It's the morning of January 28, 1986, at an elementary school in Ohio.

A young teacher walks through the crowded cafeteria.

She surveys the hundreds of students whose eyes are glued to a television set that's been wheeled in on a cart.

She joins other teachers at the back of the room, feeling just as excited as the students are.

Today, the normal Tuesday morning lessons have been set aside.

Instead, students and teachers watch a live television broadcast from Florida,

where the space shuttle challenger is about to blast off.

Looking at the crowd of students, young teacher considers how profound this moment is,

and just how many young people are likely watching. And indeed, all across America,

more than two and a half million students have tuned in for this momentous occasion.

Over the past five years, there have been many space shuttle

flights. But there has never been a mission like this one before. Among the seven astronauts on board

is another school teacher named Krista McCalliv. Krista is the winner of a competition to put an

educator in space. The competition was put on by the American Space Agency NASA. And today,

in a lunchroom in Ohio, this young teacher is rooting for the success of her fellow educator

as she prepares to go to space. The excitement grows in the cafeteria as the final countdown begins.

And lift-off, lift-off of the 25th space shuttle mission, and it has cleared the tower.

The cafeteria erupt with cheers and excitement as Challenger soars into blue skies.

The spacecraft climbs higher and higher, throttling up to a speed of a thousand miles an hour

as it powers its way towards orbit.

But then, after just over one minute, there's a sudden flash.

The young teacher covers her mouth with her hands.

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