Brimming with thousands of crickets, snails and other creatures, shuttle Columbia soared into orbit Friday on a two-week mission to explore the mysteries of inner space - the brain.

"It's a little bit like a Cecil B. DeMille production: years in the making, cast of thousands, and it went off like it was supposed to," said NASA's chief veterinarian, Joseph Bielitzki.The space agency expects the mission to provide the best look yet at how the brain and nervous system adapt and develop in weightlessness.

Columbia vaulted into a clear afternoon sky to the delight of the tens of thousands who jammed the Kennedy Space Center in a post-holiday crush. The ship glittered for nearly five minutes as it sped toward the east.

One day late in taking off, Columbia was outfitted with a new data processor to replace one that failed in the final hours of Thursday's countdown. It also was loaded with a fresh batch of crickets and mice.

As if there weren't enough animals on board - crickets, snails, fish, rats and mice, 2,052 animals to be exact - a bat tried to hitch a ride.

The small, black bat attached itself to the back of the huge external fuel tank late in the countdown, said launch director Dave King. As soon as the booster rockets ignited, the bat let go and tried to fly away. In all likelihood, officials said, the bat became toast.

Four hours after liftoff, the astronauts floated into Columbia's bus-size laboratory and began setting it up for 16 to 17 days of neurological tests. Exams - some of them unpleasant - will be conducted on the seven-member crew and the animals.

The shuttle is carrying 1,514 crickets, nearly half in the soon-to-hatch egg stage. None is old enough to chirp. Also aboard are 18 pregnant mice, 152 rats, 60 snails and 75 snail eggs, and 233 fish.