Briefs: Mechanical & Fluid Systems
Modular Propulsion Clusters

A report proposes the development of modular propulsion clusters (MPCs) — small, self-contained propulsion systems that would be standardized, mass-produced, and readily installed on a variety of miniature future spacecraft. The MPCs would be inexpensive, "turn-key" alternatives to expensive conventional...

Briefs: Mechanical & Fluid Systems
Positioning System for a Human Habitat in a Large Centrifuge

A report describes the system for controlling the radial position and tilt of a spacecraftlike habitat for humans in NASA's Space Flight Environmental Simulator (SFES) — a 16-m-diameter centrifuge used previously to evaluate effects of hypergravitational acceleration on...

Briefs: Mechanical & Fluid Systems
Launch-on-Demand Servicing Microsatellites

A report describes an emerging class of miniature, highly capable, relatively inexpensive satellites that could be launched rapidly by nontraditional methods. Of particular interest is a subclass of proposed launch-on-demand microsatellites for inspecting and servicing other satellites (targets)...

Briefs: Physical Sciences
First-Generation Integrated Free-Flying Micro-Spacecraft

The concept of free-flying micro-spacecraft was to develop a miniature spacecraft system fully integrated with a scientific sensor. A fleet of such tiny spacecraft would be deployed in space for multi-probe measurements of a three-dimensional phenomenon and to separate the...

Briefs: Mechanical & Fluid Systems
Miniature Electrothermal Thruster

A report proposes a miniature electrothermal spacecraft engine. The engine would include a chamber with an inside length of ≈1.5 cm and inside diameter of ≈0.25 cm, with a dielectric (ideally diamond) sidewall lining, a metal-coated expansion nozzle at one end, and a metal electrode at the other end. A...

Briefs: Medical
Using Photosynthetic Bacteria To Make Oxygen on Mars

A report presents a proposal to harness photosynthetic bacteria to generate essential materials needed during human and robotic exploration on the surface of Mars. Utilizing an extremely small amount of H2O and an ample amount of CO2 (and N2 and/or...

Briefs: Physical Sciences
DNS of a Transitional Supercritical C7H16/N2 Mixing Layer

This report discusses direct numerical simulations (DNS) of a mixing layer, between a nitrogen stream and a heptane stream initially flowing at different velocities, under supercritical conditions and undergoing a transition to turbulence. Thermodynamically, supercritical conditions...

The figure depicts the optical layout and meridional-plane ray-trace diagram of a four-element superachromatic near-infrared (IR) lens system. The system features a 30-mm-diameter...

A proposed robotic apparatus for underground exploration would propel itself downward in a percussive manner reminiscent of a jackhammer, pile driver, or hammer-and-chisel combination....

Briefs: Photonics/Optics
Software for Multidisciplinary Concurrent Optical Design

The Integrated Optical Design Analyzer (IODA) is a computer program that facilitates multidisciplinary concurrent engineering of highly precise optical instruments. (IODA should not be confused with a multidisciplinary optical-system-analysis program, called "IMOS," that has been reported...

Briefs: Robotics, Automation & Control
Ultrasonic Detector and Identifier of Land Mines

A robotic apparatus equipped with ultrasonic probes and other instrumentation has been proposed to reduce the danger and cost and increase the speed of searching for land mines. The apparatus...

Briefs: Photonics/Optics
Multibeam Beacon Laser Assembly

An optical assembly that combines the output of mutually incoherent lasers into a multibeam source for transmission into free space was designed, assembled, and tested. This design was motivated by the need...

Briefs: Motion Control
Software for Selecting Modes of Vibration of a Structure

A computer program facilitates the selection of the dominant modes of vibration of a structure - especially the dominant modes that interact with specific locations on the structure. This program is intended for use in conjunction with any of the various vibration-mode-analysis programs...

