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A P U B L I C A T I O N O F T H E A M E R I C A N I N S T I T U T E O F A E R O N A U T I C S A N D A S T R O N A U T I C S

December 2012

2012Year in review

51st AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

Where It All Comes Together! The Aerospace Sciences Meeting and Exposition is the first, and largest, major multidisciplinary event of the year for aerospace scientists and engineers from around the world to share and disseminate scientific knowledge and research results.

Program HighlightsNew Horizons ForumLt Gen Larry James, Commander, USAF, Maj Gen Neil McCasland, Commander, AFRL, and other keynote speakers and insightful panelists engage in timely topical discussions about the issues, solutions, and opportunities that are likely to impact our professional lives.

Technical SessionsThousands of the most innovative advances in science and technology are the result of aerospace research and development. At ASM, more than 1,300 papers present research that can address a multitude of business sectors beyond aerospace.

Aerospace ExpositionThe Aerospace Exposition showcases exhibits from various sectors of the aerospace community from large organizations to small businesses. The Exposition provides opportunities for one-on-one discussions with exhibitors, hardware and software demonstrations, and side meetings with these organizations throughout the week.

Courses and WorkshopsTechnical, career, and public policy courses and workshops give you the knowledge and skills to advance your career.r 4JY%FHSFFTPG'SFFEPN.PEFMJOHPG

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Aerospace America (ISSN 0740-722X) is published monthly, except August, by the American Institute of Aeronautics and Astronautics, Inc. at 1801 Alexander Bell Drive, Reston, Va. 20191-4344[703/264-7500]. Subscription rate is 50% of dues for AIAA members (and is not deductible therefrom). Nonmember subscription price: U.S. and Canada, $163, foreign, $200. Single copies $20 each.Postmaster: Send address changes and subscription orders to address above, attention AIAA Customer Service, 703.264.7500. Periodical postage paid at Herndon, Va. and at additional mailingoffices. Copyright 2010 by the American Institute of Aeronautics and Astronautics, Inc., all rights reserved. The name Aerospace America is registered by the AIAA in the U.S. Patent and TrademarkOffice. 40,000 copies of this issue printed. This is Volume 50, No. 11.

December 2012

Adaptive structures 4Aeroacoustics 12Aerodynamic decelerators 26Aerodynamic measurementtechnology 14

Air-breathing propulsion systemsintegration 46

Aircraft design 28Air transportation 27Applied aerodynamics 15Astrodynamics 17Atmospheric and space environments 16Atmospheric flight mechanics 13Balloon systems 29Communication systems 36Computer systems 40Design engineering 5Digital avionics 41Directed energy systems 70Electric propulsion 47Energetic components 48Energy optimized aircraftand equipment systems 71

Flight testing 30Fluid dynamics 18Gas turbine engines 49General aviation 31Gossamer Spacecraft 31Ground testing 20Guidance, navigation, and control 19High-speed air-breathing propulsion 50Hybrid rockets 51Hypersonics technologyand aerospace planes 73

Intelligent systems 42

Legal aspects 36Life sciences and systems 58Lighter-than-air systems 32Liquid propulsion 52Management 37Meshing, visualization and computational environments 22

Microgravity and space resources 59Missile Systems 60Modeling and simulation 21Multidisciplinary design optimization 6

Nuclear and future flight propulsion 53Plasmadynamics and lasers 23Propellants and combustion 54Sensor systems 43Society and aerospace technology 38Software 44Solid rockets 55Space architecture 61Space automation 62Space colonization 63Space exploration 74Space operations and support 64Space resources 65Space systems 66Space tethers 67Space transportation 68Structural dynamics 8Structures 9Survivability 10Systems engineering 39Terrestrial energy systems 56Thermophysics 24Weapon system effectiveness 69

THE YEAR IN REVIEW

EDITORIAL 3

OUT OF THE PAST 76

2012 SUBJECT AND AUTHOR INDEX 78

CAREER OPPORTUNITIES 83

BULLETINAIAA Meeting Schedule B2AIAA Courses and Training Program B4AIAA News B5Meeting Program B12Calls for Papers B18

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In light of the November 2012 elections, taking part in the 2013 Congressional Visits Day Program is more important than ever.

Come to Washington to let the newly elected Congress hear how vital our community is to national and economic security, and take an active role in helping shape the future of that community.

On Wednesday, 20 March, AIAA members will share their passion about aerospace issues on Capitol Hill.

Join us as we meet with congressional decision makers to discuss the importance of science, engineering, and technology to our national security and prosperity.

To register for AIAA Congressional Visits Day 2013 please visit www.aiaa.org/CVD2013 or contact Duane Hyland at [email protected] or 703.264.7558.

AIAA

12-0497_Nov

As we look back over significant events of the year, two remarkable accom-plishments immediately come to mind, and remind us of the possibilities forgreatness that can be found in both the public and private sectors of the aero-space industry.

In May, even as many of us were still watching the fleet of space shuttlesbeing ferried to their final destinations, SpaceX made history when its Dragonspacecraft, on its first demonstration flight, became the first commercial vehiclein history to successfully berth with the international space station. After anexchange of cargo, the capsule returned to Earth and was successfully retrieved. This was followed in October by a commercial delivery flight to thestation and then a safe splashdown with return cargo. The resumption of U.S.deliveries to and from the ISS is an exciting first step toward the return of domestic crew transportation.

Excitement of another kind came for many in the early morning hours, as people around the world watched the celebration at the Jet PropulsionLaboratory as the Mars Science Laboratory landed its automobile-sized roverwith pinpoint accuracy on the surface of that planet. This astounding feat wasdocumented not just by signals transmitted from the surface but by an imagecaptured by the Mars Reconnaissance Orbiter as it passed overhead. Just hourslater, after a 36-week, 350-million-mile journey, Curiosity started beaming backimages of its new home.

Either of these accomplishments alone would have made 2012 a red letteryear. Together, they resulted in an outstanding one.

But there is one more event to be considered as we examine the year andthe significant role aerospace can play. An enormous storm hit the East Coastof the United States in October, with a force most of the nation, or the world,had not witnessed before. Sandy leveled homes, buildings, beaches, andwhole towns, leaving populations struggling to find food, shelter, and lovedones, and to grapple with the enormity of its devastation.

Sadly, lives were lostbut not the untold thousands that might have been.To a great degree, possessions were destroyed, but families were not. Businesseswere wiped out, but possibilities remained. It may take months or even yearsto recover, but the opportunity for recovery was preserved.

That the horror that might have been did not happen was thanks to someold, but dependable, resources. NOAA satellites, along with Europes newlylaunched Metop-B, provided the detailed data that enabled remarkably accuratecomputer models to forecast the path of the storm days ahead of landfall, allowing the majority of the population in its path to escape from harms way.

As happy an ending as this story has, it also comes with a warning. Thepolar orbiting satellites that provided most of the data showing us Sandyspath and power are aging, and by one estimate many of the instruments havejust a few years of useful life left. Their replacements, however, are far fromready, delayed by a combination of funding and technology woes.

We were not luckywe were informed. It is up to us to make sure we staythat way.

Elaine CamhiEditor-in-Chief

is a publication of the American Institute of Aeronautics and Astronautics

Elaine J. CamhiEditor-in-ChiefPatricia JeffersonAssociate EditorGreg WilsonProduction EditorJerry Grey, Editor-at-LargeChristine Williams, Editor AIAA Bulletin

CorrespondentsRobert F. Dorr,WashingtonPhilip Butterworth-Hayes, EuropeMichael Westlake, Hong Kong

Contributing WritersRichard Aboulafia, James W. Canan,Marco Cceres, Craig Covault, LeonardDavid, Philip Finnegan, Edward Goldstein, Tom Jones, James Oberg,David Rockwell, J.R. Wilson

Fitzgerald Art & Design Art Direction and Design

Michael Griffin, PresidentSandra H. Magnus, PublisherCraig Byl, Manufacturing and Distribution

STEERING COMMITTEECol. Neal Barlow, USAF Academy;Carol Cash, Carol Cash & Associates;Brian D. Dailey; Basil Hassan, Sandia;Robert E. Lindberg, National Institute ofAerospace; Vigor Yang, Georgia Institute ofTechnology; Susan X. Ying; Boeing

EDITORIAL BOARDNed Allen, Jean-Michel Contant, Eugene Covert, L.S. Skip Fletcher,Michael Francis, Cam Martin,Don Richardson, Douglas Yazell

ADVERTISING Robert Silverstein, [email protected] Brody [email protected]

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Send materials to Craig Byl, AIAA, 1801Alexander Bell Drive, Suite 500, Reston, VA20191-4344. Changes of address should besent by e-mail at [email protected], or by faxat 703.264.7606.Send correspondence to [email protected].

December 2012, Vol. 50, No. 11

The very best of old and new

velopment, and Engineering Center, teamedwith Boeing and Sikorsky, kicked off theMulti-Role Rotor program. MRR will matureand demonstrate integrated active rotortechnologies that improve both hover andcruise efficiencies and reduce the vibrationand acoustic levels of the Armys next-gen-eration rotorcraft fleet.

Structural health monitoring (SHM) isanother area of development. Arizona StateUniversity is creating hybrid methodologiesfor real-time SHM of metallic and compos-ite aerospace components. The probabilis-tic approach to damage localization in com-plex geometry is comprised of a Bayesianframework and sensor fusion to account foruncertainty. Recent accomplishments in-clude an efficient physics-based multiscalemodel using statistical volume elements, afully coupled electromechanical elastody-namic model for wave propagation, and astochastic signal processing and feature ex-traction algorithm.

