After the disaster, the shuttle program was grounded for 32 months. NASA redesigned the solid rocket booster joints (a new sealing system, joint heaters) and introduced stricter launch-decision rules.
The program returned to flight on 29 September 1988 with Discovery's STS-26 mission. A new orbiter, Endeavour, was built to replace the lost Challenger and first flew in 1992.
Barbara Morgan, Christa McAuliffe's backup in the "Teacher in Space" project, went on to become a professional astronaut and finally flew to space in 2007 on STS-118 — the first career teacher in space, twenty-one years after the disaster. The STS-51-L crew is commemorated by the Space Mirror Memorial at Kennedy Space Center.
NASA — Challenger (STS-51-L) Accident · NASA — Crew of STS-51-L · NASA — STS-51-L (mission overview) — full list on STS-51-L