CHALLENGER SPACE CHALLENGER SPACE SHUTTLE SHUTTLE

Disaster : Disaster : January 28 , January 28 , 19861986

The space shuttle challenger launched by The space shuttle challenger launched by

NASA is most widely written case in NASA is most widely written case in

engineering ethics because of the extensive engineering ethics because of the extensive

media coverage at the time of the accident.media coverage at the time of the accident.

On 28On 28thth January the American space January the American space

program suffered one of its greatest tragedies program suffered one of its greatest tragedies

when the space shuttle challenger was when the space shuttle challenger was

destroyed 76 seconds into the mission killing destroyed 76 seconds into the mission killing

all seven crew members.all seven crew members.

CREW MEMBERSCREW MEMBERS

Who’s WhoWho’s Who

NASANASA : National Aeronautics and Space : National Aeronautics and Space

Administration.Administration.

Morton Thiokol Morton Thiokol : Private Company that : Private Company that won the contract from NASA for building won the contract from NASA for building the solid rocket Boosters for the Shuttle.the solid rocket Boosters for the Shuttle.

NASA : NASA :

(1). LARRY MULLOY – Solid Rocket (1). LARRY MULLOY – Solid Rocket Booster Project Manager at NASA.Booster Project Manager at NASA.

From Morton Thiokol From Morton Thiokol ::

[1].[1].Roger Mulloy and Arnie JohnsonRoger Mulloy and Arnie Johnson

- Engineers who worked on the Solid - Engineers who worked on the Solid Rocket Booster Development Programme.Rocket Booster Development Programme.

[2]. [2]. Joe Kilminster Joe Kilminster : Engineering : Engineering

Manager on Solid Rocket Booster Manager on Solid Rocket Booster

Development Programme.Development Programme.

Thiokol People involved …Thiokol People involved …

[3].Alan Mc Donald : Director of Solid [3].Alan Mc Donald : Director of Solid

Rocket Booster Rocket Booster

Project.Project.

[4].Bob Lund : Vice President for [4].Bob Lund : Vice President for

Engineering.Engineering.

[5].Jerald Mason : General Manager.[5].Jerald Mason : General Manager.

CONSTRUCTIONCONSTRUCTION

CONSTRUCTIONCONSTRUCTION

The Reusable launch vehicle called The Reusable launch vehicle called challenger consist of an challenger consist of an

orbiterorbiter two solid Propellant boosters two solid Propellant boosters single liquid-propellant booster.single liquid-propellant booster.

The orbiter was equipped with three The orbiter was equipped with three main engines in which liquid hydrogen main engines in which liquid hydrogen was the main fuel.was the main fuel.

The liquid propellant booster functions The liquid propellant booster functions mainly to lift the shuttle into orbit.mainly to lift the shuttle into orbit.

The boosters are capable of burning The boosters are capable of burning about one million-pound load of fuel about one million-pound load of fuel mixture each.mixture each.

The orbiter descends to a safe landing The orbiter descends to a safe landing by using limited thrust, at the by using limited thrust, at the completion of mission.completion of mission.

Booster rocket consist of cylindrical Booster rocket consist of cylindrical segments.segments.

Seals made of pairs of O-rings are Seals made of pairs of O-rings are used in four field joints in the used in four field joints in the segments.segments.

O rings O rings : Made from a type of : Made from a type of Synthetic Rubber, not particularly Synthetic Rubber, not particularly

Heat Resistant.Heat Resistant.

To prevent the hot gases from To prevent the hot gases from damaging the O rings, a heat damaging the O rings, a heat

resistant PUTTY is placed in the resistant PUTTY is placed in the joint.joint.

ProblemsProblems

When the Rocket is ignited, the When the Rocket is ignited, the internal pressure causes the Booster internal pressure causes the Booster wall to expand outward, putting wall to expand outward, putting pressure on the field joint. This pressure on the field joint. This pressure causes the joint to open pressure causes the joint to open slightly, a process called “ JOINT slightly, a process called “ JOINT ROTATION”.ROTATION”.

EARLY PROBLEMS WITH SOLID EARLY PROBLEMS WITH SOLID BOOSTERSBOOSTERS

When everything was set and ready for When everything was set and ready for

the final phase of launching, Allan of the final phase of launching, Allan of

Morton -Thiokol at Cape Kennedy had Morton -Thiokol at Cape Kennedy had

great apprehensions about the adverse great apprehensions about the adverse

effects that freezing temperatures would effects that freezing temperatures would

have in the launching.have in the launching.

Before the Launch…Before the Launch…

A Teleconference was arranged between A Teleconference was arranged between the Engineers and the Management from the Engineers and the Management from the Kennedy Space Center.the Kennedy Space Center.

During this, ROGER BOISJOLY and During this, ROGER BOISJOLY and ARNIE THOMPSON (Thiokol Engineers) ARNIE THOMPSON (Thiokol Engineers) gave an Hour long presentation on how gave an Hour long presentation on how the cold weather would increase the the cold weather would increase the problems of JOINT ROTATION and problems of JOINT ROTATION and sealing of joint by O Rings.sealing of joint by O Rings.