The University of Michigan, through thesupport of NASA, has been characterizingguided waves (GW) for SHM of compositesandwich structures. An innovative local in-teraction simulation approach, based on it-erative equations where the coefficients de-pend only on the local physical properties,was successful in capturing GW propaga-tion characteristics accurately in compositelaminates. Current effort focuses on extend-ing the method for complex compositesandwich structures and damage interactionof GW.

In other research, the University of Mich-igan experimentally demonstrated a novelshape memory alloy knitted rib skin for ac-tive flow control of aircraft. The pattern ac-tuates normal to the surface, producingspanwise discrete periodic arrays that canwithstand aerodynamic forces while simul-taneously supplying displacement.

Decades of progress in engine noise re-duction have made airframe aeroacousticnoise an equal contributor to overall noiseduring approach and landing. Earlier workidentified mechanisms and notional solu-tions for aeroacoustic noise in the flow fieldaround high-lift systems of typical commer-cial transport aircraft. Recent work at NASALangley focused on adaptive structural con-cepts to make such notional solutions phys-ically attainable. The most promising solu-tions involve highly deformable structuresintegrating superelastic shape memory al-loy and elastomeric materials to adapt be-tween very disparate configurations.

Adaptive structures

Motivated by the idea of hiding in plainsight, the adaptive structures team in theAerospace Systems Directorate at the AirForce Research Laboratory developed afolding-wing concept for perching of smallautonomous vehicles. The vehicle folds itswings while perched to reduce visibility anddecrease the likelihood of being dislodged.The team, with the University of Dayton Re-

search Institute, gener-ated control concepts forsuccessful perching land-ings and demonstratedperching maneuvers inan indoor flight facility.AFRL is also working onreconfigurable skin con-cepts for morphing appli-cations based on cellularstructures consisting ofindividually addressableregions of variable-stiff-ness material.

University of Mary-land graduate students,

in collaboration with Penn State University,conducted an unprecedented flight test of acustom-built avian-scale flapping wingUAV. The test, conducted at the AFRL MicroAir Vehicle Laboratory (the largest Viconmotion capture system lab in the U.S.),evaluated the performance of the ornithop-ter, whose compliant wing structure mimicsthe function of an avian wrist.

Penn State conducted research in sev-eral other areas as well. Researchers exper-imentally validated a method for reducinghigh cycle fatigue in turbomachinery blades,with emphasis on monolithic blisks havinglow intrinsic damping. The method reducesthe resonant structural dynamic responseassociated with changes in engine speed.Blade stiffness properties are modified byswitching the electrical boundary condi-tions on integral piezoelectric elements. Inaddition, the university is investigating avariable-thermal-conductivity baseplate forspacecraft to passively prevent unaccept-able temperature excursions of electronicsmodules. Success requires shape and mate-rials optimization to increase thermallydriven displacements, reduce thermal con-tact resistance, and decrease the need forhigh-precision manufacturing.

The Army Aviation Missile Research, De-by Louis R. Centolanza

AEROSPACE DESIGN AND STRUCTURES

The AFRL developed a folding wing concept for perching small autonomous air vehicles.

The University of Marylandconducted a flight test ofa custom-built avian-scaleflapping wing.

4 AEROSPACE AMERICA/DECEMBER 2012

AEROSPACE AMERICA/DECEMBER 2012 5

where it successfully berthed with the ISS.The capsule later returned to Earth and wasrecovered after performing a parachutelanding into the Pacific Ocean. With thenew generation of commercial space cap-sules, the design philosophy for safety ischanging from redundancy to quick-actingescape mechanisms to achieve fail-safe reli-ability. The new commercial capsules arealso attempting to achieve cost efficienciesthrough dual-use propulsion systems thatcan be used for both launch escape andon-orbit maneuvers.

Another example of the trend towardautonomous vehicles is the X-47B. This tail-less strike fighter-class unmanned aircraftwas developed by Northrop Grumman aspart of the Navys Unmanned Combat AirSystem Carrier Demonstration program.The company, which was awarded the de-velopment contract in 2007, has designed,produced, and is currently flight testing twoX-47B aircraft. The plane made its firstflight from Naval Air Station Patuxent Riverin July, and these aircraft will be used in2013 to demonstrate the first carrier-basedlaunches and recoveries by an autonomousunmanned aircraft. In 2014, the X-47B isscheduled to demonstrate autonomous aer-ial refueling.

Design engineering

Exploration of Mars continues following thesuccessful launch of the Mars Science Labo-ratory (MSL) spacecraft from Cape Cana-veral AFS on November 26, 2011, and theCuriosity rovers subsequent landing.

One of the major trends in aviation de-sign is greater autonomy for vehicles, fromremotely piloted aircraft to vehicles withentirely autonomous operations. The MSLspacecraft demonstrated this with its com-pletely autonomous entry, descent, androver landing. Entry of the MSL began withseparation of the cruise stage from the de-scent stage. The descent stage then steereditself through the Martian atmosphere witha series of S-curve maneuvers, followed bythe use of a parachute, jettisoning of theheat shield, jettisoning of the parachute andback shell, retrorocket firing, and finally,while hovering over the Martian surface,the unfolding of Curiosity, which the de-scent stage lowered to the surface by atether, afterward flying away and landing ina separate location.

For the rover landing, use of the SkyCrane and tether maneuver rather than theprevious airbag landing system was neces-sary because Curiosity weighed over 1 ton(much more than previous rovers) and be-cause of the desire to be much more pre-cise in where it landed. If not for this im-proved precisionabout five times betterthan that of previous missionsthe GaleCrater landing site would have been con-sidered unsafe because of its close proxim-ity to the crater wall.

The descent stages structure is a light-weight space-efficient truss and stiffenedpanel design. The MSL faced severe designchallenges from mass limits, launch vehiclepayload dimensional constraints, and launchsite integration of the cruise stage, backshell, descent stage, rover, and heat shield.

Curiosity did inherit many design ele-ments from previous rovers, such as a six-wheel drive, a rocker-bogie suspension sys-tem, and mast mounted cameras. The rovercan roll over obstacles up to 65 cm (25 in.)high, and can travel up to about 200 m (660ft) per day on Mars.

The U.S. governments shift toward us-ing commercial space companies for spaceaccess reached a major milestone in Maywhen a SpaceX Falcon 9 rocket boosted aSpaceX Dragon supply capsule into orbit, by Jerry Brown

The X-47B is an example ofthe trend toward auton-omous vehicles. Courtesy:Northrop Grumman.

An artists rendering depicts theSky Crane lowering Curiosity tothe Martian surface. Imagecredit: NASA.


for visualizing Pareto frontiers and a desk-top application using self-organizing mapsto visualize the characteristics of high-dimensional design spaces. Researchers atPenn State and the Applied Research Labare developing multidimensional data visu-alization tools to enable manufacturingtradeoff analysis and feedback in supportof DARPAs upcoming Adaptive VehicleMake design challenges.

MDO contributed to the design, build,and test of prototype vehicles. The Univer-sity of Southampton developed an opti-mization environment to design UAVs forair-sea rescue, and conducted optimizationfollowed by detailed design, build, and testfor a prototype aircraft. EADS InnovationWorks presented a prototype of a portableUAV produced by additive layer manufac-turing technology and designed by studentsfrom the University of Leeds, using AltairsHyperWorks software. The University ofOklahoma is developing trajectory opti-mization for glide and climb of a super-sonic interceptor, using the Chebyshevpseudospectral method.

The AFRL/Virginia Tech/Wright StateUniversity Collaborative Center for Multidis-ciplinary Sciences achieved developmentsin efficient supersonic air vehicles, microair vehicles (with University of Maryland),SensorCraft (with Quaternion Engineering),flight testing to understand nonlinear aero-elastic behavior of scaled models, and anextended markup language that improvestechnical information exchange at the con-ceptual and preliminary design stages.

The University of Michigan optimizedvehicles for occupant safety and fuel effi-ciency, and implemented analytical targetcascading for commercial systems at Hyun-dai Motor with the support of Altair. Boeingused its MDO capabilities in the energy do-main, applying its energy security assess-ment tool at several Air Force bases. Thistool optimizes investment portfolios for can-didate projects with respect to value of sav-ings, CO2 emissions, and energy security/as-surance concerns.

The University of Illinois developedtechniques for integrated physical and con-trol system design and for optimal redesignof mechatronic systems with application torobotic manipulators. N.C. State exploredreconfigurability and adaptability to achieveresiliency in complex engineered systems,and collaborated with General Motors totailor designs using respondent-level utili-ties from the marketing domain.

Multidisciplinary design optimization

New MDO methods are enabling incorpo-ration of higher fidelity analyses and con-sideration of more complex systems. TheUniversity of Michigan achieved optimalaeroelastic tailoring by integrating CFD withfinite-element structural models and opti-mizing hundreds of aerodynamic shapeand structural sizing variables simultane-ously. These tools are being used to opti-mize high-aspect-ratio wings in collabora-tion with NASA. The University of Arizonadeveloped an optimization algorithm thatcombines Kriging and support vector ma-chines. It is well suited for problems thathave many constraints and response dis-continuities. MIT adapted information en-tropy concepts to create a metric for systemcomplexity, and developed Bayesian esti-mation methods to characterize and man-age uncertainty in complex system design.

Wright State University developed top-ology optimization methods for thermal-structural disciplines that are unique to air-craft engine exhaust wash structures andthermal protection systems. The Universityof Bath developed practical robust topol-ogy optimization methods, addressing chal-lenges of buckling constraints, and opti-mized bistable piezocomposites geometryfor morphing applications. This concept isbeing investigated for broadband vibration-based energy harvesting in collaborationwith the University of Michigan.

