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Experimental impacts into teflon targets and ldef thermal blankets
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Bernhard, R. P. Cintala, M. J. Zolensky, M. E. Hoerz, F. See, T. H. |
| Copyright Year | 1994 |
| Description | The Long Duration Exposure Facility (LDEF) exposed approximately 20 sq m of identical thermal protective blankets, predominantly on the Ultra-Heavy Cosmic Ray Experiment (UHCRE). Approximately 700 penetration holes greater than 300 micron in diameter were individually documented, while thousands of smaller penetrations and craters occurred in these blankets. As a result of their 5.7 year exposure and because they pointed into a variety of different directions relative to the orbital motion of the nonspinning LDEF platform, these blankets can reveal important dynamic aspects of the hypervelocity particle environment in near-earth orbit. The blankets were composed of an outer teflon layer (approximately 125 micron thick), followed by a vapor-deposited rear mirror of silver (less than 1000 A thick) that was backed with an organic binder and a thermal protective paint (approximately 50 to 75 micron thick), resulting in a cumulative thickness (T) of approximately 175 to 200 microns for the entire blanket. Many penetrations resulted in highly variable delaminations of the teflon/metal or metal/organic binder interfaces that manifest themselves as 'dark' halos or rings, because of subsequent oxidation of the exposed silver mirror. The variety of these dark albedo features is bewildering, ranging from totally absent, to broad halos, to sharp single or multiple rings. Over the past year experiments were conducted over a wide range of velocities (i.e., 1 to 7 km/s) to address velocity dependent aspects of cratering and penetrations of teflon targets. In addition, experiments were performed with real LDEF thermal blankets to duplicate the LDEF delaminations and to investigate a possible relationship of initial impact conditions on the wide variety of dark halo and ring features. |
| File Size | 177581 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19940031634 |
| Archival Resource Key | ark:/13960/t6p033j63 |
| Language | English |
| Publisher Date | 1994-01-01 |
| Access Restriction | Open |
| Subject Keyword | Astrophysics Earth Orbital Environments Thermal Insulation Projectile Cratering Sandwich Structures Spacecraft Construction Materials Hypervelocity Impact Binders Materials Silver Penetration Delaminating Oxidation Long Duration Exposure Facility Impact Damage Teflon Trademark Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
