Sample records for accent propulsion lander

  1. Lander Propulsion Overview and Technology Requirements Discussion

    NASA Technical Reports Server (NTRS)

    Brown, Thomas M.

    2007-01-01

    This viewgraph presentation reviews the lunar lander propulsion requirements. It includes discussion on: Lander Project Overview, Project Evolution/Design Cycles, Lunar Architecture & Lander Reference Missions, Lander Concept Configurations, Descent and Ascent propulsion reviews, and a review of the technology requirements.

  2. Propulsion and Cryogenics Advanced Development (PCAD) Project Propulsion Technologies for the Lunar Lander

    NASA Technical Reports Server (NTRS)

    Klem, Mark D.; Smith, Timothy D.

    2008-01-01

    The Propulsion and Cryogenics Advanced Development (PCAD) Project in the Exploration Technology Development Program is developing technologies as risk mitigation for Orion and the Lunar Lander. An integrated main and reaction control propulsion system has been identified as a candidate for the Lunar Lander Ascent Module. The propellants used in this integrated system are Liquid Oxygen (LOX)/Liquid Methane (LCH4) propellants. A deep throttle pump fed Liquid Oxygen (LOX)/Liquid Hydrogen (LH2) engine system has been identified for the Lunar Lander Descent Vehicle. The propellant combination and architecture of these propulsion systems are novel and would require risk reduction prior to detailed design and development. The PCAD Project addresses the technology requirements to obtain relevant and necessary test data to further the technology maturity of propulsion hardware utilizing these propellants. This plan and achievements to date will be presented.

  3. NASA Propulsion Concept Studies and Risk Reduction Activities for Resource Prospector Lander

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.; Williams, Hunter; Burnside, Chris

    2015-01-01

    The Resource Prospector mission is to investigate the Moon's polar regions in search of volatiles. The government-version lander concept for the mission is composed of a braking stage and a liquid-propulsion lander stage. A propulsion trade study concluded with a solid rocket motor for the braking stage while using the 4th-stage Peacekeeper (PK) propulsion components for the lander stage. The mechanical design of the liquid propulsion system was conducted in concert with the lander structure design. A propulsion cold-flow test article was fabricated and integrated into a lander development structure, and a series of cold flow tests were conducted to characterize the fluid transient behavior and to collect data for validating analytical models. In parallel, RS-34 PK thrusters to be used on the lander stage were hot-fire tested in vacuum conditions as part of risk reduction activities.

  4. NASA Propulsion Sub-System Concept Studies and Risk Reduction Activities for Resource Prospector Lander

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.

    2015-01-01

    NASA's exploration roadmap is focused on developing technologies and performing precursor missions to advance the state of the art for eventual human missions to Mars. One of the key components of this roadmap is various robotic missions to Near-Earth Objects, the Moon, and Mars to fill in some of the strategic knowledge gaps. The Resource Prospector (RP) project is one of these robotic precursor activities in the roadmap. RP is a multi-center and multi-institution project to investigate the polar regions of the Moon in search of volatiles. The mission is rated Class D and is approximately 10 days, assuming a five day direct Earth to Moon transfer. Because of the mission cost constraint, a trade study of the propulsion concepts was conducted with a focus on available low-cost hardware for reducing cost in development, while technical risk, system mass, and technology advancement requirements were also taken into consideration. The propulsion system for the lander is composed of a braking stage providing a high thrust to match the lander's velocity with the lunar surface and a lander stage performing the final lunar descent. For the braking stage, liquid oxygen (LOX) and liquid methane (LCH4) propulsion systems, derived from the Morpheus experimental lander, and storable bi-propellant systems, including the 4th stage Peacekeeper (PK) propulsion components and Space Shuttle orbital maneuvering engine (OME), and a solid motor were considered for the study. For the lander stage, the trade study included miniaturized Divert Attitude Control System (DACS) thrusters (Missile Defense Agency (MDA) heritage), their enhanced thruster versions, ISE-100 and ISE-5, and commercial-off-the-shelf (COTS) hardware. The lowest cost configuration of using the solid motor and the PK components while meeting the requirements was selected. The reference concept of the lander is shown in Figure 1. In the current reference configuration, the solid stage is the primary provider of delta

  5. Lunar lander and return propulsion system trade study

    NASA Technical Reports Server (NTRS)

    Hurlbert, Eric A.; Moreland, Robert; Sanders, Gerald B.; Robertson, Edward A.; Amidei, David; Mulholland, John

    1993-01-01

    This trade study was initiated at NASA/JSC in May 1992 to develop and evaluate main propulsion system alternatives to the reference First Lunar Outpost (FLO) lander and return-stage transportation system concept. Thirteen alternative configurations were developed to explore the impacts of various combinations of return stage propellants, using either pressure or pump-fed propulsion systems and various staging options. Besides two-stage vehicle concepts, the merits of single-stage and stage-and-a-half options were also assessed in combination with high-performance liquid oxygen and liquid hydrogen propellants. Configurations using an integrated modular cryogenic engine were developed to assess potential improvements in packaging efficiency, mass performance, and system reliability compared to non-modular cryogenic designs. The selection process to evaluate the various designs was the analytic hierarchy process. The trade study showed that a pressure-fed MMH/N2O4 return stage and RL10-based lander stage is the best option for a 1999 launch. While results of this study are tailored to FLO needs, the design date, criteria, and selection methodology are applicable to the design of other crewed lunar landing and return vehicles.

  6. Telerobotics control of ExoGeoLab lander instruments

    NASA Astrophysics Data System (ADS)

    Lillo, A.; Foing, B. H.

    2017-09-01

    This document is about the improvement of the autonomy and capabilities of the prototype lander ExoGeoLab, designed to host remote controlled instruments for analogue Moon/Mars manned missions. Accent is put on new exploration capabilities for the lander to reduce the need for EVA.

  7. Propulsive Maneuver Design for the 2007 Mars Phoenix Lander Mission

    NASA Technical Reports Server (NTRS)

    Raofi, Behzad; Bhat, Ramachandra S.; Helfrich, Cliff

    2008-01-01

    On May 25, 2008, the Mars Phoenix Lander (PHX) successfully landed in the northern planes of Mars in order to continue and complement NASA's "follow the water" theme as its predecessor Mars missions, such as Mars Odyssey (ODY) and Mars Exploration Rovers, have done in recent years. Instruments on the lander, through a robotic arm able to deliver soil samples to the deck, will perform in-situ and remote-sensing investigations to characterize the chemistry of materials at the local surface, subsurface, and atmosphere. Lander instruments will also identify the potential history of key indicator elements of significance to the biological potential of Mars, including potential organics within any accessible water ice. Precise trajectory control and targeting were necessary in order to achieve the accurate atmospheric entry conditions required for arriving at the desired landing site. The challenge for the trajectory control maneuver design was to meet or exceed these requirements in the presence of spacecraft limitations as well as other mission constraints. This paper describes the strategies used, including the specialized targeting specifically developed for PHX, in order to design and successfully execute the propulsive maneuvers that delivered the spacecraft to its targeted landing site while satisfying the planetary protection requirements in the presence of flight system constraints.

