Failura Analysis Project: Case Analysis
PV329
FAPaper1.pdf
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An Analysis of the Columbia Accident
Contents
1 Introduction ....................................................................................................................... 2
1.1 Circumstances of the Columbia Accident ..................................................................................2 1.2.1 Productive Pressures .................................................................................................................................. 3 1.2.2 Breakdowns in Communication ................................................................................................................. 4 1.2.3 Excessive Formalism ................................................................................................................................... 4
2 Failure Analysis Methods ................................................................................................... 4
2.1 Destructive Testing Methods ...................................................................................................4
2.2 Non-Destructive Testing Methods ............................................................................................5
3 Recommendations ............................................................................................................. 6
3.1 On the Design of the Space Craft ..............................................................................................7
3.2 On the Prevention of Failure Reoccurrence ..............................................................................7
3.3 On Communication within NASA and Crew Awareness .............................................................7
3.4 On the Design of Survival Suits .................................................................................................7
4 Conclusion ......................................................................................................................... 7
References ............................................................................................................................ 8 Figure 1 -- the bipod ramp that was responsible for damaging the Reinforced Carbon-Carbon panel [2] .......................................................................................................................................... 3 Figure 2 -- an illustration of the 22 Reinforced Carbon-Carbon panels on the left wing of the Columbia [2] .................................................................................................................................... 3 Figure 3 -- an image of the testing assembly used to recreate the launch failure [2] ................... 5 Figure 4 -- an image of the hole created by the test projectile on RCC panel 8 [2] ....................... 5 Figure 5 -- a render of the LS-DYNA model created to test the effect of the foam projectile on the RCC panel [1] ............................................................................................................................ 6 Figure 6 -- a render of the impact of the foam projectile on the RCC assembly 6 milliseconds after impact [1] ............................................................................................................................... 6
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1 Introduction
On February 1, 2003, the Space Shuttle Columbia disintegrated upon re-entering the atmosphere,
claiming the lives its seven crew members [2]. This event marked the second fatal disaster in the
Space Shuttle program’s history. Seven months of testing and analysis went into the
investigation of the catastrophe. It was determined that during the launch of STS-107, a piece of
insulating foam separated from the bipod ramp of the external tank (Figure 1) and struck the
shuttle’s left wing. It impacted the Reinforced Carbon-Carbon panel 8 (Figure 2) at a relative
speed of 800km/hr. [5], 81.9 seconds after launch [2]. This created a breach in the Thermal
Protection System and allowed superheated gases to gradually melt the aluminum structure upon
re-entry. This resulted in the weakening of the shuttle’s frame until the wing failed and the
orbiter separated [2].
1.1 Circumstances of the Columbia Accident
Email correspondence exchanged on January 23rd between a NASA mission operator and the
shuttle crew indicates the administration’s detection of the bipod ramp failure. The crew was
made aware that the -Y bipod (Figure 1) impacted the orbiter’s left wing but were reassured that
the failure had occurred before and posed no threat to their safety during re-entry [6]. The
decision to ignore this problem ultimately costed the lives of the STS-107 crew.
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Figure 1 -- the bipod ramp that was responsible for damaging the Reinforced Carbon-Carbon panel [2]
Figure 2 -- an illustration of the 22 Reinforced Carbon-Carbon panels on the left wing of the Columbia [2]
As pointed out by the NASA operator, mission STS-107 was not the first time that the left bipod
ramp foam loss was observed; the Columbia launch observed the seventh event take place [5].
The repeated failure to address this issue can be attributed to productive pressures, breakdowns
in communication, and excessive formalism. [5].
1.2.1 Productive Pressures
The presence of budgets and time constraints from higher levels of organization often affects the
abilities of the subordinates to perform as expected. During the 1990s, the prevailing idea held
by the NASA leadership was “Faster, Better, Cheaper” [5]. In order to maintain the faster and
cheaper production process, quality was often foregone. According to members of the
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investigation board who studied the case, this neglection of safety as a primary concern was a
primary root cause for the incident [4].
1.2.2 Breakdowns in Communication
There was very little correspondence exchanged between the mission management and the
shuttle crew. Although the crew was informed of the incident, they were not informed about the
uncertainties and discussion pertaining to it [6]. This excluded the crew from participating inn
decisions that had the potential to affect their safety.
1.2.3 Excessive Formalism
On the seventh day of the Space Shuttle mission, a member of Nasa’s Debris Assessment Team
composed an email regarding his thoughts on the decision to ignore the problem. He stated that
“the heating and resulting damage to the underlying structure at the most critical location [. . .]
could present potentially grave hazards” [5]. When questioned about his reluctance to send the
email, he explained that did not want to jump the chain of command (he did not want to confuse
a previous request for imagery [5].
2 Failure Analysis Methods
There was a significant amount of testing that went into the investigation of the failure. All of
these testing methods can be accessed via source [2]. This paper will only focus on a select few
of these testing methods.
