Briefs: Software
Converting From XML to HDF-EOS

A computer program recreates an HDF-EOS file from an Extensible Markup Language (XML) representation of the contents of that file. (“HDF-EOS” and variants thereof are defined in the first of five related articles that immediately precede this article.) This program is one of two programs written to enable...

Briefs: Software
Simulating Attitudes and Trajectories of Multiple Spacecraft

A computer program called “42” simulates the attitudes and trajectories of multiple spacecraft flying in formation anywhere in the Solar System. The rotational dynamics are represented by high-fidelity models of spacecraft, each comprising as many as three connected rigid bodies...

Tech Needs
Alternative Approaches to Basis Weight Reduction in Paper

A company seeks technology to replace wood fiber in paper with a bulk filler material having less mass. The company seeks to make small, micron-scale, low-density particles. The filler material would have no negative impact on today’s lightweight paper specifications, including bulk...

Briefs: Information Technology
Specialized Color Function for Display of Signed Data

This Mathematica script defines a color function to be used with Mathematica’s plotting modules for differentiating data attaining both positive and negative values. Positive values are shown as shades of blue, and negative values are shown in red. The intensity of the color reflects the...

Briefs: Software
Delivering Alert Messages to Members of a Work Force

Global Alert Resolution Network (GARNET) is a software system for delivering emergency alerts as well as less-urgent messages to members of the Goddard Space Flight Center work force via an intranet or the Internet, and can be adapted to similar use in other large organizations. Messages can...

Briefs: Materials
Oxide Fiber Cathode Materials for Rechargeable Lithium Cells

LiCoO2 and LiNiO2 fibers have been investigated as alternatives to LiCoO2 and LiNiO2 powders used as lithium-intercalation compounds in cathodes of rechargeable lithium-ion electrochemical cells. In making such a cathode, LiCoO2 or...

Briefs: Materials
Electrocatalytic Reduction of Carbon Dioxide to Methane

A room-temperature electrocatalytic process that effects the overall chemical reaction CO2 + 2H2O → CH4 + 2O2 has been investigated as a means of removing carbon dioxide from air and restoring oxygen to the air. The process was originally...

Briefs: Materials
Progress Toward Making Epoxy/Carbon-Nanotube Composites

A modicum of progress has been made in an effort to exploit single-walled carbon nanotubes as fibers in epoxy-matrix/fiber composite materials. Two main obstacles to such use of carbon nanotubes are the following: (1) bare nanotubes are not soluble in epoxy resins and so they tend to...

A heterogeneous material construction has been devised for sensing coils of super-conducting quantum interference device (SQUID) magnetometers that are subject to a combination of...

Briefs: Materials
Predicting Properties of Unidirectional-Nanofiber Composites

A theory for predicting mechanical, thermal, electrical, and other properties of unidirectional-nanofiber/matrix composite materials is based on the prior theory of micromechanics of composite materials. In the development of the present theory, the prior theory of micromechanics was...

Briefs: Mechanical & Fluid Systems
Deployable Crew Quarters

The deployable crew quarters (DCQ) have been designed for the International Space Station (ISS). Each DCQ would be a relatively inexpensive, deployable box-like structure that is designed to fit in a rack bay. It is to be occupied by one crewmember to provide privacy and sleeping functions for the crew. A DCQ comprises...

Briefs: Mechanical & Fluid Systems
Nonventing, Regenerable, Lightweight Heat Absorber

A lightweight, regenerable heat absorber (RHA), developed for rejecting metabolic heat from a space suit, may also be useful on Earth for short-term cooling of heavy protective garments. Unlike prior space-suit-cooling systems, a system that includes this RHA does not vent water. The closed...

Briefs: Mechanical & Fluid Systems
“Bootstrap” Configuration for Multistage Pulse-Tube Coolers

A “bootstrap” configuration has been proposed for multistage pulse-tube coolers that, for instance, provide final-stage cooling to temperatures as low as 20 K. The bootstrap configuration supplants the conventional configuration, in which customarily the warm heat exchangers of...

Briefs: Mechanical & Fluid Systems
Miniature High-Force, Long-Stroke SMA Linear Actuators

Improved long-stroke shape-memory-alloy (SMA) linear actuators are being developed to exert significantly higher forces and operate at higher activation temperatures than do prior SMA actuators. In these actuators, long linear strokes are achieved through the principle of displacement...

