Abstract: A mast defined by three flexible longerons with cross elements coils into a canister. Extension and retraction are controlled by three axially oriented lead screws which engage protuberances spaced along the longerons. The lead screws are mutually synchronzied by an annular planet gear, and are driven by a spiroidal gear set. At a predetermined mast extension, motor drive is switched over for rotation of the mast rather than extension-retraction. The switch over is controlled by an actuator in the form of a movable guide element dimensioned to clear normal-sized protuberances but to be seized and carried by an oversize protuberance at the desired mast extension. The actuator is coupled to a lock which unlocks the annular gear to the canister so that motor drive results in mast rotation. An auxiliary lock allows re-locking of the canister to the support structure for allowing resumption of the mast extension-retraction mode.

Abstract: A plurality of indexing brackets having indexing apertures are secured to a retractable boom in spaced relation. A like plurality of indexing bulkheads are hinged to a foldable panel array (or collapsible spiral antenna) at spaced hinge axes. The bulkheads have indexing prongs which engage the indexing apertures, the brackets pullings the bulkheads therewith as the indexing apertures and prongs engage. Force contact spring motors urge the brackets and bulkheads together in the engaged state. Alignment guides align the brackets and bulkheads during engagement and disengagement of the indexing apertures and prongs.

Abstract: A solar panel satellite subsystem includes a first and second set of solar panels and booms joined together end to end in series and to opposite sides of the spacecraft by spring bias hinges. These hinges include viscous fluid dampers. Each damper has its own heater and thermostat coupled thereto to maintain essentially the same damper temperature as the ground test temperature at each hinge and maintain essentially the same desired rate of deployment at each hinge.

Abstract: The shaft of a hinge is fixed to one of the hinge elements and is both rotatable and is moveable in the direction of its axis relative to the other hinge element. The shaft is formed with a detent element at one end thereof which is engageable with a second detent element which is fixed relative to the other hinge element, when the shaft is in a particular rotational orientation and is moved axially in the direction of the second detent element. The shaft is axially biased toward the second detent element and its one end is conically shaped and engageable with a conically shaped brake surface fixed to the other hinge element when the two detent elements mate.