INTRO: U-S space shuttle Discovery astronauts installed a major structure to the outside of the international space station Saturday, despite an electrical failure that made the effort tougher. V-O-A science correspondent David McAlary tells us that Discovery's astronauts did some quick maintenance so the job could proceed.

TEXT: Japanese astronaut Koichi Wakata [KO-EE-CHEE WAH-KAH-TAH] used the shuttle's crane to hoist an 86-hundred kilogram box-like truss out of the cargo compartment and attach it to the outside of the station's U-S module.

The cast aluminum truss contains communications antennas and motion-control gyroscopes to stabilize the station.

Saturday's work was delayed more than two hours when a short circuit knocked out a shuttle television camera and a computerized vision system Mr. Wakata needed to see what he was doing.

The crew switched to a backup vision system that helped him align the truss by matching big dots painted on it with guides on the U-S module. Astronaut Mike Lopez-Alegria [AL-uh-GREE-uh] viewed the operation from inside the module, providing visual backup for the lost camera.

When the station's latches captured the truss, there was audible relief in the shuttle mission control room in Houston, where the person who relayed instructions to the astronauts Ellen Ochoa [oh-CHO-uh] praised Mr. Wakata.

/// OCHOA ACT ///

Koichi, you da man!!! [You are the man!!!] [APPLAUSE]

/// END ACT ///

The connection was secured by Pilot Pamela Melroy who used a laptop computer to command 16 bolts to tighten the truss to the station.

/// MELROY ACT ///

Okay, we look like we've got a good capture first stage and Mike reports from the node that it looks like there was a good capture visually also.

/// END ACT ///

The work delay caused mission officials to postpone other work scheduled for Saturday, including the transfer of some medical, electrical, and computer equipment from Discovery to the Russian "Zarya" module. Lead shuttle flight director Chuck Shaw says he wanted to avoid overtaxing the astronauts.

/// SHAW ACT ///

They've had a big day just as we did. This is still early in the flight, so I want to keep us on the timeline and keep the crew's strength saved. So rather than overworking them today trying to make up or it, we have plenty of time left in the mission to do that.

/// END ACT ///

The work continues Sunday when two astronauts embark on a spacewalk [at 10:32 a.m. EDT] to connect the truss electrically to the station. It will be the first of four consecutive spacewalks by two alternating teams to put the finishing touches on the truss. Eventually the truss will be extended and solar power panels and other hardware will be mounted on it.

On Monday, Koichi Wakata will control the crane again to install another docking port on the U-S module. It will be a second entrance for future shuttle dockings to the station.

This is the last shuttle visit to the space station before a U-S astronaut and two Russian cosmonauts become the first long-duration crew to occupy it in about two-and-a-half weeks. (SIGNED)