Technology Focus

Electronics/Computers

Software

Materials

Mechanics/Machinery

Manufacturing

Bio-Medical

Physical Sciences

Information Sciences

Books and Reports

03-14 March 2014

NASA Tech Briefs, March 2014 1

INTRODUCTION

Tech Briefs are short announcements of innovations originating from research and development

activities of the National Aeronautics and Space Administration. They emphasize information considered likely to be transferable across industrial, regional, or disciplinary lines and are issued to

encourage commercial application.

Additional Information on NASA Tech Briefs and TSPs

Additional information announced herein may be obtained from the NASA Technical Reports Server:

http://ntrs.nasa.gov.

Please reference the control numbers appearing at the end of each Tech Brief. Information on NASA’s

Innovative Partnerships Program (IPP), its documents, and services is available on the World Wide Web

at http://www.ipp.nasa.gov.

Technology Transfer Offices are located at NASA field centers to provide technology-transfer access to industrial users. Inquiries can be made by contacting NASA field centers listed below.

Ames Research Center

Selected technological strengths: Information

Technology; Biotechnology; Nanotechnology;

Aerospace Operations Systems; Rotorcraft; Thermal Protection Systems.

David Morse

(650) 604-4724

david.r.morse@nasa.gov

Armstrong Flight Research Center

Selected technological strengths: Aerodynamics;

Aeronautics Flight Testing; Aeropropulsion; Flight

Systems; Thermal Testing; Integrated Systems

Test and Validation.

Laura Fobel

(661) 276-3967

laura.j.fobel@nasa.gov

Glenn Research Center

Selected technological strengths: Aeropropulsion;

Communications; Energy Technology; High-Temperature Materials Research.

Kimberly A. Dalgleish-Miller

(216) 433-8047

kimberly.a.dalgleish@nasa.gov

Goddard Space Flight Center

Selected technological strengths: Earth and Planetary Science Missions; LIDAR; Cryogenic Systems; Tracking; Telemetry; Remote Sensing; Command.

Nona Cheeks

(301) 286-5810

nona.k.cheeks@nasa.gov

Jet Propulsion Laboratory

Selected technological strengths: Near/DeepSpace Mission Engineering; Microspacecraft;

Space Communications; Information Systems; Remote Sensing; Robotics.

Dan Broderick

(818) 354-1314

daniel.f.broderick@jpl.nasa.gov

Johnson Space Center

Selected technological strengths: Artificial Intelligence and Human Computer Interface; Life

Sciences; Human Space Flight Operations;

Avionics; Sensors; Communications.

John E. James

(281) 483-3809

john.e.james@nasa.gov

Kennedy Space Center

Selected technological strengths: Fluids and Fluid

Systems; Materials Evaluation; Process Engineering; Command, Control, and Monitor Systems;

Range Systems; Environmental Engineering and

Management.

David R. Makufka

(321) 867-6227

david.r.makufka@nasa.gov

Langley Research Center

Selected technological strengths: Aerodynamics;

Flight Systems; Materials; Structures; Sensors;

Measurements; Information Sciences.

Kathy Dezern

(757) 864-5704

kathy.a.dezern@nasa.gov

Marshall Space Flight Center

Selected technological strengths: Materials; Manufacturing; Nondestructive Evaluation; Biotechnology; Space Propulsion; Controls and Dynamics; Structures; Microgravity Processing.

Terry L. Taylor

(256) 544-5916

terry.taylor@nasa.gov

Stennis Space Center

Selected technological strengths: Propulsion Systems; Test/Monitoring; Remote Sensing; Nonintrusive Instrumentation.

Ramona Travis

(228) 688-3832

ramona.e.travis@ssc.nasa.gov

NASA HEADQUARTERS

Daniel Lockney, Technology Transfer

Program Executive

(202) 358-2037

daniel.p.lockney@nasa.gov

Small Business Innovation Research (SBIR) & Small

Business Technology Transfer (STTR) Programs

Rich Leshner, Program Executive

(202) 358-4920

rleshner@nasa.gov

NASA Field Centers and Program Offices

5 Technology Focus: Data Acquisition

5 Data Fusion for Global Estimation of Forest Characteristics From Sparse Lidar Data

5 Debris & Ice Mapping Analysis Tool — Database

6 Data Acquisition and Processing Software — DAPS

7 Manufacturing & Prototyping

7 Metal-Assisted Fabrication of Biodegradable Porous

Silicon Nanostructures

7 Post-Growth, In Situ Adhesion of Carbon Nanotubes

to a Substrate for Robust CNT Cathodes

8 Integrated PEMFC Flow Field Design for Gravity-Independent Passive Water Removal

9 Thermal Mechanical Preparation of Glass Spheres

11 Materials & Coatings

11 Mechanistic-Based Multiaxial-Stochastic-Strength

Model for Transversely-Isotropic Brittle Materials

13 Electronics/Computers

13 Methods for Mitigating Space Radiation Effects, Fault

Detection and Correction, and Processing Sensor

Data

13 Compact Ka-Band Antenna Feed with Double Circularly Polarized Capability

14 Dual-Leadframe Transient Liquid Phase Bonded

Power Semiconductor Module Assembly and Bonding Process

15 Quad First Stage Processor: A Four-Channel Digitizer

and Digital Beam-Forming Processor

17 Mechanics/Machinery

17 Protective Sleeve for a Pyrotechnic Reefing

Line Cutter

17 Metabolic Heat Regenerated Temperature

Swing Adsorption

18 CubeSat Deployable Log Periodic Dipole Array

18 Re-entry Vehicle Shape for Enhanced Performance

21 Physical Sciences

21 NanoRacks-Scale MEMS Gas Chromatograph System

21 Variable Camber Aerodynamic Control Surfaces and

Active Wing Shaping Control

22 Spacecraft Line-of-Sight Stabilization Using

LWIR Earth Signature

23 Technique for Finding Retro-Reflectors in Flash

LIDAR Imagery

23 Novel Hemispherical Dynamic Camera for EVAs

25 Software

25 360° Visual Detection and Object Tracking on

an Autonomous Surface Vehicle

25 Simulation of Charge Carrier Mobility in

Conducting Polymers

25 Observational Data Formatter Using CMOR

for CMIP5

27 Information Technology

27 Propellant Loading Physics Model for Fault Detection

Isolation and Recovery

27 Probabilistic Guidance for Swarms of

Autonomous Agents

28 Reducing Drift in Stereo Visual Odometry

28 Future Air-Traffic Management Concepts

Evaluation Tool

29 Examination and A Priori Analysis of a Direct

Numerical Simulation Database for High-Pressure

Turbulent Flows

30 Resource-Constrained Application of Support Vector

Machines to Imagery

NASA Tech Briefs, March 2014 3

This document was prepared under the sponsorship of the National Aeronautics and Space Administration. Neither the United States

Government nor any person acting on behalf of the United States Government assumes any liability resulting from the use of the information contained in this document, or warrants that such use will be free from privately owned rights.

03-14 March 2014

NASA Tech Briefs, March 2014 5

Technology Focus: Data Acquisition

The Debris & ICE Mapping Analysis

Tool (DIMAT) system is a Web-based system that supports communication, data

integration, data sharing, and problem

definition/resolution through use of an

integrated presentation framework for

ice and debris description and analysis.

It provides an integrated engineering

problem description, visualization

analysis, and resolution presentation

framework for ice and debris issues.

These include, but are not limited to:

pre-launch debris walk-downs; ice formation during tanking, pre-launch,

and launch; debris hits on Orbiter

identified on-orbit or post-landing; and

external tank (ET) foam damage/texture mapping. The DIMAT system

leverages the EMaps application and

models, as well as Design Visualization

Group (DVG) models to provide highfidelity 3D models of the Orbiter, ET,

Solid Rocket Boosters (SRB), and Pad.

Proposed solutions generated by

DIMAT integrate these models with

ice/frost/debris location data, and can

include 3D visualizations and digital

photographs of ice and/or orbiter TPS

(thermal protection system) debris

hits. Ice/debris displayed on the

EMaps model will represent actual size

and location. The user will be able to

access data and photograph displays by

selecting the ice on the EMaps model.

The DIMAT analysis component allows the user to enter ice/debris data

into the system from the Web, and to

link to program-related databases and

documents. The DIMAT inspector component is a laptop-based system that the

ice/debris team uses to enter data, including digital photographs, in real

time. It incorporates the diverse data

repositories into a single database.

The software is simple for engineers

and management to use, and automates

data input into a repetitive report. The

software easily adapts to another database

Debris & Ice Mapping Analysis Tool — Database

The software is simple for engineers and management to use.

Lyndon B. Johnson Space Center, Houston, Texas

This lidar data fusion approach is

based on associating samples from

sparse lidar data with groups of region

objects determined by a unique image

segmentation approach, HSeg (Hierarchical Segmentation). This segmentation approach, which was previously developed by co-innovator James Tilton, is

ideal for this application because HSeg

automatically produces a hierarchical

set of image segmentations, i.e., a set of

several image segmentations of the same

image at different levels of detail in

which the segmentations at coarser levels of detail can be produced from simple merges of regions at finer levels of

detail. This enables a simple approach

for selecting an appropriate level of segmentation detail. HSeg also automatically classifies the spatially continuous

region objects into region classes,

through a tight intertwining of region

growing segmentation, which produces

spatially connected region objects, with

non-adjacent region object aggregation,

which groups sets of region objects together into region classes. No other

practical, operational image segmentation approach has this tight integration

of region growing, object finding with

non-adjacent region aggregation. HSeg

produces image segmentations with

high spatial fidelity — enabled by the

tight intertwining of region growing segmentation with non-adjacent region object aggregation.

Also, Hseg controls the importance of

spatially adjacent region merging relative to spatially non-adjacent region

merging (aggregation) through the

Swght parameter, which can vary from 0.0

to 1.0. At Swght = 0.0 no non-adjacent region object aggregation is performed,

and with Swght = 1.0, equal weighting is

given to spatially adjacent and spatially

non-adjacent region merging.

The initial tests were performed using

Landsat TM data transformed into

brightness, greenness, and wetness tasseled cap features in an area where there

is “wall-to-wall” lidar data from the Laser

Vegetation Imaging Sensor, LVIS. This

Landsat TM data was collected on Sept.

5, 2007 from over central Maine, and the

LVIS data was collected in August 2009.