Problems…Problems…

The Lowest Temperature at which shuttle The Lowest Temperature at which shuttle had previously been launched was 53 had previously been launched was 53 degree F, on January 24, 1985.degree F, on January 24, 1985.

Expected O ring Temperature during Expected O ring Temperature during CHALLENGER launch was predicted to be CHALLENGER launch was predicted to be 29 degree F far below the temperature at 29 degree F far below the temperature at which NASA had previous experience.which NASA had previous experience.

Problems …Problems …

According to BOB LUND, the Vice According to BOB LUND, the Vice president for Engineering at Morton president for Engineering at Morton Thiokol recommended that – NASA should Thiokol recommended that – NASA should delay the launch until the O Ring delay the launch until the O Ring temperature should be atleast 53 deg F.temperature should be atleast 53 deg F.

Famous QuoteFamous Quote

After much discussion, JERALD MASON, After much discussion, JERALD MASON, a senior Manager with Thoikol, turned to a senior Manager with Thoikol, turned to Lund and said,” TAKE OFF YOUR Lund and said,” TAKE OFF YOUR ENGINEERING HAT AND PUT ON YOUR ENGINEERING HAT AND PUT ON YOUR MANAGEMENT HAT”.MANAGEMENT HAT”.

LUND reversed his previous decision and LUND reversed his previous decision and recommended that the Launch proceed.recommended that the Launch proceed.

The engineers were aware, from previous The engineers were aware, from previous

launches, that the O-rings became greatly launches, that the O-rings became greatly

strained at a specific low temperature.strained at a specific low temperature.

The points raised by Morton-Thiokol The points raised by Morton-Thiokol

engineers were not given any consideration engineers were not given any consideration

at the Cape Kennedy center..at the Cape Kennedy center..

The launch was approved and the command The launch was approved and the command

for the countdown was given. for the countdown was given.

Soon after take off, heavy smoke was seen Soon after take off, heavy smoke was seen

evolving from one of the field joints on the evolving from one of the field joints on the

right-hand booster rocket. right-hand booster rocket.

This sparked off a fire which caused the fuel This sparked off a fire which caused the fuel

tank containing liquid hydrogen to explodetank containing liquid hydrogen to explode

The booster rocket then crashed into one The booster rocket then crashed into one

of the challenger’s wings smashing it.of the challenger’s wings smashing it.

It happened about a minute after the take It happened about a minute after the take

off when the challenger was at an altitude off when the challenger was at an altitude

of around 50,000 feet.of around 50,000 feet.

Within seconds, only a ball of fire Within seconds, only a ball of fire

plummeting down to earth was visible . plummeting down to earth was visible .

The space craft finally plunged into the The space craft finally plunged into the

ocean killing all of the astronauts on ocean killing all of the astronauts on

board.board.

THE POLITICAL CLIMATETHE POLITICAL CLIMATE

The huge budget allocation to NASA The huge budget allocation to NASA was directly governed by the congress was directly governed by the congress senate in USA.senate in USA.

The congress was very uncomfortable The congress was very uncomfortable and unhappy with the inordinate delay and unhappy with the inordinate delay in executing the space shuttle projects.in executing the space shuttle projects.

All these crucial developments forced All these crucial developments forced NASA to approve the launching NASA to approve the launching programmes.programmes.

SAFETY ISSUESSAFETY ISSUES

All these crucial developments forced NASA All these crucial developments forced NASA

to approve the launching programmes.to approve the launching programmes.

Space shuttle challenger was so designed Space shuttle challenger was so designed

as to have simultaneously ignition of all the as to have simultaneously ignition of all the

fuel in the tank at the time of launching.fuel in the tank at the time of launching.

It was previously contemplated as a It was previously contemplated as a

precautionary safety measure, to introduce precautionary safety measure, to introduce

an abort module in the design with its own an abort module in the design with its own

thruster that would enable the instant thruster that would enable the instant

separation of the orbiter if there was any separation of the orbiter if there was any

leakage in the field-joints.leakage in the field-joints.

But this proposal was turned down due to its But this proposal was turned down due to its

highly expensive cost.highly expensive cost.

Despite the fact that the shuttle programme was Despite the fact that the shuttle programme was

initiated only as an “experimental and research initiated only as an “experimental and research

undertaking”, it appears highly ridiculous that the undertaking”, it appears highly ridiculous that the

minimum level of safety procedures were not at minimum level of safety procedures were not at

all considered in the launching of the challenger. all considered in the launching of the challenger.

CONCLUSIONCONCLUSION

The poor and unreliable assessment of The poor and unreliable assessment of

system’s reliability and quality by NASA system’s reliability and quality by NASA

clearly points out its negligent and casual clearly points out its negligent and casual

attitude towards the safety norms of the attitude towards the safety norms of the

space shuttle programmes.space shuttle programmes.