  8. Mars lander survey

    NASA Technical Reports Server (NTRS)

    Stump, William R.; Babb, Gus R.; Davis, Hubert P.

    1986-01-01

    The requirements, issues, and design options are reviewed for manned Mars landers. Issues such as high 1/d versus low 1/d shape, parking orbit, and use of a small Mars orbit transfer vehicle to move the lander from orbit to orbit are addressed. Plots of lander mass as a function of Isp, destination orbit, and cargo up and down, plots of initial stack mass in low Earth orbit as a function of lander mass and parking orbit, detailed weight statements, and delta V tables for a variety of options are included. Lander options include a range from minimum landers up to a single stage reusable design. Mission options include conjunction and Venus flyby trajectories using all-cryogenic, hybrid, NERVA, and Mars orbit aerobraking propulsion concepts.

  9. NASA Propulsion Concept Studies and Risk Reduction Activities for Resource Prospector Lander

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.; Williams, Hunter; Burnside, Chris

    2015-01-01

    The trade study has led to the selection of propulsion concept with the lowest cost and net lowest risk -Government-owned, flight qualified components -Meet mission requirements although the configuration is not optimized. Risk reduction activities have provided an opportunity -Implement design improvements while development with the early-test approach. -Gain knowledge on the operation and identify operation limit -Data to anchor analytical models for future flight designs; The propulsion system cold flow tests series have provided valuable data for future design. -The pressure surge from the system priming and waterhammer within component operation limits. -Enable to optimize the ullage volume to reduce the propellant tank mass; RS-34 hot fire tests have successfully demonstrated of using the engines for the RP mission -No degradation of performance due to extended storage life of the hardware. -Enable to operate the engine for RP flight mission scenarios, outside of the qualification regime. -Provide extended data for the thermal and GNC designs. Significant progress has been made on NASA propulsion concept design and risk reductions for Resource Prospector lander.

  10. Solar Electric and Chemical Propulsion Technology Applications to a Titan Orbiter/Lander Mission

    NASA Technical Reports Server (NTRS)

    Cupples, Michael

    2007-01-01

    Several advanced propulsion technology options were assessed for a conceptual Titan Orbiter/Lander mission. For convenience of presentation, the mission was broken into two phases: interplanetary and Titan capture. The interplanetary phase of the mission was evaluated for an advanced Solar Electric Propulsion System (SEPS), while the Titan capture phase was evaluated for state-of-art chemical propulsion (NTO/Hydrazine), three advanced chemical propulsion options (LOX/Hydrazine, Fluorine/Hydrazine, high Isp mono-propellant), and advanced tank technologies. Hence, this study was referred to as a SEPS/Chemical based option. The SEPS/Chemical study results were briefly compared to a 2002 NASA study that included two general propulsion options for the same conceptual mission: an all propulsive based mission and a SEPS/Aerocapture based mission. The SEP/Chemical study assumed identical science payload as the 2002 NASA study science payload. The SEPS/Chemical study results indicated that the Titan mission was feasible for a medium launch vehicle, an interplanetary transfer time of approximately 8 years, an advanced SEPS (30 kW), and current chemical engine technology (yet with advanced tanks) for the Titan capture. The 2002 NASA study showed the feasibility of the mission based on a somewhat smaller medium launch vehicle, an interplanetary transfer time of approximately 5.9 years, an advanced SEPS (24 kW), and advanced Aerocapture based propulsion technology for the Titan capture. Further comparisons and study results were presented for the advanced chemical and advanced tank technologies.

  11. An Overview of Propulsion Concept Studies and Risk Reduction Activities for Robotic Lunar Landers

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P.; Story, George; Burnside, Chris; Kudlach, Al

    2010-01-01

    In support of designing robotic lunar lander concepts, the propulsion team at NASA Marshall Space Flight Center (MSFC) and the Johns Hopkins University Applied Physics Laboratory (APL), with participation from industry, conducted a series of trade studies on propulsion concepts with an emphasis on light-weight, advanced technology components. The results suggest a high-pressure propulsion system may offer some benefits in weight savings and system packaging. As part of the propulsion system, a solid rocket motor was selected to provide a large impulse to reduce the spacecraft s velocity prior to the lunar descent. In parallel to this study effort, the team also began technology risk reduction testing on a high thrust-to-weight descent thruster and a high-pressure regulator. A series of hot-fire tests was completed on the descent thruster in vacuum conditions at NASA White Sands Test Facility (WSTF) in New Mexico in 2009. Preparations for a hot-fire test series on the attitude control thruster at WSTF and for pressure regulator testing are now underway. This paper will provide an overview of the concept trade study results along with insight into the risk mitigation activities conducted to date.

  12. Development and Integration of the Janus Robotic Lander: A Liquid Oxygen-Liquid Methane Propulsion System Testbed

    NASA Astrophysics Data System (ADS)

    Ponce, Raul

    Initiatives have emerged with the goal of sending humans to other places in our solar system. New technologies are being developed that will allow for more efficient space systems to transport future astronauts. One of those technologies is the implementation of propulsion systems that use liquid oxygen and liquid methane (LO2-LCH4) as propellants. The benefits of a LO2-LCH4 propulsion system are plenty. One of the main advantages is the possibility of manufacturing the propellants at the destination body. A space vehicle which relies solely on liquid oxygen and liquid methane for its main propulsion and reaction control engines is necessary to exploit this advantage. At the University of Texas at El Paso (UTEP) MIRO Center for Space Exploration Technology Research (cSETR) such a vehicle is being developed. Janus is a robotic lander vehicle with the capability of vertical take-off and landing (VTOL) which integrates several LO2-LCH 4 systems that are being devised in-house. The vehicle will serve as a testbed for the parallel operation of these propulsion systems while being fed from common propellant tanks. The following work describes the efforts done at the cSETR to develop the first prototype of the vehicle as well as the plan to move forward in the design of the subsequent prototypes that will lead to a flight vehicle. In order to ensure an eventual smooth integration of the different subsystems that will form part of Janus, requirements were defined for each individual subsystem as well as the vehicle as a whole. Preliminary testing procedures and layouts have also been developed and will be discussed to detail in this text. Furthermore, the current endeavors in the design of each subsystem and the way that they interact with one another within the lander will be explained.

