Abstract: A deployment method unfurls a plurality of flat panels interconnected by rotating hinges into a predetermined curved surface such as a spherical enclosure for use as a solar panel sphere or as any other arbitrary curved surface, for example, as a curved geodetic tent for terrestrial recreational use. Internal supporting struts and interconnecting panel frames and hinges are inflated during unfurling to automatically form the curved surface.

Abstract: A predistortion method use a modified linear-log model for linearizing the output of nonlinear high power amplifiers having inherent amplitude modulation to amplitude modulation distortion, and inherent amplitude modulation to phase modulation distortion, during conversions of an input signal to an output signal. A complex baseband linearizer provides predistortion at baseband for reducing spectral regrowth and improves bit error performance. The predistortion effects are matched to the amplifier distortions to cancel out the distortions to provide linearized conversions. The modified linear-log model is used to reduce the clipping effects through the peak operating point for a specified output power loss with minimum distortion.

Abstract: An improved magneto-optic trap is used to generate a high brightness low velocity continuous source of atoms as a continuous atomic beam. The improved magneto-optic atom trap is using gradient magnetic fields and a single circularly polarized laser beam incident upon a right angle conical mirror with apex aperture through which the continuous cold atom beam and central portion of the incident laser trapping light exit along a dark column. For use in an atomic clock system, a collimating and deflecting pumping laser provides transverse cooling of the atoms beam to bend and separate the cold atom beam from trapping laser light for reducing light shifts of the atomic clock operating frequency. The atomic clock can be a microwave cavity or Raman-type atomic clock.

Abstract: A predictive guidance algorithm maneuvers a fly-by vehicle in a direction towards an object vehicle with a time varying line-of-sight rate. After initial predictive guidance, a modified proportional navigation maneuvering phase accelerates the fly-by vehicle towards an object vehicle on an intercept line-of-sight path. The proportion navigation maneuvering is terminated prior to interception so that the fly-by vehicle does not intercept the object vehicle, but rather flies by the object vehicle at a desired miss distance, well suited for fly-by monitoring and imaging missions of space vehicles and planetary objects.

Abstract: Multiple layers of a clear insulating material, such as clear polyimide, with horizontal metalization layers therebetween and with vertical feed through metal traces therethrough form a flexible three dimension circuit printed circuit board upon which semiconductor devices, such as thin film solar cell can be directly deposited for forming a flexible electronic module, and upon which electronic discrete component can be bonded and electrically connected. In one exemplar configuration, a flexible thin film solar cell power module has thin film solar cells deposited on one side and power converters bonded on the other for a solar array power system. The flexible printed circuit board is well suited for forming electronic systems about a curved surface such as a power sphere nanosatellite.

Abstract: A power sphere preferably used as part of a nanosatellite is formed using a plurality of flat panels solar arrays interconnected together by rotating hinges to approximate a spherical shape for use as an enclosure of a payload. The solar array panels are supported by an extending internal strut. The spherical shape provides attitude insensitive solar energy collection and heat radiation.

Abstract: A high altitude lidar system propagates a beam of laser pulses through clearings in a cloud formation which reflects off the surface of the earth thereby providing first earth surface returns and reflections towards the base of a cloud that again reflects the pulses back towards the earth surface to be reflected again to provide cloud base returns. The time differential between the earth surface returns and the cloud base returns are used to determine the altitude of the base of the cloud.

Abstract: A maximum power tracker maximizes the power deliverable from a power source, such as a solar array using increasing, decreasing and maintaining states controlled by a set point signal modulated by a dither signal for stabilized regular power tracking during under demand conditions and maximum power tracking during periods with over demand conditions of a load. Multiple converters and respectively maximum power trackers can be coupled in parallel using shared bus control signal for fault tolerant equalized power conversion through the converters.

Abstract: A fast thermal cycler has a temperature chamber divided into a top, hot compartment heated by heating lamps and a bottom cold compartment cooled by liquid nitrogen, for optimizing thermal cycling rates for devices under test, such as solar cells, for rapid thermal life testing where both compartments use pressurized gaseous nitrogen for thermal conduction and regulation and a motor drive repetitively transports a test device mounted on a panel transiting between the two compartments. The thermal cycler is enhanced by computer control, enabling in-situ electrical testing, fail-safe heating, precision temperature heating and cooling phases, operator alerting and thermal gradient control during the temperature cycling.

Abstract: A pseudo gyro emulates mechanical gyros by software processes by processing space system appendage measurement data and reaction wheel tachometer data within reference and control systems of a satellite using principals of conservation of momentum to compute the vehicular bus angular velocity rate data by accounting for external torque, the momentum transfer between the satellite, the bus, and the appendages for providing accurate relative vehicular position and angular velocity rate data as an integral part of attitude reference and control systems now having higher reliability, longer life times, lower power consumption, and more accurate vehicular angular velocity rate data generated within high bandwidth operations. A specific improvement is the use of a bias torque estimator for accounting for uncertainties in external torque estimations for accurate total system momentum computations.