MDO frameworks continue to evolve.NASA Glenn is developing OpenMDAO, anopen source framework. A joint develop-ment by Genworks, Noesis Solutions, andTU Delft coupled Optimus (an industry-standard workflow and MDO framework)with Genworks GenDL (a language for rep-resenting engineering knowledge througheasily authored object definitions).

Iowa States Virtual Reality ApplicationsCenter is providing intuitive tools for visu-ally exploring optimal design spaces. Theseinclude a virtual reality CAVE environmentby Karen Willcox


The DECODE software system created by the University ofSouthampton was used to carryout MDO and then detaileddesign, build, and test for thisprototype aircraft, which useslaser sintered nylon structureswith carbon spars. It also carriesan inertially stabilized camerasystem with full onboard auton-omy allowing for automatedtakeoff, mission segments, andlanding. Credit: University ofSouthampton.

analysis and design tools for thermal pro-tection systems for objects traveling at hy-personic velocities. The tools enable per-formance safety and reliability assessments.Despite these efforts, significant errors anduncertainties persist, which limit the accu-racy and utility of this predictive capability.

Furthermore, gaps exist in the currentbody of work, particularly regarding thecharacterization of the input probabilitydensity functions used to represent uncer-tain parameters. This is largely due to a lackof sufficient experimental datasets. Thus in-put distributions for the cited analyses haveusually been generated using ad hoc ap-proaches, with assumptions of PDF func-tional forms, statistical moments, and pa-rameter independences. And there hasbeen little emphasis placed on determiningthe effect these assumptions have on out-put statistics and reliability metrics.

It is possible to construct an experimen-tally based set of probability density func-tions, interval or ellipsoid bounds, or otheruncertainty representations for ablator ma-terial properties, performing a standard un-certainty propagation, contributor break-down, and sensitivity analysis for a prob-lem of relevance to the ablation modelingcommunity. Such a construction, by errorcharacterization of PDFs as functions of thequality of the input distributions, enablesintelligent design of experiments to effi-ciently capture the most important contrib-utors to overall uncertainty and establishthe relationship between input quality andoutput error. It also establishes the ex-pected variation in the quantities of interest,highlighting potential sources of epistemicuncertainties in the model. As more databecome available, this can help construct aseamless process by which experimentaltest results can be incorporated directly intothe analysis.

Nondeterministic approaches

Diagnosis and prognosis have become es-sential elements of safe, intelligent, effi-cient, and cost-effective systems. Structuralhealth methodologies have enabled use ofexisting information to understand interac-tions among subsystems, components, anduncertainties that help develop proceduresfor system-level diagnosis and prognosis. Acomprehensive reliability-based damageprognosis consists of monitoring criticalcomponents, assessing their structural in-tegrity, and predicting the remaining life ofthe component and systems.

There is an increasing need for reliabil-ity-based uncertainty assessment of a sys-tem that can be validated with a limitednumber of hardware and component tests.Assessment models that are built from fun-damental principles and calibrated to matchexperimental results must also provide pre-dictive accuracy under changes in externalload parameter and environment. One ex-ample of real-time health and integrity as-sessment using real-time inspection resultsis crack growth in airframe bolts/joints andaircraft engine components.

New approaches and standards are es-tablished through probabilistic and sensitiv-ity analysis for the assessment of risk due tomanufacturing and mission variability.

The R&D of complex engineering de-sign emphasizes system optimization forhigh reliability, ease of maintainability, andlower cost. OUU (optimization under uncer-tainty) and RBO (reliability-based optimiza-tion), along with modeling and analysis thatare complementary to probabilistic ap-proaches, hold promise for facilitating thesetypes of system optimizations.

For sensing and communication systemsperformance depends strongly on their ter-restrial operating environments. Even whenhigh-fidelity physics models are availableand the properties of disturbances are wellknown, these environments typically can-not be characterized with sufficient detail topermit precise predictions of detection per-formance. Multifaceted uncertainties in theproperties of these environments, proba-bilistic models of their constitutive proper-ties, and the resulting signal propagationcharacteristics are essential.

High-fidelity analysis and simulation ca-pabilities have been developed to deliver

by Shyama Kumari, Ben Thacker, and Isaac Elishakoff


A two-dimensional, nonparametrical PDF is comparedto measured and sampled amplitudes.


accumulation on the leading edge of thetail. Extensive instrumentation was carriedonboard the model, including Kulite un-steady pressure transducers at four span-wise stations on both the upper and lowersurfaces. The test conditions ranged fromlow subsonic Mach numbers up to a maxi-mum Mach number of 1.05.

The maximum oscillating frequencyachieved was 27 Hz (limited by modelstructural dynamics), and the correspon-ding reduced frequency was 0.5 Hz. Thedata will be used to calibrate productionunsteady aerodynamic codes, which are oflower order than state-of-the-art unsteadyCFD capability. The use of these codes isnecessitated by the sheer number of casesto be run in a finite amount of time duringan aircraft design cycle. Phase 2 of the testwill be a dynamic flutter model, scaled toflutter in the TDT boundary. This will pro-vide the test correlation of the correctedproduction methodologies.

Polytecs new remote sensing vibrometer(RSV) was used for the first time in a contin-uous-scan mode by Matt Allen and his re-search group at the University of Wisconsin-Madison to measure the mode shapes of awind turbine blade under ambient excita-tion. The new RSV laser was able to meas-ure the mode shapes of the blade from over70 m away without the need to apply anyretroreflective tape. The measurements alsoshowed remarkably low speckle noise, evenas the laser swept along the surface at morethan 400 m/sec.

The Air Force Institute of Technology hasbeen evaluating the flight characteristics ofthe wing of Manduca sexta, the hawkmoth, for micro air vehicle applications.The wing structure has been studied in airas well as in vacuum conditions, both ex-perimentally and using finite-element anal-ysis, as it goes through its flapping motion.A great deal of effort has gone into theevaluation of the vein properties and di-mensions as well as the material propertiesof both the veins and the membrane. An at-tempt to duplicate the wing camber wasalso carried out. The wing has a longitudi-nal length of 50 mm and a chord length ofabout 27 mm; this should give one a betterappreciation of the dimensionality leadingto dynamics that are very different from thenormal aircraft wing structure.

Gulfstream Aerospace executed the firstphase of an unsteady aerodynamics andflutter research campaign to advance thestate of the art in production flutter and dy-namic gust analyses. The first phase con-sisted of testing a rigid horizontal tailmodel, oscillating in pitch, at high transonicspeeds, in the Transonic Dynamics Tunnel(TDT) at NASA Langley.

The test conditions included both airand heavy gas, as well as the effects of ice


The image on theleft is the real wingof the hawk moth;at right is the finite-element model.

by D. Todd Griffith

Gulfstream Aerospace executed the first phase of anunsteady aerodynamics andflutter research campaign to advance the state of theart in production flutter and dynamic gust analyses.

Structural dynamics


by Harry H. Hilton

new matrix system that uses poly (ionic liq-uids) will replace the traditional epoxy,bringing additional sensing and healingbenefits to composite structures under serv-ice conditions.

At NASA Glenn, smart materials are be-ing used to achieve performance improve-ments. Studies have shown that substantialgains in engine noise, fuel efficiency, andemissions can be achieved not just by in-creasing material properties but also by in-dividually optimizing different componentsfor different portions of a flights missioncycle. Thus the main structural componentscould remain as those of today, but couldthen be used in configurations that take ad-vantage of properties optimized to specificenvironments. Analytical and experimentalmethods on piezoelectric blade vibrationdamping have produced the first successfuldemonstration of vibration damping onGEs GEnx engine composite fan blades.The damping levels achieved lead to re-duced dynamic stresses. New compositionshave been developed to extend the tem-perature capability of high-performancepiezoelectrics to near 400 C.

The Structures and Materials Division atGlenn has established the NASA MultiscaleAnalysis Center of Excellence, to develop,integrate, and vali-date physics-basedmodels and the as-sociated multiscalecomputational de-sign, analysis, andoptimization toolsrequired to makethese models ac-cessible to the en-gineering and ma-terials science communities. Working withindustry (GE Aircraft Engines, HyperSizer,Firehole Composites) and academia (Uni-versity of Michigan, Mississippi State, Uni-versity of Alabama, Miami University, Clark-son), NASA is developing methods andtools for advanced composites (PMCs,CMCs), high-temperature metallic alloys,and smart (piezoelectric, shape memory al-loy) materials that link microstructure-scalemechanisms to structural performance.Projects include modeling of lightning dam-age on PMCs, deformation and fatigue lifeprediction for hot engine componentCMCs, efficient multiscale microstructuralmodeling of nickel-based superalloys, anddevelopment of nano-informed damagemodels for polymer matrix materials.

Structures

Mississippi State University is investigatingkey elements in the development of a dam-age tolerance plan for multifunctional com-posites that accounts for loss of structuralintegrity as well as degradations in multi-functionality. While the effect of in-serviceor discrete source damage on compositestructural integrity is relatively well under-stood, the effect of damage on safety-of-flight aspects of multifunctionality remainsto be explored. A crucial consideration isfor cases where loss of mission-critical com-posite functionality occurs while structuralintegrity is preserved. Such issues must beaddressed if the full weight-saving potentialof multifunctional structural composites isto be realized.

The Air Force Institute of Technologycontinues to work on the biological charac-teristics of a Manduca sexta for applicationto a flapping-wing micro air vehicle. Theteam has dissected the species and studiedthe thorax to evaluate the dorsal ventralmuscle and determine its lifting power. Thistiny creature, appropriately 1.5 g in mass,can produce a lifting power of 73 W/kg. Itsthorax/wing structure can be modeled as amechanical spring system. Loads applied tothe thorax by the flight muscles cause com-pression, which in turn moves the wingsthrough hinges on either side of the thorax.

