Tech Briefs

Broad area cooling shields are a massefficient alternative to conductively cooled thermal radiation shielding. The shield would actively intercept a large portion of incident thermal radiation and transport the heat away using cryogenic helium gas. The design concept...

For safety and efficiency, nuclear reactors must be carefully monitored to provide feedback that enables the fission rate to be held at a constant target level via adjustments in the position of neutron- absorbing rods and moderating coolant flow rates. For automated reactor control, the...

A process has been examined for bonding a platinum resistance thermometer (PRT) onto potential aerospace materials such as flat aluminum surfaces and a flexible copper tube to simulate coaxial cables for flight applications. Primarily, PRTs were inserted into a...

Tactile sensors are currently being designed to sense interactions with human hands or pen-like interfaces. They are generally embedded in screens, keyboards, mousepads, and pushbuttons. However, they are not well fitted to sense interactions with all kinds of objects.

A paper describes the laser truss sensor (LTS) for detecting piston motion between two adjacent telescope segment edges. LTS is formed by two point-topoint laser metrology gauges in a crossed geometry.

A microshutter array (MSA) has been developed for use as an aperture array for multi-object selections in James Webb Space Telescope (JWST) technology. Light shields, molybdenum nitride (MoN) coating on shutters, and aluminum/ aluminum oxide coatings on interior walls are put on each shutter for...

Hall thrusters utilize identical hollow cathode technology as ion thrusters, yet must operate at much higher mass flow rates in order to efficiently couple to the bulk plasma discharge. Higher flow rates are necessary in order to provide enough neutral collisions to transport electrons across magnetic fields so...

In the past, solid electrolytes have mainly been used as oxygen sensors for automobiles. This type of sensor measures the difference between the oxygen partial pressures of a reference electrode and a measurement electrode, and always requires a...

Improved devices have been proposed for collecting sweat for biochemical analysis — especially for determination of the concentration of Ca2+ ions in sweat as a measure of loss of Ca from bones. Unlike commercially available sweat-collection patches used previously in monitoring...

A cytometer now under development exploits spatial sorting of sampled cells on a microarray chip followed by use of grating-coupled surface-plasmon-resonance imaging (GCSPRI) to detect the sorted cells. This cytometer on a chip is a prototype of contemplated future miniature cytometers that would be suitable for rapidly...

Tissue lithography will enable physicians and researchers to obtain macromolecules with high purity (>90 percent) from desired cells in conventionally processed, clinical tissues by simply annotating the desired cells on a computer screen. After identifying the desired cells, a suitable lithography mask will be generated t...

Although suited astronauts are currently cooled with a Liquid Cooled Ventilation Garment (LCVG), which can remove up to 85 percent of body heat, their effectiveness is limited because cooling must penetrate layers of skin, muscle, fat, bone, and tissue to reach the bloodstream, where its...

This invention relates to surface modification of porosified silicon (pSi) structures with poly(alkylene) glycols for the purpose of controlled degradation of the silicon matrix and tailored release of encapsulated substances for biomedical applications. The pSi structures are currently...

A symmetric reflectarray, consisting of variable-size square patch elements with a commonly used mathematical model for the horn in the form of a cosine function, has been designed using the transmit mode technique for different f/D ratios with –10 dB edge taper. Subsequently,...

Cables are very important electrical devices that carry power and signals across multiple instruments. Any fault in a cable can easily result in a catastrophic outcome. Therefore, verifying that all cables are built to spec is a very important part of Electrical Integration Procedures. Currently, there are two methods used in lab...

Low-current, high-impedance microelectronic devices can be affected by electric current shot noise more than they are affected by Nyquist noise, even at room temperature. An approach to implementing a sub-shot noise current source for powering such devices is based on direct conversion of amplitude-...

A critical PECL (positive emitter-coupled logic) interface to Xilinx interface needed to be changed on an existing flight board. The new Xilinx input interface used a CMOS (complementary metal-oxide semiconductor) type of input, and the driver could meet its thresholds typically, but not in...

A programmable oscillator is a frequency synthesizer with an output phase that tracks an arbitrary function. An offset, phase-locked loop circuit is used in combination with an error control feedback loop to precisely control the output phase of the oscillator.

A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that...

An architecture for a Direct RF-digitization Type Digital Mode RADAR was developed at GSFC in 2008. Two variations of a basic architecture were developed for use on RADAR imaging missions using aircraft and spacecraft. Both systems can operate with a pulse repetition rate up to 10 MHz with 8 received RF...

Commercial digital signal processors (DSPs) for use in high-speed satellite computers are challenged by the damaging effects of space radiation, mainly single event upsets (SEUs) and single event functional interrupts (SEFIs). Inno vations have been developed for mitigating the effects of SEUs and SEFIs, enabling...

The purpose of this system is to simulate an internal short on battery cells by causing deformation (a crushing force) in a cell without penetration. This is performed by activating a hydraulic cylinder on one side of a blast wall with a hydraulic pump located on the other. The operator can control the rate of the crush by...

The Active Response Gravity Offload System (ARGOS) provides the ability to simulate with one system the gravity effect of planets, moons, comets, asteroids, and microgravity, where the gravity is less than Earth’s gravity. The system works by providing a constant force offload through an overhead hoist...

The Force Limit System (FLS) was developed to protect test specimens from inadvertent overload. The load limit value is fully adjustable by the operator and works independently of the test system control as a mechanical (nonelectrical) device.