Space Shuttle Lifts Off for Last Rendezvous With Mir

Space shuttle Discovery thundered into orbit Tuesday on NASA’s last voyage to Mir, a flight to bring home the seventh and final American to stay aboard the Russian space station.

The shuttle and its crew of six took off right on time and soared through a sweltering early-evening sky. “Poyekhali!” shouted commander Charles Precourt, which in Russian means “Off we go!”

It was the hottest launch day anyone could remember. The temperature climbed to 97 degrees at one point in the countdown, prompting NASA to keep close watch on the hydraulic systems at the pad, especially the movable walkway. The limit for launching is 99 degrees.

About 250 miles above Earth, Mir’s automatic thrusters were firing on cue, keeping the station on an unswerving course. The cosmonauts fixed the steering system Monday, three days after it shut down. Without automatic steering, Mir would have been too shaky for a shuttle docking.

Discovery is scheduled to reach Mir on Thursday and bring NASA astronaut Andrew Thomas back to Earth on June 12 after his four-month station stay.

From then on, NASA will concentrate on the international space station; construction will begin in orbit at the end of the year.

The Russians plan to continue flying aboard Mir through 1999, after which they will let it burn up in the atmosphere. Then they, too, will focus all their efforts on the new joint space station.

Discovery’s crew includes Valery Ryumin, 58, a Russian former cosmonaut now in charge of the Mir-shuttle program. He will inspect Mir during the four days that the space station and the shuttle will be linked in orbit.

The countdown was tenser than usual, not just because of the on-then-off anxiety over Mir but because of the new lightweight fuel tank bolted to Discovery during liftoff.

The tank, never before tested in flight, is 7,500 pounds lighter when empty than the 65,500-pound previous models so that NASA can haul heavier cargo once space station construction begins. NASA said early indications show the tank worked well.