Columbia carried a crew of seven people (five men and two women) when it launched into space on January 16, 2003:
Rick D. Husband was the Mission Commander
William P. ("Willie") McCool was the Pilot
Kalpana Chawla was a Mission Specialist
David M. Brown was a Mission Specialist
Laurel B. Clark was a Mission Specialist
Ilan Ramon was a Mission Specialist
Before any shuttle crew lifts off into space, they must go through a "Terminal Countdown Demonstration Test" which simulates the final hours of a launch countdown. It serves as a practice exercise for both the crew and the launch team. Everyone rehearses launch-day time lines and procedures. The test actually simulates ignition and automated shutdown of the shuttle's main engines.
After the practice countdown reaches "T-0," the astronauts are briefed on emergency procedures. The shuttle is equipped with a slide-wire system which the crew can use to escape if a malfunction occurs before ignition. The final test also simulates real-time failures of both the vehicle and ground systems.
When Columbia's commander and crew arrived at Kennedy Space Center to report for their terminal countdown demonstration test, everyone was in high spirits. Successfully completing one of their last pre-launch protocols, the crew and the shuttle were ready for a January 16, 2003 launch.