Thermal Micrometeoroid Garment

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

The TMG has three functions: to insulate the suit occupant and prevent heat loss, to shield the occupant from harmful solar radiation, and to protect the astronaut from micrometeoroids and other 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.

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.