Causes of the Space Shuttle Columbia disaster

This presentation explores the causes of the Space Shuttle Columbia disaster, including inadequate design of the bipod ramp and foam application, and underestimation of risks.

Causes of the Space Shuttle Columbia disaster
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Space Shuttle Columbia and Challenger disaster
• A space shuttle is a reusable spacecraft and one of its kind in the world history
capable of carrying large satellites to and from the earth’s orbit.
• Space Shuttle Columbia was the first orbiter delivered to NASA in 1979.
• The second orbiter to be delivered to NASA in 1983 was the Challenger which
completed about 9 missions before exploding during ascent in 1986 while on
the tenth mission about 73 seconds into lift (Weiser et al., 2004).
• The Columbia shuttle disaster could have been prevented if proper
considerations were taken during the first disaster of the Challenger shuttle.
• This presentation therefore illuminates on the relationship between Challenger
and Columbia disaster and the causes of the Columbia shuttle disaster.

Space Shuttle Columbia
• The space shuttle Columbia completed 112 space missions successfully
since 1979 to 2003 however, the 113th mission was unsuccessful.
• After 15 days of successful data collection and orbit exploration by the
STS-107 flight crew from 16th January 2003, the shuttle broke apart on
re-entry into earth’s orbit on 1st February 2003, and all its debris and
crew’s remains spread all over Texas and Louisiana (Columbia Accident
Investigation Board (CAIB), 2003).
• This was a tragic day for NASA and the US since all the crew members
died.
• It was the first shuttle to the program and the second to incur disaster.

Causes of space shuttle Columbia
disaster
• The space shuttle Columbia disaster emerged due to several
factors some of which are listed below;
• Inadequate design of the bipod ramp on the external tank in
relation to the poor understanding of the foam and its
application.
• Inadequate decision making with regards to dismissal of
technical concerns and underestimation of the risks
associated (Columbia Accident Investigation Board (CAIB),
2003).

Inadequate design of the bipod
ramp
• The bipod ramp attaches the orbiter to the external tank as two umbilical fittings which
contains fluid and electrical connections between the two compartments.
• The area of attachment is by fittings of titanium forgings bolted to the external tank.
• The area where the bipod struts attaches to the external tank is structurally,
geometrically and materially complex in terms of its construction and fitting.
• The complex nature of this region requires detailed and disciplined foam application
failure of which might result in foam shedding.
• Furthermore, the external tank was designed some decades ago thus the facets were
designed in relative isolation one after the other for instance thermal and structural
facets hence, the geometric complexity of its location and the structurally optimum
fitting design posed many challenges in terms of ramp defects (Columbia Accident
Investigation Board (CAIB), 2003).

Inadequate understanding of
foam• Foam constitutes the thermal protection system of the external tank as insulates it efficiently by
maintaining internal and external temperatures to keep oxygen and hydrogen in liquid state while
preventing ice and frost formation on tank surface.
• Foam as a material has not yet been clearly understood in terms of properties and its
composition.
• For instance, foam exhibits different properties while in motion and there are also several
variabilities regarding aspects such as its composition.
• Since it is of hollow cells, its composition often varies and this together with the many differential
properties it is often very difficult to model analytically or characterize physically thus posing a
difficulty in predicting its response in different conditions such as during launch and ascent of the
shuttle (Columbia Accident Investigation Board (CAIB), 2003).
• Very little effort has been taken over the years to clearly understand these properties thus some
of the disasters such as the Columbia shuttle could have been contributed to by this lack of
proper understanding of foam.

Inadequate foam application
• Foam application criteria in the bipod region also posed as a great source of variability.
• Since foam is composed of two chemical components, mixing these chemicals should be
to the specified ratios failure of which could result in foam complications.
• The foam used in space shuttles is of the hand spraying variety which often requires
certain parameters during application more so in the complex bipod region.
• For instance, the foam application should be uniform in all aspects such as distance of
application and time taken to ensure adequate rise and cure before next application.
• The foam also requires specific conditions such as temperatures and humidity in order
to be perfectly blended between the layers and observing these requirements is often
not an easy task since it requires specialists and failure to adhere to the foam
application criteria results in voids, pockets and eventually debris which may cause
disasters as in the case of Columbia shuttle (Weiser et al., 2004).

Inadequate decision making
• Extracted from the investigatory reports, it is also evident that among the
causes of the Columbia shuttle disaster was ignorance by NASA’s team of
scientists relating to some pre-existing situations such as foam shedding.
• Therefore;
• Several of the risks were immensely underestimated by the team.
• There was also continued dismissal of some technical concerns.
• These factors derailed the decision making process regarding the shuttle
(Columbia Accident Investigation Board (CAIB), 2003).

Underestimation of the risks
• Despite the fact that several ‘foam shedding’ had occurred in several of the
previous shuttle launches, the effects were insignificant in that there was no
impacts felt or mission derailment of any way.
• Therefore, the impact that could be caused by the debris from external tank,
foam, was severely underestimated until the Columbia shuttle disaster which
was mainly associated with brief case size foam shedding (Columbia Accident
Investigation Board (CAIB), 2003).
• Furthermore, despite the team of engineering realizing that there was a dent in
the reinforced carbon-carbon panels, they allowed the shuttle back to earth
without fixing the panels as they assumed that the risk was minimal just as the
previous others however they were wrong and the shuttle broke apart.

Dismissal of technical concerns
• According to the reports by the Columbia Investigation Board, it was evident that
the experts at NASA and a team of engineering had a chance to view a footage of
the shuttle uplift and they were able to deduct from the video that a foam debris
had struck the orbiter’s left wing at around 81.7 seconds after launch.
• The next course of action was to analyze the situation and deduct conclusions,
however, despite the fact that there was a possibility that the damage might have
created an air pocket in the wing, this problem was dismissed and upon re-entry,
this was confirmed as superheated air penetrated the insulation melting the
aluminum structure of the wing making the orbiter to loose control and break
apart upon re-entry (Columbia Accident Investigation Board (CAIB), 2003).
• This technical concern was dismissed and it resulted in catastrophic consequence.

Conclusion
• In conclusion, the Columbia space shuttle disaster arose due to several
factors some of which include inefficient bipod ramp design,, inadequate
understanding of foam and its application.
• Furthermore, relating to the disaster is also the issue of ignorance on decision
making by dismissing technical concerns and underestimating risks.
• For several years now a similar disaster has not occurred and this could be
attributed to the efforts being made by NASA scientists regarding deeper
understanding and research on foam, bipod ramp and covering all the bases
during a mission.

References
• Columbia Accident Investigation Board (CAIB) 2003, Report volume 1,
(HW Gehman, Chairman), NASA and the Government Printing Office,
Washington, D.C.
• Weiser, ES, St. Clair, TL and Nemeth, MP 2004, Assessment of
technologies for the Space Shuttle External Tank Thermal Protection
System and recommendations for technology improvement Part 1:
materials characterization and analysis, NASA Center for Aerospace
Information, Hanover, Maryland.