  13. Extended duration lunar lander

    NASA Technical Reports Server (NTRS)

    Babic, Nikola; Carter, Matt; Cosper, Donna; Garza, David; Gonzalez, Eloy; Goodine, David; Hirst, Edward; Li, Ray; Lindsey, Martin; Ng, Tony

    1993-01-01

    Selenium Technologies has been conducting preliminary design work on a manned lunar lander for use in NASA's First Lunar Outpost (FLO) program. The resulting lander is designed to carry a crew of four astronauts to a prepositioned habitat on the lunar surface, remain on the lunar surface for up to 45 days while the crew is living in the habitat, then return the crew to earth via direct reentry and land recovery. Should the need arise, the crew can manually guide the lander to a safe lunar landing site, and live in the lander for up to ten days on the surface. Also, an abort to earth is available during any segment of the mission. The main propulsion system consists of a cluster of four modified Pratt and Whitney RL10 rocket engines that use liquid methane (LCH4) and liquid oxygen (LOX). Four engines are used to provide redundancy and a satisfactory engine out capability. Differences between the new propulsion system and the original system include slightly smaller engine size and lower thrust per engine, although specific impulse remains the same despite the smaller size. Concerns over nozzle ground clearance and engine reliability, as well as more information from Pratt and Whitney, brought about this change. The power system consists of a combination of regenerative fuel cells and solar arrays. While the lander is in flight to or from the moon, or during the lunar night, fuel cells provide all electrical power. During the lunar day, solar arrays are deployed to provide electrical power for the lander as well as electrolyzers, which separate some water back into hydrogen and oxygen for later use by the fuel cells. Total storage requirements for oxygen, hydrogen, and water are 61 kg, 551 kg, and 360 kg, respectively. The lander is a stage-and-a-half design with descent propellant, cargo, and landing gear contained in the descent stage, and the main propulsion system, ascent propellant, and crew module contained in the ascent stage. The primary structure for both

  14. Waterhammer Transient Simulation and Model Anchoring for the Robotic Lunar Lander Propulsion System

    NASA Technical Reports Server (NTRS)

    Stein, William B.; Trinh, Huu P.; Reynolds, Michael E.; Sharp, David J.

    2011-01-01

    Waterhammer transients have the potential to adversely impact propulsion system design if not properly addressed. Waterhammer can potentially lead to system plumbing, and component damage. Multi-thruster propulsion systems also develop constructive/destructive wave interference which becomes difficult to predict without detailed models. Therefore, it is important to sufficiently characterize propulsion system waterhammer in order to develop a robust design with minimal impact to other systems. A risk reduction activity was performed at Marshall Space Flight Center to develop a tool for estimating waterhammer through the use of anchored simulation for the Robotic Lunar Lander (RLL) propulsion system design. Testing was performed to simulate waterhammer surges due to rapid valve closure and consisted of twenty-two series of waterhammer tests, resulting in more than 300 valve actuations. These tests were performed using different valve actuation schemes and three system pressures. Data from the valve characterization tests were used to anchor the models that employed MSCSoftware.EASY5 v.2010 to model transient fluid phenomena by using transient forms of mass and energy conservation. The anchoring process was performed by comparing initial model results to experimental data and then iterating the model input to match the simulation results with the experimental data. The models provide good correlation with experimental results, supporting the use of EASY5 as a tool to model fluid transients and provide a baseline for future RLL system modeling. This paper addresses tasks performed during the waterhammer risk reduction activity for the RLL propulsion system. The problem of waterhammer simulation anchoring as applied to the RLL system is discussed with results from the corresponding experimental valve tests. Important factors for waterhammer mitigation are discussed along with potential design impacts to the RLL propulsion system.

  15. COMPASS Final Report: Low Cost Robotic Lunar Lander

    NASA Technical Reports Server (NTRS)

    McGuire, Melissa L.; Oleson, Steven R.

    2010-01-01

    The COllaborative Modeling for the Parametric Assessment of Space Systems (COMPASS) team designed a robotic lunar Lander to deliver an unspecified payload (greater than zero) to the lunar surface for the lowest cost in this 2006 design study. The purpose of the low cost lunar lander design was to investigate how much payload can an inexpensive chemical or Electric Propulsion (EP) system deliver to the Moon s surface. The spacecraft designed as the baseline out of this study was a solar powered robotic lander, launched on a Minotaur V launch vehicle on a direct injection trajectory to the lunar surface. A Star 27 solid rocket motor does lunar capture and performs 88 percent of the descent burn. The Robotic Lunar Lander soft-lands using a hydrazine propulsion system to perform the last 10% of the landing maneuver, leaving the descent at a near zero, but not exactly zero, terminal velocity. This low-cost robotic lander delivers 10 kg of science payload instruments to the lunar surface.

  16. Lander Technologies

    NASA Technical Reports Server (NTRS)

    Chavers, Greg

    2015-01-01

    Since 2006 NASA has been formulating robotic missions to the lunar surface through programs and projects like the Robotic Lunar Exploration Program, Lunar Precursor Robotic Program, and International Lunar Network. All of these were led by NASA Marshall Space Flight Center (MSFC). Due to funding shortfalls, the lunar missions associated with these efforts, the designs, were not completed. From 2010 to 2013, the Robotic Lunar Lander Development Activity was funded by the Science Mission Directorate (SMD) to develop technologies that would enable and enhance robotic lunar surface missions at lower costs. In 2013, a requirements-driven, low-cost robotic lunar lander concept was developed for the Resource Prospector Mission. Beginning in 2014, The Advanced Exploration Systems funded the lander team and established the MSFC, Johnson Space Center, Applied Physics Laboratory, and the Jet Propulsion Laboratory team with MSFC leading the project. The lander concept to place a 300-kg rover on the lunar surface has been described in the New Technology Report Case Number MFS-33238-1. A low-cost lander concept for placing a robotic payload on the lunar surface is shown in figures 1 and 2. The NASA lander team has developed several lander concepts using common hardware and software to allow the lander to be configured for a specific mission need. In addition, the team began to transition lander expertise to United States (U.S.) industry to encourage the commercialization of space, specifically the lunar surface. The Lunar Cargo Transportation and Landing by Soft Touchdown (CATALYST) initiative was started and the NASA lander team listed above is partnering with three competitively selected U.S. companies (Astrobotic, Masten Space Systems, and Moon Express) to develop, test, and operate their lunar landers.

  17. Robotic Lunar Lander Development Project Status

    NASA Technical Reports Server (NTRS)

    Hammond, Monica; Bassler, Julie; Morse, Brian

    2010-01-01

    This slide presentation reviews the status of the development of a robotic lunar lander. The goal of the project is to perform engineering tests and risk reduction activities to support the development of a small lunar lander for lunar surface science. This includes: (1) risk reduction for the flight of the robotic lander, (i.e., testing and analyzing various phase of the project); (2) the incremental development for the design of the robotic lander, which is to demonstrate autonomous, controlled descent and landing on airless bodies, and design of thruster configuration for 1/6th of the gravity of earth; (3) cold gas test article in flight demonstration testing; (4) warm gas testing of the robotic lander design; (5) develop and test landing algorithms; (6) validate the algorithms through analysis and test; and (7) tests of the flight propulsion system.