The spaceborne lidar (SSL) data was

simulated by selecting tracks out of the

LVIS data at an appropriate density. The

LVIS data served as the ground reference data for the evaluation of the results.

Later, additional tests were performed using UAV SAR data with three

polarizations: HH, HV, and VV. The

original SAR data was at 5-meter pixel

resolution, but 6×6 blocks of pixels were

averaged of this data to produce 30-

meter pixel resolution SAR data to better compare the results with the tests

with the 30-meter transformed Landsat

TM data.

This work was done by James Tilton, Bruce

Cook, and Paul Montesano for Goddard Space

Flight Center. Further information is contained in a TSP (see page 1).GSC-16535-1

Data Fusion for Global Estimation of Forest Characteristics

From Sparse Lidar Data

A new approach automatically produces a hierarchical set of image segmentations for detailed

analysis of forest data.

Goddard Space Flight Center, Greenbelt, Maryland
6 NASA Tech Briefs, March 2014

and is comparative to system architecture. The model will be capable of being

utilized for engineering analysis, and integrates and displays CAD-based drawings. The model can display integrated

views/JPEGS from NSTS documents.

DIMAT can display and translate between any of the element coordinate

systems, and has the ability to calculate

x,y,z from manual/visual user input.

Using x,y,z coordinates provides relative

distances or clearances between points.

It visually locates ice/debris on the

model and determines x,y,z location. It

has the ability to provide accurate

size/geometry of reported ice/debris,

and can isolate specific zones for identifying locations of ice/debris and surrounding hardware.

The model will contain locations,

type, field of view, and simulated camera view for specified OTVs (Orbital

Transfer Vehicles), and has the capability to link OTV to the application to display real-time status/picture of reported

ice/debris. The model will have the capability to accept live feed from a selected OTV and overlay on the model.

This work was done by Robert Luecking

and Cindy Nguyen of The Boeing Company

for Johnson Space Center. Further information

is contained in a TSP (see page 1). MSC25030-1

DAPS was designed to support the

DAWN-AIR project participating in the

Genesis and Rapid Intensification

Processes (GRIP) hurricane campaign.

It controls the data acquisition system

consisting of a scanner that directs the

lidar beam, an inertial navigation system/GPS (INS/GPS) unit for monitoring aircraft motion, a DSP module,

and serial and video modules while acquiring and processing lidar data in

real time. DAPS was optimized to meet

the project requirement: acquiring

and processing more than 550,000

samples per second. DAPS was capable

of managing such extensive computational loads without experiencing a

single incident of crash or system failure during the entire 130 flight hours

of the GRIP mission.

The latest wind profiling algorithm accurately estimates the horizontal wind

speed and direction. It is robust enough

to identify abrupt changes in the horizontal wind parameters that are difficult

to be detected by other conventional

methods. Some of the unique features of

DAPS and the latest data processing algorithm are as follows:

1. DAPS can operate both in real

time and offline while performing

full tasks faster than 10 Hz of execution rate.

2. DAPS has informative data displays

such as the Doppler shift and the

power distribution of line of sights,

horizontal and vertical wind profiles,

and color-coded history displays of

wind profiles. It also displays important

user inputs and real-time GPS data.

3. DAPS is smart software that is capable of automatic error correction

and calibration of the scanner and

the digitizer.

4. DAPS is robust and is capable of longhaul operations without an incident

of system error or crash.

5. The latest wind profiling algorithm

can produce robust horizontal wind

parameters.

6. The algorithm has smart routines to

increase the signal-to-noise ratio and

effective INS/GPS data interpretation

and application.

7. The algorithm runs at the minimal

error resolution of 1 m/s in wind

speed with 512-FFT.

This work was done by Jeffrey Beyon of Langley Research Center. Further information is contained in a TSP (see page 1). LAR-18033-1

Data Acquisition and Processing Software — DAPS

Langley Research Center, Hampton, Virginia
NASA Tech Briefs, March 2014 7

Manufacturing & Prototyping

Post-Growth, In Situ Adhesion of Carbon Nanotubes to a

Substrate for Robust CNT Cathodes

This technology can be used down-hole in oil wells, and in high-temperature, high-pressure, corrosive environments in the automotive industry.

NASA’s Jet Propulsion Laboratory, Pasadena, California

The field emission electron sources

using carbon nanotubes (CNTs) are

being targeted for low-power vacuum microelectronic applications for harsh-environment operation (high temperature,

pressure, and corrosive atmosphere).

While CNTs have demonstrated excellent properties in terms of low threshold

field, low-power operation, and high current densities, one problem with vacuum

electronic applications is poor adhesion

of CNTs to the substrate on which they

are synthesized. The chemical vapor deposition (CVD) process used to grow

CNTs on silicon or other metallic substrates using an iron catalyst with a thin

oxide diffusion barrier layer has consistently provided reproducible growth.

The CNTs are only surface-adhering in

these cases, and are easily removed from

the surface with the application of minor

forces — typically pressures of 20 to 60

kPa. This causes catastrophic failures of

CNT field emitters since the applied

field could exceed the adhesion strength

of CNTs to the substrate.

An in situ process was developed that

allows welding of CNT bundles to the

support substrate. An efficient field

emission architecture of CNTs has been

Metal-Assisted Fabrication of Biodegradable Porous

Silicon Nanostructures

Silicon nanostructures are fabricated from single-crystal silicon by an electroless

chemical etch process.

Lyndon B. Johnson Space Center, Houston, Texas

Porous silicon nanowires are fabricated by two-step, metal-assisted electroless chemical etching of p-type or n-type

silicon wafers. This method, in combination with nanolithography or

nanopatterning, can be applied to fabricate porous silicon nanostructures of

different shapes and sizes, such as

nanorods, nanobelts, nanostrips, and

nanochains. The specific resistivity of

the silicon substrate, and composition

of the etching solution, determine the

porosity and pore size or lack thereof of

the resulting nanostructures. Silicon

doping, type of metal catalyst, concentrations of H2O2, and solvent all affect

the formation of porous nanostructures

at various resistivity ranges of silicon. A

phase diagram summarizing the relation of porosification and doping,

metal, concentrations of H2O2, and solvent can be generated.

In this innovation, high-aspect-ratio

porous silicon nanostructures, such as

those previously mentioned, were fabricated from single-crystal silicon by an

electroless chemical etch process. A

metal film, metal nanofeatures, or

metal nanoparticles were coated on

the silicon substrate first, and a solution of HF and hydrogen peroxide was

then used to anisotropically etch the

silicon to form the porous silicon

nanostructures. Up to hundreds of micron-long high-aspect-ratio porous silicon nanostructures can be fabricated,

and the patterns of the cross-section of

porous silicon structures can be controlled by photolithography, nanolithography, or nanoparticle-assisted patterning. The porosity is related to the

resistivity range of the silicon substrate, the metal catalysts, the chemical

concentration, and the additive solvent. The fabricated porous silicon

nanostructure is biodegradable, and

the degradation time can be controlled by surface treatments.

Porous silicon nanowires can be fabricated with a two-step process. A nanostructured metal layer can be deposited

on a silicon substrate by an electroless

chemical deposition or electrochemical deposition. This step determines

the shape of the final nanowires. Alternatively, metal nanoparticles can be

spun on the silicon surface to form a

metal layer, or a metal layer can be

physically or chemically deposited on

the silicon through a nanopatterned

mask. The metal-coated silicon can be

etched in a solution of HF, water, and

H2O2 to produce porous silicon

nanowires. Solvent can be added to the

solution to modulate the features of

the porous silicon nanowires.

This work was done by Mauro Ferrari,

Xuewu Liu, and Ciro Chappini of the University of Texas Health Science Center at

Houston for Johnson Space Center. For further information, contact the JSC Innovation

Partnerships Office at (281) 483-3809.

In accordance with Public Law 96-517,

the contractor has elected to retain title to this

invention. Inquiries concerning rights for its

commercial use should be addressed to:

The University of Texas

Health and Science Center at Houston

Office of Technology Management

7000 Fannin Street, Suite 720

Houston, TX 77030

Refer to MSC-24690-1, volume and number of this NASA Tech Briefs issue, and the

page number.
8 NASA Tech Briefs, March 2014

Integrated PEMFC Flow Field Design for Gravity-Independent

Passive Water Removal

The design solves safety as well as reliability issues.

Lyndon B. Johnson Space Center, Houston, Texas

A gravity-independent PEM (proton

exchange membrane) fuel cell stack has

been developed that will operate at

high-pressure H2 and O2 conditions

with the requirement for relatively modest H2 and O2 gas circulation. Until

now, in order to get higher efficiency,

excess reactant gas flow was required to

prevent water slug formation in gas

channels, thus reducing fuel cell performance. In addition, this excess gas

flow is typically supported by mechanical pumps and/or a high-pressure ejector system. All of these in a closed space

environment contributed to potential

safety as well as reliability issues due to

the potential failure of mechanical

pumps and ejectors.

ElectroChem’s Integrated Flow Field

(IFF) design for a PEM fuel cell solves

all these issues. It is based on a multilayered integrated flow-field structure that

forms a porous structure with distinct

wetting properties. It results in increased exposure of the catalyst to the

reactant gas, resulting in higher cell

voltage. This results in higher efficiency

than the conventional plate designs. In

addition, the entire flow field makes full

contact between the porous structure

and the electrodes, thus avoiding damage to membrane electrode assemblies

(MEAs) at elevated operating pressure

conditions. The same design also provides transport of product water back to

the entire flow field for humidification

and greater performance.

In the IFF cell there is no need for excess reactant gas, since the design is

based on a non-flow-through operation.

The IFF fuel cell allows the operation at

100% reactant gas utilization. The design also enables passive removal of

water at various cell orientations.

The figure demonstrates a complete

passive water removal at non-flow-through

operation condition and a response to

Demonstration of a Non-Flow-Through Fuel Cell Operation following NASA load profile testing. The

IFF fuel cell performed passive water removal without gas circulation.

