Space Shuttle Blasts Off to Finish Mission

Space shuttle Columbia and a crew of seven returned to orbit Tuesday to complete a science mission that had to be cut short in April because of equipment trouble.

“It’s good to be back,” astronaut Janice Voss said as she opened the shuttle laboratory.

Contrary to the forecast--which gave only a 10% chance of acceptable weather--it turned out to be a fine afternoon for a launch.

“Well, gang, I’ve got to tell you, that’s not bad for a 90% chance of no go, huh?” NASA spaceflight chief Wilbur Trafton Jr. said.

Although it poured at the launch pad 1 1/2 hours before liftoff, the sky soon cleared and the flight ended up being postponed just 12 minutes because of some clouds.

“We’ll take good care of the ship, and see you in 16 days,” said the commander, James Halsell Jr.

Halsell and his crew spent only four days in orbit last time. NASA aborted the mission because of alarming voltage swings in one of the fuel cells, which generate electricity. The fuel cell was replaced after Columbia returned to Earth on April 8, and the same crew was reassembled for another go at it.

The same 33 laboratory experiments are flying as before: fire, plant, crystal and metal studies that resemble the kind of research to be conducted on the future international space station.

Engineers still do not know why the fuel cell malfunctioned, although it’s now apparent that the shuttle could have remained safely in orbit, said shuttle program manager Tommy Holloway.

Columbia’s fuel cells appeared to be working well this time, but when the shuttle reached orbit, alarms went off as pressure dropped in one of three hydraulic units used to steer the spacecraft during landing.

NASA launch manager Loren Shriver said it did not appear to be much of a problem; in any event, the hydraulic units are not needed again until the shuttle returns to Earth on July 17.

This is the first time in 36 years of U.S. human spaceflight that a crew has flown in space together more than once, and is the quickest return to space for any American--only 84 days.