Abstract: An impact test method excites a bridge by an impact hammer at an impact point to create impact waves traveling through the bridge toward distal and proximal ends of the bridge where transient responses are measured in time reference to impact excitation. Time delays from an impact trigger time referenced to the reception of the transient responses over respective distances traveled by the impact wave provide wave speed indices that can be used to indicate structural change or damage of the bridge when compared to pre-damaged wave speed indices.

Abstract: Opposing end fittings of a cylindrical tube pressure test fixture uses slanted abutting surfaces between retaining rings and ferrules that securely clamps a tube under high pressure testing. Retaining ring and ferrule friction and applied radial compression induce shear force upon the tube and prevent leaks during pressure testing.

Abstract: A wet and vapor acid etching method releases a microelectromechanical systems (MEMS) structure from a substrate by dissolving a sacrificial layer disposed between the MEMS and the substrate. The sacrificial layer may be a silicon dioxide (SiO2) layer having a field portion over which the MEMS does not extend and a support portion over which the MEMS does extend. The field portion of the SiO2 layer is quickly removed using conventional wet hydrofluoric (HF) etching followed by rinsing and drying and then the support portion is removed using conventional vapor HF etching from a solution greater than 45% by weight percent. The wet HF chemical etch quickly removes the large field portion of the sacrificial layer. The HF vapor etch removes the small support portion of the sacrificial layer below the MEMS to release the MEMS from the substrate without stiction thereby preventing damage to the MEMS when released.

Abstract: A slider washer bearing in a bolted interface assembly allows relative differential thermal expansion and contraction motion between a component plate fastened to a base plate by a bolt, without inducing large strains and stresses upon the plates or the bolt. The slider washer bearing, thereby, functions as a thin spacer between the component and base plates, enabling high preload tightening of the bolted assembly while also enabling relative uni-directional alternating motion of the plates. The slider washer includes at least one mating groove arranged unidirectionally and extending horizontally between the top and bottom flexure plates. The grooves provide a guide for relative alternating back and forth unidirectional motion while the full strength of the bolt remains available to support the component plate without allowing high friction shear forces.

Abstract: A zero gravity simulator rotates an electrolytic device, such as nickel hydrogen battery cells, to simulate the effect of zero gravity on the battery cells by providing a cumulative zero gravity vector upon the device under test. The simulator has electrical connections to the device under test for monitoring the electrical performance of the device for determining the expected performance of the device under test when deployed and used in space.

Abstract: A clip flexure slider washer bearing in a bolted interface assembly allows differential thermal expansion and contraction between a component mounting plate or flange fastened to a base plate by a bolt. The bearing functions as a thin lubricated spacer between the component plate and the base plate, allowing the bolted assembly to be tightened to a high preload while enabling relative sliding motion without inducing large strains and stresses in the plates or the bolt. The slider washer portions of the bearing are sandwiched between the two horizontal parallel portions of the metal clip flexure. A side portion of the clip flexure bent as a right angle to the horizontal portions and extending vertically from one edge constrains the relative sliding motion of the component and base plate to unidirectional alternating back and forth translation, thus preventing lateral motion.

Abstract: A time-domain baseband measurement method measures modulated microwave signals typically used in communication systems by converting microwave signals to baseband before measurement for improved accuracy compared to direct measurement at the microwave frequency. A downconverting receiver is first characterized using a prior characterization method and then the modulated microwave signal is applied to the downconverting receiver and the response of the downconverting receiver is removed to provide an accurate characterization of the modulated microwave signal. Such an accurate measurement of the modulated microwave signal can be used for communications system performance verification as well as for characterizing communications devices and systems. One particular application is the measurement of input/output characteristics of nonlinear power amplifiers using such modulated microwave signals.

Abstract: A charging and discharging method for lithium-ion and lithium-polymer batteries determines overcharged, undercharged, normal and degraded operating conditions and adjusts a recharge fraction of recharge capacity to discharge capacity for improving battery life while maintaining the battery cells at a high charge state.

Abstract: A shear test fixture and method determines the shear strength of a honeycomb having elongated cells extending between two ends filled with a filler material with a load applied to one end relative to the other end introducing shear stress without introducing compression or tension stress for improved shear strength testing.

Abstract: A feed-forward linearization of a traveling wave tube amplifier linearizes the transfer function of the tube through a linearization voltage derived at baseband from the instantaneous amplitude of the input signal to control the cathode voltage causing induced phase modulation to offset the normal amplitude modulation to phase modulation conversion distortion. The feed forward linearization control results in reduced distortion for improved phase linearization of the tube over the operating range of the tube.