1.1

1

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0 60 120 180 240 300 360 420

0 60 120 180 240 300 360 420

0

10

20

30

40

50

60

70

80

90

100

110

Test Time, Minutes Stack Current

Cell Potentials, Volts; Cell Differential, x100 mV;

Gross Stack Power, kW Cell #1

Cell #2

Cell #3

Cell #4

Stack Gross Power

Stack Current A

mps.

reported and patented by JPL. This architecture consists of arrays of CNT bundles of 1 to 2 micrometers in diameter,

spaced 5 micrometers apart. These bundles can be grown on any substrate that

is conducive for lithographic patterning

and catalyst deposition for CNT growth

(Fe, Ni, etc.). A diffusion barrier layer,

typically an oxide layer, is deposited underneath the metal catalyst.

Growth of CNTs on titanium substrate with a diffusion barrier at 575 to

600 °C has been demonstrated. Following the growth process, the CNT bundle arrays are welded into Ti by heating

the Ti substrates to 1,050 °C such that

the surface of Ti softens and the CNTs

get rooted inside. This welding process

provides CNT field emission samples

that are robust and are tightly bound to

the substrate. They have been shown to

withstand high electric fields without

getting dislodged.

The novelty here is the single process

step that allows the growth and in situ

welding to produce vertically aligned,

patterned CNTs on a metallic substrate.

Even though the process was developed

for titanium substrate, it is possible to implement the same with other metallic

substrates and catalyst combinations. It is

possible to deposit any of the metal layers

on any other metal substrates to create a

multi-metal substrate on which CNT bundle arrays or simply CNTs are grown. The

main advantage is that it allows creation

of array patterns of CNTs, and welds

them into place as opposed to previously

reported processes that required depositing loose CNTs on metallic films followed

by a welding process. It is not possible to

achieve vertically oriented and patterned

CNTs with such a welding process.

This work was done by Harish Manohara,

Valerie Kristof, and Risaku Toda of Caltech for

NASA’s Jet Propulsion Laboratory. Further information is contained in a TSP (see page 1).

In accordance with Public Law 96-517,

the contractor has elected to retain title to this

invention. Inquiries concerning rights for its

commercial use should be addressed to:

Innovative Technology Assets Management

JPL

Mail Stop 321-123

4800 Oak Grove Drive

Pasadena, CA 91109-8099

E-mail: iaoffice@jpl.nasa.gov

Refer to NPO-48953, volume and number

of this NASA Tech Briefs issue, and the

page number.
NASA Tech Briefs, March 2014 9

Samples of lunar regolith have included small glass spheres. Most literature

has suggested the small spheres were

formed by meteorite impacts. The resulting transformation of kinetic energy to

thermal energy caused the lunar surface

to melt. The process yielded glass spheres.

Recreating a meteorite impact that yields

glass spheres is very challenging. Furthermore, the melting temperature of certain

minerals on the Moon precludes the use

of standard thermal techniques.

Glass spheres are created by using a

thermal and pneumatic process. The

process allows extremely high-meltingtemperature material to be transformed

into sub-750-micron spheres. The thermal and mechanical process developed

transforms the molten material to the

lowest energy morphology, a sphere,

while locking in the glass chemistry.

To produce a high volume of sub750-micron glass spheres, the feedstock

material was melted with a plasma system. The system uses high-power, remotely coupled electric plasma. The

molten material is then routed through

a molybdenum orifice and allowed to

fall vertically by gravity. Approximately

one meter from the discharge, a highvelocity pneumatic jet is positioned perpendicular to the glass stream. At the

impingement zone, the molten glass

material is pneumatically removed

from the primary stream path and rapidly cooled to glass morphology while

traveling to the collection area. At the

collection area, the spheres are mechanically collected.

The integrated plasma system and

mechanical forming process allow a

very wide variety of material to be

processed into spheres. Also, the rapid

pneumatic quench locks ensure glass

morphology and precludes any significant devitrification.

Glass spheres are currently used in a

wide variety of consumer and commercial applications. The ability to thermally

react feedstock materials at plasma temperatures extends the range of possible

glass chemistries available. The demonstrated ability to produce spheres directly

from a molten glass stream increases the

upper diameter limit realized in traditional solid to sphere processes. Examples of current research work using the

plasma process include production of

high-strength glass spheres for drilling

proppants, and the integration of catalyst materials in bio-degradable glass for

ground water remediation applications.

This work was done by Mike Weinstein of

Zybek Advanced Productions, Inc. for Marshall Space Flight Center. For more information, contact Sammy Nabors, MSFC Commercialization Assistance Lead, at sammy.a.

nabors@nasa.gov. Refer to MFS-32938-1.

Thermal Mechanical Preparation of Glass Spheres

The forming process allows a very wide variety of material to be processed into spheres.

Marshall Space Flight Center, Alabama

3–1 power ratio demand. It is an IFF fuel

cell stack with 4 cells of 200 cm2 electrode

surface area.

The results of IFF fuel cell configuration have demonstrated 100% reactant

gas utilization, reduced cost and weight

penalties, and system simplification with

higher reliability.

This IFF design was developed for use

in a PEM fuel cell power plant for space

application, but it could also be used for

high-altitude balloon flight and air-independent applications (e.g., manned and

unmanned underwater vehicles). When

the IFF design is used in a PEM electrolyzer, it functions as an internal phase

separator, which enhances overall system

efficiency.

This work was done by Michael Pien of

ElectroChem, Inc. for Johnson Space Center.

Further information is contained in a TSP

(see page 1).

In accordance with Public Law 96-517,

the contractor has elected to retain title to this

invention. Inquiries concerning rights for its

commercial use should be addressed to:

Michael S. Pien, Ph.D.

Vice-President of Research and Development

ElectroChem, Inc.

400 W Cummings Park # 5600

Woburn, MA 01801

Phone No.: (781) 938-5300

E-mail: sales@fuelcell.com

Refer to MSC-24587-1, volume and number of this NASA Tech Briefs issue, and the

page number.

NASA Tech Briefs, March 2014 11

A methodology has been developed

and the software written to predict the

probability of failure of transversely

isotropic (a type of anisotropy) materials

under generalized thermomechanical

loading. This methodology is mechanistic in that it is based on the physical

characteristics of brittle fracture, and

morphological in that it considers the

size, shape, and orientation distribution

of strength controlling defects or flaws.

On that basis, it can also account for a

material’s failure modes and direction of

damage initiation from loading. It is capable of predicting an anisotropic material’s probability of failure under transient and cyclic loading. This innovation

can be applied to materials such as

graphite, coatings, or the individual brittle constituents of composite materials.

The strength of an isotropic brittle material is independent of the direction of

the applied load. However, for many brittle materials, the strength of the material

changes with the direction of the applied

load. These are termed anisotropic materials. The most common type of material

strength anisotropy is transverse isotropy,

where material strength is isotropic

within a plane but orthogonal to that

plane, the strength is greater than or less

than the in-plane strength.

The unit sphere methodology is an attempt to provide an improved mechanistic basis to the problem of predicting

strength response of an anisotropic and

composite material under multiaxial

loading as compared to polynomial interaction equation formulations. It has

multiple unique features including flaw

orientation and fracture toughness

anisotropy. These physically based

anisotropy functions are general and

can model tightly defined or more diffuse material anisotropy textures describing flaw populations. Innovative

equations were developed in order to

achieve this capability. The methodology also includes consideration of

strength scatter to predict material

probability of failure, shear sensitivity of

flaws, and accounting for multiple failure modes regarding overall failure response. One novel feature of this

methodology is the ability to predict the

orientation of critical flaws under multiaxial loading.

With this capability, the model can be

tuned to the physical attributes of the

material by, for example, mapping the

toughness response of the material with

respect to orientation for indentation

testing, or mapping the observed orientation anisotropy of the pre-existing

flaws in the material. In principle, by this

methodology, the physical attributes of

the anisotropic material can also be used

to predict the multiaxial strength response of the material.

It is intended for aerospace applications where trade-offs must be performed regarding safety, durability, and

weight. It is anticipated that this software

will be used with finite element or micromechanics-based codes describing

the behavior of composite materials.

This incorporation would allow the full

exercise of the new methodology, including incremental time/load steps,

and fatigue of composite laminates and

woven composite structures.

This work was done by Noel N. Nemeth of

Glenn Research Center. Further information is

contained in a TSP (see page 1).

Inquiries concerning rights for the commercial use of this invention should be addressed

to NASA Glenn Research Center, Innovative

Partnerships Office, Attn: Steven Fedor, Mail

Stop 4–8, 21000 Brookpark Road, Cleveland,

Ohio 44135. Refer to LEW-19018-1.

Mechanistic-Based Multiaxial-Stochastic-Strength Model for

Transversely-Isotropic Brittle Materials

The methodology is applicable to a wide variety of graphite, coatings, and composite materials.

John H. Glenn Research Center, Cleveland, Ohio

Materials & Coatings

NASA Tech Briefs, March 2014 13

Electronics/Computers

The Integrated Modular Avionics

(IMA) architecture being developed for

space applications requires that sensor

data be autonomously sampled and

transmitted to the system network. This

transmission needs to occur on a predetermined, fixed schedule to avoid conflicts on the network. It needs to be capable of building packets of sensor data

for individual application partitions

(i.e., environmental control, propulsion, and vehicle management). It must

be easily configured for flexibility in system scheduling.

Once a minor frame interrupt (MFI)

is received from the network, the timing

within a frame begins. The poll list table

controls the timing. It starts the

input/output module (IOM) sample list

execution within each IOM. After

enough time has elapsed for the IOMs

to step through their respective sample

lists, the poll list initiates the command

to start assembling the packets. These

may include, for example, a packet that

contains only data for the environmental control system, another packet could

include data for the propulsion system,

and yet another packet may contain RIU

(remote interface unit) status information. These packets are transferred to

the network interface card (NIC). The

tables in the NIC schedule the transmission onto the network for each packet.

The tables may be unique by minor

frame. This allows different packets of

data to be sent on different minor

frames of the system schedule.

Self-checking lockstep processor architectures, by their nature, are intended to detect differences between redundant elements and to prevent their

further propagation. Traditional methods of dealing with detected differences

between the halves of a lockstep processor pair are to cease lockstep operation

and to initiate recovery. In an integrated

processor application, ceasing lockstep

operation impacts all software applications on the platform, as they are unable

to perform their function until the recovery has been completed and lockstep

operation is resumed. The method

being described here eliminates the loss

of lockstep operation under certain conditions such that the recovery can be

done “seamlessly” to all applications

other than the one directly accessing the

resource that caused the detected difference between lockstep halves.

