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NASA NTRS2010

Technology Advancement of the Visible Nulling Coronagraph

The critical high contrast imaging technology for the Extrasolar Planetary Imaging Coronagraph (EPIC) mission concept is the visible nulling coronagraph (VNC). EPIC would be capable of imaging jovian planets, dust/debris disks, and potentially super-Earths and contribute to answering how bright the debris disks are for candidate stars. The contrast requirement for EPIC is 10(exp 9) contrast at 125 milli-arseconds inner working angle. To advance the VNC technology NASA/Goddard Space Flight Center, in collaboration with Lockheed-Martin, previously developed a vacuum VNC testbed, and achieved narrowband and broadband suppression of the core of the Airy disk. Recently our group was awarded a NASA Technology Development for Exoplanet Missions to achieve two milestones: (i) 10(exp 8) contrast in narrowband light, and, (ii) 10(ecp 9) contrast in broader band light; one milestone per year, and both at 2 Lambda/D inner working angle. These will be achieved with our 2nd generation testbed known as the visible nulling testbed (VNT). It contains a MEMS based hex-packed segmented deformable mirror known as the multiple mirror array (MMA) and coherent fiber bundle, i.e. a spatial filter array (SFA). The MMA is in one interferometric arm and works to set the wavefront differences between the arms to zero. Each of the MMA segments is optically mapped to a single mode fiber of the SFA, and the SFA passively cleans the sub-aperture wavefront error leaving only piston, tip and tilt error to be controlled. The piston degree of freedom on each segment is used to correct the wavefront errors, while the tip/tilt is used to simultaneously correct the amplitude errors. Thus the VNT controls both amplitude and wavefront errors with a single MMA in closed-loop in a vacuum tank at approx.20 Hz. Herein we will discuss our ongoing progress with the VNT.

Lyon, Richard G.↗
NASA NTRS2010

COTS/CRS: KSC Evolving Host Initiatives with Commercial Space Partners

NASA's Commercial Crew and Cargo Program Office (C3PO) leads the agency's commercial efforts to stimulate United States private companies as the shuttle program comes to a close. Through the Commercial Orbital Transportation Services (COTS) program, two companies, SpaceX and Orbital, were selected to demonstrate their ability to perform flights to the International Space Station. The Commercial Resupply Services (CRS) Project leverages off the COTS experience, and awarded these two private companies contracts to resupply the International Space Station after shuttle fly out. As a 2010 summer intern, I supported the COTS/CRS team in their team meetings, attended and contributed to project discussions and planning, and assisted in developing visual representations for the variety of processes and organizational endeavors required for the program to run smoothly. One aspect of the COTS/CRS program gives the involved private companies the opportunity to request available services from Kennedy Space Center (KSC); one of my projects included assisting in the development of a related Task Order Request (TOR) process. In addition, an integral part of the project was to maintain and enhance the team database for processing the variety of TORS. My experience in the project gave me great insight into the growing field of commercial space activities. The development of the TOR process involved coordinating representatives from a variety of backgrounds at KSC. A clear and concise visual representation of the TOR process in the form of a flow chart was necessary to successfully implement a task order request from one of NASA's commercial partners. The goals of the process charts were to communicate the team's ideas and foster a common thought process while at the same time allow the process to grow and evolve. It was critical that the requests from the private companies were addressed quickly and thoroughly as the process developed this summer is expected to have extensive future use.

Yohpe, Megan↗
NASA NTRS2010

Comparison of Traditional and Innovative Techniques to Solve Technical Challenges

Although NASA has an adequate food system for current missions, research is required to accommodate new requirements for future NASA exploration missions. The Inadequate Food System risk reflects the need to develop requirements and technologies that will enable NASA to provide the crew with a safe, nutritious and acceptable food system while effectively balancing appropriate resources such as mass, volume, and crew time in exploratory missions. As we go deeper into space or spend more time on the International Space Station (ISS), there will be requirements for packaged food to be stored for 3 5 years. New food packaging technologies are needed that have adequate oxygen and water barrier properties to maintain the foods' quality over this extended shelf life. NASA has been unsuccessful in identify packaging materials that meet the necessary requirements when using several traditional routes including literature reviews, workshops, and internal shelf life studies on foods packaged in various packaging materials. Small Business Innovative Research grants were used for accelerating food packaging materials research with limited success. In order to accelerate the process, a theoretical challenge was submitted to InnoCentive resulting in a partial award. A similar food packaging challenge was submitted to Yet2.com and several potential commercial packaging material suppliers were identified that, at least partially, met the requirements. Comparisons and results of these challenges will be discussed.

