Abstract: A capillary wick for use in capillary evaporators has properties that prevent nucleation inside the body of the wick, resulting in suppression of back-conduction of heat from vapor channels to the liquid reservoir. Use of a central liquid flow channel in the wick is eliminated, and pore size in the wick is chosen to maximize available pressure for fluid pumping, while preventing nucleation in the wick body. The wick is embodied with different geometries, including cylindrical and flat. A flat capillary evaporator has substantially planar heat input surfaces for convenient mating to planar heat sources. The flat capillary evaporator is capable of being used with working fluids having high vapor pressures (i.e., greater that 10 psia). To contain the pressure of the vaporized working fluid, the opposed planar plates of the evaporator are brazed or sintered to opposing sides of a metal wick. Additionally, a terrestrial loop heat pipe and a loop heat pipe having overall flat geometry are disclosed.

Abstract: A two-dimensional field of regard is scanned with a single plane mirror in the object space of a telescope, maintaining a fixed relationship between the rotational direction of scan and the projection of the telescope's focal plane. The two dimensional field of regard is covered by a series of conical arcs, each arc being scanned by rotation at constant angular velocity about the inner axis of the two-axis system. This scanning system accommodates applications such as TDI that require an opto-mechanical scan with a constant linear velocity (magnitude and direction) in the focal plane. Shading of IR images is mitigated by calibration at the ends of each scan line and by a scan geometry that minimizes changes in reflection angle.

Abstract: An insert according to the present invention has a very low transverse Coefficient of Thermal Expansion. This is the result of an isolation and compensation structure formed by a sleeve surrounding a post. The sleeve isolates the post from the thermal expansion effects of the panel. This eliminates the influence of thermal expansion/contraction of both the panel and the bonding material. Since the post itself will also expand and contract with temperature, the attachment point of the post to the sleeve is deliberately selected so as to compensate for the post's own dimensional changes.

Abstract: A capillary wick for use in capillary evaporators has properties that prevent nucleation inside the body of the wick, resulting in suppression of back-conduction of heat from vapor channels to the liquid reservoir. Use of a central liquid flow channel in the wick is eliminated, and pore size in the wick is chosen to maximize available pressure for fluid pumping, while preventing nucleation in the wick body. The wick is embodied with different geometries, including cylindrical and flat. A flat capillary evaporator has substantially planar heat input surfaces for convenient mating to planar heat sources. The flat capillary evaporator is capable of being used with working fluids having high vapor pressures (i.e., greater that 10 psia). To contain the pressure of the vaporized working fluid, the opposed planar plates of the evaporator are brazed or sintered to opposing sides of a metal wick. Additionally, a terrestrial loop heat pipe and a loop heat pipe having overall flat geometry are disclosed.

Abstract: A pin puller combines an actuator with an anti-friction release mechanism, according to a bilaterally symmetric geometry. The anti-friction tension release mechanism ensures that only negligible friction forces need to be overcome to operate the tension release mechanism. Thus, the actuator is isolated from the large tension force that bears on the tension release mechanism. The bilateral symmetric aspect of the structure provides for mechanical redundancy, so that, in the event that one half of the pin puller fails, it is sufficient that the other half operate properly for the tension to be successfully released. This pin puller avoids premature release because it is not susceptible to static electricity or electromagnetic radiation. The pin puller also avoids generation of large shock waves due to its slow speed of operation and because of the gradual release interaction of mechanical parts within the anti-friction release mechanism.

Abstract: A cryogenic thermal switch operates based on the principle of differential coefficients of thermal expansion of differing materials. A small gap is either closed or opened, dependant upon the relative dimensions of two pieces of differing materials. As the temperature of the pieces is raised, the piece having the greater coefficient of thermal expansion (CTE) increases its dimensions at a greater rate, causing a gap to open up. Conversely, when the temperature of the pieces is lowered, the piece having the greater CTE shrinks proportionally faster, thereby closing the gap. The present invention makes use of a reliable flat-faced geometry for the two sides of the gap.

Abstract: A process of bonding metal parts to one another to form seamless, hollow metal articles, particularly made from beryllium. Tooling is assembled to the parts, prior to hot pressing, to cause pressure to be applied to selective portions of the parts. The parts, assembled together with the tooling, are then subjected to hot isostatic pressing at a temperature of about 1700° F. to 1750° F., and at a pressure of about 2000 psi to 2500 psi, for around 3 hours. The tooling surrounding the metal parts functions to limit the amount of compression of the parts. Articles formed by this process are particularly useful in space flight applications because they are formed of a homogeneous material. Strength of the bond is enhanced because no filler metal is used. The absence of a filler metal also eliminates any thermal stress problems as a result of differences in coefficients of thermal expansion.

Abstract: A mechanical actuator assembly is disclosed. The actuator assembly comprises an actuator body with an element moveable with respect to said body to perform a function. In general, the moveable element is in the form of a piston or a rod. The actuator assembly further comprises a mounting mechanism allowing the movement of the actuator body relative to the moving element or piston in response to preset conditions of pressure or force.

Abstract: The present invention uses a light-pipe for beam splitting, combining, hybrid space-wavelength multiplexing, hybrid space-wavelength demultiplexing, dense wavelength division multiplexing, and dense wavelength division demultiplexing. A light-pipe has a first end where light enters the light-pipe and a second end where the light exits the light-pipe. The light-pipe is a polygonal rod or a hollow reflective cavity. To perform beam splitting, light enters the first end of the light-pipe and reflects off of the side surfaces inside the light-pipe producing additional light beams. By placing an imaging lens at the output end of the light-pipe, all of the virtual images (n-1) of the additional light beams and the original light entering the light-pipe become the object of the imaging lens. As a result, the light-pipe acts as a 1-to-n splitter.

Abstract: A pin puller combines a metal alloy actuator with an anti-friction release mechanism, according to a bilaterally symmetric geometry. The actuator operates based on a metal alloy that has a relatively low melting temperature. The anti-friction tension release mechanism ensures that only negligible friction forces need to be overcome to operate the tension release mechanism. Thus, the metal alloy actuator is isolated from the large tension force that bears on the tension release mechanism. The bilateral symmetric aspect of the structure provides for mechanical redundancy, so that, in the event that one half of the pin puller fails, it is sufficient that the other half operate properly for the tension to be successfully released. This pin puller avoids premature release because it is not susceptible to static electricity, electromagnetic radiation, or high ambient temperatures.

Abstract: A lightweight photovoltaic concentrator is disclosed. The concentrator comprises at least two sections each comprising a cell panel, a radiator panel and a reflector panel. In one embodiment, the concentrator system of the present invention comprises at least two hinged sections each comprising a solar cell panel, a flat radiator panel, and a curved reflective concentrator panel. The solar cell panel comprises at least one photovoltaic cell for generating electrical power in response to radiation. The solar cell panel is aligned with the radiator panel at an angle less than 180 degrees but not less than 90 degrees facing the reflective concentrator panel. In another embodiment, the cell panels on adjoining sections are angled in opposite directions with respect to the radiator panels and wherein the reflective concentrator panels are located on opposite sides of the radiator panels. A heat pipe or loop heat pipe is located in the radiator panel to dissipate heat from the solar cells.