Special Coverage

Distributed Propulsion Concepts and Superparamagnetic Energy Harvesting Hummingbird Engine
Wet Active Chevron Nozzle for Controllable Jet Noise Reduction
Magnetic Relief Valve
Locking Mechanism for a Flexible Composite Hinge
Active Aircraft Pylon Noise Control System
Unmanned Aerial Systems Traffic Management
Method of Bonding Dissimilar Materials
Sonar Inspection Robot System

Fast Block Transforms on Large Binary Datasets in the Cloud Using Hadoop Streaming

NASA’s Jet Propulsion Laboratory, Pasadena, California A software framework on top of Hadoop Streaming enables both the processing of binary data in the cloud, and the freedom for the developer to implement his or her mapper and reducer programs in any language, rather than re-implementing existing solutions in Java, or repackaging existing binary data into a text format. Binary data is partitioned into chunks that are kept in a persistent data storage medium. A textual list of filenames for these chunks is piped into a Hadoop Streaming mapper program, which then reads the corresponding files, computes block transforms locally, and writes the results back to persistent data storage. The mapper program is stored on all compute nodes, and the filenames are distributed in parallel across the cluster, so that the workload is evenly distributed and the end-to-end block transform speedup is roughly given by the number of nodes in the cluster.

Posted in: Briefs, TSP, Electronics & Computers, Software, Computer software and hardware, Data management


Mars Science Laboratory Frame Manager

NASA’s Jet Propulsion Laboratory, Pasadena, California One of the highly desired enhancements to the Mars Exploration Rover (MER) and Phoenix flight missions was the centralized coordinate transform database maintained onboard. Without the database, there are quite a few operations that require cumbersome, error-prone manual calculations on the ground such as pointing a mast camera to an arm tool and driving the rover to the goal defined in a previous site. The Mars Science Laboratory (MSL) Frame Manager flight software implements a centralized frame tree database, which eliminates these cumbersome, error-prone calculations of coordinate entries for commands.

Posted in: Briefs, Electronics & Computers, Software, Computer software and hardware, Flight management systems, Data management


SIVO-PyD: A Python Distribution for Scientific Computing Visualization

Goddard Space Flight Center, Greenbelt, Maryland SIVO-PyD gathers and automatically installs (in various computing platforms) a collection of Python-related packages for scientific computing and visualization. All of the packages in distribution are accessible within the Python framework. The distribution is self-contained and can be extended with minimal work.

Posted in: Briefs, TSP, Electronics & Computers, Information Sciences, Software, Computer software and hardware, Imaging and visualization


Formal Validation of Model-Based Fault Management Design Solutions

A number of advantages of modeling fault protection logical design, executing the model, and running a model checker are identified.Model-Based System Engineering is becoming widely adopted at JPL and in industry because model-centric systems introduce improved methods of system engineering. As systems with ever-increasing complexity are developed at JPL, model-centric engineering be comes essential for design, test, and validation. Validation of FP designs is historically problematic, with many examples of inadequate resources (people, time, and budget) and/or unexpected problems. Many factors contribute to these issues, but the problem can be traced to a lack of appreciation of system complexity. When considering a system, there are significantly more ways the system can fail (contingency paths) than ways it can succeed (nominal paths). As NASA continues to develop more complex and capable spacecraft, the behavior state space will increase, stressing the ability of teams to properly understand system behavior.

Posted in: Briefs, TSP, Electronics & Computers, Information Sciences, Software, Design processes, Simulation and modeling, Systems engineering, Spacecraft


Development of Free Molecule Flow Equations from a Transient, Asymmetric Source

Molecular flow model is explored as a tool to describe an unusual variety of plume interaction issues. Goddard Space Flight Center, Greenbelt, Maryland The analysis and simulation of gases expanding from sources such as rocket nozzles into vacuum, or the effects plumes from these sources create when they interact with solid surfaces, present a considerable challenge to the scientific and engineering communities. As a plume expands into vacuum, density levels, and hence collision rates, decrease rapidly by many orders of magnitude. The main difficulty lies in accurately describing a flow field extending from continuum flow at the nozzle exit, through the transition regime, and reaching free molecule behavior within a relatively short distance downstream. For thrusters, flow at the nozzle exit is usually characterized by high exit velocities and relatively high Mach numbers. Even in regions where significant intermolecular collision rates occur, relative velocity levels are low, and little thermal scattering occurs normal to the mainly radial streamlines. Such observations lead one to consider describing the expansion under certain circumstances using free molecule theory.

Posted in: Briefs, TSP, Electronics & Computers, Information Sciences, Software, Computational fluid dynamics, Nozzles, Rocket engines


iPhone App to Facilitate Airborne Radar Operations

NASA’s Jet Propulsion Laboratory, Pasadena, California The Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is an Earth imaging radar that flies on a Gulf-Stream Jet. Its mission is to collect data for NASA scientists who are using Synthetic Aperture Radar to develop methods for monitoring changes in the Earth’s surface. As with many other technologies, there is always the possibility of technological or human errors. Since smartphones are mobile, common, and powerful devices, they can be used to reduce the possibility of operator error when the radar is being configured for flight.

Posted in: Briefs, Electronics & Computers, Software, Imaging and visualization, Radar


Spherical Empirical Mode Decomposition

Goddard Space Flight Center, Greenbelt, Maryland The spherical empirical mode decomposition algorithm is an adaptation in the spherical space of the 2D empirical mode decomposition in Euclidian space. This algorithm is a signal analysis method for any spherical data, such as orbital measurements. The two primary advantages of this innovation are the absence of edge effects in the results, and the computational efficiency of the processing.

Posted in: Briefs, TSP, Electronics & Computers, Information Sciences, Software, Mathematical models


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