Perchonok, Michele↗
NASA NTRS2010

Inspiring the Next Generation in Space Life Sciences

Competitive summer internships in space life sciences at NASA are awarded to college students every summer. Each student is aligned with a NASA mentor and project that match his or her skills and interests, working on individual projects in ongoing research activities. The interns consist of undergraduate, graduate, and medical students in various majors and disciplines from across the United States. To augment their internship experience, students participate in the Space Life Sciences Summer Institute (SLSSI). The purpose of the Institute is to offer a unique learning environment that focuses on the current biomedical issues associated with human spaceflight; providing an introduction of the paradigms, problems, and technologies of modern spaceflight cast within the framework of life sciences. The Institute faculty includes NASA scientists, physicians, flight controllers, engineers, managers, and astronauts; and fosters a multi-disciplinary science approach to learning with a particular emphasis on stimulating experimental creativity and innovation within an operational environment. This program brings together scientists and students to discuss cutting-edge solutions to problems in space physiology, environmental health, and medicine; and provides a familiarization of the various aspects of space physiology and environments. In addition to the lecture series, behind-the-scenes tours are offered that include the Neutral Buoyancy Laboratory, Mission Control Center, space vehicle training mockups, and a hands-on demonstration of the Space Shuttle Advanced Crew Escape Suit. While the SLSSI is managed and operated at the Johnson Space Center in Texas, student interns from the other NASA centers (Glenn and Ames Research Centers, in Ohio and California) also participate through webcast distance learning capabilities.

Hayes, Judith↗
NASA NTRS2010

Developing Nontraditional Partnerships to Disseminate the Space Science Story

NASA Space Science Days (NSSD) was established in 2004 to bring the story of the Mars Exploration Rovers (MER) to a community far removed from areas NASA traditionally serves. The original NSSD invited 400 5th and 8th graders from the Texas Rio Grande Valley area to the University of Texas Brownsville campus to participate in a one day Saturday event filled with information about MER with related hands on activities. Currently the program has grown to over 700 5th and 8th grade participants who are mentored by trained university students from several Texas universities and community colleges and growing to include universities from throughout the U.S. A collaboration between three major institutions: The NASA Johnson Space Center (JSC) Astromaterials Research and Exploration Science Directorate (ARES), the Society of Hispanic Professional Engineers/Advancing Hispanic Excellence in Technology Engineering, Math, and Science, (SHPE/AHETEMS), and the University of Texas at Brownsville (UTB) has been established to enable the dissemination of Solar System related educational materials throughout the U.S. Already in its 8th year, UTB has developed and tested a NSSD model that has successfully disseminated space science materials to students throughout South Texas Rio Grande Valley. With this newly formed collaboration this model s expansion will allow trained SHPE students and professionals to conduct events throughout its established nation-wide delivery systems. Each year a new NSSD site will be established through an application process solicited from SHPE student and professional chapters. Once a chapter is awarded, upper-level high school and university students will travel to NASA- JSC for a two day workshop where students learn about the current year s theme and are trained to present hands-on activities related to the theme. Additional training by ARES and UTB occurs one month before the new event in their own communities. Both local middle school teachers and mentors are trained locally. This allows the teachers time to prepare their students with the background material for NSSD and give the mentors time to decide which activity they feel comfortable with to lead. Several events using this process have already been successful and an increase in interest from SHPE chapters wanting to establish their NSSD event is growing.

Galindo, Charles↗
NASA NTRS2010

Framework Resources Multiply Computing Power

As an early proponent of grid computing, Ames Research Center awarded Small Business Innovation Research (SBIR) funding to 3DGeo Development Inc., of Santa Clara, California, (now FusionGeo Inc., of The Woodlands, Texas) to demonstrate a virtual computer environment that linked geographically dispersed computer systems over the Internet to help solve large computational problems. By adding to an existing product, FusionGeo enabled access to resources for calculation- or data-intensive applications whenever and wherever they were needed. Commercially available as Accelerated Imaging and Modeling, the product is used by oil companies and seismic service companies, which require large processing and data storage capacities.