The Orion VMC (vehicle management computer) processor design is

based upon the re-use of a processor design from a commercial avionics product. That design includes the use of several commercial off-the-shelf (COTS)

components for which there are no

equivalent space-rated components.

One of those COTS components is

NOR flash that is used to store program

and database information for the

processor. A design solution that maximizes the advantages of re-use, while satisfying the radiation requirements of

the product when using these COTS

NOR flash devices in the program flash

array, was needed.

This work was done by Mike Bartels, Dean

Sunderland, Terry Ahrendt, Tim Moore,

David Yeager, Kevin Stover, James Tyrrell,

and Bob Poucher of Honeywell for Johnson

Space Center. Further information is contained in a TSP (see page 1).MSC-24769-

1/81-1/5-1.

Methods for Mitigating Space Radiation Effects, Fault Detection

and Correction, and Processing Sensor Data

A combination of three innovations enables increased efficiency, stability, and flexibility of data

management and systems functionality.

Lyndon B. Johnson Space Center, Houston, Texas

NASA has an interest in utilizing the

Ka-band frequency allocation. One of

the main reasons for migrating to Kaband is the need for higher frequency

bandwidth to enable higher data rates. A

dual circular polarized wideband antenna for Ka-band communications applications was designed leveraging a

novel Ka-band polarizer design used in

Lunar Reconnaissance Orbiter/Solar

Dynamics Observatory (LRO/SDO).

The proposed design merges two components (polarizer and antenna) into

one unit, reducing its overall size. Its

simulated bandwidth extends beyond

the allocated bandwidth for NASA at Kaband. This novel design could be used as

well for the feed component in highgain antennas (HGAs).

Satellite communications at the Kaband frequencies has been a topic of

interest for the last decade. NASA has

had a Ka-band frequency allocation underused for many years due to various

reasons. When the transmitter’s output

data rate after encoding is 450 Msps,

the spectrum needs to be severely filtered to avoid interference with

NASA’s DSN frequency allocation,

which promotes large amounts of intersymbol interference at the receiver.

Transitioning to Ka-band will mitigate

this problem since the allocated bandCompact Ka-Band Antenna Feed with Double Circularly

Polarized Capability

This design could be used for the feed component in high-gain antennas.

Goddard Space Flight Center, Greenbelt, Maryland
14 NASA Tech Briefs, March 2014

width is larger, allowing much higher

data rates to be sustained without such

signal distortions.

The Earth-shaped reflector antenna

at Ka-band consists of a single reflector

configuration where the feed is located

at the focal point of the system using

supporting struts, and the reflector is

shaped to produce an Earth-shaped radiation pattern. The waveguide used to

carry energy to the antenna feed can

be located along one of, or be part of,

the struts supporting the feed above

the reflector.

The antenna design consists of merging a corrugated feed antenna with a polarizer to produce a satisfactory solution

of blockage reduction (size reduction)

of the reflector aperture. What is usually

a two-component system has been reduced to a single part, reducing mass,

size, and cost. This antenna could be

used in Ka-band HGA or Earth-shaped

antenna reflector combinations. The polarizer/antenna combination also allows

it to be used in dual circular polarization

applications. The overall return loss is

better than 20 dB for the simulated frequency range of 23.5 to 28.5 GHz, showing an excellent impedance match over

NASA’s frequency allocation. The port

isolation between the ports has not been

optimized, but can be optimized for the

application at hand.

For the current design, the isolation

for the standalone feed antenna and polarizer combination varies between –15

to –18 dB over the frequency band. For a

standalone application (no reflector),

this could be improved by improving the

internal wave impedance match between

the polarizer and feed antenna. For a reflector application, it can be optimized

to partially cancel the reflection from the

reflector back into the feed, which is typically of the same order of magnitude.

This work was done by Cornelis du Toit

of QSS and Kenneth Hersey of MEI Technologies for Goddard Space Flight Center.

Further information is contained in a TSP

(see page 1). GSC-16773-1

Dual-Leadframe Transient Liquid Phase Bonded Power

Semiconductor Module Assembly and Bonding Process

This module package and bonding process enable device operation at temperatures

exceeding 400 °C.

John H. Glenn Research Center, Cleveland, Ohio

A high-temperature-capable widebandgap semiconductor power module

package, coupled with a new high-temperature-capable bonding process (with

an optimized assembly and manufacturing process), has been developed that,

together, can allow device operation at

temperatures exceeding 400 °C, with the

potential for higher-temperature operation depending on the semiconductor

device characteristics.

The semiconductor module is an

ultra-compact, hybrid power module

that uses double leadframes and direct

leadframe-to-chip transient liquid phase

(TLP) bonding. The unique advantages

include very high current-carrying capability, low package parasitic impedance,

low thermomechanical stress at high

temperatures, double-side cooling, and

modularity for easy system-level integration. The new power module will have a

very small form factor with 3 to 5× reduction in size and weight from the prior

art, no failure-prone bond wires, and will

be capable of operating from 450 to –

125 °C.

Traditional power semiconductor

modules use solder to attach the die to

the substrate, which requires that the device be heated to a temperature higher

than the normal operating temperature.

For very-high-temperature-operation devices, it isn’t feasible to use a soldering

process. However, in this innovation, the

Top Baseplate

Top Substrate

Ceramic Adhesive

SiC MOSFET Die

Bottom Substrate

Bottom Baseplate

Gate High

Switch Node

Bus +

Bus -

Gate Low

An exploded view of the Semiconductor Module stackup.
NASA Tech Briefs, March 2014 15

Transient Liquid Phase (TLP) bonds at a

temperature between the operations

temperature range of the device. It is

also a low-cost manufacturing process.

A high-temperature module design

may have a profound impact on power

electronics and energy conversion technologies. For commercial applications,

the new packaging and bonding process

technology can be used in its current

form, or can be scaled down to medium

or conventional temperature ranges

with a significantly reduced cost, making

it a viable and economical option for

large commercial markets such as hybrid

electric vehicles, renewable energy conversion, and power supplies.

This work was done by John C. Elmes of Advanced Power Electronics Corporation, and

Brian Grummel, Zehng John Shen, and Wendell Brokaw of the University of Central Florida

for Glenn Research Center. Further information

is contained in a TSP (see page 1).

Inquiries concerning rights for the commercial use of this invention should be addressed

to NASA Glenn Research Center, Innovative

Partnerships Office, Attn: Steven Fedor, Mail

Stop 4–8, 21000 Brookpark Road, Cleveland,

Ohio 44135. Refer to LEW-19091-1/2-1.

A 4-channel digitizer was designed,

built, and tested. The very large, complex board enables SweepSAR. The proposed Deformation, Eco-Systems, and

Dynamics of Ice Radar (DESDynl-R) Lband SAR instrument employs multiple

digital channels to optimize resolution

while keeping a large swath on a single

pass. High-speed digitization with very

fine synchronization and digital beam

forming are necessary in order to facilitate this new technique.

The Quad First Stage Processor (qFSP)

was developed to achieve both the processing performance as well as the digitizing fidelity in order to accomplish this

sweeping SAR technique. The qFSP utilizes high-precision and high-speed analog-to-digital converters (ADCs), each

with a finely adjustable clock distribution

network to digitize the channels at the fidelity necessary to allow for digital beam

forming. The Xilinx-produced FX130T

Virtex 5 part handles the processing to

digitally calibrate each channel as well as

filter and beam-form the receive signals.

Demonstrating the digital processing

required for digital beam forming and

digital calibration is instrumental to the

viability of the proposed DESDynl instrument. The qFSP development brings

this implementation to Technology

Readiness Level (TRL) 6.

This work was done by Chung-Lun

Chuang, Scott J. Shaffer, Robert F. Smythe,

Eric N. Liao, Samuel S. Li, Arin C. Morfopoulos, Louise A. Veilleux, Chester N. Lim,

and Noppasin Niamsuwan of Caltech for

NASA’s Jet Propulsion Laboratory. Further

information is contained in a TSP (see page

1). NPO-48936

Quad First Stage Processor: A Four-Channel Digitizer and

Digital Beam-Forming Processor

NASA’s Jet Propulsion Laboratory, Pasadena, California

NASA Tech Briefs, March 2014 17

Mechanics/Machinery

A metallic sleeve provides protection

and guidance for the actuating lanyard

pull of a parachute system reefing line cutter. This device ensures that the reefing

line cutter is not damaged during packing

or deployment. In addition, the device ensures that the actuating lanyard that initiates the cutter is pulled within the device’s

specification cone angle. Combined, these

features increase the durability of the reefing line cutter used in parachute reefing

systems, and significantly increases the reliability of the underlying reefing cutter.

Protecting such a critical element of the

controlled deployment of parachutes significantly improves the operation of the

parachute reefing system.

The sleeve is designed as an “add on”

component to provide lanyard pull

guidance and cutter bending resistance.

The end user can procure off-the-shelf

hardware with no changes, and then

choose to add the cutter sleeve at a later

time based on usage and environment.

This metallic sleeve is reusable and allows for a decrease in unit cost of the

reefing line cutter.

The cutter sleeve provides containment of gases or shrapnel in the event

of an unexpected cutter failure/rupture. It also provides a more positive retention location, in the form of a

groove around its diameter, for attachment to a parachute through stitching/sewing. Testing of reefing line cutters without the protective sleeve

resulted in failures that included broken pull loops and bent cutters. Testing

with the protective sleeve resulted in all

cutters functioning correctly.

This work was done by James H.

McMichael, Hai D. Nguyen, Mark Landeck,

and Richard Hagen of Johnson Space Center.

Further information is contained in a TSP

(see page 1). MSC-25523-1

Protective Sleeve for a Pyrotechnic Reefing Line Cutter

The sleeve provides improved operation of a parachute reefing system.

Lyndon B. Johnson Space Center, Houston, Texas

The Cutter Sleeve features a round end to protect the pull lanyard, a hole for the reefing line cutter

safety pin, and a groove that allows the sleeve to be sewn into the parachute.