Briefs: Mechanical & Fluid Systems
Reducing Liquid Loss During Ullage Venting in Microgravity

A centripetal-force-based liquid/gas separator has been proposed as a means of reducing the loss of liquid during venting of the ullage of a tank in microgravity as a new supply of liquid is pumped into the tank. Centripetal-force-based liquid/gas separators are used on Earth, where...

To ensure a system’s accuracy meets required needs, system error budgets must be an integral part of system design. Considerations should include necessary levels of accuracy for system...

Briefs: Electronics & Computers
Ka-Band Transponder for Deep-Space Radio Science

A one-page document describes a Ka-band transponder being developed for use in deep-space radio science. The transponder receives in the Deep Space Network (DSN) uplink frequency band of 34.2 to 34.7 GHz, transmits in the 31.8 to 32.3 GHz DSN downlink band, and performs regenerative ranging on a...

Briefs: Electronics & Computers
Replication of Space-Shuttle Computers in FPGAs and ASICs

A document discusses the replication of the functionality of the onboard space-shuttle general-purpose computers (GPCs) in field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs). The purpose of the replication effort is to enable utilization of proven...

Briefs: Mechanical & Fluid Systems
Demisable Reaction-Wheel Assembly

A document discusses the concept of a demisable motor-drive-and-flywheel assembly [reaction-wheel assembly (RWA)] used in controlling the attitude of a spacecraft. “Demisable” as used here does not have its traditional legal meaning; instead, it signifies susceptible to melting, vaporizing, and/or otherwise...

Briefs: Information Technology
Spatial and Temporal Low-Dimensional Models for Fluid Flow

A document discusses work that obtains a low-dimensional model that captures both temporal and spatial flow by constructing spatial and temporal four-mode models for two classic flow problems. The models are based on the proper orthogonal decomposition at two reference Reynolds numbers....

Podcasts
Garrett Reisman, Astronaut, NASA Johnson Space Center, Houston, TX

In March 2008, astronaut Garrett Reisman flew aboard the Space Shuttle Endeavour to the International Space Station, where he spent 95 days living and working in space. After performing his first spacewalk to help install the Space Station’s new robotic manipulator, called...

Briefs: Green Design & Manufacturing
Electrocatalytic Reduction of Carbon Dioxide to Methane

A room-temperature electrocatalytic process has been investigated as a means of removing carbon dioxide from air and restoring oxygen to the air. The process was originally intended for...

Briefs: Electronics & Computers
Oxide Fiber Cathode Materials for Rechargeable Lithium Cells

Fibers have been investigated at Johnson Space Center as alternatives to other powders used as lithium-intercalation compounds in cathodes of rechargeable lithium-ion electrochemical cells. The fibers can be pressed and sintered to form a cathode, without need for a binder or a...

Briefs: Energy
Electromagnetically Clean Solar Arrays
The term “electromagnetically clean solar array” (EMCSA) refers to a panel that contains a planar array of solar photovoltaic cells. The cells are laminated with shielding, narrow-current-loop wiring, and structural supports. EMCSAs could be useful in applications that require limited electromagnetic interference.
Briefs: Green Design & Manufacturing
System for Removing Pollutants From Incinerator Exhaust

A system for removing pollutants - primarily sulfur dioxide and mixed oxides of nitrogen - from incinerator exhaust has been demonstrated at Johnson Space Center. The system is also designed secondarily to remove particles, hydrocarbons, and CO, and is intended for use in an enclosed...

Features: Green Design & Manufacturing
NASA Study Shows How Oil Production Impacts Climate

When and how global oil production will peak has been debated, making it difficult to anticipate emissions from the burning of fuel and to precisely estimate its impact on the climate. To...

Briefs: Imaging
Range Imaging Without Moving Parts

Range-imaging instruments of a type now under development are intended to generate the equivalent of three-dimensional images from measurements of the round-trip times of flight of laser pulses along known directions. These instruments could also provide information on characteristics of targets, including...

Articles: Motion Control
Flowmeters Are Not All Alike

When it comes to choosing a flowmetering device, some users assume “one size fits all.” In reality, there are significant differences between flowmeter types, and each design has its unique “pros and...

Articles: Robotics, Automation & Control
Mechanical Carbon Machine Parts Ease Liquid Handling

For over a hundred years, machine parts composed of mechanical carbon have provided an alternative solution in applications where temperature and atmosphere conditions prevent the use of...

Videos