Carbon nanotube, graphene, oxidenanoparticle, and nanoclay-reinforced poly-mer nanocomposites research continues atMichigan Technological University (MTU)and MIT, which are collaborating on model-experiment comparison and correlationacross length scales for next-generationcomposites for NASA applications. MIT isworking on large-scale bulk structured ma-terials that have nanoscale reinforcementand take advantage of nanoscale physics.MIT and Metis Design (MDC) have collabo-rated on Air Force and Navy programs toleverage multifunctional nanoengineeredlaminate properties for ice protection sys-tems and structural health monitoring.Nanomaterials are literally getting bigger asevidenced by the recent MIT-MDC full-scaletest of a nanoengineered composite.

Arizona State researchers are synthesiz-ing novel multifunctional core-shell com-posite particles, composed of a polymericcore and an inorganic shell, which are responsive to environmental damages. The

Antiicing was demonstrated onunmanned air system aerosurface.Left: Aeosurface (white) withCNT-modified regions. Right: Deicing during ice tunnel testing.Courtesy: MIT and MDC.

that new certification requirements for en-gine icing are being prepared.

For military aircraft, the USAF has kickedoff its live fire test and evaluation (LFT&E)program for the in-flight KC-46A fuel tanker.The LFT&E strategy for this tanker is to con-duct a comprehensive evaluation of KC-46Asystem-level vulnerabilities against the bal-listic and advanced threats expected in com-bat. The program includes live fire tests(LFT), modeling, simulation, and analysis,and the evaluation of existing data (experi-mental and otherwise) for vulnerability as-sessments. LFT and other experiments in-clude evaluations of hydrodynamic ram onthe wings; fire extinguishing capabilities inengine nacelles; vulnerabilities on enginepylons and air refueling pods; threat-in-duced fires on wing and landing gear drybays, fuselage, and refueling components;and crew/passenger armor.

The results of the LFT&E program areused by the Air Force and the director ofoperational test and evaluation in the Officeof the Secretary of Defense to make inde-pendent assessments on the overall combatsurvivability of the aircraft.

For space systems, two survivabilityevents had happy endings following yearsof study and designs. First was the survivalof the SpaceX Dragon crew capsule, whichreentered the atmosphere and parachutedinto the Pacific on May 25 after berthingwith the ISS and surviving 3,000 F at reen-try. The reentry was with no crew, as a test,before regular cargo flights began. NASApartially funded the private company forsupport of the ISS after the shuttle programended. Also, NASAs crew capsule Orion(developed by Lockheed Martin underNASA funding) successfully tested its para-chutes on July 18 and was dropped forlow-speed water impact testing in an artifi-cial pond on August 23.

The second survivability success wasthe August 6 landing of the Mars Curiosityrover, which survived Mars reentry heatthrough a successful thermal shield. Curios-ity is expected to send information aboutthe Martian surface for two years.

On other survivability topics, the USAFmade efforts to test and evaluate the effectof high-energy lasers on aircraft survivabil-ity by testing different materials and en-ergy levels. The Air Force also continuedconcentrated modeling and simulation ef-forts on threat-induced fires through con-tinued enhancements in the fire predictionmodels.

Survivability

There is a newly recognized threat facingcivilian commercial aviation: engine flame-out due to crystal ice at 20,000-30,000 ft, amedium altitude range routinely traveled bycommercial airliners. The physical phenom-enon is under investigation but is still notfully understood; the possibility that ice canaccumulate in a hot running engine is notalways believed. As in the case of the vol-canic ash that stopped most civil aviationfrom Iceland over Europe in April 2010, thedamage is not mainly due to the ice crystalsimpacting an engines fans or compressorblades, but rather due to entering, accumu-lating, and then breaking out and coolingthe combustion chamber, causing eitherpower loss or complete flameout to bothengines, if one is fortunate enough to havemore than one engine.

NASA Glenn in Cleveland has begun aprogram to study the phenomenon and ispreparing one of its wind tunnels with en-gine ice crystal equipment for a full-scaleengine at simulated low-temperature, low-pressure altitude. The ice crystals are sofine that they are not detected on radar (un-like the volcanic ash); therefore, pilots arenot warned of flying areas to avoid. Canadais joining the U.S. in the study and has per-formed preliminary tests in Ottawa. TheFAA and the European aviation safetyagency have informed the aviation industry



by Ameer G. Mikhail,Jaime J. Bestard, and John J. Murphy Jr.

The USAF kicked off its live fire test and evaluation program for the KC-46A fuel tanker.


Problems for Airframe Noise Computations,organized by AIAA and NASA, was held inconjunction with this years aeroacousticsconference. Noise sources studied includeda trailing edge, tandem cylinders, three land-ing gear, and two slats. Research groupsaround the world provided experimentaldata and numerical predictions, and sometests were blind. Turbulence-resolving sim-ulations have reached good consensus be-tween teams and with experiments. Calcu-lation of radiated noise from these simu-lations is not as mature.

NASA successfully conducted a sonicboom community response study directedtoward understanding the potential impactof overland supersonic flight of low-boomaircraft. The Edwards AFB housing areawas exposed to low-amplitude sonic booms;100 volunteer residents responded to ques-tions for each boom event experienced athome and at the end of the day to the mul-tiple booms heard that day. To quantifyboom variation over the test area, 13 net-worked sonic boom monitors were placedthroughout the community to record the in-dividual sonic boom events.

The GE/NASA/FAA open-rotor test cam-paign completed both high- and low-speedwind tunnel entries for the second genera-tion of modern blade designs. The teamcharacterized the aero and acoustic per-formance of several advanced designs forisolated rotor systems and pylon-installedconfigurations. Technologies to mitigate thepylon installation influence were validated.These blade designs demonstrated substan-tial noise reduction relative to both legacydesigns and Stage 4 regulations while main-taining the efficiency of open rotor systems.

NASA and Honeywell are partnering ona research effort to measure the unsteadytemperature and pressure fluctuations gen-erated inside the core of a gas turbine en-gine. Efforts have focused on bench testingof a dual wire thermocouple probe meas-urement system previously developed byNASA and Pratt & Whitney.

Honeywell completed installed acousticscompatibility testing on its newest auxiliarypower unit (APU), the HGT1700, within theA350XWB aircraft tail cone. During the test,Optinav demonstrated its 24-microphonephased array system to identify the posi-tions of known and contaminating noisesources. This new application of phased ar-ray technology within Honeywell providedunprecedented understanding of installedAPU source locations and magnitudes.

Aeroacoustics

Noise reduction continues to be a majordriver in aerospace R&D amid growingconcern for community noise reductionand for protection from hearing loss in mil-itary applications, with more stringent re-quirements on the horizon for civil aviation.

The jet noise reduction component ofthe Office of Naval Research Noise InducedHearing Loss Program is supporting eightresearch projects that address noise gener-ated by tactical fighter aircraft. These proj-ects focus on gaining a better understand-ing of the noise source mechanisms, char-acterization of the noise in the near and farfields, nonlinear propagation effects, ad-verse health effects of exposure to high lev-els of very-low-frequency noise, and thedevelopment of active and passive noise re-duction technologies.

The investigations are split among com-putational aeroacoustics, development ofnew jet noise measurement techniques, andbench testing novel noise suppressionmethods. Promising results have been re-ported by Penn State researchers who havedeveloped a technique that uses distributedblowing inside the divergent section ofconverging-diverging nozzles to create flu-idic inserts that mimic hard-walled insertsbeing developed at the University of Missis-sippi. Actively controlled levels of blowingin small-scale experiments significantly de-crease large-scale structure noise as well asbroadband shock-associated noise.

The second Workshop on BenchmarkbyWalter Eversman

AEROSPACE SCIENCES

Detailed flow field measurementsfor an open rotor with pylon installed were made in the9x15-ft Low Speed Wind Tunnel at NASA Glenn.


The Long Endurance Multi-IntelligentVehicle, developed by Northrop Grummanand Hybrid Air Ve-hicles, made an ini-tial 90-min flight onAugust 10 in ademonstration ofthe optionally pi-loted lighter-than-air configuration.The operational ve-hicle is expected tofly for more than 3weeks in a recon-naissance role. Theaircraft is designedto incur less drag than typical airships andwill have improved speed, range, and effi-ciency while carrying large payloads to alti-tudes above 22,000 ft.

byMujahid Abdulrahim,Dan D. Vicroy, Kamal Shweyk,and Steve Komadina

Atmospheric flight mechanics

The remotely piloted X-48C aircraft madeits maiden flight on August 7 at NASA Dry-den. The vehicle is a modified version ofthe X-48B predecessor with configurationmodifications to enhance the fan and jetnoise shielding provided by the blended-wing-body concept. The modifications in-volved extending the aft centerbody sectionand moving the wing tip rudders to thenew extended aft centerbody. The propul-sion system was reconfigured from a trijetto a twin-jet design. Ongoing flight testswill explore low-speed flight dynamics andcontrol. The Air Force Research Laboratory,Boeing, Cranfield Aerospace, and NASAjointly sponsored the research.

The Northrop Grumman X-47B Navyunmanned combat air system has contin-ued flight tests at Patuxent River, Maryland,and is scheduled to begin precision landingtests on an aircraft carrier in 2013. A flighton July 30 included an evaluation of thecommand interface, aerodynamic perform-ance, and flight control system. The 36-minflight included two precision patterns inwhich the aircraft achieved an altitude of7,500 ft and an airspeed of 180 kt.

