| 摘要 |
PURPOSE: To emit heat stored in a heat protective system at a high flight altitude to the external at a low flight altitude by reducing the diameter of fibers and/or increasing density of fiber layers from outer parts inward in a multilayer heat insulating material. CONSTITUTION: In a packet to synthesize a multilayer heat insulating material to insulate a spacecraft, an enclosure body 14 comprising ceramic filler 11 enclosed has a high-reflectance, it is separated by a gas-permeable metal foil 12, and the inner side of it is covered with polyimide foam material 13. Density of the ceramic filler 11 is increased from outer parts inward, and its average fiber diameter is reduced from outer parts inward. With the multilayer heat insulating material in the above constitution, heat stored in a heat protective system at a high flight altitude can be emitted to the external at a low flight altitude in a transition period of re-entry into atmosphere. |
