Original subtitles

At 11:38 a.m.

on January 28th, 1986.

It's go time.

We have main engine start.

Four, three,

two, one.

But little did the crew or mission control know,

there was a major problem.

At lift-off,

a puff of grey smoke spews from the booster.

Then, at 58 seconds after lift-off

at the same location, a flame becomes visible,

indicating the fuel is making its way through the booster.

Challenger.

Go and throttle up.

Go and throttle up.

73 seconds

after lift-off, at an altitude of 46,000ft, the over 500,000

gallons of liquid hydrogen and oxygen from the main tank

suddenly explode.

Flight throttle.

Go ahead.

R.S.O. reports vehicle exploded.

The crew compartment is ejected

and ascends to an altitude of 65,000ft before freefalling

into the Atlantic Ocean.

On the ground and around the world,

shock, as millions of viewers witness the catastrophe in real time.

Mission control knows it's too late.

The crew compartment hit the ocean at over 200mph.

Without parachutes, there was no chance of survival.

All seven astronauts are gone.

Salvage crews

spent several weeks recovering pieces of the Challenger and carefully

bringing up the remains of the seven astronauts.

In the end, the entire failure can be traced

to the O-rings, rubber seals between the joints on the solid rocket booster.