Today marks the 30th anniversary of the Challenger spaceship, which disintegrated after 73 seconds into its flight. The Challenger launched from the Kennedy Space Center in Florida on January 28, 1986 and its explosion was NASA's first in-flight tragedy.

The seven crew members, including Christa McAuliffe, a civilian high school teacher, died immediately.

"Everything seemed to be totally normal," said reporter Frank Mottek. He was broadcasting the launch live for CBS Radio when the disaster happened.

(Via @usairforce)
(Via @usairforce)

"The weather was very, very cold that morning," Mottek said. "We were told the cold was not going to be a factor in launching the shuttle that day."

It was later discovered that the cold weather did play a part, along with a seal on one of the rocket boosters which was not working properly. The seals were designed to separate sections of the rocket booster, however disaster happened instead.

"It looked like a perfectly normal launch," Mottek said. "Then just over a minute later the unthinkable happened when fireball appeared in the sky and the announcement came over that there was a major malfunction ­– that the shuttle Challenger had exploded and we had witnessed a major tragedy."

Mottek was not the only one to witness this disaster. The launch was being broadcasted live on televisons in schools across the country because of the presence of McAuliffe on the crew.

The New Hampshire social studies teacher, McAuliffe was the winner of a nationwide competition to be the first teacher in space. She was also supposed to broadcast lessons to schools across the country from space.

Mottek described the moments following the launch as an emotional and terrifying experience for all who were watching.

"We didn't know if the shuttle would emerge from the fireball and maybe attempt to land, but that was not possible. It appeared, as we quickly learned, that the shuttle had completely disintegrated," Mottek said.

"It was just an awful tragedy; the seven-member crew was lost immediately," he continued. "Instantly going from elation – seeing the launch and everything looking great – to suddenly just intense sadness really."

The sadness lasted for quite a while, with President Reagan addressing the tragedy later that evening in a national broadcast.

"Your loved ones were daring and brave, and they had that special grace, that special spirit that says, 'Give me a challenge and I'll meet it with joy,'" President Reagan said. "They had a hunger to explore the universe and discover its truths. They wished to serve and they did."

President Reagan also specifically addressed the children watching across the nation.

"And I want to say something to the schoolchildren of America who were watching the live coverage of the shuttle's take-off," he said. "I know it's hard to understand, but sometimes painful things like this happen. It's all part of the process of exploration and discovery."

Though the accident grounded NASA space missions and put the program under scrutiny from the media and the public, space exploration did not end with the Challenger. The legacy of the Challenger and its crew continue to live on 30 years after the event.

Staff Reporters Morgan Chen, Holly Thomas and Veronica Quezada also contributed to this article.