The space shuttle Challenger is lost just after liftoff on this day in 1986, killing the seven astronauts aboard.

The Challenger was the second shuttle built by the National Aeronautics and Space Administration (NASA). It took its first flight into space on April 4, 1983, and made a total of nine voyages prior to January 1986. The 10th trip for Challenger included a teacher from New Hampshire, Christa MacAuliffe, among the astronauts, as part of a new Teacher in Space project.

The Challenger was scheduled to launch on January 22, but a series of problems with the weather delayed the launch until January 28. It was a cold morning at Cape Canaveral and engineers working on the shuttle team warned their superiors that certain equipment on the shuttle was vulnerable to failure at cold temperatures. However, these warnings went unheeded and at 11:39 a.m., the Challenger was launched. Problems began immediately.

First, the O-ring seal on the Challenger‘s solid rocket booster, which had become brittle in the cold temperatures, failed. Flames then broke out of the booster and damaged the external fuel tank. Within 73 seconds, the shuttle began breaking apart, and then it plunged into the ocean. All seven astronauts died but it remains unclear what caused their deaths. A later investigation revealed that the forces involved in the shuttle breakup were not sufficient to have killed them, but that they may have lost consciousness only seconds later as their module lost cabin pressure.

President Ronald Reagan postponed the State of the Union address that was scheduled for that evening and instead addressed the nation about the tragedy. He appointed a commission to investigate the accident and the shuttle program was put on hiatus.

The Rogers Commission determined that Morton Thiokol, the company that designed the solid rocket boosters, had ignored warnings about potential flaws. NASA managers were aware of these design problems, but also failed to take action. Famously, scientist Richard Feynman, a member of the Rogers Commission, demonstrated the O-ring flaw to the public using a simple glass of ice water.

Ten years after the disaster, two large pieces from the Challenger washed ashore on a Florida beach. The remaining debris from the Challenger is now stored in a missile silo at Cape Canaveral.