  18. Accent Attribution in Speakers with Foreign Accent Syndrome

    ERIC Educational Resources Information Center

    Verhoeven, Jo; De Pauw, Guy; Pettinato, Michele; Hirson, Allen; Van Borsel, John; Marien, Peter

    2013-01-01

    Purpose: The main aim of this experiment was to investigate the perception of Foreign Accent Syndrome in comparison to speakers with an authentic foreign accent. Method: Three groups of listeners attributed accents to conversational speech samples of 5 FAS speakers which were embedded amongst those of 5 speakers with a real foreign accent and 5…

  19. Robotic Lunar Landers for Science and Exploration

    NASA Technical Reports Server (NTRS)

    Chavers, D. G.; Cohen, B. A.; Bassler, J. A.; Hammond, M. S.; Harris, D. W.; Hill, L. A.; Eng, D.; Ballard, B. W.; Kubota, S. D.; Morse, B. J.; hide

    2010-01-01

    NASA Marshall Space Flight Center (MSFC) and The Johns Hopkins University Applied Physics Laboratory (APL) have been conducting mission studies and performing risk reduction activities for NASA s robotic lunar lander flight projects. This paper describes some of the lunar lander concepts derived from these studies conducted by the MSFC/APL Robotic Lunar Lander Development Project team. In addition, the results to date of the lunar lander development risk reduction efforts including high pressure propulsion system testing, structure and mechanism development and testing, long cycle time battery testing and combined GN&C and avionics testing will be addressed. The most visible elements of the risk reduction program are two autonomous lander flight test vehicles: a compressed air system with limited flight durations and a second version using hydrogen peroxide propellant to achieve significantly longer flight times and the ability to more fully exercise flight sensors and algorithms.

  20. Explosive propulsion applications. [to future unmanned missions

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.; Varsi, G.; Back, L. H.

    1974-01-01

    The feasibility and application of an explosive propulsion concept capable of supporting future unmanned missions in the post-1980 era were examined and recommendations made for advanced technology development tasks. The Venus large lander mission was selected as the first in which the explosive propulsion concept can find application. A conceptual design was generated and its performance, weight, costs, and interaction effects determined. Comparisons were made with conventional propulsion alternatives. The feasibility of the explosive propulsion system was verified for planetology experiments within the dense atmosphere of Venus as well as the outer planets. Additionally, it was determined that the Venus large lander mission could be augmented ballistically with a significant delivery margin.

  1. Mission Plan for the Mars Surveyor 2001 Orbiter and Lander

    NASA Technical Reports Server (NTRS)

    Plaut, J. J.; Spencer, D. A.

    1999-01-01

    The Mars Surveyor 2001 Project consists of two missions to Mars, an Orbiter and a Lander, both to be launched in the spring of 2001 for October 2001 (Orbiter) and January 2002 (Lander) arrival at Mars. The Orbiter will support the Lander mission primarily as a communications relay system; the Lander will not have direct-to-Earth communications capability. Science data collected from the Orbiter will also be used to aid in the geologic interpretation of the landing site, along with data from past missions. Combining the Orbiter and Lander missions into a single Project has enabled the streamlining of many activities and an efficient use of personnel and other resources at the Jet Propulsion Laboratory and at the spacecraft contractor, Lockheed Martin Astronautics.

  2. Robotic Lunar Landers For Science And Exploration

    NASA Technical Reports Server (NTRS)

    Cohen, B. A.; Bassler, J. A.; Morse, B. J.; Reed, C. L. B.

    2010-01-01

    NASA Marshall Space Flight Center and The Johns Hopkins University Applied Physics Laboratory have been conducting mission studies and performing risk reduction activities for NASA s robotic lunar lander flight projects. In 2005, the Robotic Lunar Exploration Program Mission #2 (RLEP-2) was selected as an ESMD precursor robotic lander mission to demonstrate precision landing and determine if there was water ice at the lunar poles; however, this project was canceled. Since 2008, the team has been supporting SMD designing small lunar robotic landers for science missions, primarily to establish anchor nodes of the International Lunar Network (ILN), a network of lunar geophysical nodes. Additional mission studies have been conducted to support other objectives of the lunar science community. This paper describes the current status of the MSFC/APL robotic lunar mission studies and risk reduction efforts including high pressure propulsion system testing, structure and mechanism development and testing, long cycle time battery testing, combined GN&C and avionics testing, and two autonomous lander test articles.

  3. Mission and Design Sensitivities for Human Mars Landers Using Hypersonic Inflatable Aerodynamic Decelerators

    NASA Technical Reports Server (NTRS)

    Polsgrove, Tara P.; Thomas, Herbert D.; Collins, Tim; Dwyer Cianciolo, Alicia; Samareh, Jamshid

    2017-01-01

    Landing humans on Mars is one of NASA's long term goals. The Evolvable Mars Campaign (EMC) is focused on evaluating architectural trade options to define the capabilities and elements needed for a sustainable human presence on the surface of Mars. The EMC study teams have considered a variety of in-space propulsion options and surface mission options. As we seek to better understand how these choices affect the performance of the lander, this work informs and influences requirements for transportation systems to deliver the landers to Mars and enable these missions. This paper presents the effects of mission and vehicle design options on lander mass and performance. Beginning with Earth launch, options include fairing size assumptions, co-manifesting other elements with the lander, and Earth-Moon vicinity operations. Capturing into Mars orbit using either aerocapture or propulsive capture is assessed. For entry, descent, and landing both storable as well as oxygen and methane propellant combinations are considered, engine thrust level is assessed, and sensitivity to landed payload mass is presented. This paper focuses on lander designs using the Hypersonic Inflatable Aerodynamic Decelerators (HIAD), one of several entry system technologies currently considered for human missions.

  4. In-Situ Propellant Supplied Lunar Lander Concept

    NASA Astrophysics Data System (ADS)

    Donahue, Benjamin; Maulsby, Curtis

    2008-01-01

    Future NASA and commercial Lunar missions will require innovative spacecraft configurations incorporating reliable, sustainable propulsion, propellant storage, power and crew life support technologies that can evolve into long duration, partially autonomous systems that can be used to emplace and sustain the massive supplies required for a permanently occupied lunar base. Ambitious surface science missions will require efficient Lunar transfer systems to provide the consumables, science equipment, energy generation systems, habitation systems and crew provisions necessary for lengthy tours on the surface. Lunar lander descent and ascent stages become significantly more efficient when they can be refueled on the Lunar surface and operated numerous times. Landers enabled by Lunar In-Situ Propellant Production (ISPP) facilities will greatly ease constraints on spacecraft mass and payload delivery capability, and may operate much more affordably (in the long term) then landers that are dependant on Earth supplied propellants. In this paper, a Lander concept that leverages ISPP is described and its performance is quantified. Landers, operating as sortie vehicles from Low Lunar Orbit, with efficiencies facilitated by ISPP will enable economical utilization and enhancements that will provide increasingly valuable science yields from Lunar Bases.

  5. Historical perspective - Viking Mars Lander propulsion

    NASA Technical Reports Server (NTRS)

    Morrisey, Donald C.

    1989-01-01

    This paper discusses the Viking 1 and 2 missions to Mars in 1975-1976 and describes the design evolution of the Viking Terminal Descent Rocket Engines responsible for decelerating the Viking Mars Landers during the final portion of their descent from orbit. The Viking Terminal Descent Rocket Engines have twice the thrust of the largest monopropellant hydrazine engine developed previously but weigh considerably less. The engine has 18 nozzles, the capability of 10:1 throttling, is totally sealed until fired, employs no organic unsealed materials, is 100 percent germ free, utilized hydrazine STM-20 as the propellant, and starts at a temperature more than 45 F below the propellant's freezing point.

