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Effect of Air and Vacuum Storage on the Tensile Properties of X-Ray Exposed Aluminized-FEPMetallized Teflon(Registered Trademark) FEP (fluorinated ethylene propylene), a common spacecraft thermal control material, from the exterior layer of the Hubble Space Telescope (HST) has become embrittled and suffers from extensive cracking. Teflon samples retrieved during Hubble servicing missions and from the Long Duration Exposure Facility (LDEF) indicate that there may be continued degradation in tensile properties over time. An investigation has been conducted to evaluate the effect of air and vacuum storage on the mechanical properties of x-ray exposed FEP. Aluminized-FEP (Al-FEP) tensile samples were irradiated with 15.3 kV Cu x-rays and stored in air or under vacuum for various time periods. Tensile data indicate that samples stored in air display larger decreases in tensile properties than for samples stored under vacuum. Air-stored samples developed a hazy appearance, which corresponded to a roughening of the aluminized surface. Optical property changes were also characterized. These findings indicate that air exposure plays a role in the degradation of irradiated FEP, therefore proper sample handling and storage is necessary with materials retrieved from space.
Document ID
Document Type
Preprint (Draft being sent to journal)
deGroh, Kim K.
(NASA Glenn Research Center Cleveland, OH United States)
Gummow, Jonathan D.
(Ohio Aerospace Inst. Brook Park, OH United States)
Date Acquired
September 7, 2013
Publication Date
May 1, 2000
Subject Category
Nonmetallic Materials
Report/Patent Number
NAS 1.15:210066
Meeting Information
Materials in a Space Environment(Arachon)
Funding Number(s)
Distribution Limits
Work of the US Gov. Public Use Permitted.

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