigation, foster safer landings and permit longer flights.

The most difficult task to be attempted by the crew will be rescue of Intelsat-VI, a 9,000-pound, 17 1/2-foot-tall, 12-foot-wide communications satellite. It was lost in a useless, low-Earth orbit in March, 1990, when a booster mounted atop a commercial Titan rocket failed to fire.

Intelsat--the International Telecommunications Satellite Organization--is a consortium of 122 nations that owns and operates a 17-satellite system that transmits television, telephone, facsimile, data and telex signals. The organization is paying NASA $93 million for the rescue and re-boost operation.

If successful, the mission will put the satellite in position in time to transmit images of the 1992 Summer Olympics in Barcelona around the world.

The operation will begin hours after launch, when satellite controllers at Intelsat headquarters in Washington start maneuvering the Intelsat-VI into an orbit 200 nautical miles above Earth, 100 miles lower than its current flight path.

Four days into the mission, Endeavour’s commander, Navy Capt. Daniel C. Brandenstein, 49, and its pilot, Air Force Lt. Col. Kevin P. Chilton, 36, will move the shuttle into rendezvous position. As the shuttle approaches, astronauts Pierre J. Thuot, 36, a Navy commander, and Rick Hieb, also 36, will begin the first of the mission’s three space walks.

Thuot will ride the shuttle’s mechanical arm toward the slowly rotating satellite. In one of the trickiest maneuvers of the mission, Thuot will attach a “capture bar” to the bottom of the satellite, secure the bar with a special tool and then manually halt the satellite’s rotation with a wheel built into the bar.

Astronaut Bruce E. Melnick, 42, a U.S. Coast Guard commander working inside the shuttle, will use the mechanical arm to pull the satellite into the cargo bay. There, Thuot and Hieb will attach the satellite to a 23,000-pound, solid-fuel rocket motor carried aloft by the shuttle.

Then the satellite and its new motor will be jettisoned from the spacecraft by four large springs. When the rocket motor is fired, it will propel the satellite into a transition orbit 45,000 miles above the Earth, before setting it down in a permanent position about 23,000 miles above the Atlantic.

This part of the mission is particularly dangerous, Pike said. “Any (spacewalk) is risky in the sense that deep sea diving is risky,” he said. “You’re in a very hostile environment and there’s not much between you and that hostile environment. You have all of the same pressure problems . . . plus you have space debris to worry about.”

The mass and rotation of the satellite add to the potential problems, Pike said. “It’s kind of like floating around a swimming pool with a bunch of elephants.”

After they deploy the satellite, Endeavour astronauts will twice more venture outside, five and six days into the mission, to practice techniques that will be used beginning in late 1995 to assemble Space Station Freedom in orbit.

Astronauts Kathryn G. Thornton, 39, and U.S. Air Force Lt. Col. Thomas D. Akers, 40, will team up for the second spacewalk, while Thuot and Hieb will handle the third.

During the walks, the astronauts will build a pyramid intended to simulate a section of the 300-foot-long aluminum truss structure that will serve as the backbone of the space station. They will use the pyramid as a substitute for the orbiting station, and practice the complex berthing maneuvers that will be required when the shuttle brings up additional pieces of the station for assembly in space.

And the astronauts will test five devices intended to assist future astronauts in working outside the space shuttle and the space station.

Engineers at McDonnell Douglas Space Systems are particularly interested in the ability of the astronauts “to be able to position that (pyramid) in the correct place, to be able to dock it, and mate it to the other station component,” Overmyer said.

In addition, Overmyer said, engineers are “eagerly awaiting information to come back to us on the preference on the size and shape of the hand holds, for better gripping . . . so we can get on with our design.”

Originally scheduled for Monday evening, the beginning of Endeavour’s maiden voyage was moved back to Thursday to permit a daylight launch.