Northrop Grummans optionally mannedFirebird continued flight tests in 2012 with avariety of sensor payloads designed to pro-vide high-resolution aerial intelligence.Firebird is designed to be flown either withan onboard pilot or remotely, which re-quires it to satisfy requirements for both pi-loted handling qualities and autonomouscapability.

Flight tests of theFirebird continuedthis year.

The X-48C technology demonstrator awaits its first flight on August 7 at Edwards AFB.

Flight testing of the X-47B continuesat Patuxent River.


performed hydrogen and oxygen atomTPLIF line images as well as 2D planar im-aging in a series of laminar and turbulentdiffusion flames. Such measurements areproviding unprecedented critical experi-mental data for validating complex turbu-lent combustion models.

The Laboratory for Turbulence Researchin Aerospace and Combustion at MonashUniversity in Melbourne, has combined ul-tra-high-speed magnified digital holographyand coherent imaging to investigate parti-cle/shock interactions in a supersonic jetflow. Ultra-high-speed recording a1 millionHz enables simultaneous tracking of 3Dparticle motion and shock wave interaction.Results have provided some of the firsttime-resolved visualizations of the interac-tion between micron-sized particles and thecomplex shock structure, including bowshocks in the wake of the particles as theyare entrained into the gas phase and accel-erate toward supersonic speeds.

To date, it has proved challenging tomeasure temperatures and pressures on thesurface of a rotating propeller blade. Spa-tially resolved 2D techniques are highly de-sirable to enable certain flow structures tobe resolved on the surface, such as separa-tion bubbles and boundary layer transi-tions. The DLR, in cooperation with theUniversity of Hohenheim, has synthesizedspecial fast paint formulations for unsteadytemperature-sensitive paint and pressure-sensitive paint, and tested them in meas-urements on a propeller rotating at 15,000rpm in a Mach 0.2 flow to obtain pressureand temperature distributions. The tech-nique enabled visualization of laminar-to-turbulent transition regions of the boundarylayer on a propeller blade.

JAXA applied time-resolved PIV to anunsteady transonic flow field around arocket fairing model in their 2x2-m tran-sonic wind tunnel. Images were acquired at20 kHz using a high-speed CMOS (comple-mentary metal oxide semiconductor) cam-era. Measurements in the transonic flowfield provided mean velocity and powerspectral densities of velocity fluctuationwith high temporal resolution. Also in thesame wind tunnel, velocity distributions ofthe supersonic boundary layer on a flaredcone model were measured using a long-range micro-PIV system. The result wasfound to agree qualitatively with the CFDprediction, and explained a characteristictransition pattern of the supersonic bound-ary layer on the model.

Aerodynamic measurement technology

Researchers at Auburn University have de-veloped a novel 3D three-component (3C)particle image velocimetry (PIV) techniquebased on the light-field-capturing capabilityof a plenoptic camera. This type of camerauses a microlens array and CCD sensor torecord both the position and angle of lightrays entering the camera. The technique al-lows images to be computationally refo-cused, or new views to be generated from asingle snapshot. Tomographic reconstruc-tions of a pair of time-correlated particlevolumes produced a 3D 3C volumetric ve-locity field in a turbulent boundary layerusing PIV.

At NASA Langley, the first quantitativefreestream density measurements in a Mach10 freestream were made using laser Ray-leigh scattering. The same team also per-

formed the firstquantitative off-body air densitym e a s u r e m e n t salong a line in aMach 10 wake us-ing iodine Cordes-bands laser-inducedfluorescence. Airdensities behind amultipurpose crewvehicle model weremeasured to be14.5% of the free-stream density. Inaddition, a three-

laser, quantitative NO2 photodissociationtagging velocimetry method was applied tostudy hypersonic boundary layers in the 31-in. Mach 10 wind tunnel.

Researchers at the Air Force ResearchLab, aided by Spectral Energies and Innova-tive Scientific Solutions, have used fem-tosecond two-photon laser-induced fluores-cence (fs-TPLIF) to demonstratekilohertz-rate imaging of hydrogen and oxy-gen atoms in hydrocarbon flames. Thegroup obtained an excellent match betweenthe shapes of the experimental fs-TPLIF lineprofiles and numerical flame calculations.

The method enables efficient nonlinearexcitation, while the low energy nearlyeliminates interfering single-photon photo-dissociation processes, which can generatethe same species being probed. They also

by Thomas P. Jenkinsand theAIAA AerodynamicMeasurement TechnologyTechnical Committee

AEROSPACE SCIENCES

A rotating propeller is coatedwith pressure (magenta) andtemperature (yellow) paints.Obtained by DLR and theUniversity of Hohenheim.


Applied aerodynamics

The AIAA Aeroelastic Prediction Workshoptook place in April, with 23 analysis teamsfrom 11 countries submitting computationalresults for three configurations. Existing ex-perimental data sets were selected forbenchmarking and were made available tothe participants. The workshop yieldedcode-to-code and analysis-to-experimentcomparisons.

Key conclusions on the aeroelastic pre-dictive capabilities showcased include:

Reynolds-averaged Navier-Stokes ap-pears to be the state of the art, based onparticipants code selection.

Seemingly simple cases captured com-plex and important flow phenomena.

Substantial variations were observedamong the CFD analyses and between theCFD analyses and experiments.

Key phenomenological challenges toimproved predictive capabilities includedoscillatory shock behavior, shock-inducedflow separation, and tunnel wall boundary-layer influences.

NASAs Fundamental Aerodynamics N+2program worked with a Lockheed/GE/Rolls-Royce/Stanford team and with Boeingon next-generation supersonic transportconcepts, validating low sonic boom con-figurations and low airport noise propul-sion for supersonic commercial transportsbeyond 2020. The low boom design wasenabled through application of advancedcomputational methodologies, includingstructured Mach aligned swept cells, un-structured grids, and adjoint CFD-based de-sign refinement. These efforts resulted in abreakthrough for a critical supersonic en-ablercomplete cruise low boom withoutperformance degradation.

In the airport noise arena, new three-stream nozzle concepts from GE and Rolls-Royce were tested at NASA Glenn acousticslabs and demonstrated potential for achiev-ing noise levels below FAR-36 stage 4.

The DOD 12-year Computational Re-search and Engineering Acquisition Toolsand Environments (CREATE) program wasestablished in 2008 to enable major im-provements in engineering design and anal-ysis processes. It seeks to develop and de-ploy scalable multidisciplinary physics-based computational engineering productsfor the design and analysis of ships, air ve-hicles, and RF antennas. The Air Vehicles by Nathan Hariharan

program, CREATE-AV, released three prod-ucts this year: the fixed-wing analysis toolKESTRELv3.0, the rotorcraft analysis toolHELIOSv3.0, and the grid generation toolCAPSTONEv3.0. KESTRELv3 adds auto-mated overset capabilities for moving air-craft/body simulations. HELIOSv3 enablesoff-body adaptive mesh refinement andprovides the ability to handle multirotorconfigurations. CAPSTONEv3 allows fordirty geometry cleanup, surface mesh gen-eration, and volume mesh generation forCFD/ CSD applications.

The NASA SubsonicFixed Wing projectworked with NorthropGrumman to developN+3 advanced high-liftleading-edge technol-ogy for laminar flowwings. Two configura-tions were successfullytested to TRL 4, ex-ceeding target lift im-provement goals byabout 30%. The firstconfiguration was aNorthrop-developedblown leading-edgeconcept that achieved amaximum section liftcoefficient of 4.6. The second configura-tion, a drooped leading edge with a blownshoulder, achieved a maximum lift coeffi-cient of 5.0. Both configurations assumedthe use of an integrated slot design that en-ables laminar flows during cruise; they alsoshared a common 45-deg, blown trailing-edge flap.

The Fifth Drag Prediction Workshopwas held in conjunction with the 29th Ap-plied Aerodynamics Conference. The work-shop centered on a common grid and buf-fet study for the NASA Common ResearchModel. An additional case for turbulencemodel verification was also included. Aspecial session showcasing results fromseveral contributors will be held in January.

Applied CFD work at NAVAIR made fur-ther inroads in predictive modeling of navalair vehicles, focusing on complex unsteadyaerodynamics effects. One example is thesimulation of the unmanned combat air ve-hicle 1303 configuration, to leverage DODinterest in weaponized UAVs. CREATE-AVKestrel delayed detached eddy simulationtools were used to predict bay-cavity soundpressure levels and tonal content within10% of wind tunnel measurements.

NASA 2020 N+2 worked on low-noise supersonictransport studies, such as the Low Boom AdjointDesign Computation of Drag.


the University of Alabama in Huntsville.The algorithm on which the site is baseduses data from geostationary satellites totrack cumulus clouds as they develop and,as much as an hour before they show upon Doppler radar, provides a color-codedforecast of which clouds are likely to pro-duce rain or lightning. The website can beviewed at http://nsstc.uah.edu/SATCAST/.Six samples of pristine and dust-

abraded outer layer spacesuit fabrics wereincluded in the Mate-rials InternationalSpace Station Experi-ment-7, or MISSE-7,which was returnedin May 2011. Thefabrics had been ex-posed to the wake-side LEO environ-ment on the ISS for18 months to deter-mine whether abra-sion by lunar dustincreases radiationdegradation. Com-parison of pre- andpostflight characteri-zations carried out atNASA Glenn showedthat the environmentdarkened and red-dened all six fabrics,increasing their inte-

grated solar absorptance by 7-38%. Therewas a decrease in the ultimate tensilestrength and elongation to failure of lunardust-abraded Apollo spacesuit fibers by afactor of four, and an increase in the elasticmodulus by a factor of two. Clearly space-suits will need to be protected from thisdegradation if they are eventually to beused for long-term space exploration.A new AIAA standard entitled Low Earth

Orbit Spacecraft Charging Design StandardRequirement and Associated Handbook(BSR/ANSI/AIAA S-115-2013) has been de-veloped and is set for release in early 2013.This standard presents an overview of cur-rent understanding of the various plasma in-teractions that can result when a high-volt-age system is operated in the Earthsionosphere. In addition, common designpractices that have exacerbated plasma in-teractions in the past are referenced, andstandard practices for eliminating or mitigat-ing such reactions are recommended.(Copies may be obtained at www.aiaa.orgwithout charge to AIAA members.)

