Poll: Significance of WLE Upgrade

Years before the Columbia tragedy, NASA had identified a need to
upgrade the orbiter's wing leading edges in order to address their
assessment that "...the risk of a catastrophic puncture of an Orbiter
wing leading edge has increased." (quoted from
http://spaceflight.nasa.gov/shuttle/upgrades/wle.html)

But this upgrade was subsequently cancelled due to a reprioritization
of funding, so none of the orbiters had gotten this increase in
robustness for their wing leading edges.

CAIB determined that the STS-107 LOCV occurred due to a catastrophic
puncture of Columbia's wing leading edge, but their final report makes
no mention of the WLE MMOD Protection Upgrade.

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If you were a CAIB member, how would you rate the relevance
of the cancelled WLE upgrade?

a) Critical. It was a key part of the story that needed to be told
in Vol 1 of the final report.
b) Important. It needed to be mentioned
in Vol 1 of the final report.
c) Relevant, but less important. It needed to be included
in one of the follow-on appendices (Vol 2-6).
d) Irrelevant. It was proper for CAIB to not mention
the cancelled WLE upgrade in the final report.
e) Other.

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~ CT

On 31 Mar 2004 21:03:26 -0800, (Stuf4) wrote:

If you were a CAIB member, how would you rate the relevance
of the cancelled WLE upgrade?

d) Irrelevant. It was proper for CAIB to not mention
the cancelled WLE upgrade in the final report.

Nice try...

Dale

Well, there was at least one other person who cares enough about this
topic to post their input here.

http://spaceflight.nasa.gov/shuttle/upgrades/wle.html)

There may be others in the future who will want to reference this
page, so here's the text in its entirety:

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NATIONAL AERONAUTICS
AND SPACE ADMINISTRATION HUMANSPACEFLIGHT
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Wing Leading Edge Micro-Meteoroid Orbital Debris Protection
(WLE MMOD)


Problem: With the increase of Orbital debris due to space craft
events, the risk of a catastrophic puncture of an Orbiter
wing leading edge has increased. With a puncture, heat
from the plasma during entry will erode the Inconel foil
of the insulators exposing the wing front spar and attach
fittings to the plasma. Previously, the Shuttle Program
has reduced this risk by flying attitudes that provide
the maximum protection from debris. In evaluation of
International Space Station (ISS) assembly and support,
the Orbiter attitude is driven by ISS and cannot adjust
attitude to protect the WLE.

Solution: Design being implemented provides additional insulation
(Nextel 440 fabric) behind the Inconel foil for WLE
panels 5-13.

Initial Phase II Upgrade
Operation OV-102 STS-103 (12/2/99)
Date: OV-103 STS- 97(4/8/99)
OV-104 STS-92 (1/14/99)
OV-105 STS-96 (12/9/98)

Technology No new technologies involved.
Goal:

Goals 1) Fly Safely
Supported: [http://spaceflight.nasa.gov/shuttle/...es/goals.html]

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Curator: Kim Dismukes | Responsible NASA Official: John I. Petty |
Updated: 04/07/2002
Web Accessibility and Policy Notices


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~ CT