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Shuttle foam shedding
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My e-mail exchange with NASA

At 01:04 PM 8/10/2005, I sent e-mail to Dr. Richard Gilbrec: (NASA):

Shuttle piggybacking on an external foam insulated tank is conceptually wrong, since foam always have tendency to peels during lift-off. How I see, it is because during lift-off tank violently vibrates (jerks). These jerks produce foam shake-off (“bathing birds”) effect. In addition,   small packets of high-low air pressure are created around a tank. As a result, we have tearing off forces applied to the foam. Every shuttle launch is a Russian roulette enterprise. We are lucky that for many years we were very lucky.

One of the possible (temporary) solutions to this problem is to apply over foam a high-temperature-resistant external coating. In addition, to smother a lift-off, a current vehicle stabilization control system must be replaced by a system with significantly shortened reaction time.



On the same day, I received a reply::


Dear Mr. Flikop,
  Your suggestion to Dr. Richard Gilbrech has been received by the NASA Engineering and Safety Center (NESC) system.  Thank you for contacting NESC and for your suggestion on the use of a high-temperature-resistant external coating applied to the foam of the External tank and your comment to replace the current vehicle stabilization control with one with a shortened reaction time to respond to lift-off emergencies. We will review your submittal through our NESC review process (Dr. Gilbrech is part of this process) to determine the appropriate course of action.  I will provide the results of the NESC review to you.  In the meantime, if you have any questions, please feel free to contact me.

Thank you!
Peggy Chun

Systems Engineering Office

NASA Engineering and Safety Center



At 12:24 PM 8/23/2005, I sent another e-mail::

Dear Peggy,
I want to add some corrections to my message.

To find a reason why foam is shedding from the external tank, NASA has to consider that tank is a FLEXIBLE body filed with liquid. During liftoff, tank deforms in all three dimensions. Deformed tank skin cracks foam and loosens it.
Shivering of a tank skin, tank vibrations, trajectory correction jolts and small packets of high-low air pressure created around a tank produce a foam shake-off (“bathing birds”) effect.
A highly-tear-resistant and flexible coating applied over the foam can prevent its shedding.


On 8/25/2005 I received a reply::


Dear Mr. Flikop,
  Sorry it has taken me awhile to respond to you.  I have been on travel status this week to a different NASA center.  Thank you for the additional observation.  I will add this to your original submittal to enhance the information.  Please feel free to contact me if you have any additional information or questions.  I do not have any results of the on-going reviews, yet.

   Peggy Chun

Systems Engineering Office

NASA Engineering and Safety Center



On 11/16/2005, I received the following e-mail:


Dear Mr. Flikop:
This is an update of the status on the review of the suggestion which you submitted to the NASA Engineering and Safety Center (NESC) regarding coating the External Tank foam and some additional information.  The NESC has reviewed your suggestion through our NESC processes and determined that it should be given to two technical groups set up to establish both the root cause of the foam problems and to determine and implement a solution.  As a result, the NESC has already forwarded a copy of your suggestion to the technical tiger team (composed of NASA, industry and academic experts) investigating the External Tank foam debris anomalies and we plan to provide your recommendation directly to the Shuttle Program for additional review.  Due to the overwhelming number of suggestions, the Shuttle Program will not contact you directly unless your idea is implemented, but should you have any questions regarding the status, please feel free to continue to contact Ms. Chun or myself.

Answers to email inquiries about foam loss have been posted by the Shuttle Program at: http://www.nasa.gov/returntoflight/main/email_responses.html.  


For further information about the possible causes of the foam loss and recommendations by the External Tank Tiger Team please see the External Tank Tiger Team Interim Report at: http://www.nasa.gov/pdf/136219main_FS_ET_Tiger_Team_Report.pdf. 


Thank you!  We appreciate your concern, your ideas and your thoughts.


Mark Terrone
NASA Engineering and Safety Center

Systems Engineering Office