  6. Resource Prospector Propulsion System Cold Flow Testing

    NASA Technical Reports Server (NTRS)

    Williams, Hunter; Holt, Kim; Addona, Brad; Trinh, Huu

    2015-01-01

    Resource Prospector (RP) is a NASA mission being led by NASA Ames Research Center with current plans to deliver a scientific payload package aboard a rover to the lunar surface. As part of an early risk reduction activity, Marshall Space Flight Center (MSFC) and Johnson Space Flight Center (JSC) have jointly developed a government-version concept of a lunar lander for the mission. The spacecraft consists of two parts, the lander and the rover which carries the scientific instruments. The lander holds the rover during launch, cruise, and landing on the surface. Following terminal descent and landing the lander portion of the spacecraft become dormant after the rover embarks on the science mission. The lander will be equipped with a propulsion system for lunar descent and landing, as well as trajectory correction and attitude control maneuvers during transit to the moon. Hypergolic propellants monomethyl hydrazine and nitrogen tetroxide will be used to fuel sixteen 70-lbf descent thrusters and twelve 5-lbf attitude control thrusters. A total of four metal-diaphragm tanks, two per propellant, will be used along with a high-pressure composite-overwrapped pressure vessel for the helium pressurant gas. Many of the major propulsion system components are heritage missile hardware obtained by NASA from the Air Force. In parallel with the flight system design activities, a simulated propulsion system based on flight drawings was built for conducting a series of water flow tests to characterize the transient fluid flow of the propulsion system feed lines and to verify the critical operation modes such as system priming, waterhammer, and crucial mission duty cycles. The primary objective of the cold flow testing was to simulate the RP propulsion system fluid flow operation through water flow testing and to obtain data for anchoring analytical models. The models will be used to predict the transient and steady state flow behaviors in the actual flight operations. All design and

  7. Mission and Design Sensitivities for Human Mars Landers Using Hypersonic Inflatable Aerodynamic Decelerators

    NASA Technical Reports Server (NTRS)

    Polsgrove, Tara P.; Thomas, Herbert D.; Dwyer Ciancio, Alicia; Collins, Tim; Samareh, Jamshid

    2017-01-01

    Landing humans on Mars is one of NASA's long term goals. NASA's Evolvable Mars Campaign (EMC) is focused on evaluating architectural trade options to define the capabilities and elements needed to sustain human presence on the surface of Mars. The EMC study teams have considered a variety of in-space propulsion options and surface mission options. Understanding how these choices affect the performance of the lander will allow a balanced optimization of this complex system of systems problem. This paper presents the effects of mission and vehicle design options on lander mass and performance. Beginning with Earth launch, options include fairing size assumptions, co-manifesting elements with the lander, and Earth-Moon vicinity operations. Capturing into Mars orbit using either aerocapture or propulsive capture is assessed. For entry, descent, and landing both storable as well as oxygen and methane propellant combinations are considered, engine thrust level is assessed, and sensitivity to landed payload mass is presented. This paper focuses on lander designs using the Hypersonic Inflatable Aerodynamic Decelerators, one of several entry system technologies currently considered for human missions.

  8. Robotic Lunar Lander Development Status

    NASA Technical Reports Server (NTRS)

    Ballard, Benjamin; Cohen, Barbara A.; McGee, Timothy; Reed, Cheryl

    2012-01-01

    NASA Marshall Space Flight Center and John Hopkins University Applied Physics Laboratory have developed several mission concepts to place scientific and exploration payloads ranging from 10 kg to more than 200 kg on the surface of the moon. The mission concepts all use a small versatile lander that is capable of precision landing. The results to date of the lunar lander development risk reduction activities including high pressure propulsion system testing, structure and mechanism development and testing, and long cycle time battery testing will be addressed. The most visible elements of the risk reduction program are two fully autonomous lander flight test vehicles. The first utilized a high pressure cold gas system (Cold Gas Test Article) with limited flight durations while the subsequent test vehicle, known as the Warm Gas Test Article, utilizes hydrogen peroxide propellant resulting in significantly longer flight times and the ability to more fully exercise flight sensors and algorithms. The development of the Warm Gas Test Article is a system demonstration and was designed with similarity to an actual lunar lander including energy absorbing landing legs, pulsing thrusters, and flight-like software implementation. A set of outdoor flight tests to demonstrate the initial objectives of the WGTA program was completed in Nov. 2011, and will be discussed.

  9. Propulsion Technology Needs for Exploration

    NASA Technical Reports Server (NTRS)

    Brown, Thomas

    2007-01-01

    The objectives of currently planned exploration efforts, as well as those further in the future, require significant advancements in propulsion technologies. The current Lunar exploration architecture has set goals and mission objectives that necessitate the use of new systems and the extension of existing technologies beyond present applications. In the near term, the majority of these technologies are the result of a need to apply high performing cryogenic propulsion systems to long duration in-space applications. Advancement of cryogenic propulsion to these applications is crucial to provide higher performing propulsion systems that reduce the vehicle masses; enhance the safety of vehicle systems and ground operations; and provide a path for In-situ Resource Utilization (ISRU).Use of a LOX/LH2 main propulsion system for Lunar Lander Descent is a top priority because more conventional storable propellants are far from meeting the performance needs of the current architecture. While LOX/LH2 pump feed engines have been used in flight applications for many years, these engines have limited throttle capabilities. Engines that are capable of much greater throttling while still meeting high performance goals are a necessity to achieving exploration goals. Applications of LOX/CH4 propulsion to Lander ascent propulsion systems and reaction control systems are also if interest because of desirable performance and operations improvements over conventional storable systems while being more suitable for use of in-situ produced propellants. Within the current lunar architecture, use of cryogenic propulsion for the Earth Departure Stage and Lunar Lander elements also necessitate the need for advanced Cryogenic Fluid Management technologies. These technologies include long duration propellant storage/distribution, low-gravity propellant management, cryogenic couplings and disconnects, light weight composite tanks and support structure, and subsystem integration. In addition to

  10. The Penefit of Salience: Salient Accented, but Not Unaccented Words Reveal Accent Adaptation Effects.

    PubMed

    Grohe, Ann-Kathrin; Weber, Andrea

    2016-01-01

    In two eye-tracking experiments, the effects of salience in accent training and speech accentedness on spoken-word recognition were investigated. Salience was expected to increase a stimulus' prominence and therefore promote learning. A training-test paradigm was used on native German participants utilizing an artificial German accent. Salience was elicited by two different criteria: production and listening training as a subjective criterion and accented (Experiment 1) and canonical test words (Experiment 2) as an objective criterion. During training in Experiment 1, participants either read single German words out loud and deliberately devoiced initial voiced stop consonants (e.g., Balken-"beam" pronounced as (*) Palken), or they listened to pre-recorded words with the same accent. In a subsequent eye-tracking experiment, looks to auditorily presented target words with the accent were analyzed. Participants from both training conditions fixated accented target words more often than a control group without training. Training was identical in Experiment 2, but during test, canonical German words that overlapped in onset with the accented words from training were presented as target words (e.g., Palme-"palm tree" overlapped in onset with the training word (*) Palken) rather than accented words. This time, no training effect was observed; recognition of canonical word forms was not affected by having learned the accent. Therefore, accent learning was only visible when the accented test tokens in Experiment 1, which were not included in the test of Experiment 2, possessed sufficient salience based on the objective criterion "accent." These effects were not modified by the subjective criterion of salience from the training modality.

