What was the purpose of Challenger?

The purpose of the Space Shuttle Challenger, designated OV-099, was to serve as NASA's second operational reusable spaceplane orbiter for carrying out a wide variety of missions in low Earth orbit as part of the Space Transportation System program. Challenger was built from a test article and first flew in April 1983 on STS-6, and its purpose included deploying commercial and military satellites, carrying scientific laboratories like Spacelab for microgravity research, conducting spacewalks, and demonstrating routine access to space with diverse crews. Challenger carried the first American woman in space Sally Ride in 1983, the first African American in space Guion Bluford in 1983, and was scheduled to carry the first Teacher in Space Christa McAuliffe on STS-51-L. Its missions included launching the first Tracking and Data Relay Satellite, carrying the European built Spacelab, and testing new technologies. Challenger flew nine successful missions from 1983 to 1985, and its intended purpose was to make spaceflight more frequent and cost-effective with a reusable orbiter. On its tenth flight on January 28, 1986, its purpose was to deploy a satellite and conduct educational lessons from space. After its loss, its legacy led to major safety reforms and emphasis on safety culture that shaped the rest of the shuttle program.