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NASA NTRS2010

Fuel Cell Stations Automate Processes, Catalyst Testing

Glenn Research Center looks for ways to improve fuel cells, which are an important source of power for space missions, as well as the equipment used to test fuel cells. With Small Business Innovation Research (SBIR) awards from Glenn, Lynntech Inc., of College Station, Texas, addressed a major limitation of fuel cell testing equipment. Five years later, the company obtained a patent and provided the equipment to the commercial world. Now offered through TesSol Inc., of Battle Ground, Washington, the technology is used for fuel cell work, catalyst testing, sensor testing, gas blending, and other applications. It can be found at universities, national laboratories, and businesses around the world.

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NASA NTRS2010

Aerogels Insulate Against Extreme Temperatures

In 1992, NASA started to pursue the development of aerogel for cryogenic insulation. Kennedy Space Center awarded Small Business Innovation Research (SBIR) contracts to Aspen Systems Inc., of Marlborough, Massachusetts, that resulted in a new manufacturing process and a new flexible, durable, easy-to-use form of aerogel. Aspen Systems formed Aspen Aerogels Inc., in Northborough, Massachusetts, to market the product, and by 2009, the company had become the leading provider of aerogel in the United States, producing nearly 20 million square feet per year. With an array of commercial applications, the NASA-derived aerogel has most recently been applied to protect and insulate people s hands and feet.

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NASA NTRS2010

Inflatable Antennas Support Emergency Communication

Glenn Research Center awarded Small Business Innovation Research (SBIR) contracts to ManTech SRS Technologies, of Newport Beach, California, to develop thin film inflatable antennas for space communication. With additional funding, SRS modified the concepts for ground-based inflatable antennas. GATR (Ground Antenna Transmit and Receive) Technologies, of Huntsville, Alabama, licensed the technology and refined it to become the world s first inflatable antenna certified by the Federal Communications Commission. Capable of providing Internet access, voice over Internet protocol, e-mail, video teleconferencing, broadcast television, and other high-bandwidth communications, the systems have provided communication during the wildfires in California, after Hurricane Katrina in Mississippi, and following the 2010 Haiti earthquake.

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NASA NTRS2010

Burnishing Techniques Strengthen Hip Implants

In the late 1990s, Lambda Research Inc., of Cincinnati, Ohio, received Small Business Innovation Research (SBIR) awards from Glenn Research Center to demonstrate low plasticity burnishing (LPB) on metal engine components. By producing a thermally stable deep layer of compressive residual stress, LPB significantly strengthened turbine alloys. After Lambda patented the process, the Federal Aviation Administration accepted LPB for repair and alteration of commercial aircraft components, the U.S. Department of Energy found LPB suitable for treating nuclear waste containers at Yucca Mountain. Data from the U.S. Food and Drug Administration confirmed LPB to completely eliminate the occurrence of fretting fatigue failures in modular hip implants.

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NASA NTRS2010

Do-It-Yourself Additives Recharge Auto Air Conditioning

In planning for a return mission to the Moon, NASA aimed to improve the thermal control systems that keep astronauts comfortable and cool while inside a spacecraft. Goddard Space Flight Center awarded a Small Business Innovation Research (SBIR) contract to Mainstream Engineering Corporation, of Rockledge, Florida, to develop a chemical/mechanical heat pump. IDQ Inc., of Garland, Texas, exclusively licensed the technology and incorporates it into its line of Arctic Freeze products for automotive air conditioning applications. While working on the design, Mainstream Engineering came up with a unique liquid additive called QwikBoost to enhance the performance of the advanced heat pump design.

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NASA NTRS2010

NASA Earth Observations Track the Gulf Oil Spill

The NASA Applied Sciences Program created the Gulf of Mexico Initiative (GOMI) in 2007 "to enhance the region s ability to recover from the devastating hurricanes of 2005 and to address its coastal management issues going into the future." The GOMI utilizes NASA Earth science assets to address regional priorities defined by the Gulf of Mexico Alliance, a partnership formed by the states of Alabama, Florida, Louisiana, Mississippi, and Texas, along with 13 federal agencies and 4 regional organizations to promote regional collaboration and enhance the ecological and economic health of the Gulf of Mexico. NASA's GOMI is managed by the Applied Science and Technology Project Office at Stennis Space Center and has awarded over $18 million in Gulf of Mexico research since 2008. After the Deepwater Horizon oil spill, GOMI personnel assisted members of the Gulf of Mexico Alliance with obtaining NASA remote sensing data for use in their oil spill response efforts.

Jones, Jason B.↗
NASA NTRS2011

Crowdsourcing for Challenging Technical Problems - It Works!