Rounded end 

to protect pull 

lanyard

Hole for reefing

line cutter 

safety pin

Groove to allow 

the sleeve to be 

sewn into parachute

Two fundamental problems facing the

development of a portable system to sustain life on extraterrestrial surfaces are

(1) heat rejection and (2) rejection of

metabolically produced CO2 to an environment with a ppCO2 of 0.4 to 0.9 kPa

as is present on Mars. Portable life support systems typically use water for heat

rejection via sublimation. Consequently,

the water is removed from the life support system and into the surrounding

environment after use. This wastes a

valuable resource required for human

life that is expensive to transport from

Earth. Furthermore, rejecting the water

vapor to the surrounding environment

contaminates it, severely interfering with

any search for life on extraterrestrial surfaces. A portable life support system

should be able to use a variety of fluids

for heat rejection, especially liquid CO2,

as it can be easily acquired and cheaply

stored on the surface of Mars. The use of

liquid CO2 as a coolant has the advantage that it will not interfere with scientific investigations by contaminating the

area as it is sublimated from the life support system for heat rejection.

A subsystem has been developed for a

portable life support system (PLSS) called

Metabolic heat regenerated Temperature

Swing Adsorption (MTSA). MTSA simultaneously addresses heat rejection and

CO2 rejection to an environment ranging

from vacuum to a ppCO2 of 0.9 kPa or

greater. The invention utilizes an adsorbent-based subsystem that is cooled with

liquid CO2, and is used to cleanse the vent

loop of metabolically produced CO2.

Once the adsorbent is fully loaded with

metabolically produced CO2, metabolic

waste heat from the expired breath is

used to warm and regenerate the adsorbent bed. Exhausted adsorbent cooling

fluid is used to aid in additional heat rejection and further cool the user.

The basic principle is removal of CO2

by an adsorbent with regeneration

Metabolic Heat Regenerated Temperature Swing Adsorption

Liquid CO2 as a coolant will not contaminate the area as it is sublimated from the life support

system for heat rejection.

Lyndon B. Johnson Space Center, Houston, Texas
18 NASA Tech Briefs, March 2014

through temperature swing adsorption

(TSA) over the temperature range

bound by the sublimation temperature

of CO2 (less than 195 K) and the metabolic vent loop (310 K). There are two

beds to facilitate continuous removal of

metabolically produced CO2 from the

vent loop: one for loading the adsorbent via a vent loop exiting the helmet/undergarment of an astronaut’s

portable life support system, and another for regenerating the adsorbent.

This work was done by Taber MacCallum of Paragon Space Development Corp.

for Johnson Space Center. Further information is contained in a TSP (see page 1).

MSC-24859-1

CubeSat Deployable Log Periodic Dipole Array

Any small satellite with a need for a VHF antenna might benefit from this design, in addition to

communications and military applications.

NASA’s Jet Propulsion Laboratory, Pasadena, California

The antenna is composed of two main

deployable structural components that

help it achieve the large packing factor

necessary to fit within the small volume

of the CubeSat. The primary component

of the antenna array is a tension stiffened truss, which is preloaded using a

large tape spring. The truss bays are

formed from solid discs connected by

thin Kevlar thread. The Kevlar threads

are set up in a hexapod configuration,

and are fully tensioned and preloaded

from the force of the tape spring, which

runs through the center of the truss.

The truss gets its overall stiffness from

the properties and configuration of

these Kevlar wires.

There are 21 elements on the antenna corresponding to the full desired

frequency range of 30 to 300 MHz. The

assembly, including cable spooler and

motor, fits within a 2-U CubeSat. This is

achieved by keeping the dipole discs

thin, and by stacking them back-toback. Additionally, the tape spring

boom rolls up on itself to provide excellent stowed volume.

When stowed, the dipoles are sandwiched inside the fixed tube of the

CubeSat, and cannot deploy until they

are forced outward by the tape spring.

To ensure the hexapod thread does not

get tangled or frayed during antenna

stowing and deployment, a scheme was

devised where each individual wire is

wrapped in a figure-eight configuration

around two posts. The wire is laid on top

of itself in subsequent wraps around the

posts, with little chance of forming a tangle or knot. When the discs are pulled

apart, there is minimal force required to

dislodge the wire from the posts. This

thread management scheme is effective;

however, it does have drawbacks in that

it is very tedious and requires several sets

of hands working simultaneously. The

posts also serve a dual purpose and provide a torsional locking feature between

adjacent discs.

This work was done by Mark W. Thomson,

Vine M. Bach, Phillip E. Walkemeyer, Daniel

L. Kahn, Andrew Romero-Wolf, and Samuel

C. Bradford of Caltech for NASA’s Jet Propulsion Laboratory. Further information is contained in a TSP (see page 1). NPO-49107

The Antenna Array assembly, including cable spooler and motor, fits within a 2-U CubeSat. At left is a

CAD model of the VHF array stowed in a 3U CubeSat structure; at right is the initial stowed prototype

of the LPDA.

Confining

Tube

Tape Spring

Boom

Tape

Spool

Dipole Discs

3U CubeSat Structure

Cable Spooler

A vehicle entering the atmosphere of a

planet will do so at hypersonic speeds

and will need to decelerate and maneuver through that atmosphere while protecting its payload from excessive heating. As a consequence, the vehicle shape

must be designed to provide optimal

aerodynamic lift and drag properties,

while minimizing convective and radiative heating to the vehicle outer surfaces.

These needs are met by this invention, which provides a convex structure

with a continuous slope that can be described by four linear segments and six

curvilinear segments joined together to

provide a convex shape defined by nine

parameters. Viewed parallel to the yaxis in a Cartesian coordinate system,

Re-entry Vehicle Shape for Enhanced Performance

A convex structure is used with a continuous slope.

Ames Research Center, Moffett Field, California
NASA Tech Briefs, March 2014 19

the projected cross-sectional shape includes first and second linear segments,

spaced apart from each other and located on opposite sides of an x-axis,

with each of the first and second segments being oriented substantially at a

selected non-zero angle qc relative to

the x-axis, each segment having a first

segment end of closest approach to the

x-axis with each closest approach segment end being located at substantially

the same distance R from the x-axis.

The projected shape includes a third

linear segment that is oriented substantially perpendicular to the x-axis adjacent to the end of closest approach to

the x-axis for each of the first and second linear segments.

The present invention provides an improvement over prior blunt body shapes

in that the shape is actually of a class of

geometric shapes that is describable by a

relatively small number of geometryshape parameters, and that provides a

broad range of geometric shapes with favorable aerodynamic and aerothermal

properties. These properties can then

be analyzed by optimization methods for

desired performance.

Optimization of the vehicle geometryshape parameters can, for example, minimize heating levels subject to constraints that reduce aerodynamic

performance, such as lift/drag, or can

minimize weight of a thermal protection

system, allowing a greater payload.

Other properties can be optimized or established as constraints on a geometric

parameter search, such as a requirement

that a minimum lift/drag be met or exceeded, while minimizing center of gravity offset from vehicle centerline, to ease

packing of a working vehicle while in

space operations.

This work was done by James L. Brown,

Joseph A. Garcia, and Dinesh K. Prabhu of

Ames Research Center. Further information is

contained in a TSP (see page 1).

Inquiries concerning rights for the commercial use of this invention should be addressed

to the Ames Technology Partnerships Division

at 1-855-NASA-BIZ (1-855-6272-249) or

sumedha.garud@nasa.gov. Refer to ARC15606-1.

NASA Tech Briefs, March 2014 21

Physical Sciences

A new concept of aircraft aerodynamic control surfaces has been developed in connection with another new

concept of active wing shaping control

for reducing aircraft drag that will result

in less fuel burn. The first concept is referred to as a variable camber continuous trailing edge flap or, alternatively, a

variable camber continuous leading

edge slat. The variable camber trailing

edge flap (or leading edge slat) comprises multiple chord-wise segments

(three or more) to form a cambered flap

surface, and multiple span-wise segments to form a continuous trailing

edge (or leading edge) curve with no

gaps that could be prescribed by a mathematical function or the equivalent with

boundary conditions enforced at the

end points to minimize tip vorticities.

Aerodynamic simulations have shown

that this type of flap can reduce aerodynamic drag substantially as compared to

a conventional flap. A new active wingshaping control concept is proposed in

connection with the presently disclosed

variable camber continuous trailing

edge flap (or leading edge slat). The active wing-shaping control is designed to

change a wing shape in-flight in order to

achieve a desired optimal wing shape for

optimal drag reduction.

Currently, as fuel is burned, wing loading is reduced and causes the wing

shape to change in bending and twist.

This wing shape change causes the wings

to be less aerodynamically efficient. This

problem can be further exacerbated by

modern high aspect flexible wing design. Aircraft designers typically address

the fuel efficiency goal by usually reducing aircraft weights, improving propulsion efficiency, and/or improving the

aerodynamics of aircraft wings passively.

In so doing, the potential drag penalty

due to changes in the wing shapes would

still exist at off-design conditions.

The unique or novel features of the

new concepts are:

1. Variable camber flap provides the

same lift capability for lower drag as

Variable Camber Aerodynamic Control Surfaces and Active

Wing Shaping Control

Concepts are examined to reduce aerodynamic drag and decrease fuel consumption.

Ames Research Center, Moffett Field, California

In order to study atmospheric or

evolved gases, it is highly advantageous

for an instrument (e.g. mass spectrometer (MS), thermal conductivity detector

(TCD)) to simplify the gas stream with a

front-end gas chromatograph (GC).

When used for planetary missions, highperformance GCs have to satisfy the additional challenging requirements of

surviving high inertial loads with low

mass, power, and volume in order to be

included in Ventures-, Discovery- and

New Frontiers-class missions in today’s

budget-constrained reality.

The development and adoption of advanced MEMS-GCs at JPL would provide a

key enabling technology for near-term missions to Mars or Venus. A MEMS (MicroElectro-Mechanical Systems)-based GC system would be significantly smaller, about 1

kg (including electronics), with a power

consumption of less than 1 W (for isothermal operation). It would also not have the

many complicated fittings and joints of a

conventional GC, significantly enhancing

inertness and robustness.

JPL partnered with Cbana Labs to

couple their MEMS-GC to a miniaturized adaptation of a JPL ion trap mass

spectrometer, a version of which is currently operating in the Vehicle Cabin Atmosphere Monitor (VCAM) on the International Space Station (ISS).

However, since a MEMS-GC has never

flown in space before, JPL is looking at

ways to reduce risk and to test the

MEMS-GC cheaply and rapidly using the

NanoRacks service to the ISS.

The MEMS-GC system includes the

MEMS-GC chip (with MEMS-preconcentrator, MEMS-valves, MEMS-column in

the middle of a Vespel block), a MEMSTCD (in a separate Vespel block), a

miniature diaphragm sample pump, and

electronics. Cabin air would be used as

the carrier gas.

