FROM THE ARCHIVES: Today marks 33 years since the Space Shuttle Challenger exploded, killing all seven crew members on board. “It happened just over one minute into flight,” NBC’s Dan Molina reported that day on NBC Nightly News with Lester Holt. “From mission control: silence.” | NBC Nightly News with Tom Llamas

35 YEARS LATER: On this day in 1986, the Space Shuttle Challenger exploded after liftoff, killing all seven astronauts on board. The Challenger broke apart at 11:39 a.m., falling into the Atlantic Ocean. Investigators would later discover the disaster was caused by the failure of an “O ring” seal in one of the two solid-fuel rockets. As a result of the horrific accident, NASA did not send astronauts into space for more than two years as it redesigned a number of space shuttle features for improv