The NASA Johnson Space Center Space Life Sciences Directorate (SLSD) and Wyle Integrated Science and Engineering (Wyle) will conduct a one-day business cluster at the 62nd IAC so that IAC attendees will understand the benefits of open innovation (crowdsourcing), review successful results of conducting technical challenges in various open innovation projects, and learn how an organization can effectively deploy these new problem solving tools to innovate more efficiently and effectively. Results from both the SLSD open innovation pilot program and the open innovation workshop conducted by the NASA Human Health and Performance Center will be discussed. NHHPC members will be recruited to participate in the business cluster (see membership http://nhhpc.nasa.gov) and as IAF members. Crowdsourcing may be defined as the act of outsourcing tasks that are traditionally performed by an employee or contractor to an undefined, generally large group of people or community (a crowd) in the form of an open call. The open call may be issued by the organization wishing to find a solution to a particular problem or complete a task, or by an open innovation service provider on behalf of that organization. In 2008, the SLSD, with the support of Wyle, established and implemented pilot projects in open innovation (crowdsourcing) to determine if these new internet-based platforms could indeed find solutions to difficult technical challenges. These unsolved technical problems were converted to problem statements, called Challenges by some open innovation service providers, and were then posted externally to seek solutions to these problems. In addition, an open call was issued internally to NASA employees Agency wide (11 Field Centers and NASA HQ) using an open innovation service provider crowdsourcing platform to post NASA challenges from each Center for the others to propose solutions). From 2008 to 2010, the SLSD issued 34 challenges, 14 externally and 20 internally. The 14 external problems or challenges were posted through three different vendors: InnoCentive, yet2.com and TopCoder. The 20 internal challenges were conducted using the InnoCentive crowdsourcing platform designed for use internal to an organization and customized for NASA use, and promoted as NASA@Work. The results were significant. Of the seven InnoCentive external challenges, two full and five partial awards were made in complex technical areas such as predicting solar flares and long-duration food packaging.

Davis, Jeffrey R.↗
NASA NTRS1995

NASA Tech Briefs, November 1995

The contents include: 1) Mission Accomplished; 2) Resource Report: Marshall Space Flight Center; 3) NASA 1995 Software of the Year Award; 4) Microbolometers Based on Epitaxial YBa2Cu3O(sub 7-x) Thin Films; 5) Garnet Random-Access Memory; 6) Fabrication of SNS Weak Links on SOS Substrates; 7) High-Voltage MOSFET Switching Circuit; 8) Asymmetric Switching for a PWM H-Bridge Power Circuit; 9) Better Ohmic Contacts for InP Semiconductor Devices; 10) Low-Bandgap Thermovoltaic Materials and Devices; 11) Digital Frequency-Differencing Circuit; 12) Imaging Magnetometer; 13) Computer-Assisted Monitoring of a Complex System; 14) Buffered Telemetry Demodulator; 15) Compact Multifunction Inspection Head; 16) Optical Detection of Fractures in Ceramic Diaphragms; 17) Eddy-Current Detection of Cracks in Reinforced Carbon/Carbon; 18) Apparent Thermal Conductivity of Multilayer Insulation; 19) Optimizing Misch-Metal Compositions in Metal Hydride Anodes; 20) Device for Sampling Surface Contamination; 21) Probabilistic Failure Assessment for Fatigue; 22) Probabilistic Fatigue and Flaw-Propagation Analysis; 23) Windows Program for Driving the TDU-850 Printer; 24) Subband/Transform MATLAB Functions for Processing Images; 25) Computing Equilibrium Chemical Compositions; 26) Program Processes Thermocouple Readings; 27) ICAN-Second-Generation Integrated Composite Analyzer; 28) Integrated Composite Analyzer with Damping Capabilities; 29) Computing Efficiency of Transfer of Microwave Power; 30) Program Calculates Power Demands of Electronic Designs; 31) Cost-Estimation Program; 32) Program Estimates Areas Required by Electronic Designs; 33) Program to Balance Mapped Turbopump Assemblies; 34) BiblioTech; 35) Controlling Mirror Tilt With a Bimorph Actuator; 36) Burst-Disk Device Simulates Effect of Pyrotechnic Device; 37) Bearing-Mounting Concept Accommodates Thermal Expansion; 38) Parallel-Plate Acoustic Absorbers for Hot Environments; 39) Adjustable-Length Strut Withstands Large Cyclic Loads; 40) Tool Indicates Contact Angles in Bearing Raceways; 41) Gravity Slides With Magnetic Braking; 42) High-Torque, Lightweight, Pneumatically Driven Wrench for Small Spaces; 43) Device for Testing Compatibility of an O-Ring; 44) Magnetic Heat Pump Containing Flow Diverters; 45) Variable-Tilt Helicopter Rotor Mast; 46) "Beach-Ball" Robotic Rovers; 47) Apparatus Would Measure Temperatures of Ball Bearings; 48) Flexible Borescope for Inspecting Ducts; 49) Texturing Copper To Reduce Secondary Emission of Electrons; 50) Automated Laser Cutting in Three Dimensions; 51) Algorithm Helps Monitor Engine Operation; 52) Flexible Revision of Data-Processing Communications; 53) Software for Managing the Use of Land; 54) Thermal Strap Increases Cryocooling Efficiency; 55) Reversible Nut With Engagement Indication; 56) Control Algorithms for Kinematically Redundant Manipulators; 57) Computed Hydrogen-Flow Splits in a Rocket Engine; 58) Pressure and Thermal Modeling of Rocket Launches; 59) Field of View of a Spacecraft Antenna: Analysis and Software; 60) Digital Controller for Laser-Beam-Steering Subsystem; 61) More About Beam-Steering Subsystem for Laser Communication; 62) Digital Controller for Laser-Beam-Steering Subsystem: Part 2; 63) Interface Circuit Board for Space-Shuttle Communications; 64) Automated Planning of Spacecraft Telecommunications; 65) Artifacts of Spectral Analysis of Instrument Readings; 66) Neural-Network Controller for Vibration Suppression; 67) Adaptive Finite-Element Computation in Fracture Mechanics; 68) Attitude Control for the Cassini Spacecraft; 69) Analytical Model for Fluid Dynamics in a Microgravity Environment; 70) Study of Rocket-Engine Joints Bonded by NVCU/NARloy-Z; 71) Improved Silicon Nitride for Advanced Heat Engines; 72) Parameters for Welding Aluminum/Lithium Alloys; 73) Lightweight Composite Intertank Structure; 74) Foil Patches Seal Small Vacuum Leaks; 75) Data Base on Cables and Connectors; 76) Effect of Clock Mode on Radiation Hardnessf an ADC; and 77) Fault-Tolerant Control for a Robotic Inspection System.

