Briefs: Mechanical & Fluid Systems
Miniature Robotic Spacecraft for Inspecting Other Spacecraft

A report discusses the Miniature Autonomous Extravehicular Robotic Camera (Mini AERCam) — a compact robotic spacecraft intended to be released from a larger spacecraft for exterior visual inspection of the larger spacecraft. The Mini AERCam is a successor to the AERCam Sprint...

Briefs: Mechanical & Fluid Systems
Miniature Ring-Shaped Perisaltic Pump

An experimental miniature peristaltic pump exploits piezoelectrically excited flexural waves that travel around a ring: A fluid is carried in the containers formed in the valleys between the peaks of the...

Semiconductor electronic devices and circuits based on silicon carbide (SiC) are being developed for use in high-temperature, high-power, and/or high-radiation conditions under which...

Briefs: Materials
Nonlinear Thermoelastic Model for SMAs and SMA Hybrid

A constitutive mathematical model has been developed that predicts the nonlinear thermomechanical behaviors of shape-memory alloys (SMAs) and of shape- memory-alloy hybrid composite (SMAHC) structures, which are composite-material structures that contain embedded SMA actuators. SMAHC...

One of the major challenges for NASA's next-generation reusable-launch-vehicle (RLV) program is the design of a cryogenic lightweight composite fuel...

Briefs: Materials
Formulations for Stronger Solid Oxide Fuel-Cell Electrolytes

Tests have shown that modification of chemical compositions can increase the strengths and fracture toughnesses of solid oxide fuel-cell (SOFC) electrolytes. Heretofore, these solid electrolytes have been made of yttria- stabilized zirconia, which is highly conductive for oxygen ions...

Briefs: Software
Simulation Testing of Embedded Flight Software

Virtual Real Time (VRT) is a computer program for testing embedded flight software by computational simulation in a workstation, in contradistinction to testing it in its target central processing unit (CPU). The disadvantages of testing in the target CPU include the need for an expensive test bed,...

Briefs: Software
Updated System-Availibility and Resource-Allocation Program

A second version of the Availability, Cost and Resource Allocation (ACARA) computer program has become available. The first version was reported in "System-Availability and Resource- Allocation Program" (LEW-15713), NASA Tech Briefs, Vol. 19, No. 8 (August 1995), page 54. To...

Briefs: Software
Software for Fault-Tolerant Matrix Multiplication

Formal Linear Algebra Recovery Environment is a computer program for high-performance, fault-tolerant matrix multiplication. The program is based on an extension of the prior theory and practice of fault-tolerant matrix·matrix multiplication of the form C = AB. This extension provides...

Briefs: Software
Routines for Computing Pressure Drops in Venturis

A set of computer- program routines has been developed for calculating pressure drops and recoveries of flows through standard venturis, nozzle venturis, and orifices. Relative to prior methods used for such calculations, the method implemented by these routines offers greater accuracy because it...

A cylindrical-punch indentation technique has been developed as a means of measuring the nonlinear elastic responses of materials - more specifically, for measuring the moduli of...

Briefs: Manufacturing & Prototyping
Improved Thin, Flexible Heat Pipes

Flexible heat pipes of an improved type are fabricated as layers of different materials laminated together into vacuum-tight sheets or tapes. In comparison with prior flexible heat pipes, these flexible...

A method, now undergoing development, of forming nanochannels in planar substrates is intended to enable the fabrication of advanced fluidic devices that could be integrated with...

As noted in the previous article, the field-induced force density on a magnetic fluid is proportional to the magnetic susceptibility times the gradient of the magnetic field squared. The direction of...

Briefs: Robotics, Automation & Control
Pumping Liquid Oxygen by Use of Pulsed Magnetic Fields

An effort is underway to develop a method of pumping small amounts of liquid oxygen by use of pulsed magnetic fields. This development is motivated by a desire to reduce corrosion and hazards of explosion and combustion by eliminating all moving pump parts in contact with the pumped...

Briefs: Robotics, Automation & Control
A Software Architecture for Semiautonomous Robot Control

A software architecture has been developed to increase the safety and effectiveness with which tasks are performed by robots that are capable of functioning autonomously but sometimes are operated under control by humans. The control system of such a robot designed according to a prior...

Briefs: Robotics, Automation & Control
Compact Plasma Accelerator

A plasma accelerator has been conceived for both material-processing and spacecraft-propulsion applications. This accelerator generates and accelerates ions within a very small volume. Because of its compactness,...

A product line of improved electrohydraulic linear actuators has been developed. These actuators are designed especially for use in actuating valves in rocket-engine test facilities. They are also...

Briefs: Mechanical & Fluid Systems
Autonomous Formation Flight

NASA's Strategic Plan for the Aerospace Technology Enterprise includes ambitious objectives focused on affordable air travel, reduced emissions, and expanded aviation-system capacity. NASA Dryden Flight Research...

Intelligent fasteners with embedded microprocessors remotely controlled by wireless tools or a data network can advance the speed, flexibility, flow, and cost...

Provisions for specification of hazards faced by a robotic vehicle (rover) equipped with a rocker-bogie suspension, for prediction of collisions between the vehicle and the hazards,...

Briefs: Mechanical & Fluid Systems
Wavy-Planform Helicopter Blades Make Less Noise

Wavy-planform rotor blades for helicopters have been investigated for the first time in an effort to reduce noise. Two of the main sources of helicopter noise are blade/vortex interaction (BVI)...

Briefs: Mechanical & Fluid Systems
Expandable Purge Chambers Would Protect Cryogenic Fittings

Expandable ice-prevention and cleanliness-preservation (EIP-CP) chambers have been proposed to prevent the accumulation of ice or airborne particles on quick-disconnect (QD) fittings, or on ducts or tubes that contain cryogenic fluids. In the original application for which the EIP-CP...

Controlled Ultraviolet (UV) laser ablation is a viable method of micro-machining micro-electro-mechanical systems (MEMS) and micro-optical-electro-mechanical systems (MOEMS). It enables users to...

The figure schematically depicts an instrumentation system, called a "fiber optic-based integration system" (FOBIS), that is undergoing development to enable real-time monitoring of...

Briefs: Electronics & Computers
Backed Bending Actuator

Bending actuators of a proposed type would partly resemble ordinary bending actuators, but would include simple additional components that would render them capable of exerting large forces at small displacements....

Briefs: Electronics & Computers
Compact Optoelectronic Compass

A compact optoelectronic sensor unit measures the apparent motion of the Sun across the sky. The data acquired by this chip are processed in an external processor to estimate the relative orientation of the...

Briefs: Electronics & Computers
Micro Sun Sensor for Spacecraft

A report describes the development of a compact micro Sun sensor for use as a part of the attitude determination subsystem aboard future miniature spacecraft and planetary robotic vehicles.

Space missions requiring the highest upset rate immunity typically turn to rad-hard system designs. Unfortunately, these systems are many generations behind...

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