Today marks the 28th anniversary of the Shuttle Challenger Disaster, an incident which has lived on in the memories of people around the world and to many, signaled the end of an era. The shuttle’s explosion, which took place at 11:39:13 am EST on January 28th, 1986, occurred just 73 seconds into flight after it took off from Cape Canaveral on the Florida coast.

According to investigators, the accident occurred when the O-ring seal in the shuttle’s solid rocket booster failed during liftoff, which allowed pressurized hot gas from within the solid rocket motor to reach the outside. This malfunction led to the separation of the right-hand solid rocket booster’s aft attachment and the structural failure of the external tank.

The fallen crew members included NASA astronauts Greg Jarvis, Ronald McNair, Ellison Onizuka, Judith Resnik, Michael J. Smith and Dick Scobee, as well as school teacher Christa McAuliffe. It was because of McAuliffe’s presence on the shuttle –  as the first member of the Teacher in Space Project – that roughly 17 percent of Americans were tuned to their TVs during the time of the accident and witnessed the tragedy.

The disaster resulted in a 32-month hiatus in the shuttle program and the formation of the Rogers Commission, a presidential commission charged with investigating the accident. It revealed, amongst other things, that NASA’s organizational culture was in part responsible for the disaster. In short, NASA managers had known that the O-Rings in the Solid Rocket Booster (SRB) design contained a fatal flaw, one which was overlooked.

The investigation also revealed that engineers at Morton Thiokol, the manufacturer of the rocket boosters, had warned them prior to the launch of the flaw. One such engineer was Roger Boisjoly, who realized that a shuttle launch in the cold weather that Florida was experiencing would pose a grave danger. As he had indicated, the rockets weren’t designed to launch safely in weather below 40 degrees Fahrenheit.

NASA officials at the time rejected Boisjoly’s warning, saying that he was acting on a gut feeling rather than science. Boisjoly told The Times in an interview in 2003 that NASA tried to blacklist him from the industry, and  went so far as to argue that some NASA officials should be indicted for manslaughter charges, and the agency should be abolished.

There are many memorials to the fallen crew, but one of the most cited in education is the 40 Challenger Learning Centers that are located in the United States, Canada, United Kingdom and South Korea. The network was founded by June Scobee Rogers (the widow of commander Scobee) and includes participation from other Challenger family members.

According to their website, their goal is to:

[G]ive students the chance to become astronauts and engineers and solve real-world problems as they share the thrill of discovery on missions through the Solar System.

As a result of the disaster, the Air Force decided to cancel its plans to use the Shuttle for classified military satellite launches from Vandenberg Air Force Base in California, deciding to use the Titan IV instead. Media coverage of the accident was also extensive, with one study indicating that 85 percent of Americans had heard the news within an hour of the accident.

Challenger’s anniversary comes in a week that includes other tragic anniversaries, including the Apollo 1 pad fire that occurred on Jan. 27th, 1967 and claimed the lives of three astronauts’ lives; the Columbia shuttle breakup that happened on Feb. 1st, 2003 and killed seven. Many other astronauts have died in training accidents, and their names are listed at the Astronaut Memorial Foundation.

The disaster has also been used as a case study in many discussions of engineering safety and workplace ethics. And it serves as a constant reminder of the bravery of those who choose to go into space for the sake of advancing science and our understanding of the cosmos. It’s also a reminder that the only safeguard against tragic accidents is eternal vigilance!

Let us all hope and pray no such incidents happen as we embark on a renewed age of space exploration and discovery!