Abstract: A folding, retractable dome for protecting a feature, such as a docking mechanism, a hatch or other equipment at an exterior surface of a space vehicle, includes a plurality of arcuate ribs, each having opposite ends respectively pinioned at opposite sides of the feature at the surface of the vehicle for rotational movement about an axis of rotation extending through the opposite ends and through an arcuate path of revolution extending over the feature, and a flexible cover attached to each of the ribs such that, in a deployed configuration of the dome, in which adjacent ribs are rotated apart from each other at a maximum relative angle therebetween, the cover is stretched generally tangentially between the adjacent ribs to form a generally arcuate shield over the feature, and in a retracted position of the dome, in which adjacent ribs are rotated together at a minimum relative angle therebetween, the cover is collapsed to define folded pleats between the adjacent ribs.

Abstract: Linear actuators including coupled elongate members formed of shape memory alloys are provided. Members that lengthen when heated are coupled to members that shorten when heated such that stroke amplification gains are derived from each member. The members may be tubular and may be coaxially arranged for telescopic extension and collapse. Sections of a modular structure such as a space vehicle may be latched and clamped together for assembly or for docking by utilizing linear actuators having shape memory alloys that are actuated thermally.

Abstract: A thermal expansion joint having a plurality of bendable tabs which flex to minimize the stress caused by thermal expansion. The tabs flex at their slot radii by the base of the tabs, allowing the tip of the tabs to move. Apertures in the tabs near the tip connect the tabs to a solid body or to tabs on another body. The tabs' flexing relieves stress in the body undergoing thermal expansion at the point it is connected to a body which has a different thermal expansion rate and/or experiences a different temperature. A plurality of tabs so connecting two bodies provides a stiff joint and reduces the thickness of the material otherwise needed to provide a connection what will not crack or otherwise break due to thermal strains at the connection between two bodies.

Abstract: The invention is a failure detecting system including fiber optic cables of different lengths disposed in the vicinity of a secured region between two or more adherends, and an electro-optical analysis circuit for analyzing signals detected by the fiber optic cables. The fiber optic cables extend transversely across the connected adherends, with each cable extending a different length so that the width of the structure is divided into discrete regions. In this way, the measurable strain can be integrated over the entire length of the fiber where the fiber remains bonded to the material. The cables are coupled to laser circuitry, detector circuitry and network analyzer circuitry, and signals from the cables are processed in the network analyzer circuitry using a Fast Fourier Transform to reduce complex frequency information to time domain representation of reflection pulses. Thereafter, they are compared with reference signals to indicate the presence and degree of disbond.