Thermal Micrometeoroid Garment

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Cross-section of layers in space suit construction

An (Integrated) Thermal Micrometeoroid Garment (TMG or ITMG) is the outer layer of a

orbital debris, which could puncture the suit and depressurize it. (This latter function is provided for spacecraft by Micrometeoroid and Orbital Debris (MMOD) Protection systems.[1]
)

The specific design of TMGs varies between different

space agencies
and different suits, though they all serve the same purpose.

A7L suit (Apollo/Skylab)

Micrometeoroid impacts in Beta cloth

Outside a

lunar dust. This layer was supplemented with Teflon abrasion patches at the knees and other areas.[2]

EMU suit (Space Shuttle/ISS)

The construction of the TMG on the EMU suits in use on the Space Shuttle and International Space Station differs somewhat from the construction of the Apollo/Skylab TMG.

The EMU TMG includes seven layers of aluminized Mylar laminated with Dacron, rather than five, and eliminates the use of Kapton. The outermost layer is white Ortho-Fabric, made with a blend of Gore-Tex, Kevlar, and Nomex. This layer can withstand temperatures from −300 to 300 °F (−180 to 150 °C). The outer layer provides both micrometeoroid and thermal protection, by reflecting most of the sun's thermal radiation.

References

  1. ^ "Micrometeoroid and Orbital Debris (MMOD) Protection" (PDF). NASA. Archived from the original (PDF) on December 26, 2010. Retrieved 2013-05-10.
  2. ^ Carson, Maurice A.; Rouen, Michael N.; Lutz, Charles C.; McBarron, James W. II. Biomedical Results of Apollo - Section VI - Chapter 6 - Extravehicular Mobility Unit. Lyndon B. Johnson Space Center.