Hughes Aircraft Company

Preston S DuPont

Robert E Ritter

John P Stafford

M Edmund Ellion

Howard H Rogers

Norman Bilow

Kenneth A Fouts, Iii

Brent G Schaffer

Robert A Meese

Brian A McGrath

A protective coating for solar cells, particularly solar cells positioned in space and which coating is a polyimide which is colorless, transparent, relatively non-brittle, has a high degree of thermal stability and readily transmits solar radiation without appreciable degradation. The coating is heat resistant and does not degrade significantly when exposed to ultraviolet radiation, and is highly effective in repelling low energy proton particles. In a preferred embodiment, the protective polymide coating is a polymer having the following recurring structural unit: ##STR1##

Polyimide composition and method for protecting photoreactive cells

A honeycomb facesheet material, and honeycomb made therewith, wherein the facesheet includes a layer of graphite paper bonded to a layer of graphite cloth, woven from widely spaced graphite fibers. The facesheet is impregnated with an epoxy resin during manufacture, and the facesheet is bonded to an open end of the honeycomb under elevated pressure and temperature to effect curing of the epoxy resin. The graphite paper supports the layer of graphite cloth during handling to prevent misalignment of the fibers, and also effects a widely distributed bond between the fibers and the underlying honeycomb.

Honeycomb facesheet material and honeycomb made therewith

Conductive coating (20) is a thorough mixture of 0.03 parts per weight of carbon black together with 0.003 to 0.01 parts per weight of wetting agent and 20 parts of solvent, and further mixing in by low shearing mixing 1/2 to 1 part per weight of thermosetting resin. This is then sprayed into place on the substrate and thermoset. In this particular case, the substrate is exterior face sheet (12) of honeycomb structure (10) which may serve as part of a spacecraft, to electrically conduct away surface charges.

Conductive coating

Electrically conductive composite structure

Conductive coating (20) is produced by the process of first mixing by high shear mixing a mixture of 0.03 parts per weight of carbon black together with 0.003 to 0.01 parts per weight of wetting agent and 20 parts of solvent, and further mixing in by low shear mixing 1/2 to 1 part per weight of thermosetting resin. Prior to application this is then sprayed into place on the substrate. In this particular case, the substrate is exterior face sheet (12) of honeycomb structure (10) which may serve as part of a spacecraft, to electrically conduct away surface charges.

Conductive coating process

Specific impulse of hydrazine thruster is augmented by electrothermally heating the hot gas in heater passages 36 and 37 as it passes from hydrazine dissociation chamber 14 to thrust nozzle 28. Tubular ceramic electric resistance heater 31 performs primary heating. Specific impulse can be raised from 230 to 300 seconds.

Electrothermally augmented hydrazine thruster

Substrate for nickel hydrogen battery electrode is etched from nickel sheet metal to provide inner and outer rims 54, 56 for self centering, a tab 62 on which a lead can be welded and properly distributed openings through conductors for optimum ion flow and electric conduction.

Growing community of inventors

Northridge, CA, United States of America

Preston S DuPont