CHALLENGER EMBEDDED IN MINDS OF MANY

It started as an average, routine Tuesday for most people in Southeast Missouri: Children went to school, parents went to work, the space shuttle Challenger took flight.

But the routine ended 73 seconds after liftoff when the Challenger exploded. All seven members of the crew were killed, including a teacher from New Hampshire.

Today marks the 10th anniversary of the Challenger explosion.

Since it was such a "routine" flight, most students in Southeast Missouri weren't watching the televised launch even though a teacher was aboard.

Christa McAuliffe, a teacher from New Hampshire, was to be the first civilian to fly in space. She was going to use the shuttle as an orbital classroom.

"I think everybody can identify with Christa McAuliffe," said Dan Hecht, a high school teacher in Chaffee. "She was a teacher -- not a politician or astronaut, -- just an average, everyday person looking for the ultimate feeling of being in space looking down at Earth."

Teaching students about the Challenger explosion is easy since most remember the event vividly, Hecht said, adding that he watched the launch as an eighth-grade student at Altenburg public schools.

"I really didn't understand what was happening, just that seven people died," Hecht said. "I didn't understand the impact it had."

After 73 seconds, Challenger ruptured 8.9 miles above the Atlantic Ocean while traveling at 1,460 mph, or nearly twice the speed of sound. The pressure seals, or O-rings, in a critical joint of the right solid-fuel rocket booster had given way in the cold -- it was 36 degrees at launch time -- and failed to contain the combustible rocket gases.

It was like a blowtorch, fast and furious, creating a hole in the external fuel tank, which collapsed. At the same time, the tip of the leaking booster rotated and crashed into the upper part of the external tank, the final blow.

Vickie Carlisle, a student at Southeast Missouri State University, remembers being excited that a lay person was going to be part of the space adventure when the Challenger lifted off.

"When it happened we were concerned about the effect it would have on the children in the classroom," she said, "and the negative things that would come from this in their lives. It was a tragedy for the whole country."

But few children were aware of the extent of the tragedy until the end of the school day. However, most remember it as something that defines their generation, Hecht said.

"It's very similar to the Kennedy assassination; they remember exactly where they were," he said. "They remember Christa McAuliffe. But it's unbelievable that so many negative things have come out. It taints the legacy of what she taught us."

Television programs like "60 Minutes" reported recently that some NASA officials were aware of the danger of a liftoff Jan. 28 and warned against it.

Bonnie Crites, a chemistry teacher at Central High School, remembers seeing the explosion on television newscasts. But she doesn't remember this launch being treated any differently than others before it.

"I guess because there was a teacher on there it stuck out in my mind," Crites said.

Jeanette Mastin has a videotaped newscast of the explosion so that she can never forget the picture. Mastin is a librarian at Scott City High School.

"It was such a shock," she said. "We had faith they would go up and do what they do and come home. We no longer have that. Every time they shoot off, we hold our breath."

Although there have been 49 space shuttle launches in the last decade, the NASA program was put on hold for several years following the explosion.

"I feel like it woke up America," said Robert Holmes, a university student. "It managed to make it safer. I'm glad they didn't stop because of it."

Will Anderson, a 20-year-old student at Southeast Missouri State University remembers seeing a halted launch as a child.

He was visiting his grandparents in Florida during the summer of 1985 and saw a test launch.

"I was really excited at that age," he said. "We were outside in my grandparents' yard and it was about 20 seconds left and they stopped because of technical difficulties."

When the Challenger launch ended in an explosion only months later, he was shocked. "It was more real because I'd seen it," he said.

The Associated Press contributed to this story.