Atmospheric and space environments

This year brought a variety of develop-ments in the fields of atmospheric andspace environments. Testing capabilitieswere upgraded, weather forecasting toolsdeveloped, flight experiments conducted,and new guidelines produced.

Construction is complete on the icecrystal upgrade to Propulsion Systems Lab-oratory test cell three (PSL-3) at NASAGlenn in Cleveland, Ohio. PSL-3 is a direct-connect, altitude simulation engine test fa-cility that was retrofitted with water injec-tion spray bars to enable production of anice crystal cloud throughout a typical com-mercial turbofan engine mission profile. PSL-3 is undergoing integrated systems

testing, with cloud calibration testing sched-uled to take place by years end. The firsttunnel validation testing with a fully func-tional and operating turbofan engine isscheduled for January-February 2013. Thetest cell is designed to operate at pressurealtitudes of 4,000-40,000 ft and at tempera-tures ranging between -50 F and 15 F. Icewater content ranges from 0.5 to 9 g/m3.Beginning this year, anyone in the east-

ern two-thirds of the continental U.S. whois worried about a warm weather event be-ing rained out can get up-to-date nowcastsof pop-up storms from a new website cre-ated at the Earth System Science Center at

by Dustin Criderand the AIAA Atmosphericand Space EnvironmentsTechnical Committee

AEROSPACE SCIENCES

NASA engineers measure iceaccretion thickness on a clouduniformity grid during a PSL-3system checkout.

Free-air gravity from GRAIL depicts a region of theMoonsfarsidehighlands.Red correspondsto mass excesses and blues andpurples correspond tomass deciencies. Thecrater at centerleft is about 150 km in diameter.The gure illustrates how GRAILresolvesdetailsof the Moonshighland crust as well as craterstructures. Courtesy NASA/JPL

Caltech/MIT.


The Dawn spacecraft, which began or-biting the protoplanet Vesta in July 2011,has explored that uncharted world for morethan a year. Using its solar electric propul-sion system, the probe maneuvered to dif-ferent orbits to optimize its investigation.The lowest altitude orbit was achieved inDecember 2011 and mapped Vesta at anaverage altitude of 210 km for five months.Dawn then gradually spiraled away fromVesta and escaped its gravity well on Sep-tember 5. The probe is currently enroute toits second target, Ceres, and is expected toarrive in February 2015.

On December 5, 2011, NASA announcedthat Voyager 1 had entered the stagnationregion between interstellar space and oursolar system. On March 17, 2012, NASAsMESSENGER (Mercury surface, space envi-ronment, geochemistry, and ranging) space-craft successfully wrapped up a year-longprimary campaign for the first complete re-connaissance of the solar systems inner-most planet. An extended mission phasestarted on the following day where the or-bit period is reduced from 12 hr to 8 hr.

In April, Chinassecond lunar or-biter, Change 2,departed the Sun-Earth L2 point andheaded to the as-teroid 4179 Toutatisfor a flyby ex-pected in January2013. On June 18,three astronauts onShenzhou-9 suc-cessfully completedChinas first creweddocking with the Tiangong-1 module.

A fifth satellite of Pluto was discoveredfrom a Hubble Space Telescope optical sur-vey. NASAs New Horizon spacecraft isscheduled to conduct the first-ever recon-naissance of the Pluto system in 2015; thisnew finding adds invaluable informationfor designing robust flyby sequences.

Astrodynamics

This year began with the arrival of NASAsGRAIL (gravity recovery and interior labo-ratory) orbiters at the Moon. Launched on aDelta II rocket on September 10, 2011, thetwin orbiters Ebb and Flow embarked on afour-month low-energy transfer and per-formed lunar orbit insertion maneuvers onNew Years Eve and Day. Followed by twomonths of circularization, the probes wereplaced in tandem orbits around the Moonand initiated the prime science data collec-tion on March 1, making this the first inter-planetary formation-flight mission.

During the three-month prime sciencephase, the orbiters mapped lunar gravity inunprecedented detail using a techniquesimilar to that of the gravity recovery andclimate experiment mission, which onMarch 17 celebrated the 10th anniversary ofmapping Earths gravity field. The GRAILorbits were raised in late May to avoid a lu-nar eclipse and were reconfigured to initi-ate the extended mission data collection onAugust 30. GRAIL will be decommissionedthis month by impacting the lunar surface.

NASA launched another set of twins, theRadiation Belt Storm Probes, on August 30.They will be studying the Van Allen radia-tion belt.

On November 6, 2011, the Phobos-Gruntspacecraft was successfully launched aboarda Zenit launcher. However, the spacecraftfailed to respond to ground command andwas trapped in an undesirable low Earth or-bit. The 13-ton spacecraft eventually disinte-grated and on January 15 fell back to Earthover the Pacific Ocean. In between itslaunch and reentry, observers around theworld tracked Phobos-Grunt and shared es-timates and trending of orbital properties.

On August 6, the Mars Science Labora-tory spacecraft, launched in November2011, successfully landed the 1-ton roverCuriosity on Mars, inside Gale Crater. Aftersuccessfully navigating to a very tight flightpath angle requirement, the interplanetarynavigation function performed the first handover to an active guidance system,which adjusted errors during the crafts de-scent through the atmosphere on its way tothe surface. Two other spacecraft, Odysseyand the Mars Reconnaissance Orbiter, wereprecisely positioned at the time of the land-ing to receive transmissions and to take de-scent images of the rover. by Ryan S. Park

NASAs Curiosity rover and itsparachute were spotted byNASAs Mars ReconnaissanceOrbiter as Curiosity descendedto the surface on August 6.The high-resolution imagingscience experiment cameracaptured this picture whilethe orbiter listened to transmissions from the rover. Courtesy NASA/JPL-Caltech/University of Arizona.


rect numerical simulation, using immersedboundaries, is used to model turbulentspots and wedges over smooth and tex-tured surfaces such as straight or inclinedriblets. By varying the surface boundarycondition (for example, by allowing slip inthe spanwise direction or damping cross-flow fluctuations just above the surface), itis possible to show that spreading occursvia a destabilization of the surroundinglaminar flow and a turning of the spanwisevorticity into the streamwise and wall-nor-mal directions only at the boundary be-tween the turbulence and the borderinglaminar flow.

Recent advances in the application ofhigh-fidelity unsteady flow simulations in-volving high-lift devices and aircraft under-carriage have led to an ambitious attempt touse numerical simulations for the predic-tion of airframe noise associated with a full-scale aircraft in flyover configuration. Thepromising results obtained by GulfstreamAerospace and EXA are a harbinger of theeventual application of CFD as part of certi-fication-related activities.

At NASA Langley, a discretely consistenttime-dependent adjoint methodology hasbeen implemented in the unstructured-gridRANS (Reynolds-averaged Navier-Stokes)solver FUN3D. This capability enables de-sign optimization of unsteady flows usingdynamic overset grids in massively parallelcomputing environments, and has beendemonstrated on aerospace, wind energy,and micro air vehicle configurations. Theimplementation also enables mathemati-cally rigorous error estimation and meshadaptation strategies for such applications.

The Mars Science Laboratory (MSL) en-try, descent, and landing instrumentation(MEDLI) suite measured the temperatureand pressure on NASAs MSL heat shield asthe spacecraft entered the Martian atmo-sphere on August 6. MEDLI included seventransducers mounted to the 4.5-m aero-shells interior to measure pressure in thephenolic impregnated carbon ablator(PICA) heat shield material. In addition,seven thermal plugs were embedded in theheat shield to measure the PICA tempera-ture profile and recession. MEDLI data andpostflight Navier-Stokes CFD computationsare now being used to reconstruct the heatshields aerothermal environment, aerody-namic parameters (dynamic pressure, angleof attack), and PICA performance. MEDLI isa major advance that engineers hope will beincluded on every future EDL mission.

Fluid dynamics

Highlights in fluid dynamics research thisyear include advances in flow control, lam-inar-turbulent transition, unsteady flows,CFD, and flow data from the atmosphericentry of the Mars Science Laboratory.

NASA Ames is exploring novel ap-proaches to controlling free shear layers,which are found in a host of applicationsincluding combustion chambers, airfoils(fixed wing, rotary wing), cavity flows, andmany environmental flows. The approachinvolves appropriately perturbing the spa-tially growing mixing layer (close to its ori-gin) and then allowing the mixing layer toevolve downstream. Depending on the im-posed perturbations, mixing layer growthcan be enhanced or suppressed, as desired.The perturbations can be imposed via tem-perature or velocity or both. A simple linearcontrol has been demonstrated to controlthe mixing layer in a feedback loop.