This work was done by Richard D. Kidd,

Murray R. Darrach, Vachik Garkanian, and

Stojan Madzunkov of Caltech; and Byunghoon Bae of Cbana Labs for NASA’s Jet Propulsion Laboratory. Further information is contained in a TSP (see page 1). NPO-48859

NanoRacks-Scale MEMS Gas Chromatograph System

This is a compact, simple, cost-effective system.

NASA’s Jet Propulsion Laboratory, Pasadena, California

MEMS-GC System Model includes the MEMS-GC

chip (with MEMS-preconcentrator (PC), MEMSvalves, MEMS-column in the middle of a Vespel

block), a MEMS-thermal conductivity detector

(TCD, in a separate Vespel block), a miniature diaphragm sample pump, and electronics. Mass: 1

kg, power: 1 W (peak 5 W), size: 4¥4¥4 in.

(a10¥10¥10 cm) (A 1U NanoLabs module).
22 NASA Tech Briefs, March 2014

compared to a conventional flap.

2. Continuous trailing edge flap (or

leading edge slat) provides a continuously curved trailing edge (or leading edge) with no gaps to minimize

vorticities that can lead to an increase in drag.

3. The active wing-shaping control method

utilizes the novel flap (or slat) concept

described herein to change a wing shape

to improve aerodynamic efficiency by

optimizing span-wise aerodynamics.

4. An aeroelastic method for analyzing

wing deflection shape under aerodynamic loading is used in a wing-control algorithm to compute a desired

command for the flap-actuation system to drive the present flap (or slat)

system to the correct position for

wing shaping.

This work was done by Nhan Nguyen of

Ames Research Center. Further information is

contained in a TSP (see page 1).

Inquiries concerning rights for the commercial use of this invention should be addressed

to the Ames Technology Partnerships Division

at 1-855-NASA-BIZ (1-855-6272-249) or

sumedha.garud@nasa.gov. Refer to ARC16644-1.

Spacecraft Line-of-Sight Stabilization Using

LWIR Earth Signature

Applications could include remote science and planetary science missions, Earth surveillance

and reconnaissance, and deep space optical communication.

NASA’s Jet Propulsion Laboratory, Pasadena, California

Until the time of this reporting, when

a space vehicle required a reference signal for inertial pointing, the choices

were a signal beacon from an Earth location, the Earth radiance in the visible

spectrum, or a star tracker. However,

limitations can arise from using these

techniques. For example, the signal

beacon suffers from limited signal

power (either in RF or optical) and will

constrain the application to limited

ranges, errors due to stray-light and

centroiding limit the accuracy of a star

tracker, and the spatial/temporal variability of the Earth’s albedo and its illumination by the Sun introduces limitations when used in the visible or near

infrared light.

To bypass these limitations, the

bright and near-uniform image of the

Earth in the LWIR (long wavelength infrared) (8 to 13 micron) may be used

to obtain a reference signal for inertial

stabilization and pointing of a spacecraft platform.

The potential of using the bright and

near-uniform Earth thermal infrared (or

LWIR) signature as a stable reference

for accurate (microrad or less) inertial

pointing and tracking of an optical communication beacon onboard a space vehicle was investigated, including the determination of the fundamental limits of

applicability of the proposed method for

space missions in deep space. In the

thermal infrared, Earth’s emission appears relatively uniform and is independent of the Sun’s illumination.

Therefore, it can be used as a stable

pointing reference.

Objective of the stabilization is to

align the Earth’s image along the deThe brightness and near-uniformity of the Earth LWIR Signature as a function of range indicates its

great potential as a stable reference for inertial pointing of planetary spacecraft, when the Earth is

not fully illuminated by the Sun. This figure shows the multistage stabilization block diagram, and the

resulting time history of the detector line-of-sight azimuth and elevation angles with respect to a reference datum onboard the spacecraft, and demonstrates that submicroradian stabilization accuracy is

achievable with a multistage line-of-sight stabilization approach.

t [s] 

Payload Dynamics

(tip/tilt)

LOS

Stabilization

Controller

Earth

Sensor

Attitude

Controller Spacecraft

Dynamics

Attitude

Sensor

Star Tracker + Gyro

Sensor Noise

Reaction Wheel

Noise

SPACECRAFT LEVEL OUTER LOOP

Stabilized

Attitude θ

DETECTOR LEVEL INNER LOOP

Reference

Centroid

azm

elm

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 -1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

az,el [microrad]
NASA Tech Briefs, March 2014 23

sired line of sight (LOS) in the face of

existing system disturbances. Because of

the submicroradian precision levels required by high-precision pointing, a

large dynamic range is involved in the

dynamic response of the pointing system. Hence, the pointing and tracking

algorithms are based on a multistage approach that includes: (a) a coarse stage

(outer loop) based on sequential loop

closure of a vehicle attitude stabilization

feedback control loop at a low control

bandwidth (10–3 to l0–1 Hz) to compensate for typical attitude control disturbances; followed by (b) a fine stage

(inner loop) based on an image boresight stabilization feedback loop at

higher frequencies that makes use of an

articulated (tip/tilt) fast steering mirror

to track the Earth’s LWIR reference signal in the image plane.

A simulation package has been developed that generates spacecraft and gimbaled camera dynamic model, inputs realistic spacecraft disturbances, stabilizes

the spacecraft attitude dynamics via a

proportional-integral-derivative (PID)

control loop at 0.01 Hz, propagates the

azimuth and elevation states of the dynamics of the detector plane, adds the

sensor noise model to the computed detector azimuth and elevation based on a

detector model and centroiding algorithm, and stabilizes the detector line-ofsight via PID control at 100 Hz. A block

diagram is shown in the figure.

A comparison of the performance of a

quantum-well infrared photodetector

sensor array using data from actual

space-qualified components has been

carried out. Preliminary results involving the effect of the sensor performance

on the LOS system stabilization have

been studied. Using realistic noise spectra from the Mars Reconnaissance Orbiter mission, simulations demonstrated

that submicroradian stabilization accuracy, shown in the figure as time history

of the detector line-of-sight azimuth and

elevation angles with respect to a reference datum on-board-the spacecraft, is

feasible using this approach.

This work was done by Marco B. Quadrelli

and Sabino Piazzolla of Caltech for NASA’s

Jet Propulsion Laboratory. For more information, contact iaoffice@jpl.nasa.gov. NPO48934

Technique for Finding Retro-Reflectors in Flash

LIDAR Imagery

Lyndon B. Johnson Space Center, Houston, Texas

Orbital rendezvous and docking of

two spacecraft is a topic of continued interest to NASA. For crewed missions, it is

frequently the case that the target is cooperative (i.e., is equipped with some sort

of navigation aid). If one of the relative

navigation instruments is a Flash LIDAR,

then this aid may be a suite of retro-reflectors. One of the most difficult aspects of this problem (especially at close

range) is finding the retro-reflectors in a

Flash LIDAR image amongst a substantial amount of clutter.

A new technique has been developed

for autonomously finding the three-dimensional location of candidate retroreflectors in a Flash LIDAR image. With

no a-priori state information, this new

approach is capable of finding an analyst-defined number of reflectors. It is

effective at rejecting most bright non-reflector objects. This technique, which

continues to be developed and tested,

has substantially better performance

(finds more reflectors, with fewer false

positives) than simpler approaches with

only a modest increase in computational resources.

The Orion/Multi-Purpose Crew Vehicle is a new crewed vehicle being designed by NASA and Lockheed Martin

for piloted exploration missions capable

of destinations beyond low Earth orbit

(LEO). The vehicle will also maintain

the capability to perform rendezvous,

proximity operations, and docking

(RPOD) with other orbital assets and elements in the exploration architecture.

The vision navigation sensor (VNS) is a

Flash LIDAR, and will be the primary

navigation instrument used by the Orion

during the RPOD flight phase. Thus,

maturing techniques for finding reflectors in Flash LIDAR imagery of cooperative vehicles is critical to the current

Orion relative navigation architecture.

This work was done by John A. Christian of

Johnson Space Center. Further information is

contained in a TSP (see page 1). MSC25237-1

Novel Hemispherical Dynamic Camera for EVAs

John H. Glenn Research Center, Cleveland, Ohio

A novel optical design for imaging systems is able to achieve an ultra-wide field

of view (UW-FOV) of up to 208°. The design uses an integrated optical design

(IOD). The UW-FOV optics design reduces the wasted pixels by 49% when

compared against the baseline fisheye

lens. The IOD approach results in a design with superior optical performance

and minimal distortion.

This work was done by Jason Geng of

Xigen LLC for Glenn Research Center. Further information is contained in a TSP (see

page 1).

Inquiries concerning rights for the commercial use of this invention should be addressed

to NASA Glenn Research Center, Innovative

Partnerships Office, Attn: Steven Fedor, Mail

Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW-18984-1.

NASA Tech Briefs, March 2014 25

Software

360° Visual Detection and

Object Tracking on an Au- tonomous Surface Vehicle

This software addresses the problem

of an autonomous vehicle patrolling a

region for objects of interest using multiple cameras. The system must identify

and track the objects over time and localize their positions in the world. It implements an autonomous perception

and situation awareness system, which

receives images from an omnidirectional camera head, identifies objects of

interest in these images, and probabilistically tracks the objects’ presences over

time, even as they may exist outside of

sensor range.

The software consists of three functional parts. The Image Server records

the images from all cameras on the camera head simultaneously. It also records

the data from the inertial navigation system (INS) that provides the vehicle pose

at the image frame. Next, the Image

Server stabilizes the images to produce

images with horizontal, image-centered

horizons. Finally, in addition to passing

on the images and pose to the next system for further processing, the Image

Server efficiently logs this large amount

of data for offline use.

The Contact Server detects objects of

interest in the stabilized images and calculates the absolute bearing of each

contact. Two object-detection algorithms are employed, loosely trained on

templates of the 3D objects of interest.

Additionally, the Contact Server adjusts

the images for better detection results;

for example, adjusting for variable lighting conditions.

The Object-level Tracking and

Change Detection (OTCD) Server integrates the information from the Contact

Sever over time and over all cameras to

probabilistically track the objects of interest and to detect changes of interest.