  11. Benefits of Nuclear Electric Propulsion for Outer Planet Exploration

    NASA Technical Reports Server (NTRS)

    Kos, Larry; Johnson, Les; Jones, Jonathan; Trausch, Ann; Eberle, Bill; Woodcock, Gordon; Brady, Hugh J. (Technical Monitor)

    2002-01-01

    Nuclear electric propulsion (NEP) offers significant benefits to missions for outer planet exploration. Reaching outer planet destinations, especially beyond Jupiter, is a struggle against time and distance. For relatively near missions, such as a Europa lander, conventional chemical propulsion and NEP offer similar performance and capabilities. For challenging missions such as a Pluto orbiter, neither chemical nor solar electric propulsion are capable while NEP offers acceptable performance. Three missions are compared in this paper: Europa lander, Pluto orbiter, and Titan sample return, illustrating how performance of conventional and advanced propulsion systems vary with increasing difficulty. The paper presents parametric trajectory performance data for NEP. Preliminary mass/performance estimates are provided for a Europa lander and a Titan sample return system, to derive net payloads for NEP. The NEP system delivers payloads and ascent/descent spacecraft to orbit around the target body, and for sample return, delivers the sample carrier system from Titan orbit to an Earth transfer trajectory. A representative scientific payload 500 kg was assumed, typical for a robotic mission. The resulting NEP systems are 100-kWe class, with specific impulse from 6000 to 9000 seconds.

  12. Low Cost Precision Lander for Lunar Exploration

    NASA Astrophysics Data System (ADS)

    Hoppa, G. V.; Head, J. N.; Gardner, T. G.; Seybold, K. G.

    2004-12-01

    For 60 years the US Defense Department has invested heavily in producing small, low mass, precision-guided vehicles. The technologies matured under these programs include terrain-aided navigation, closed loop terminal guidance algorithms, robust autopilots, high thrust-to-weight propulsion, autonomous mission management software, sensors, and data fusion. These technologies will aid NASA in addressing New Millennium Science and Technology goals as well as the requirements flowing from the Moon to Mars vision articulated in January 2004. Establishing and resupplying a long-term lunar presence will require automated landing precision not yet demonstrated. Precision landing will increase safety and assure mission success. In our lander design, science instruments amount to 10 kg, 16% of the lander vehicle mass. This compares favorably with 7% for Mars Pathfinder and less than 15% for Surveyor. The mission design relies on a cruise stage for navigation and TCMs for the lander's flight to the moon. The landing sequence begins with a solid motor burn to reduce the vehicle speed to 300-450 m/s. At this point the lander is about 2 minutes from touchdown and has 600 to 700 m/s delta-v capability. This allows for about 10 km of vehicle divert during terminal descent. This concept of operations closely mimics missile operational protocol used for decades: the vehicle remains inert, then must execute its mission flawlessly on a moment's notice. The vehicle design uses a propulsion system derived from heritage MDA programs. A redesigned truss provides hard points for landing gear, electronics, power supply, and science instruments. A radar altimeter and a Digital Scene Matching Area Correlator (DSMAC) provide data for the terminal guidance algorithms. This approach leverages the billions of dollars DoD has invested in these technologies, to land useful science payloads precisely on the lunar surface at relatively low cost.

  13. The Penefit of Salience: Salient Accented, but Not Unaccented Words Reveal Accent Adaptation Effects

    PubMed Central

    Grohe, Ann-Kathrin; Weber, Andrea

    2016-01-01

    In two eye-tracking experiments, the effects of salience in accent training and speech accentedness on spoken-word recognition were investigated. Salience was expected to increase a stimulus' prominence and therefore promote learning. A training-test paradigm was used on native German participants utilizing an artificial German accent. Salience was elicited by two different criteria: production and listening training as a subjective criterion and accented (Experiment 1) and canonical test words (Experiment 2) as an objective criterion. During training in Experiment 1, participants either read single German words out loud and deliberately devoiced initial voiced stop consonants (e.g., Balken—“beam” pronounced as *Palken), or they listened to pre-recorded words with the same accent. In a subsequent eye-tracking experiment, looks to auditorily presented target words with the accent were analyzed. Participants from both training conditions fixated accented target words more often than a control group without training. Training was identical in Experiment 2, but during test, canonical German words that overlapped in onset with the accented words from training were presented as target words (e.g., Palme—“palm tree” overlapped in onset with the training word *Palken) rather than accented words. This time, no training effect was observed; recognition of canonical word forms was not affected by having learned the accent. Therefore, accent learning was only visible when the accented test tokens in Experiment 1, which were not included in the test of Experiment 2, possessed sufficient salience based on the objective criterion “accent.” These effects were not modified by the subjective criterion of salience from the training modality. PMID:27375540

  14. NASA's Robotic Lunar Lander Development Program

    NASA Technical Reports Server (NTRS)

    Ballard, Benjamin W.; Reed, Cheryl L. B.; Artis, David; Cole, Tim; Eng, Doug S.; Kubota, Sanae; Lafferty, Paul; McGee, Timothy; Morese, Brian J.; Chavers, Gregory; hide

    2012-01-01

    NASA Marshall Space Flight Center and the Johns Hopkins University Applied Physics Laboratory have developed several mission concepts to place scientific and exploration payloads ranging from 10 kg to more than 200 kg on the surface of the moon. The mission concepts all use a small versatile lander that is capable of precision landing. The results to date of the lunar lander development risk reduction activities including high pressure propulsion system testing, structure and mechanism development and testing, and long cycle time battery testing will be addressed. The most visible elements of the risk reduction program are two fully autonomous lander flight test vehicles. The first utilized a high pressure cold gas system (Cold Gas Test Article) with limited flight durations while the subsequent test vehicle, known as the Warm Gas Test Article, utilizes hydrogen peroxide propellant resulting in significantly longer flight times and the ability to more fully exercise flight sensors and algorithms. The development of the Warm Gas Test Article is a system demonstration and was designed with similarity to an actual lunar lander including energy absorbing landing legs, pulsing thrusters, and flight-like software implementation. A set of outdoor flight tests to demonstrate the initial objectives of the WGTA program was completed in Nov. 2011, and will be discussed.