Work at the University of Arizona hasbrought advancements in understandingthe thermal mechanisms behind high-am-plitude actuation for aerodynamic flowcontrol. The objective is to understand thebasic physics underlying flow control withlocalized thermal perturbations and theirrelatives to reveal new strategies for tailor-ing active flow control to encompass moreextensive Reynolds and Mach numbers,which remain limiting factors in the transi-tion of this technology from the laboratoryto the field. The response of mixing layersto both spatially and temporally varying en-ergy deposition from pulsed plasmas andlasers is being studied experimentallywithin a strong theoretical framework.

Researchers at the University of Texasare examining the mechanisms of lateralspreading of turbulence into an otherwiselaminar but transitional boundary layer. Di-byMichael W. Plesniak

AEROSPACE SCIENCES

Simulations by Gulfstream andEXA indicate that the details ofunsteady flow over the complexlanding gear configuration canbe captured with sufficient fidelity to permit physics-basedprediction of landing gear noisein flyover configuration. On theleft, instantaneous turbulentstructures, in color, are super-imposed with wall pressure fluctuations in grey; at right is a volume rendering of the time-average flow vorticity.


before returning to the start. However, al-though all the drones managed to take offand navigate fairly well, not a single onesuccessfully landed on a structure to collectvideo, according to DARPA. After nearly nine months of travel,

NASAs Mars Science Laboratory (MSL) ar-rived at the red planet, carrying Curiosity, arover set to explore Mars for at least oneMartian year. The spacecrafts entry, descent,and landing sequence successfully broughtthe rover from a velocity of 5,900 m/secdown to an altitude hold-hover within 7 minand safely landed it on the surface. The en-try, descent, and landing concept is basedon a guided system and supported by a SkyCrane. The MSL made a more accurate land-ing than any previous spacecraft to Mars,aiming for a small target landing ellipse only7 km by 20 km and landing only 2.4 kmfrom the center of the target.While the worldwide launch rate re-

mains flat, the launch vehicle world hasseen much development. NASA awardedthree contracts for development of com-mercial crewed vehicles. SpaceX success-fully launched its demonstration Dragoncapsule, making it the first commercial U.S.spacecraft to visit the ISS. It was followedby a commercial berthing. ESA lofted thefirst Vega launcher and conducted a flaw-less qualification flight from its spaceport inFrench Guiana. Orbital Sciences is closingin on the first flight of NASAs COTS sys-tem. While the commercial spacecraft mar-ket reduction that drove the formation ofUnited Launch Alliance has not rebounded,Atlas V and Delta IV have launched suc-cessfully 52 times. NASA continues to makeprogress on the Space Launch System andOrion multipurpose crew vehicle, effortsthat spur interest in new rendezvous, prox-imity, and avoidance GN&C approaches.

Guidance, navigation, and control

In November 2011 the Army successfullytested the Advanced Hypersonic Weapon(AHW), developed by Sandia NationalLabs. The tests objectives included demon-stration and data collection of the vehiclesaerodynamic stability, aerothermodynamicheating, and guidance, navigation, and con-trol (GN&C) of the missile and glide vehi-cle in the hypersonic regime. The flight in-volved new maneuvers that keep theweapon on a highly depressed trajectoryduring ascent; postapogee, the vehiclepulled up after an initial descent throughthe atmosphere to capture its glide altitude,from which it glided to its target, skimmingthe atmosphere over its long-range atmo-spheric approach. AHWs eight tail grid finswere used to improve the missiles aerody-namic stability and to control the glide pathduring its long in-atmosphere flight. Thiswas the first demonstration of a hypersonicgliding vehicle at such altitudes and ranges.Less successful was the X-51A Wave-

rider test conducted by the Air Force in Au-gust to evaluate hypersonic flight at speedsof Mach 6+. The X-51 is an unmanned,scramjet-powered hypersonic demonstra-tion aircraft. The plan was to release it froma B-52 at 50,000 ft; after release, a solidrocket booster (SRB) would propel theplane to Mach 4.5; the booster would thenjettison and the scramjet engines fire to ac-celerate the aircraft to its top flight speed ofMach 6+. While separation from the B-52went as planned, and the SRB fired as ex-pected, a faulty tail control fin resulted inloss of control authority once the rocketmotor jettisoned, and the vehicle was un-able to stabilize itself; thus it was termi-nated 16 sec after separation from the SRBand before the scramjet engine could be lit.In June, DARPA concluded UAVForge, a

crowd-sourced competition program de-signed to solicit the do-it-yourself UAV en-thusiast community for innovative conceptsto design and build autonomous backpack-scale UAVs with specific militarily relevantcapabilities. DARPA downselected nineteams from 140 who had submitted videosdemonstrating early flight behavior capa-bilities of their drones. The flyoff requiredeach system to perform a vertical takeoff,navigate beyond line of sight, land on astructure, and capture surveillance footage

by Leena Singh, LuisellaGiulicchi, John Reed,and Lance Page

Curiosity is prepared for final integration into the completeNASA spacecraft in the PayloadHazardous Servicing Facility at NASA Kennedy.


facilities to meet the demands of future testprograms by improving reliability, decreas-ing operational and test customer costs, andproviding commonality across facilities.

AEDC also set a record for fabricatingthe largest ground test model ever built atthe complex. The B-52H Stratofortress storeseparation effort resulted in AEDC using allits capabilities, from planning, design, fabri-cation, testing, and computations to analy-sis and reporting. Combining the centerscapabilities with ongoing external customercollaboration made the test effort a truly in-tegrated test and evaluation program.

Also, as news broke of the NASA MarsScience Laboratory Curiosity rovers suc-cessful landing on August 6, a number ofpeople across AEDCs facilities were payingclose attention. AEDC provided aerother-mal characterization of the heat shield de-sign at the Hypervelocity Wind Tunnel 9 inSilver Spring, Maryland, material characteri-zation in AEDCs arc jet facilities in Tulla-homa, Tennessee, and full-scale parachutetesting in AEDCs National Full-Scale Aero-dynamic Complex, located at NASA Ames.

At NASA Ames, reactivation of the Uni-tary Plan Wind Tunnels (UPWT) Mitsubishicompressor system was completed and isscheduled to replace the existing Clarkcompressor as the primary make-up airsource. The Mitsubishi compressor will im-prove productivity and reliability of theUPWT by providing additional air and vac-uum pumping capability. Also at the 11-FtTransonic Wind Tunnel, installation andvalidation of a noncontact stress monitoringsystem for the three-stage compressor wascompleted. The new system allows for con-tinuous monitoring and recording of com-pressor blade bending and torsion stressesduring normal test operations.

A series of sonic boom tests were com-pleted in the UPWT. Part of the Fundamen-tal Aeronautics Program, the tests were acollaborative effort with Boeing and Lock-heed Martin. One goal of the series was todevelop test techniques and hardware ca-pable of measuring sonic boom signaturesin the transonic and supersonic regimes.Data on various model designs were alsocollected and will be used to validate CFDpredictions.

Finally, an atypical test of the crew ex-ploration vehicle parachute assembly sys-tem was completed in the 11-Ft TransonicWind Tunnel. The goal of the test was to ac-quire aerodynamic and flow field data foruse in validating CFD methods and tools.

Ground testing

This year several ground test facilities madeconcerted efforts to upgrade aging systems.Many of the systems are well beyond theirdesigned life expectancy and are no longerflexible enough to meet future test require-ments. These upgrades will provide state-of-the-art facilities that meet the demandsof future test programs.

At NASA Langley, a new facility automa-tion system (FAS) and data acquisition sys-tem (DAS) are being installed in the Na-tional Transonic Facility. The upgrades willimprove technical viability by providingcontinued high-quality, high Reynolds num-ber testing and will include installing a newtunnel control system, new DAS, and mod-ern simulation tools. The FAS upgrades willallow for a fivefold increase in Mach num-ber measurement accuracy while reducingannual calibration costs. The DAS upgradeswill improve data quality and provide con-tinual support of advanced testing.

At NASA Glenn, upgrades to the Propul-sion Systems Lab test cell three (PSL-3)have been completed. They included retro-fitting the direct-connect, altitude simula-tion engine test facility with water injectionspray bars to provide the ability to producean ice crystal cloud throughout a typicalcommercial turbofan engine mission pro-file. The PSL-3 is currently undergoing inte-grated systems testing, with the first test ofa fully functional and operating turbofanengine scheduled for early next year.

At the Arnold Engineering DevelopmentComplex, upgrades to the von Krmn Fa-cility and the Propulsion Wind Tunnel Fa-cility continue. The upgrades will allow theby Ben Mills

AEDC set a record withthe largest aircraft modelto conduct a B-52Hstore separation test.

AEROSPACE SCIENCES


Several research organizations, includingthe University of Toronto and both NLRand TNO in the Netherlands, have been in-vestigating possible motion cueing im-provements. Results of these studies werereported at the 2012 Modeling and Simula-tion Technologies Conference.

Sometimes a contributing factor to anaccident is that a pilot inexplicably takesactions inconsistent with his or her simula-tor training. This is often attributed to somesort of cognitive breakdown that may havearisen from being surprised. Equaling in-flight surprise in simulation is difficult. Thisyear a NASA simulator study found that pi-lots, on average, had three to four timesmore delay in their response to unexpectedstalls than they did for expected stalls.While most everyone agrees that insertingunexpected events in simulator training of-fers benefit, the practice has not been im-plemented widely. Such research evidenceshowing the specific benefits may raise thepriority for action.

Another area receiving considerablemodeling and simulation attention is un-manned aircraft systems. Under a NASA-sponsored project, simulator facilities acrossthe U.S. have been linked together in wayssimilar to distributed simulations performedfor defense purposes. This linkage allowsfor expertise available at different loca-tionson subjects such as airspace, propri-etary vehicle models, live aircraft, and clas-sified programsto be combined into oneexperiment. A demonstration of a distrib-uted simulation took place this year withparticipation by NASA, the FAA Tech Cen-ter, NAVAIR, and Boeing.

