Engineering topics

Jacquemin, G. G.

Publications and source records attributed to Jacquemin, G. G..

8 records

NASA NTRS1987

Large Deployable Shroud

Preliminary design proposed for large, lightweight telescope shroud or light shield carried to orbit in single Space Shuttle cargo load. Shroud concept applied on Earth in portable, compactly storable displays or projection screens. Large telescope shroud includes four deployable masts erecting eight walls of hinged panels of polyimide film. Panels stored fanfolded before deployment and threaded on guide wires unwinding from spools and remain taut during deployment.

Jacquemin, G. G.↗

NASA NTRS1985

Drag-compensated, precision-powered hinge system

The design of a high precision powered hinge is complicated by the unavoidable presence of parasitic drag torque resulting mainly from friction and transfer of power, signals, and fluids across the hinge. Regardless of the type of drive system selected, it is impossible to completely eliminate all parasitic drag. However, the mechanism described here comes very close to providing a drag free system. All sources of parasitic drag torque are collected on a shaft which is powered by an electric motor independent of the main hinge drive. Under control of a sensor, the electric motor applies a compensating torque equal to that of the parasitic drag torque, allowing the main hinge drive to operate in a practically drag free environment with very high positioning precision.

Jacquemin, G. G.↗

NASA NTRS1985

Automatic Erection System for Antenna Masts

A telescoping mast does not require the payout of guy wires under tension. Erection system is built into stack of telescoping mast elements and is thereby protected from the weather. Concept is based on a telescoping tube mast, it is also applicable to an open truss with only minor modifications.

Dotson, R. D.↗

NASA NTRS1981

Spacecraft automatic umbilical system

An umbilical system design is described that incorporates all the features specified for a power system to payload interconnect capability. A proof-of-concept prototype of the umbilical system was built to determine experimentally the suitability of the threading characteristics of the ram mechanism and to verify freedom from cross threading. It is concluded that Berthing systems that utilize remote manipulator systems (RMS) can be simplified by using RMS targets, closed circuit TV cameras, tie into the RMS control system, and grapple-fixture and end-effector-like capture and secure mechanisms. To effect a remotely controlled umbilical interconnect in proximity with a manned spacecraft and to provide for extravehicular activity backup and maintenance capabilities, 18 different mechanisms are found to be necessary. The weight impact of proving for maintenance capability in a large multiple connector umbilical system was found to be in the order of +60 percent.

Goldin, R. W.↗

NASA NTRS1981

A concept for high speed assembly of erectable space platforms

A simple, fully automatic assembler associated with the on-orbit assembly of tetrahedral truss platforms erected of graphite epoxy tapered columns is described. The assembler, which can operate either as a free flyer or attached to the Orbiter, is capable of constructing a platform from a full load of truss columns and node joints in 36 hours. The geometry of this electrically-driven machine is based on a compound parallelogram system which permits backward as well as lateral translations. Concepts have been developed for half-column assembly as well as for column and node joint insertion into the platform.

Cohan, H.↗

NASA NTRS1980

Development of assembly and joint concepts for erectable space structures

The technology associated with the on-orbit assembly of tetrahedral truss platforms erected of graphite epoxy tapered columns is examined. Associated with the assembly process is the design and fabrication of nine member node joints. Two such joints demonstrating somewhat different technology were designed and fabricated. Two methods of automatic assembly using the node designs were investigated, and the time of assembly of tetrahedral truss structures up to 1 square km in size was estimated. The effect of column and node joint packaging on the Space Shuttle cargo bay is examined. A brief discussion is included of operating cost considerations and the selection of energy sources. Consideration was given to the design assembly machines from 5 m to 20 m. The smaller machines, mounted on the Space Shuttle, are deployable and restowable. They provide a means of demonstrating the capabilities of the concept and of erecting small specialized platforms on relatively short notice.

Jacquemin, G. G.↗

NASA NTRS1980

Automatic connector joins structural columns

Connector snap-locks over toothed bolthead mounted on column end, forming rigid joint that will not bend or twist. Connector is used in conventional construction to install temporary structures or as mechanical coupler. Up to nine receptacles can be clustered in one node to join up to nine converging columns.

Jacquemin, G. G.↗

NASA NTRS1979

Automatic in-orbit assembly of large space structures

The automated assembly of a large number of components required for the on-orbit erection of large tetrahedral space platforms is described. The assembly machine is a huge jig in which a multitude of mechanisms must operated continuously in the thermo vacuum environment of space and under the control of computers programmed to command every step of each motion. The concepts are presented to determine the most reliable solution. Continuous operation of mechanisms in space presents many unresolved problems, with regard to lubrication of unprotected devices, such as chain drives, which must maintain reasonable positioning tolerances.

Jacquemin, G. G.↗