CAUSE OF THE CHALLENGER EXPLOSION

 

The loss of the space Shuttle "Challenger" was caused by a failure in the joint between the two lower segments of the right Solid Rocket Motor. The specific failure was the destruction of the seals that are intended to prevent hot gases from leaking through the joint during the propellant burn of the rock motor. The evidence assembled by the Commission indicates that no other element of the Space Shuttle system contributed to this failure. 

A faulty seal on a solid rocket booster caused the Challenger explosion, plus the contributing factor that the O-rings would fail in the cold weather. The night prior to launching space Shuttle "Challenger" the temperature went down so much that, "icicles were hanging from the railing, the pipes, the stairwells. There was glazed ice on the decks". A warm O-ring that has been compressed will return to its original shape much quicker than will a cold O-ring when compression is relieved.  

There are hundreds of parts of the space shuttle that could cause a fatal accident if they fail. Experts say these are the most likely trouble spots in NASA's space shuttle fleet: 

MAIN ENGINES

They are under high stress and are so complicated that numerous problems crop up -- especially because the engines run at higher power then originally designed.

TURBO FUEL PUMP

This crucial part of the main engines has had metal fatigue and cracking problems.

O-RING SEALS

A faulty seal on a solid rocket booster caused the Challenger explosion. That part of the booster has been redesigned -- however, some experts said it was a "Band-Aid" fix.

AUXILIARY POWER UNITS

These provide hydraulic power to steer the shuttle engines, move body flaps and rudder and operate propellant valves and landing gear. Some have failed in testing.

FUEL CELLS

These are the batteries, and two of the three need to operate to keep flying. Shuttles have had fuel cell problems in the past.

GUIDANCE SYSTEM

The system and general purpose computers have had problems that have delayed launches. A failure in flight could be disastrous.

HYDROGEN LEAKS

Leaks in the external tank have plagued NASA and have been mostly solved. But the chemical is highly explosive.

EMERGENCY LANDING PLANS

Returning to Kennedy Space Center is a risky maneuver planned if two of the main engines fail. Pilots say practice landings in simulators have not gone well.

 

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