  15. Accent on communication: the impact of regional and foreign accent on comprehension in adults with aphasia.

    PubMed

    Bruce, Carolyn; To, Cinn-Teng; Newton, Caroline

    2012-01-01

    This study explored whether an unfamiliar non-native accent, differing in both segmental and prosodic features was more difficult for individuals with aphasia to understand than an unfamiliar native accent, which differed in segmental features only. Comprehension, which was determined by accuracy judgments on true/false sentences, and speed of response were assessed in the following three conditions: a familiar Southern Standard British English (SSBE) accent, an unfamiliar native Grimsby accent, and an unfamiliar non-native Chinese accent. Thirty-four English speaking adults (17 people with and 17 people without aphasia) served as listeners for this study. All listeners made significantly more errors in the unfamiliar non-native accent, although this difficulty was more marked for those with aphasia. While there was no affect of speaker accent on the response times of listeners with aphasia, listeners without aphasia were significantly slower with the unfamiliar non-native accent. The results indicate that non-native accented speech affects comprehension even on simple tasks in ideal listening conditions. The findings suggest that speaker accent, especially accents varying in both segmental and prosodic features, can be a barrier to successful interactions between non-native accented speakers and native listeners, particularly those with aphasia.

  16. Propulsion engineering study for small-scale Mars missions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Whitehead, J.

    1995-09-12

    Rocket propulsion options for small-scale Mars missions are presented and compared, particularly for the terminal landing maneuver and for sample return. Mars landing has a low propulsive {Delta}v requirement on a {approximately}1-minute time scale, but at a high acceleration. High thrust/weight liquid rocket technologies, or advanced pulse-capable solids, developed during the past decade for missile defense, are therefore more appropriate for small Mars landers than are conventional space propulsion technologies. The advanced liquid systems are characterize by compact lightweight thrusters having high chamber pressures and short lifetimes. Blowdown or regulated pressure-fed operation can satisfy the Mars landing requirement, but hardwaremore » mass can be reduced by using pumps. Aggressive terminal landing propulsion designs can enable post-landing hop maneuvers for some surface mobility. The Mars sample return mission requires a small high performance launcher having either solid motors or miniature pump-fed engines. Terminal propulsion for 100 kg Mars landers is within the realm of flight-proven thruster designs, but custom tankage is desirable. Landers on a 10 kg scale also are feasible, using technology that has been demonstrated but not previously flown in space. The number of sources and the selection of components are extremely limited on this smallest scale, so some customized hardware is required. A key characteristic of kilogram-scale propulsion is that gas jets are much lighter than liquid thrusters for reaction control. The mass and volume of tanks for inert gas can be eliminated by systems which generate gas as needed from a liquid or a solid, but these have virtually no space flight history. Mars return propulsion is a major engineering challenge; earth launch is the only previously-solved propulsion problem requiring similar or greater performance.« less

  17. Mars sample return mission architectures utilizing low thrust propulsion

    NASA Astrophysics Data System (ADS)

    Derz, Uwe; Seboldt, Wolfgang

    2012-08-01

    The Mars sample return mission is a flagship mission within ESA's Aurora program and envisioned to take place in the timeframe of 2020-2025. Previous studies developed a mission architecture consisting of two elements, an orbiter and a lander, each utilizing chemical propulsion and a heavy launcher like Ariane 5 ECA. The lander transports an ascent vehicle to the surface of Mars. The orbiter performs a separate impulsive transfer to Mars, conducts a rendezvous in Mars orbit with the sample container, delivered by the ascent vehicle, and returns the samples back to Earth in a small Earth entry capsule. Because the launch of the heavy orbiter by Ariane 5 ECA makes an Earth swing by mandatory for the trans-Mars injection, its total mission time amounts to about 1460 days. The present study takes a fresh look at the subject and conducts a more general mission and system analysis of the space transportation elements including electric propulsion for the transfer. Therefore, detailed spacecraft models for orbiters, landers and ascent vehicles are developed. Based on that, trajectory calculations and optimizations of interplanetary transfers, Mars entries, descents and landings as well as Mars ascents are carried out. The results of the system analysis identified electric propulsion for the orbiter as most beneficial in terms of launch mass, leading to a reduction of launch vehicle requirements and enabling a launch by a Soyuz-Fregat into GTO. Such a sample return mission could be conducted within 1150-1250 days. Concerning the lander, a separate launch in combination with electric propulsion leads to a significant reduction of launch vehicle requirements, but also requires a large number of engines and correspondingly a large power system. Therefore, a lander performing a separate chemical transfer could possibly be more advantageous. Alternatively, a second possible mission architecture has been developed, requiring only one heavy launch vehicle (e.g., Proton). In that

  18. Robotic Lunar Landers for Science and Exploration

    NASA Technical Reports Server (NTRS)

    Cohen, B. A.; Hill, L. A.; Bassler, J. A.; Chavers, D. G.; Hammond, M. S.; Harris, D. W.; Kirby, K. W.; Morse, B. J.; Mulac, B. D.; Reed, C. L. B.

    2010-01-01

    NASA Marshall Space Flight Center and The Johns Hopkins University Applied Physics Laboratory has been conducting mission studies and performing risk reduction activities for NASA s robotic lunar lander flight projects. In 2005, the Robotic Lunar Exploration Program Mission #2 (RLEP-2) was selected as a Exploration Systems Mission Directorate precursor robotic lunar lander mission to demonstrate precision landing and definitively determine if there was water ice at the lunar poles; however, this project was canceled. Since 2008, the team has been supporting NASA s Science Mission Directorate designing small lunar robotic landers for diverse science missions. The primary emphasis has been to establish anchor nodes of the International Lunar Network (ILN), a network of lunar science stations envisioned to be emplaced by multiple nations. This network would consist of multiple landers carrying instruments to address the geophysical characteristics and evolution of the moon. Additional mission studies have been conducted to support other objectives of the lunar science community and extensive risk reduction design and testing has been performed to advance the design of the lander system and reduce development risk for flight projects. This paper describes the current status of the robotic lunar mission studies that have been conducted by the MSFC/APL Robotic Lunar Lander Development team, including the ILN Anchor Nodes mission. In addition, the results to date of the lunar lander development risk reduction efforts including high pressure propulsion system testing, structure and mechanism development and testing, long cycle time battery testing and combined GN&C and avionics testing will be addressed. The most visible elements of the risk reduction program are two autonomous lander test articles: a compressed air system with limited flight durations and a second version using hydrogen peroxide propellant to achieve significantly longer flight times and the ability to

  19. Satellite auxiliary-propulsion selection techniques. Addendum: A survey of auxiliary electric propulsion systems

    NASA Technical Reports Server (NTRS)

    Holcomb, L. B.

    1971-01-01

    A review of electric thrusters for satellite auxiliary propulsion was conducted at JPL during the past year. Comparisons of the various thrusters for attitude propulsion and east-west and north-south stationkeeping were made based upon performance, mass, power, and demonstrated life. Reliability and cost are also discussed. The method of electrical acceleration of propellant served to divide the thruster systems into two groups: electrostatic and electromagnetic. Ion and colloid thrusters fall within the electrostatically accelerated group while MPD and pulsed plasma thrusters comprise the electromagnetically accelerated group. The survey was confined to research in the United States with accent on flight and flight prototype systems.