Briefs: Photonics/Optics
Improved Fiber-Pigtailed Non-Planar Ring Oscillator Laser

An improved non-planar ring oscillator (NPRO) of the fiber-pigtailed type has been developed. The improvements over prior lasers of this type lie in details of design and construction that are intended to enhance mechanical stability and thereby increase the stability of optical...

Briefs: Photonics/Optics
Computing Atmospheric Profiles From Spectral Measurements

The SEASCRAPE computer program estimates the composition, temperature, and pressure of the atmosphere as a function of position by fitting remote-sounding spectroscopic data to a mathematical model of the transfer of radiation through the atmosphere. SEASCRAPE consists of two integrated...

Design and development of miniature paraboloidal mirrors that would be deflected magnetically to vary their radii of curvature (and thus their focal...

Miniature electroactive-polymer rakes (MEARs) are undergoing development for eventual use as simple, lightweight, inexpensive low-power-consumption devices that would remove soil, dust, and/or other...

Engineers at Johnson Space Center have invented a relatively inexpensive, lightweight device that provides vibrational and thermal isolation for low-power electronic equipment. The...

Briefs: Photonics/Optics
Study of Stitching Errors in Shot-Shifted E-Beam Lithography

A report presents a study of the efficacy of shot shifting for reducing stitching errors in diffraction gratings made by electron-beam (E-beam) lithography. Stitching errors arise from fabricating a grating as a mosaic of smaller gratings by frequently translating the grating blank....

Briefs: Mechanical & Fluid Systems
Variable-Specific-Impulse Magnetoplasma Rocket

Johnson Space Center has been leading the development of a high-power, electrothermal plasma rocket — the variable- specific-impulse magnetoplasma rocket (VASIMR) — that is capable of exhaust modulation at constant power. An electrodeless design enables the rocket to operate at power densities...

The "smart" current-signature sensor is an instrument that noninvasively measures and analyzes steady-state and transient components of the magnetic field of (and, thus, indirectly, the...

An improved design for baseplates in silicon microsensors reduces parasitic capacitances between adjacent coplanar electrodes. It also reduces thermal-expansion mismatches, which are...

Briefs: Mechanical & Fluid Systems
Carbon Nanotube Bimorph Actuators and Force Sensors

A proposal has been made to develop bimorph actuators and force sensors based on carbon nanotubes. The proposed devices could make it possible to generate, sense, and control displacements...

"Health check" would be built into pressure transducers, according to a proposal, to enable occasional, rapid, in situ testing of the transducers between normal pressure-measurement...

Briefs: Electronics & Computers
Improvements in a Fast Transient-Voltage Recorder

Some improvements have been made in an instrument designed expressly for recording lightning-induced transient voltages on power and signal cables. The instrument as it existed prior to the improvements was described in "Fast Transient-Voltage Recorder" (KSC-11991), NASA Tech Briefs, Vol. 23,...

Briefs: Electronics & Computers
Improved Field-Emission Cathodes

Microscopic cathodes based on field emission (in contradistinction to thermionic emission) are undergoing development with a view toward using them as miniature or scalable sources of electrons in diverse...

Briefs: Software
LabVIEW as Flight Software With VxWorks Operating System

A development effort under way at the time of reporting the information for this article is directed toward producing a version of the LabVIEW data-acquisition software that would be suitable for use as flight software that could be executed in the VxWorks real-time operating system....

Briefs: Mechanical & Fluid Systems
Robot for Positioning Sensors in a Plant-Growth Chamber

The Advanced Life Support Automated Remote Manipulator (ALSARM) is a three-degree-of-freedom robotic system that positions an array of sensors inside a closed-system hydroponic chamber used in research on the production of biomass and the use of hydroponic subsystems of life-support...

Briefs: Software
MPP Port of PVM to a Beowulf Computer System

The latest version of the Parallel Virtual Machine (PVM) computer program, denoted PVM 3.4.3, incorporates a massively-parallel-processor (MPP) software port that enables a user working on a computer outside a Beowulf system (a cluster of personal computers that run the Linux operating system) to...

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