ORIENTATION LINKAGE FOR A SOLAR CELL ARRAY: OL SCA.
Final rept. 1 Jul 67-30 Jun 68,
HUGHES AIRCRAFT CO EL SEGUNDO CA SPACE SYSTEMS DIV
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A 12-month program was conducted to develop the technology for actively orienting 12- to 20-kw solar-cell arrays on actively and passively stabilized earth-oriented satellites with mission lifetimes of 3 to 5 years. A detailed design for linkage capable of carrying a 5-kw array was developed. Consideration of the general design requirements led to specification of a two-degree-of-freedom gearless mechanism incorporating sun sensing, direct shaft torquing, and power transfer by slipringbrush assemblies. Load conditions and life requirements allowed incorporation of dry-lubrication techniques throughout. It is shown that specification of relatively short sun-acquisition times for this type of system penalizes the design unnecessarily. In the general case, the mission vehicles control system should include an adequate angular-momentum storage device as well as reaction-jet attitude controls. The residual atmosphere precludes operating for any appreciable period in orbits below 400 n. mi. altitude. Satisfactory performance of dry, self-lubricating composites was demonstrated for bearing lubrication and for motor, power, and signal transfer brushes. Author
- Unmanned Spacecraft