Martin Marietta Corporation

Leo J Amore

Susan L Marr

Alexander Bogorad

Charles K Bowman, Jr

Albert Lepore, Jr

Theodore A Harris, Jr

Hamilton Wong

William P Saylor

An antenna array for use in space includes an optical solar reflector (OSR)-like structure (310, 510), with sheet of transparent dielectric material (320, 520) and a metallic mirror (322, 522) formed on the sheet. In order to allow the individual antenna elements to radiate electromagnetic energy, the metallic mirror contains apertures (330, 530) which, in one embodiment, define the antenna elements, and which, in another embodiment, are registered with the antenna elements of the array. Where the mirror exists, insolation is reflected, and the heat gain from insolation is minimized. At the locations of the apertures in the mirror, insolation passes through the OSR-like structure, which may tend to increase the temperature of the structure. According to the invention, the apertures are covered with a thin layer (370, 570) of semiconductor material such as germanium or silicon, which does not affect the electromagnetic energy flow. The semiconductor tends to reflect visible light, thereby restoring a substantial amount of the function of the OSR. The semiconductor also emits heat energy, which allows heat to radiate from the apertures to aid in controlling temperatures.

Heat rejecting spacecraft array antenna

A thermal control surface for a spacecraft includes flexible OSR tiles (310) 0.0015 inches thick. Each tile includes a transparent substrate (312) with a reflective second surface (314), such as a coating of silver. The front or space-facing side is coated with a transparent, electrically conductive layer (316) of indium oxide (IO) or indium-tin oxide (ITO), which laps over the edges of the OSR tile, and is in electrical contact with the reflective coating. The IO or ITO coating, or a separate electrically conductive coating (610) such as nichrome, forms a protective coating for the reflective surface, and maintains contact with the front surface of the tile. The IO or ITO layer (316) in conjunction with the back side coating provides front-to-back electrical conduction. The OSR is mounted to an electrically conductive surface (110) of the spacecraft, such as an aluminum or graphite-fiber-reinforced epoxy resin, by a sheet of transfer adhesive (410). In one embodiment of the invention, the transfer adhesive is electrically conductive, thereby providing an electrostatic discharge path from the outer surface of each OSR to the spacecraft ground. The size of the OSR tile is maximized relative to the inter-tile spacing, to achieve the greatest ratio of reflective-to nonreflective surface.

Optical solar reflector and mounting method

An RF-transparent sunshield membrane covers an antenna reflector such as a parabolic dish. The membrane includes a single dielectric sheet of polyimide film 1 mil thick. The surface of the film facing away from the reflector is coated with a layer of semiconductor material such as vapor-deposited germanium having a thickness in the range of 200 .ANG. to 600 .ANG.. In another embodiment of the invention, the surface of the film facing the reflector may be reinforced by an adhesively attached polyester or glass fiber mesh.

Optimized RF-transparent antenna sunshield membrane

An RF-transparent sunshield membrane covers an antenna reflector such as a parabolic dish. The membrane includes at least two dielectric sheets of polyimide film 1 mil thick. The surface of the outer film facing away from the reflector is coated with an electrically semiconductive coating such as vapor-deposited germanium having a thickness in the range of 200 .ANG. to 600 .ANG.. A member, such as a glass fiber mat, may be located in the space between the two dielectric sheets for maintaining the sheets in spaced-apart relationship. In another embodiment of the invention, the surface of the film facing the reflector may be reinforced by an adhesively attached polyester or glass fiber mesh.

Growing community of inventors

Phoenixville, PA, United States of America

Leo J Amore