CAPE CANAVERAL, Fla. -- The Endeavour rocketed into orbit Saturday on NASA's 50th shuttle flight, a $140 million Japanese- sponsored science mission featuring married astronauts and a menagerie of fish, frogs and other critters.
With commander Robert 'Hoot' Gibson, 45, and co-pilot Curtis Brown, 36, at the controls, Endeavour thundered aloft at 10:23 a.m. EDT to kick off a weeklong Spacelab flight, the sixth of eight missions planned for 1992.
Joining Gibson and Brown aboard NASA's newest shuttle were flight engineer Jay Apt, 43, payload commander Mark Lee, 40, and wife Jan Davis, 38, Mae Jemison, 35, and Mamoru Mohri, 44, the first Japanese citizen to fly on an American spacecraft.
'Sid, I've got to tell you, this is a great way to commute to work,' Apt radioed to astronaut Sid Gutierrez at the Johnson Space Center in Houston two hours after launch.
'We all wish we were up there with you, Jay,' Gutierrez replied.
'We just had an awesome pass up over the U.S. and shot a few pictures of Chicago,' Apt said.
Astronauts spent the day activating systems in the Spacelab module mounted in the cargo bay and trouble-shooting a leak of cooling water in one rack of experiments.
They isolated the leak by turning a valve to bypass the rack, which contains seven facilities for 11 experiments in materials science, while engineers debated ways to repair or work around the leak.
The liftoff marked the first time any shuttle had launched precisely on time in the post-Challenger era. The launch also was a milestone because it was the 25th flight since the 1986 Challenger disaster. Challenger had been the 25th flight in the shuttle program, which began in 1981.
NASA launch director Robert Sieck said the launch team continued to gain confidence and efficiency with each success.
'There's got to be more confidence because of all the previous ones that are under our belt,' he said.
The mission is the first sponsored by Japan, which paid $90 million to charter Endeavour and the $1 billion Spacelab module.
'This makes a very significant step for us,' said Masato Yamano, president of the National Space Development Agency of Japan, adding that 'future space activities have to depend on international cooperation.'
Brewster Shaw, deputy manager of NASA's shuttle program, said the launch was a milestone for cooperation between the United States and Japan in space.
'As you know, Japan is one of our partners in the space station project, so certainly we're going to have future cooperative adventures with Japan,' he said. 'This is just the beginning.'
Vice President Dan Quayle, his wife Marilyn and two children watched the blastoff. Quayle, chairman of the National Space Council, later joined launch team members in the traditional post-liftoff meal of beans and cornbread.
More than 235 Japanese journalists as well as Japanese officials were present for the launching of Mohri, Japan's first shuttle flier. The blindingly bright flame that sent Endeavour roaring into the blue sky made an impression.
'This is a very beautiful launch, much more beautiful than I expected,' said Matsumiko Masuda, a spokesman for NASDA, the Japanese space agency.
Other demographic records will be set by Jemison, the first black American woman to fly in space, and Lee and Davis, the first married couple to blast off together.
While media attention has focused heavily on Lee and Davis and the general topic of sex in space, the goal of the flight is basic research in a variety of disciplines to learn more about the benefits and drawbacks of weightlessness.
Twenty-four of the 43 experiments on board are devoted to materials science and manufacturing processes while the other 19 are concerned with medicine and biology. Japan supplied 34 of the experiments while the United States provided the other nine, along with launch processing, at a cost of $50 million.
NASA managers view Endeavour's flight as a major stepping stone toward the permanently manned space station the agency hopes to begin building in 1996.
Al Diaz, NASA's deputy administrator for space science, said Spacelab missions provide 'a very valuable testbed for developing incremental improvements to the hardware so we can take maximum advantage of the opportunity thatcomes with space station.'
Equally important, international flights like Endeavour's and a German-sponsored flight next year give researchers around the world a chance to find out how NASA works, experience that will make it easier to integrate European, Japanese and Canadian experiments aboard space station Freedom.
'It is a very valuable experience to have an international community planning science missions,' Diaz said. 'With all the differences in priorities, the language differences, it becomes a very essential part of the planning for space station.'
During Endeavour's flight 187 miles above Earth, the astronauts will grow a variety of near-perfect crystals in the weightlessness of space that have applications in electrical and optical systems. At the same time, the astronauts will evaluate the performance of various crystal growth devices to help engineers determine which might have industrial applications.
But most of the crew's time will be taken up with around-the-clock medical and biological research.
Jemison, a physician, plans to cull eggs from four female frogs during the flight and to fertilize them with sperm. She then will monitor the growth of the resulting tadpoles to find out how weightlessness affects their development.
'Usually, there's gravity and maybe it gives the egg an idea as to what cells end up being arms, which cells end up being legs, which cells end up being eyes,' Jemison said in a pre-launch news conference. 'Can it do that without gravity? That's one of the primary questions we're going to be answering.'
Two Japanese carp in a high-tech aquarium will be studied to find out how the lack of gravity affects organs similar to the inner ear in humans that control balance.
And in an Israeli experiment, the astronauts will monitor how 180 African hornets build their combs in weightlessness. On Earth, gravity appears to be the only factor governing how combs are oriented. By studying how the hornets react to weightlessness, scientists hope to gain insights into how other factors influence their behavior.
Other biological experiments involve 30 chicken eggs, 200 fruit flies, 2,700 fly larvae, and kidney and bone cells.