OTCD maintains a database of hypothesized true objects, along with a probability of existence that measures the confidence that the object exists at its

hypothesized location at a given time. Finally, OTCD can send downstream alerts

when a new object appears or a known

object disappears.

The software detects objects of interest from arbitrary perspectives and

widely varied lighting conditions, and localizes and tracks these objects over

time. It tracks the existence of these objects in their estimated positions, even

when they are out of sensor range, enabling a patrol vehicle to leave and come

back and hypothesize whether the same

objects of interest are in the same position viewed earlier (change detection).

The software integrates information for

multiple source cameras to provide a

360° view of the environment, and tracks

objects seamlessly as they transition between cameras. It includes several helpful analysis utilities, such as a real-time

remote viewer of the scene and identified objects, efficient multi-leveled data

logging, and the capability to process

data logs offline for replays.

This work was done by Michael Wolf,

Yoshiaki Kuwata, Christopher Assad, Robert

D. Steele, Terrance L. Huntsberger, David Q.

Zhu, Andrew Howard, and Lucas Scharenbroich of Caltech for NASA’s Jet Propulsion

Laboratory. For more information, contact

iaoffice@jpl.nasa.gov.

This software is available for commercial

licensing. Please contact Dan Broderick at

Daniel.F.Broderick@jpl.nasa.gov. Refer to

NPO-47850.

Simulation of Charge

Carrier Mobility in

Conducting Polymers

Electric conduction in polymers is one

of the key elements in avoiding catastrophic internal electrostatic discharge

in dielectrics during space missions. This

software package enables the simulation

of carrier mobility for any given site concentration, which is a material design parameter that can be varied in experimental studies. The software computes the

charge mobility for a disordered network

of carrier sites. The mobility is obtained

by computing the average drift velocity

for an applied electric field. The mobility

is given by the ratio of the drift velocity to

the electric field.

The software uses an efficient Monte

Carlo technique to sample the transit

time of carriers injected on one end of

the simulation domain. The mobility

can be obtained as a function of temperature and site concentration, which are

parameters of interest for experiments

and materials design.

This software is implemented in C++

and is highly modular. New models and

variations in the simulation process can

easily be added. Parallelization for execution on a distributed computing platform was implemented.

This program enables the calculation

of charge mobility in polymers with

varying dopant concentration, as a

function of electric field and temperature. The objective is to use this program to explore the parameter space

and identify the material parameters

that best meet the design requirements.

The program will be used to optimize a

new material system and will help solve

the problem of catastrophic internal

electrostatic discharges in dielectrics,

which is one of the largest sources of

anomaly or failure in space missions.

Deep space missions to the outer planets and their moons, where the radiation environment is particularly harsh,

will benefit most from the new modeling capability.

This work was done by Paul A. Von Allmen and Seungwon Lee of Caltech for NASA’s

Jet Propulsion Laboratory. For more information, contact iaoffice@jpl.nasa.gov.

This software is available for commercial

licensing. Please contact Dan Broderick at

Daniel.F.Broderick@jpl.nasa.gov. Refer to

NPO-48727.

Observational Data

Formatter Using CMOR

for CMIP5

The current software has been developed to work on NASA instrument

datasets, an upgrade over similar software

that only worked on datasets from climate

model output. NASA is attempting to reformat satellite data to fit the specific and

highly detailed data format and metadata

requirements for CMIP5 (Coupled Model

Intercomparison Project Phase 5). This

software has relieved science data teams

from multiple instruments from the task

of understanding and conforming to the

CMIP5 data requirements.

The software reads in netcdf files,

combined with select metadata input

from the user, and intelligently calls

functions from the CMOR (Climate

Model Output Rewriter) library to write

out new netcdf files in the proper format

for inclusion in CMIP5. Currently, the

software is capable of ingesting data from

AIRS (Atmospheric Infrared Sounder),

MLS (Microwave Limb Sounder), TES
26 NASA Tech Briefs, March 2014

(Tropospheric Emission Spectrometer),

MODIS (Moderate Resolution Imaging

Spectroradiometer), AVISO (French

space agency data provider), and

QuikSCAT (Quick Scatterometer).

The unique feature is integration of

the CMOR function library, written in

C, with code able to understand the output of science data teams. Many conventions used in the climate modeling community differ radically from those used

in the observational data community,

and this software serves as a bridge between the two.

This work was done by Steven J. Lewis of Caltech for NASA’s Jet Propulsion Laboratory. For

more information, contact iaoffice@jpl.nasa.gov.

This software is available for commercial

licensing. Please contact Dan Broderick at

Daniel.F.Broderick@jpl.nasa.gov. Refer to

NPO-48258.
NASA Tech Briefs, March 2014 27

Information Technology

Available guidance approaches for

large numbers (i.e., swarms) of artificial

agents are currently very limited.

Swarms in nature (e.g., bees, birds, ants)

typically contain hundreds to thousands

of agents. The problem is how to mimic

nature, and develop guidance laws for

artificial (man-made) swarms containing

hundreds to thousands of artificial

agents.

A new guidance solution lets go of

conventional deterministic approaches

and instead looks at statistical approaches. Because swarms contain a

statistically meaningful number of

agents, a probabilistic approach is

more relevant to the problem. In particular, a probabilistic guidance approach (PGA) has been developed that

controls the statistical ensemble (i.e.,

the desired probability density across a

swarm of agents), rather than any single individual agent’s trajectory. Because the PGA works with a statistically

large ensemble of agents, the “law of

large numbers” kicks in, and the PGA

approach actually becomes more accurate and simpler to implement as the

number of agents becomes large. This

is in sharp contrast to deterministic approaches to swarm guidance that become more complex and unwieldy as

the number of agents becomes large.

The main idea is to have each agent

follow an independent realization of a

Markov chain. The desired distribution

emerges as the ensemble of agents in

the swarm maneuvers about, asymptotically achieving a desired statistical

steady-state condition, and eliciting a

clear emergent behavior from the

swarm. The implementation of the probabilistic guidance law is completely decentralized, and leads to an important

swarm behavior that exhibits auProbabilistic Guidance for Swarms of Autonomous Agents

A probabilistic approach is simpler to implement as the number of agents becomes large.

NASA’s Jet Propulsion Laboratory, Pasadena, California

Propellant Loading Physics Model for Fault Detection Isolation

and Recovery

Microsoft Excel spreadsheet is used to simulate the operation.

John F. Kennedy Space Center, Florida

A Fault Detection, Isolation and Recovery (FDIR) system needs some internal concept of how the monitored

system operates. This “operating concept” needs mathematical logic to

represent the cause and effect relationship between constituent components of the system, health and status

of those components, and the resulting health and status of the overall

system. Models constructed with commercial simulation systems such as

MATLAB and Simulink may ignore individual component contribution to

system operation. Instead, the modeler may naturally focus on overall system parameters with lumped values

representing the individual component characteristics. The resulting

simulations faithfully calculate overall

system operation, but may miss anomalies that occur because of plugged,

stuck, or otherwise inoperable individual components.

This innovation is a spreadsheet written for Microsoft Excel with equations

that simulate cryogenic propellant loading system operating characteristics.

The spreadsheet takes commands from

an operator to open and close valves,

change pump speeds, and change pressure set-points. The spreadsheet continuously calculates the operating state of

the propellant loading system including

measurements such as pressures, flow

rates, pump speeds, and tank levels. The

simulation is component-oriented, containing comprehensive mathematical

descriptions of valves of different types

and sizes, pneumatic supply system

pumps, filters, and tanks. An “antagonist” operator may introduce faults in

certain of the components. The spreadsheet simulates the effects of the introduced faults.

The software simulates operation of

the Simulated Rapid Propellant Loading (SRPL) System hardware at the

KSC Cryogenics Laboratory. The Excel

spreadsheet uses Active Control buttons and sliders drawn in Excel that

allow valves to be opened and closed

and pumps to be controlled at various

speeds. Other Active Control sliders

allow the antagonist operator to introduce faults in all the components that

make up the physics model of the

SRPL.

The Excel spreadsheet has a unique update feature that calculates the pressures,

temperatures, and flows in the physics

model of the SRPL. The update feature

calculates all these values, then waits one

second and recalculates based on updated

tank levels, ullage quantities, and bulk liquid temperatures. Thus, the spreadsheet is

capable of continuously updating the liquid levels integrating flow rates and heat

flux in the system in real time.

Equations can be translated into C

code and used in the embedded processor. The results calculated by the C

code can be validated easily by comparing calculated values to the output of

the spreadsheet.

This work was done by Charles Goodrich,

Rebecca Oostdyk, Mark Lewis, and Christopher Forney of Kennedy Space Center. Further

information is contained in a TSP (see page

1). KSC-13631
28 NASA Tech Briefs, March 2014

tonomous self-repair and maintenance

capabilities.

The development area relies heavily

on the theory of Markov processes,

Monte-Carlo-Markov-Chain sampling

methods, graph theory, and Lyapunov

stability analysis. The development is

aided by recent research in designing

fast mixing Markov chains that converge to desired distributions and incorporate constraints on transition

probabilities, and many classical results on convergence of Markov

chains.

The main novel feature is that the

PGA guidance law is probabilistic in nature, and specifies the desired spatial

probability density distribution for the

swarm rather than the exact desired

paths of the individual agents. Consequently, PGA is a more natural and useful guidance statement when dealing

with swarms comprised of a statistically

large number of agents, compared to deterministic methods that become unwieldy as the number of agents becomes

large.

This work was done by David S. Bayard

and Behcet Acikmese of Caltech for NASA’s Jet

Propulsion Laboratory. For more information, contact iaoffice@jpl.nasa.gov.

The software used in this innovation is

available for commercial licensing. Please

contact Dan Broderick at Daniel.F.Broderick@jpl.nasa.gov. Refer to NPO-47851.

Visual odometry (VO) refers to the estimation of vehicle motion using onboard cameras. A common mode of operation utilizes stereovision to triangulate a

set of image features, track these over

time, and infer vehicle motion by computing the apparent point cloud motion

with respect to the cameras. It has been

observed that stereo VO is subject to

drift over time.

It is well known that stereo triangulation suffers from bias induced from correlation error (i.e., subpixel errors in

matching between features in the left and

right images of a stereo pair). The nature

of this bias is a complicated function of

the error statistics of the correlation and

depends on scene structure, camera configuration, and imaging geometry. The

goal of this work was to better characterize the stereo bias than has been done to

date, and explore the effect of compensating for this bias on VO drift.

