Event Sequence
1974 Morton Thiokol is awarded contract to build solid rocket boosters for Space Shuttle Challenger
1977 Morton Thiokol engineers discover joint rotation problems
1981 O-ring erosion discovered after second shuttle flight
1985 Morton Thiokol orders new steel billets for new field joint design
1985 NASA level 1 management briefed on booster problem
Jaunuary 22 1986 The Space Shuttle Challengers original launch date for it''s 10th mission.
Six day delay due to bad weather
January 27 1986 Engineers and managers at Morton Thiokol discuss weather conditions with NASA managers and Marshall Space Flight Center. Several engineers expressed their concerns about the low temperatures would have on the rubber O-rings and recommended the launch be postponed
Managers from Morton Thiokol later agree with managers from NASA that the launch proceed as scheduled
January 28 1986 At 11:38 am the Space Shuttle Challenger (STS-51-L) took off from the launch pad at Cape Canaveral, Florida. Five Astronauts and two payload specialists were on board.
Coldest weather conditions experienced at a shuttle launch.
Due to the freezing temperatures the O-rings in the right solid rocket booster malfunctioned.
73 seconds after the launch the shuttle exploded.
The five Austonauts and two payload specialists died.
System Parts
Space Shuttle Challenger
The Orbiter
Crew Cabin
Orbital maneuvering systems
Solid rocket booster
DESIGN FAILURE/PRE-CONDITION Two rubber O-rings
Booster-external tank attachment
Nozzie and thrust vector control system
solid rocket motor
External tank
"Gas tank" - liquid hydrogen tank/liquid oxygen tank
Liquid oxygen vat valve
Forward external tank/ orbit attachment
People
Manned space craft center (Mission control)
Astronauts/ Payload specialists
NASA crew
Engineers
Manufacturers/designers
Construction/ Maintenance
Bystanders/ family watching the launch
Launch pad
Kennedy Space Center
LATENT FAILURE Ice
Launch towers
Staff
Training
Tasks
Roles and responsibilities
Culture
Organisational systems/Management and regulations
Training
Roles and regulations
Organisational systems
Policies and procedures
Cost
Accountability
Rostering of staff
Safety
Design Life Cycle
Concept detailed design
Operating
Construction
De-commissiong
Commissiong
Maintenance
O-rings
External tank- Liquid oxygen and hydrogen
Controls
two solid rocket boosters
The orbiter
Flight controls
Flight controls
Mission control
Operator skills/requirements
Function
Equipment and parts required
Manufacturing
Proficiency of manufacturer
Materials
Computer system
Function
Space shuttles normally undergo an extensive decommissioning process then are put on public display
Geocoaching (2015) states that the collect debris of the vessel are currently buried in decommissioned missile silos at Launch Complex 31, Cape Carnaveral memorial at the Kennedy Space Center. :
Computer testing
Practical Design requirements
Installation
Scheduling
Adjusting
Safety requirements
Regular service maintenance/ Quality maintenance engineers
Cost
Availability of parts needed for maintenance
Computer maintenance
Updating systems
repairs
People
Workplaces
Management
Individual factors
Team Factors
Rogers Commission
NASA managers
Morton Thiokol managers
Morton Thiokol engineers
Crew control
Marshall Space Flight Center engineers
Roger Boisjoly
Family members/public
Flight crew
George Hardy
Workplace factors
Equipment design
Work environment
Fully automotive space shuttle
Most complex of the six shuttle orbiters constructed by NASA (Gebhardt,C 2011)
Flight control systems computer program
Colder temperatures than previous launches
Ice on launch pad
Violent wind shear
Pressure to launch
launch delays
cost
Organisational/ System factors
Cost
procedures/ policies
Controlled by government
Management decisions
PRE-CURSER Time pressures
Job design
Extensice 37 week training before launch
First teacher in space
7 days in space
Information transfer
No alarms sounded in the cockpit
Communication with mission control
Crew had no indication of a problem before the rapid break-up of the space shuttle system
Cost
O-rings were re-designated as 'Criticality 1"
ACTIVE FAILURE TO ENSURE SYSTEMS WERE FAILSAFE No body at Marshall suggested that the space shuttle be grounded until the safety issue was fixed
Time did not allow the redesign of the O-rings
*DESIGN FAILURE TO ENSURE FAILSAFE SYSTEMS WERE INCLUDED Did not cancel shuttle flights until the joints could be redesigned.