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NASA NTRS2011

NASA Mission Operations Directorate Preparations for the COTS Visiting Vehicles

With the retirement of the Space Shuttle looming, a series of new spacecraft is under development to assist in providing for the growing logistical needs of the International Space Station (ISS). Two of these vehicles are being built under a NASA initiative known as the Commercial Orbital Transportation Services (COTS) program. These visiting vehicles ; Space X s Dragon and Orbital Science Corporation s Cygnus , are to be domestically produced in the United States and designed to add to the capabilities of the Russian Progress and Soyuz workhorses, the European Automated Transfer Vehicle (ATV) and the Japanese H-2 Transfer Vehicle (HTV). Most of what is known about the COTS program has focused on the work of Orbital and SpaceX in designing, building, and testing their respective launch and cargo vehicles. However, there is also a team within the Mission Operations Directorate (MOD) at NASA s Johnson Space Center working with their operational counterparts in these companies to provide operational safety oversight and mission assurance via the development of operational scenarios and products needed for these missions. Ensuring that the operational aspect is addressed for the initial demonstration flights of these vehicles is the topic of this paper. Integrating Dragon and Cygnus into the ISS operational environment has posed a unique challenge to NASA and their partner companies. This is due in part to the short time span of the COTS program, as measured from initial contract award until first launch, as well as other factors that will be explored in the text. Operational scenarios and products developed for each COTS vehicle will be discussed based on the following categories: timelines, on-orbit checkout, ground documentation, crew procedures, software updates and training materials. Also addressed is an outline of the commonalities associated with the operations for each vehicle. It is the intent of the authors to provide their audience with a better understanding of the mission assurance that MOD brings to commercial ventures to the ISS

Shull, Sarah A.↗
NASA NTRS2010

STEM Education Efforts in the Ares Projects

According to the National Science Foundation, of the more than 4 million first university degrees awarded in science and engineering in 2006, students in China earned about 21%, those in the European Union earned about 19%, and those in the United States earned about 11%. Statistics like these are of great interest to NASA's Ares Projects, which are responsible for building the rockets for the U.S. Constellation Program to send humans beyond low-Earth orbit. Science, technology, engineering, and mathematics students are essential for the long-term sustainability of any space program. Since the Projects creation, the Ares Outreach Team has used a variety of STEM-related media, methods, and materials to engage students, educators, and the general public in Constellation's mission. Like Project Apollo, the nation s exploration destinations and the vehicles used to get there can inspire students to learn more about STEM. Ares has been particularly active in public outreach to schools in Northern Alabama; on the Internet via outreach and grade-specific educational materials; and in more informal social media settings such as YouTube and Facebook. These combined efforts remain integral to America s space program, regardless of its future direction.

