Shuttle Set to Begin Mission With International Flavor

The space shuttle Discovery was to blast off at 5:53 a.m. PST today on a major scientific mission involving 225 scientists from 14 countries.

The 45th flight in the shuttle program was designed partly to set the stage for events marking the International Space Year, with Canadian Roberta L. Bondar, 46, and Ulf D. Merbold, 50, of Germany, joining five Americans for the seven-day mission.

Ronald J. White, program scientist for the International Microgravity Laboratory carried in the Discovery’s cargo bay, said that in 42 primary investigations, the researchers will try to add to knowledge about how the human body adapts to weightlessness and how various plants and organisms perform in space.

The only pre-launch concern was the weather, which has been unusually cool. If the temperature is too low, ice could form on the outside of the massive fuel tank during fueling operations.

“It’s a bit on the nippy side,” shuttle test director Mike Leinbach said Tuesday, but the temperature was not expected to drop below 47 degrees and jeopardize the launch.

Contraction due to cold temperature was cited as the main reason for the failure of rubber seals that caused the explosion of the shuttle Challenger six years ago, but the redesigned seals are equipped with electric heaters in case of chilly weather.

The mission is scheduled for seven days and is to land at Edwards Air Force Base, Calif. Discovery is commanded by Ronald J. Grabe, 46. Other members of the crew are Stephen S. Oswald, 40, the pilot, and mission specialists Norman E. Thagard, 48, William F. Readdy, 39, and David C. Hilmers, 41.