Modeling and simulation

Upset prevention and recovery training forair carriers continues to be a fertile area ofactivity in the field of modeling and simula-tion. Evidence reveals that stalls are theleading cause of upsets. Prior to the intro-duction of a 2010 U.S. law, pilots practicedrecovering from the first indication of astall, such as a stick-shaker activation, insimulation. The 2010 law will soon requirepilots to be trained at angles of attack be-yond that first indication, and to recoverfrom full aerodynamic stalls.

A challenge for the simulator commu-nity is how to reasonably model thesehigher angle-of-attack regimes completely,which is beyond what has been previouspractice in most cases. For some of themore recent aircraft models, there are suffi-cient flight test data to create full-stall aero-dynamic models. For some of the older air-craft models, data access and completenesscreate challenges.

However, if one considers the trainingobjective, which is to teach the appropriatestall recovery technique under a variety ofpossible entry conditions, matching a simu-lator model to flight test data may not benecessary. Instead, it might be possible tocreate a model that has the typical dynami-cal features that occur during a typical stall,such as reduced stability, reduced controleffectiveness, and a pronounced roll-off atthe stall point. Such a model may be suffi-cient for training purposes.

This year Boeing created a poststallmodel using an extensive flight test data-base of stalls for the 737-800. Separately, ateam comprised of Cherokee Research,Bihrle Applied Research, and Testpilot cre-ated a poststall model using computationalanalysis, wind tunnel similarity data, andexpert pilot opinionfrom a pilot with ex-perience in stalling the actual aircraft inflight testfor the 737-800.

In 2013, both of these models will beevaluated in an experiment to determinewhether a poststall model needs to matchflight data for the purposes of stall training.If the latter model is feasible for such train-ing, it could potentially be cost effectiveand allow for modification of simulatorsused for training on older aircraft types.

Another question often asked for upsettraining is whether the motion cues pro-vided by the typical simulator help or hurt. by Jeffery Schroeder

Simulating aircraft in an upsetis assisting in understanding the causes and preventing theproblem.


For instance, researchers at IntelligentLight have developed a new prototype vi-sualization and CFD data analysis softwaresystem, Intelligent In-Situ Feature Detec-tion, Tracking and Visualization for Turbu-lent Flow Simulations (IFDT), which en-ables the user to readily explore, detect,track, and analyze flow features predictedby large-scale unsteady CFD simulations.The system employs volume rendering thatallows the user to automatically highlightflow features such as turbulent vortices. Afeature extractor method then tracks andextracts the flow features and determinesthe statistics of features over time. The AirForce Research Laboratory funded thiswork in collaboration with the University ofCaliforniaDavis.

Mesh generation and visualization haveproven to be useful tools not only in speed-

ing up CFD solutions and improving accu-racy, but also in exploring the origins ofsome of the strange phenomena seen in ex-perimentation. For instance, in a paper byscientists from the Royal Military College ofCanada, the use of direct numerical simula-tion and visualization has shown very longstreamwise vortices (also known as thecolored-fingers phenomenon) in CFD re-sults that mimic those reported in turbineheat transfer experiments. This may changethe communitys ideas about how thesepressure-side vortices form in turbomachin-ery applications.

Also, scientists from the University of Al-abama at Birmingham and the Japan Aero-space Exploration Agency have describedtheir approach to further automating meshgeneration. This includes novel ways ofdealing with sharp corners and marchingviscous layers off the surface.

Overset mesh generation has seen aresurgence in popularity as a method fordiscretizing domains, thanks to more avail-able storage, more robust mesh interpola-tion codes such as SUGGAR++, which wasdeveloped by researchers at Penn State,and fully capable overset mesh assemblysoftware such as that developed at NASAAmes and Celeritas Simulation Technology.

Commercial software packages such asPointwise have begun to work on stream-lining the process of overset mesh genera-tion in these products, enabling visualiza-tion of the assembly results, use of struc-tured, unstructured, and hybrid meshes increating the overset mesh, and mesh adap-tation to improve results. Organizationssuch as the Air Force Materiel Commandand Arnold Engineering Development Cen-ter have taken the lead in funding projectsto streamline the use of overset methodsfor CFD analysis.

With processors becoming faster, accel-erator technologies such as NVIDIA GPG-PUs and Intel Xeon Phi cards becomingmore widespread, and overall memorygrowing as latency shrinks, MVCE contin-ues to evolve to take advantage of thesegroundbreaking technologies, with the endgoal being truly dynamic, adaptive mesh-ing. To this end, the AIAA/DOD-sponsoredMesh Quality Workshop was held atWright-Patterson AFB, producing vigorousdiscussion. The community continues toconverge on specific metrics and qualitymeasures to amplify the power of currentCFD solution methods by holding these im-portant conversations.

byVincent Charles Betro,Earl Duque, and Nick Wyman

AEROSPACE SCIENCES

Meshing, visualization, and computational environments

Although the adage a picture is worth athousand words rings true in both the ped-agogy and practice of science, it is dis-played in perhaps its most elegant fashionin mesh generation, visualization, and com-putational environments (MVCE). Indeed,without the many advances in visualizationtechniques, debugging would be harder,sharing results would be nearly impossible,and much computational research wouldbe merely huge strings of nearly indeci-pherable numbers to be combed throughby graduate students.

IFDT created this image of turbulent flow,including vortex formation.


Federal Nuclear Center demonstrated ex-traction of 1 kW of laser light from a flow-ing diode pumped alkali laser (DPAL) usingcesium as the active lasing species.

This work complements recent suc-cesses at the Air Force Academy and the AirForce Research Laboratory in the develop-ment of flowing DPAL technology, indicat-ing strong scaling potential for this technol-ogy. Elsewhere within the Defense Dept.,the Missile Defense Agencys AirborneLaser Testbed program concluded, markingthe end of a program that successfullydemonstrated the ability to target, track,and shoot down missiles using a megawatt-class laser on an aircraft.

Airborne Aero-Optics Laboratory at theUniversity of Notre Dame, an in-situ facilityfor measurement of aerooptical aberrationsand assessment of laser turret configura-tions, was active this year characterizinghemisphere-on-cylinder and hemisphere-only turret configurations. The hemisphere-only configuration demonstrated an advan-tage with regard to measured optical pathdifference for wake optical propagation,and the hemisphere-on-cylinder had someadvantage for high elevation pointing anglepropagation.

In other work, the University of NotreDame validated application of a phase-lockloop controller to phase-lock to a low orderoptical field measurement, providing a pathtoward synchronization of a feed-forwardaerooptic correction of shear layer aberra-tions. Notre Dame also developed a usefulanalytical model based on an empirical fitof experiment optical path difference datafrom turbulent boundary layers over vary-ing size apertures in the Mach 0.4-0.6 rangewith varying laser beam deflection angles,good for aperture diameters up through 10boundary layer thicknesses.

Plasmadynamics and lasers

Plasma aerodynamics continued to be apopular research area this year. Topics ofparticular interest include developments inplasma-based flow control and plasma-as-sisted combustion.

Industry seems to be receptive to theadoption of plasma-based technology, buthas reservations about technical risk, per-formance, reliability, and integration. Thereis a need to identify applications whereplasma devices are significantly better thancompeting technologies.

Plasma-enhanced combustion is a verypromising area for both low- and high-speed regimes. Discharges are being usedto break down fuels, enhance ignition, andpromote combustion efficiency.

Laser scattering techniques are amongthe best options for making measurementsof the detailed features of electrical dis-charges, and the field is progressing rapidly.For example, nonintrusive measurementsof electric fields have recently been madevia the USED-CARS (unstable resonator en-hanced-coherent anti-Stokes Raman scatter-ing) technique.

The main challenge for numerical simu-lations is the disparity in the time andlength scales present for an electrical dis-charge in a large-scale gas flow. This chal-lenge has motivated the use of reduced-or-der models, but there is a strong need tocorroborate their accuracy with experimentand high-fidelity computations.

The accuracy of numerical modelingalso depends to a great degree on thechemical kinetic model. The kinetics ofplasmas in air and air-fuel mixtures is ex-tremely complex, and care must be taken incalculations to stay within the bounds ofvalidity of a plasma kinetic model. There isa lack of detailed experimental data tocompare with new kinetic mechanisms. Ingeneral, there is a need for consistent effortto establish the accuracy of plasma aerody-namic modeling.

This year has seen considerable activityon many fronts in laser technology devel-opment. In the gas laser area, CU Aero-space performed a scaling demonstration ofthe electric oxygen-iodine laser technology,extracting 500 W of high beam quality lightand meeting a critical milestone in the ad-vancement of this technology. In a relateddevelopment, researchers at the Russian

by Timothy J. Maddenand Jonathan Poggie

Schlieren images illustrate bowshock control at Mach 5 usingnanosecond-pulse barrier discharge actuators (left image2 sec after the pulse; right image 4 sec). Courtesy OhioState University, Dept. of Mechanical and Aerospace Engineering.


tude and range. The Army Aviation andMissile Research Development and Engi-neering Center in Huntsville, Alabama, con-ducted the thermal protection system de-velopment for the glide body, while Sandialed the design and development of thebooster and glide vehicle, including im-proved navigation, guidance, and controltechnologies. The tests objective was to col-lect data on the technologies and test rangeperformance for intermediate-range atmo-spheric flight.

This year marked the reemergence ofcapillary pumped loop (CPL) technology asa viable solution for spacecraft thermal c