2.1 Destructive Testing Methods
In order to recreate the impact of the insulating foam onto the left wing of the shuttle, the
Columbia Accident Investigation Board fired a foam projectile with a compressed-gas gun at a
flight-worthy Reinforced Carbon-Carbon panel (Figure 3) [2]. In order to determine the speed
and mass of the projectile, photo and transport analyses were conducted. In order to eliminate
discrepancies in aging hidden variables, the RCC panel 8 from the Atlantis space shuttle (which
had flown 26 missions) were used during testing. It must be noted that RCC panel 8 was tested
alongside RCC panel 6 from the Discovery space shuttle before it was discovered that the impact
occurred on panel 8 [2]. These results will be excluded from this paper.
The 1.67-pound reference insulating foam projectile impacted RCC panel 8 at 777 feet per
second at an angle of 30 degrees (or at a 25.1-degree incidence angle with the panel). It created a
hole approximately 16 inches by 17 inches, which was within range of the photographic findings
(Figure 4).
These results support the hypothesis that the impact sustained by the Columbia could have very
well created an entry point for atmospheric gases to affect the structural integrity of the Orbiter’s
left wing [2].
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2.2 Non-Destructive Testing Methods
Figure 3 -- an image of the testing assembly used to recreate the launch failure [2]
Figure 4 -- an image of the hole created by the test projectile on RCC panel 8 [2]
LS-DYNA is a general-purpose software that can simulate physical phenomena. It was used to
model the impact of the insulating foam onto RCC 8 prior to the construction of a physical
testing model. A total of 25 parts were designed for the model. 59,360 shell elements were used
to create the RCC panel assembly while 11, 636 shell elements were used to create the foam
projectile (Figure 5) [1].
6 milliseconds after impact, a hole on the RCC panel assembly was evident (Figure 6). The result
was a hole that correlated well (both qualitatively and quantitatively) with the hole observed in
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the physical test and by extension, the hole created during the failure event. LS-DYNA
successfully recreated the failure and supported the investigation’s hypothesis.
Figure 5 -- a render of the LS-DYNA model created to test the effect of the foam projectile on the RCC panel [1]
Figure 6 -- a render of the impact of the foam projectile on the RCC assembly 6 milliseconds after impact [1]
3 Recommendations
From the email correspondence exchanged by NASA and the shuttle crew and the successful
prediction of the failure event by LS-DYNA, it is clear that the catastrophe could have been
prevented if sufficient analysis went into understanding the failure before re-entry. A
culmination of systematic flaws led to a larger catastrophic failure and costed the lived of
Columbia’s crew. In order to prevent the reoccurrence of such an event, there are a few key
recommendations that must be considered for future missions.
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3.1 On the Design of the Space Craft
Future vehicle designs be optimized for the “most graceful degradation of vehicle systems and
structure to enhance chances for crew survival” [3]. Failure should be expected and should be an
optimal factor for future designs. Future spacecraft should undergo rigorous evaluations for loss
of control motion and dynamics.
3.2 On the Prevention of Failure Reoccurrence
If a design has proven to fail on multiple occasions, it should be a top priority to ensure that it
does not occur again. Because space craft are designed to be as light as possible, every
component has a purpose. If the component fails, it has the potential of damaging the system to
which it belongs or others around it (as was evident by the Columbia accident).
3.3 On Communication within NASA and Crew Awareness
There should be complete transparency between NASA and the mission crew on any failures that
occur during the mission. There should also be no restrictions on who can be contacted regarding
a safety concern during a mission, regardless of their position in the chain of command.
3.4 On the Design of Survival Suits Survival suits should be able to withstand high/low pressures, high/low temperatures, windblast
and chemical exposure [3]. Areas where the suits are weakest should be strengthened.
4 Conclusion
Spacecraft are amongst the most complicated machines that humans have built, and thus have
many possible points of failure. All of these points of failure must be accounted for prior to
launch to prevent major catastrophes. In the event of a failure, all possible action must be taken
to secure the safety of the personnel onboard. Failures should never be ignored to satisfy time
and money quotas.
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References
[1] E.L. Fasanella, K.H. Lyle. J. Gabrys, M. Melis and K. Carney, “Test and Analysis
Correlation of Form Impact onto Shuttle Wing Leading Edge RCC Panel 8,” 8th
International LS-DYNA Users Conference. [Online]. Available:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.408.1272&rep=rep1&type=pdf
[2] “Columbia Accident Investigation Board Report,” vol. 1, Government Printing Office,
Washington D.C., 2003. [Online]. Available:
https://www.nasa.gov/columbia/home/CAIB_Vol1.html
[3] “Columbia Crew Survival Investigation Report,” Engineering, Government Printing
Office, Washington D.C., 2003. [Online]. Available:
https://www.nasa.gov/pdf/298870main_SP-2008-565.pdf
[4] A. Boin, D. Fishbacher-Smith, “The importance of failure theories in assessing crisis
management: The Columbia space shuttle revisited,” Policy and Society, no. 30, pp. 77-
87, 2011.
[5] Y. Dien, M, Llory, “Effects of the Columbia Space Shuttle Accident on High-Risk
Industries or Can We Learn Lessons from Other Industries?” IChemE, Symposium
Series, no. 150, 2004.
[6] J.S. Stich to CDR AND PLT, “INFO: Possible PAO Event Question,” January 23, 2003.