The problem was approached in

terms of a stochastic propagation of

error from the image plane to triangulation. The end result is a better representation of stereo bias than has been

accomplished thus far. In early tests,

this stereo bias correction has had a

dramatic effect in reducing VO drift. In

a simulated run of 100 m, the drift was

reduced from an uncorrected 47 cm to

just 7 cm. The preliminary conclusion

is that VO drift is due primarily to

stereo bias rather than to inherent bias

in the non-linear estimator used to recover motion.

Given a model of noise in correlation

matching between the left and right images of a stereo pair, the projection of

any point in the world into the stereo

pair can be indexed by its pixel location

in the left image and the horizontal

shift of that location in the right image,

referred to as disparity. Thus, every

point in the world that is simultaneously

visible in both cameras can by described

as (x,y,d). Considering only integer values, a lookup table was constructed and

indexed by (x,y,d), where (x,y) spans the

whole of the left image, and d spans values corresponding to reasonable ranges

in the scene. At each (x,y,d), the assumed noise profile is taken from correlation and a Monte Carlo simulation is

performed to propagate that noise profile into the triangulated point in space.

The results are stored in a table indexed

by image column, row, and disparity.

Given any point correspondence, the

corresponding (x,y,d) is looked up, interpolated from integer to real values as required, and the triangulation statistics are

extracted. The lookup table generation is

a one-time process for any calibrated imaging system, and the subsequent lookup has

minimal computational overhead. From

the triangulation statistics, the likely bias is

taken and added directly to the triangulated point. In ensemble, this produces a

point cloud with higher fidelity than the

uncorrected cloud and, consequently, a

better incremental VO estimate.

VO bias compensation has focused primarily on correcting the motion estimate

rather than on correcting the stereo. This

method can be implemented in real-time

on a deployed system and shows very

promising preliminary results.

This work was done by Adnan I. Ansar of

Caltech for NASA’s Jet Propulsion Laboratory.

For more information, contact

iaoffice@jpl.nasa.gov.

This software is available for commercial

licensing. Please contact Dan Broderick at

Daniel.F.Broderick@jpl.nasa.gov. Refer to

Reducing Drift in Stereo Visual Odometry

The drift was reduced from an uncorrected 47 cm to just 7 cm.

NASA’s Jet Propulsion Laboratory, Pasadena, California

In the United States, as many as

7,000 commercial and private aircraft

may be in the air simultaneously at any

given time and date, and the total number of commercial flights in a given 24-

hour period generally exceeds 50,000.

To maintain the safety and efficiency of

air travel, this innovation receives proposed flight plans and associated flight

route information and flight parameters for aircraft operating in a given region (e.g., the continental United

Future Air-Traffic Management Concepts Evaluation Tool

An aircraft monitoring system and an aircraft user system can interact and negotiate changes

with each other.

Ames Research Center, Moffett Field, California
NASA Tech Briefs, March 2014 29

A previously created direct numerical simulation (DNS) database of mixing of species under supercritical pressure has been examined and analyzed

for the purpose of understanding the

modeling requirements in the context

of large eddy simulation (LES). Of particular interest is reproducing in LES

the feature of uphill species diffusion

that is identified in DNS. The examination of the database was performed

by employing Minkowski functionals

that provide the geometrical, topological, and morphological aspects of isosurfaces that are extracted from a field

through computing dimensionless

shapefinders: genus, planarity, and filamentarity.

The analysis is restricted to simply

connected isosurfaces having a null

genus. Isosurfaces of the second invariant of the deformation tensor and of

the dissipation calculated as a result of

all transport processes were found to be

quite different; those derived from the

second invariant turned out to have

more randomness when compared to

those derived from the dissipation that

had better defined volumetric extent.

Upon filtering, at the same filter width,

there were more structures of greater

extent and with well-defined morphology resulting more from the dissipation

than from the second invariant.

Independent of the filter width, the

dissipation-related isosurfaces had

more complex structure than those issued from the second invariant, as evidenced by larger planarity and filamentarity. In general, the structures

originating from the second invariant

were filamentary, a feature that was retained when filtering, whereas those

originating from the dissipation had

more comparable planarity and filamentary values. Having thus examined

the template LES solution, the activity

of terms in the differential LES equations was examined and, in addition to

the classical subgrid-scale (SGS) terms

issued from the convective terms of the

original equations, other SGS terms

were identified.

When evaluated on the database,

some of these new terms were shown

to have important contributions in the

LES equations. The importance of the

contribution of each term increased

with increasing pressure. Several models were proposed and tested for these

significant SGS terms with the goal of

preserving, in future LES, the features

observed in the template LES solution.

The model that best reduced the error

on all terms compared to the template

values was based on an Approximate

Deconvolution Model combined with

explicit filtering that succeeded in reducing the error by more than a factor

of two on terms occurring in the momentum, species, and energy equations. Particularly crucial was the effect

of the model for recovering the flux of

species experiencing uphill diffusion,

a phenomenon identified for multispecies but not for binary-species mixing. Based on this study, caution is advised on simply extrapolating results

from supercritical-pressure binaryspecies mixing to multi-species mixing.

This work was done by Josette Bellan and

Giulio Borghesi of Caltech for NASA’s Jet

Propulsion Laboratory. For more information, contact iaoffice@jpl.nasa.gov. NPO49179

Examination and A Priori Analysis of a Direct Numerical

Simulation Database for High-Pressure Turbulent Flows

Minkowski functionals are employed that provide the geometrical, topological, and

morphological aspects of isosurfaces.

NASA’s Jet Propulsion Laboratory, Pasadena, California

States), and provides actual flight

routes and schedules based on expected air traffic. This innovation

avoids or minimizes air traffic incidents

by changing one or more flight plan

parameters where appropriate, for one

or more of these aircraft.

This innovation comprises methods

for evaluating and implementing air

traffic management tools, and approaches for managing and avoiding

an air traffic incident before an incident can occur. A first system receives

parameters for flight plan configurations (e. g., initial fuel carried, flight

route, flight route segments followed,

flight altitude for a given flight route

segment, aircraft velocity for each

flight route segment, flight route ascent rate, flight route descent rate,

flight departure site, flight departure

time, flight arrival time, flight destination site and/or alternate flight destination site), flight plan schedules, expected weather along each flight route

segment, aircraft specifics, airspace (altitude) bounds for each flight route

segment, and what navigational aids

are available.

The invention provides flight-plan

routing and direct routing, or wind optimal routing, using great-circle navigation and spherical Earth geometry. It

also provides for aircraft dynamic effects, such as wind effects at each altitude, altitude changes, airspeed

changes, and aircraft turns to provide

predictions of aircraft trajectory and,

optionally, aircraft fuel use.

A second system provides several aviation applications using the first system.

Several classes of potential incidents

are analyzed, and averted, by appropriate changes en route of one or more parameters in the flight plan configuration, as provided by a conflict detection

and resolution module and/or traffic

flow management modules. These applications include conflict detection

and resolution, miles-in-trail or minutes-in-trail aircraft separation, flight

arrival management, flight re-routing,

weather prediction and analysis, and interpolation of weather variables based

upon sparse measurements.

This work was done by Banavar Sridhar,

Kapil S. Sheth, Gano Broto Chatterji, Karl

D. Bilimoria, Shon Grabbe, and John F.

Schipper of Ames Research Center. Further

information is contained in a TSP (see page

1).

Inquiries concerning rights for the commercial use of this invention should be addressed to the Ames Technology Partnerships

Division at 1-855-NASA-BIZ (1-855-6272-

249) or sumedha.garud@nasa.gov. Refer to

ARC-14653-2.
30 NASA Tech Briefs, March 2014

Resource-Constrained Application of Support Vector

Machines to Imagery

Fast computation of the SVM decision function over an image using minimal RAM.

NASA’s Jet Propulsion Laboratory, Pasadena, California

Machine learning techniques have

shown considerable promise for automating common visual inspection

tasks. For example, Support Vector Machine (SVM) classifiers that have been

learned from labeled training data deliver strong detection performance both

for finding human faces in photographs

and locating geologic landforms such as

craters and volcanoes in planetary images gathered by spacecraft. However,

SVMs are computationally expensive to

apply to an image using the traditional

spatial scanning method in which a rectangular window is slid across the image

one pixel at a time and the SVM is evaluated on each patch of pixels under the

window. The new software uses small fast

Fourier transforms (FFTs) and the overlap-and-add technique from signal processing to quickly and efficiently compute the exact SVM decision function

over an entire image using minimal random access memory (RAM).

SVMs classify a feature vector by computing a weighted combination of kernel evaluations between the feature vector and a set of “support vectors.” The

support vectors are positive and negative

examples from the training set that were

identified during the learning phase.

Each kernel evaluation is essentially a

nonlinear measurement of the similarity

between the feature vector and a given

support vector. For many of the commonly used kernels, the kernel evaluation can be expressed as a linear dot

product between the feature vector and

the support vector followed by additional nonlinear operations. The linear

part of the computation actually dominates the workload, which enables the

software to achieve a significant speedup

by performing the linear calculations

over the entire image with FFTs. A further refinement uses the overlap-andadd technique to limit the amount of

RAM required. Overlap-and-add computes small, localized FFTs and then

pieces partial results together to establish the final answer.

The software provides an effective way

to apply SVMs to image data and is particularly well suited for resource-constrained environments such as onboard

a spacecraft. The technique allows exact

computation of the SVM decision function over an image using minimal RAM

(typically less than 5% of the size of the

image). Also, the approach is complementary to “reduced set” methods,

which speed up SVM calculations by reducing the number of support vectors

required. Used together, the two methods can yield a multiplicative gain in performance. The software implementation

is not specific to any particular domain.

Thus far, it has been demonstrated for

the crater detection problem; however,

in principle, it can be used for a variety

of image inspection tasks. One could envision a variety of smartphone apps

based around the ability to take a picture and detect/classify/count objects

in the picture.

This work was done by Michael C. Burl of

Caltech, and Philipp G. Wetzler of the University of Colorado, Boulder for NASA’s Jet

Propulsion Laboratory. Further information is

contained in a TSP (see page 1).

The software used in this innovation is

available for commercial licensing. Please contact Dan Broderick at Daniel.F.Broderick@

jpl.nasa.gov. Refer to NPO-48072.

National Aeronautics and

Space Administration