Doreswamy, Rajiv↗
NASA NTRS2011

Crowd Sourcing for Challenging Technical Problems and Business Model

Crowd sourcing may be defined as the act of outsourcing tasks that are traditionally performed by an employee or contractor to an undefined, generally large group of people or community (a crowd) in the form of an open call. The open call may be issued by an organization wishing to find a solution to a particular problem or complete a task, or by an open innovation service provider on behalf of that organization. In 2008, the Space Life Sciences Directorate (SLSD), with the support of Wyle Integrated Science and Engineering, established and implemented pilot projects in open innovation (crowd sourcing) to determine if these new internet-based platforms could indeed find solutions to difficult technical challenges. These unsolved technical problems were converted to problem statements, also called "Challenges" or "Technical Needs" by the various open innovation service providers, and were then posted externally to seek solutions. In addition, an open call was issued internally to NASA employees Agency wide (10 Field Centers and NASA HQ) using an open innovation service provider crowd sourcing platform to post NASA challenges from each Center for the others to propose solutions). From 2008 to 2010, the SLSD issued 34 challenges, 14 externally and 20 internally. The 14 external problems or challenges were posted through three different vendors: InnoCentive, Yet2.com and TopCoder. The 20 internal challenges were conducted using the InnoCentive crowd sourcing platform designed for internal use by an organization. This platform was customized for NASA use and promoted as NASA@Work. The results were significant. Of the seven InnoCentive external challenges, two full and five partial awards were made in complex technical areas such as predicting solar flares and long-duration food packaging. Similarly, the TopCoder challenge yielded an optimization algorithm for designing a lunar medical kit. The Yet2.com challenges yielded many new industry and academic contacts in bone imaging, microbial detection and even the use of pharmaceuticals for radiation protection. The internal challenges through NASA@Work drew over 6000 participants across all NASA centers. Challenges conducted by each NASA center elicited ideas and solutions from several other NASA centers and demonstrated rapid and efficient participation from employees at multiple centers to contribute to problem solving. Finally, on January 19, 2011, the SLSD conducted a workshop on open collaboration and innovation strategies and best practices through the newly established NASA Human Health and Performance Center (NHHPC). Initial projects will be described leading to a new business model for SLSD.

Davis, Jeffrey R.↗
NASA NTRS2009

Latency and User Performance in Virtual Environments and Augmented Reality

System rendering latency has been recognized by senior researchers, such as Professor Fredrick Brooks of UNC (Turing Award 1999), as a major factor limiting the realism and utility of head-referenced displays systems. Latency has been shown to reduce the user's sense of immersion within a virtual environment, disturb user interaction with virtual objects, and to contribute to motion sickness during some simulation tasks. Latency, however, is not just an issue for external display systems since finite nerve conduction rates and variation in transduction times in the human body's sensors also pose problems for latency management within the nervous system. Some of the phenomena arising from the brain's handling of sensory asynchrony due to latency will be discussed as a prelude to consideration of the effects of latency in interactive displays. The causes and consequences of the erroneous movement that appears in displays due to latency will be illustrated with examples of the user performance impact provided by several experiments. These experiments will review the generality of user sensitivity to latency when users judge either object or environment stability. Hardware and signal processing countermeasures will also be discussed. In particular the tuning of a simple extrapolative predictive filter not using a dynamic movement model will be presented. Results show that it is possible to adjust this filter so that the appearance of some latencies may be hidden without the introduction of perceptual artifacts such as overshoot. Several examples of the effects of user performance will be illustrated by three-dimensional tracking and tracing tasks executed in virtual environments. These experiments demonstrate classic phenomena known from work on manual control and show the need for very responsive systems if they are indented to support precise manipulation. The practical benefits of removing interfering latencies from interactive systems will be emphasized with some classic final examples from surgical telerobotics, and human-computer interaction.

Ellis, Stephen R.↗