The Challenger explodes above the Kennedy Space Centre in Florida. Photo / Getty Images
The Challenger explodes above the Kennedy Space Centre in Florida. Photo / Getty Images
The year was 1986. The world watched as the space shuttle Challenger hurtled through the air at twice the speed of sound above Florida, bound for orbit.
Pilot Michael Smith noticed something alarming. He looked out his window and likely saw a flash.
"Uh oh," he said. It was tobe his last words.
Space shuttle Challenger disaster. Photo / Getty Images
Down on the ground at Mission Control, a computer screen indicated falling pressure in the right booster rocket. It was leaking fuel.
As was later learned, the cold of the Florida morning had stiffened the rubber O-rings that held the booster sections together, containing the explosive fuel inside. The rings failed to expand fully in the cold, leaving a gap of less than a millimetre between booster sections.
Seventy-three seconds into the flight, a massive explosion took the lives of seven crew members - five Nasa astronauts, and two payload specialists.
Now, in a new book, author Kevin Cook says he has uncovered the "errors and corner-cutting that led an overconfident space agency to launch a crew that had no chance to escape".
He also claims the crew likely survived the dramatic explosion before the space shuttle plunged to earth and crashed into the Atlantic Ocean.
The capsule carrying crew members Michael Smith, Francis (Dick) Scobee, Ronald McNair, Ellison Onizuka, Judith Resnik, Gregory Jarvis and teacher Christa McAuliffe was ejected intact into the fireball, according to Cook.
(Back, L-R) Ellison S. Onizuka, Teacher-in-Space participant Sharon Christa McAuliffe, Greg Jarvis and Judy Resnick. (Front, L-R) Pilot Mike Smith, Dick Scobee and Ron McNair. Photo / Getty Images
The book claims the crew "were conscious, at least at first, and fully aware that something was wrong" in the immediate moments after the explosion over the Atlantic Ocean.
The interior of the crew cabin, which was protected by heat-resistant silicon tiles made to withstand re-entry, was not burned up.
The space shuttle Challenger malfunctions shortly after take-off, resulting in the deaths of all seven crew members. Photo / Getty Images
The crew would have been subjected to 20 Gs of force, which was far more than the three Gs their training had accustomed them to.
An investigation later found the jump in G-force had been survivable.
The investigation found no sign of sudden depressurisation, which would have knocked the passengers unconscious.
Examination of the wreckage also found that three of the astronauts' emergency air supplies had been switched on, indicating that some of the crew had survived the initial explosion.
It is also believed that Smith tried to restore power to their shuttle, as switches on his control panel had been moved.
The debris took two minutes to drop into the Atlantic Ocean, reaching a terminal velocity of more than 320km/h.
The crew could have had six to 15 seconds of "useful consciousness" inside the crew compartment after the blast, says Dr Joseph Kerwin, an astronaut-physician who investigated the cause of death for the crew.
The force of the crew compartment hitting the ocean was so destructive, however, that the precise cause of death for the crew could not be determined.
Christa McAuliffe's family reacts to explosion of the Space Shuttle Challenger. Photo / Getty Images
Pictures from the day show horrified spectators after they witnessed the explosion.
Then-president Ronald Reagan ordered a probe into the Challenger catastrophe, where it was found that poor management and a disregard of safety advice were said to have played a role in the accident.
The failure resulted in a nearly three-year lapse in Nasa's shuttle programme.