DESIGN FAILURE-PRE CONDITION In 1985, post flight analysis discovered worst o-ring damage
DESIGN FAILURE Engineer from Morton Thiokol knew there was a problem with the shuttle rocket boosters since 1977. Expressed concerns about shuttle launch in lowest temperatures. Argued that cold weather would exaggerate the problems of joint rotation and delay o-ring seating.
Was 'appalled' when Morton Thiokol engineers argued that Space Shuttle Challenger shouldn't fly in such cold temperatures (Berkes, H 2016)
5 astronauts, 2 payloads including a school teacher
call for shuttle flights to stop knowing the joints needed to be re-designed. Issued and waived launch constraints for six consecutive flights (Report of the Presidential Commission on the Space Shuttle Challenger Accident, 1986)
ACTIVE FAILURE/ MANAGEMENT POLICY/ PROCEDURE FAILURE Went against all warnings from engineers about concerns regarding low temperatures and o-rings
Expressed concerns regarding low temperatures and o-rings
Supported engineers when recommended the launch be postponed
ACTIVE FAILURE/ MANAGEMENT POLICY/ PROCEDURE FAILURE Management later agreed with NASA that the launch should proceed as scheduled
People/Workplaces and Management
PRE-CURSER Bad weather caused launch delays for several days
Economic considerations, political pressures and scheduling backlogs
An ice team had worked through the night to remove ice from the launch pad, yet engineers still expressed their concern
ACTIVE FAILURE Engineers concerned about shuttle launch in lowest temperatures causing problems of joint rotation and delay in o-rings
Raval (2014) states that there was a lack of understanding in some of NASA's highest ranking managers
Raval (2014) states that in 1984 President Ronald Reagan and announced the "Teacher in Space Project' an initiative was intended to inspire students and to sustain public interest in the over-budgeted shuttle program
ACTIVE FAILURE/ MANAGEMENT POLICY PROCEDURE FAILURE NASA mangers decided to approve the boosters for launch despite the fact that the predicted launch temperature was outside their operational specification
Human- machine interface
Cacciabue (2004) discusses how human-machine system can be defined as a composite at any level of complexity of personal, procedures, materials, tools, equipment, facilities and software
The elements of a human-machine system are used together in the intended operational or support environment to perform a given task or achieve a specific production, support or mission required (Cacciabue 2004)
Ericson (2015) states that safety concerns during this phase include operator actions, hardware failure, hazardous system designs and safe design changes and system upgrades
Cacciabue (2004) Systems behave and respond via the automation and follow the rules and principles provided by their designers
Srinvasan & Halada (2012) States that a design flaw is generated when designers fail to create a level of product quality that satisfies the customer
Design flaws
FAILURE TO RECOGNISE MISMATCH WITH O-RINGS AND COLD TEMPERATURE Srinvasan & Halada (2012) states that the primary causes of engineering disasters are usually considered to be human factors, design flaws, material failures, extreme conditions and a combination of these reasons
Ericson (2015) explains that a safety system program is a formal approach to eliminate hazards through engineering, design, education, management policy and supervisory control of conditions and practices
LATENT FAILURE Engineer from Morton Thiokol knew there was a problem with the shuttle rocket boosters since 1977
Ericson (2015) explains that in order to proactively design safety into a product, it is essential that the safety process start at the concept definition phase and continue throughout the life cycle.
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SPACE SHUTTLE CHALLENGER