  20. Integration Of Launch Vehicle Simulation/Analysis Tools And Lunar Cargo Lander Design. Part 2/2

    NASA Technical Reports Server (NTRS)

    DeJean, George Brian; Shiue, Yeu-Sheng Paul; King, Jeffrey

    2005-01-01

    Part 2, which will be discussed in this report, will discuss the development of a Lunar Cargo Lander (unmanned launch vehicle) that will transport usable payload from Trans- Lunar Injection to the moon. The Delta IV-Heavy was originally used to transport the Lunar Cargo Lander to TLI, but other launch vehicles have been studied. In order to uncover how much payload is possible to land on the moon, research was needed in order to design the sub-systems of the spacecraft. The report will discuss and compare the use of a hypergolic and cryogenic system for its main propulsion system. The guidance, navigation, control, telecommunications, thermal, propulsion, structure, mechanisms, landing gear, command, data handling, and electrical power sub-systems were designed by scaling off other flown orbiters and moon landers. Once all data was collected, an excel spreadsheet was created to accurately calculate the usable payload that will land on the moon along with detailed mass and volume estimating relations. As designed, The Lunar Cargo Lander can plant 5,400 lbm of usable payload on the moon using a hypergolic system and 7,400 lbm of usable payload on the moon using a cryogenic system.

  1. Mars Smart Lander Simulations for Entry, Descent, and Landing

    NASA Technical Reports Server (NTRS)

    Striepe, S. A.; Way, D. W.; Balaram, J.

    2002-01-01

    Two primary simulations have been developed and are being updated for the Mars Smart Lander Entry, Descent, and Landing (EDL). The high fidelity engineering end-to-end EDL simulation that is based on NASA Langley's Program to Optimize Simulated Trajectories (POST) and the end-to-end real-time, hardware-in-the-loop simulation testbed, which is based on NASA JPL's (Jet Propulsion Laboratory) Dynamics Simulator for Entry, Descent and Surface landing (DSENDS). This paper presents the status of these Mars Smart Lander EDL end-to-end simulations at this time. Various models, capabilities, as well as validation and verification for these simulations are discussed.

  2. Europa Small Lander Design Concepts

    NASA Astrophysics Data System (ADS)

    Zimmerman, W. F.

    2005-12-01

    Title: Europa Small Lander Design Concepts Authors: Wayne F. Zimmerman, James Shirley, Robert Carlson, Tom Rivellini, Mike Evans One of the primary goals of NASA's Outer Planets Program is to revisit the Jovian system. A new Europa Geophysical Explorer (EGE) Mission has been proposed and is under evaluation. There is in addition strong community interest in a surface science mission to Europa. A Europa Lander might be delivered to the Jovian system with the EGE orbiter. A Europa Astrobiology Lander (EAL) Mission has also been proposed; this would launch sometime after 2020. The primary science objectives for either of these would most likely include: Surface imaging (both microscopic and near-field), characterization of surface mechanical properties (temperature, hardness), assessment of surface and near-surface organic and inorganic chemistry (volatiles, mineralogy, and compounds), characterization of the radiation environment (total dose and particles), characterization of the planetary seismicity, and the measurement of Europa's magnetic field. The biggest challenges associated with getting to the surface and surviving to perform science investigations revolve around the difficulty of landing on an airless body, the ubiquitous extreme topography, the harsh radiation environment, and the extreme cold. This presentation reviews some the recent design work on drop-off probes, also called "hard landers". Hard lander designs have been developed for a range of science payload delivery systems spanning small impactors to multiple science pods tethered to a central hub. In addition to developing designs for these various payload delivery systems, significant work has been done in weighing the relative merits of standard power systems (i.e., batteries) against radioisotope power systems. A summary of the power option accommodation benefits and issues will be presented. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under a

  3. Recognising English Accents in the Community: Omani Students' Accent Preferences and Perceptions of Nativeness

    ERIC Educational Resources Information Center

    Buckingham, Louisa

    2015-01-01

    Previous research has revealed that although EFL students may claim to prefer British/US accents they often have difficulty identifying them, especially when such accents may differ from "standard" accents presented in ELT materials. In the Gulf, English is widely used as a lingua franca or as a second language by the large expatriate…

  4. Northeast View From Pathfinder Lander

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This panorama of the region to the northeast of the lander was constructed to support the Sojourner Rover Team's plans to conduct an 'autonomous traverse' to explore the terrain away from the lander after science objectives in the lander vicinity had been met. The large, relatively bright surface in the foreground, about 10 meters (33 feet) from the spacecraft, in this scene is 'Baker's Bench.' The large, elongated rock left of center in the middle distance is 'Zaphod.'

    This view was produced by combining 8 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  5. Project UM-HAUL (UnManned Heavy pAyload Unloader and Lander): The design of a reusable lunar lander with an independent cargo unloader

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Project UM-Haul is the preliminary design of a reusable lunar transportation vehicle that travels between a lunar parking orbit and the lunar surface. This vehicle is an indispensible link in the overall task of establishing a lunar base as defined by the NASA Space Exploration Initiative. The response to this need consists of two independent vehicles: a lander and an unloader. The system can navigate and unload itself with a minimum amount of human intervention. The design addresses structural analysis, propulsion, power, controls, communications, payload handling and orbital operations. The Lander has the capacity to decend from low lunar orbit (LLO) to the lunar surface carrying a 7000 kg payload, plus the unloader, plus propellant for ascent to LLO. The Lander employs the Unloader by way of a motorized ramp. The Unloader is a terrain vehicle capable of carrying cargoes of 8,500 kg mass and employs a lift system to lower payloads to the ground. The system can perform ten missions before requiring major servicing.

  6. Integrated Pressure-Fed Liquid Oxygen / Methane Propulsion Systems - Morpheus Experience, MARE, and Future Applications

    NASA Technical Reports Server (NTRS)

    Hurlbert, Eric; Morehead, Robert; Melcher, John C.; Atwell, Matt

    2016-01-01

    An integrated liquid oxygen (LOx) and methane propulsion system where common propellants are fed to the reaction control system and main engines offers advantages in performance, simplicity, reliability, and reusability. LOx/Methane provides new capabilities to use propellants that are manufactured on the Mars surface for ascent return and to integrate with power and life support systems. The clean burning, non-toxic, high vapor pressure propellants provide significant advantages for reliable ignition in a space vacuum, and for reliable safing or purging of a space-based vehicle. The NASA Advanced Exploration Systems (AES) Morpheus lander demonstrated many of these key attributes as it completed over 65 tests including 15 flights through 2014. Morpheus is a prototype of LOx/Methane propellant lander vehicle with a fully integrated propulsion system. The Morpheus lander flight demonstrations led to the proposal to use LOx/Methane for a Discovery class mission, named Moon Aging Regolith Experiment (MARE) to land an in-situ science payload for Southwest Research Institute on the Lunar surface. Lox/Methane is extensible to human spacecraft for many transportation elements of a Mars architecture. This paper discusses LOx/Methane propulsion systems in regards to trade studies, the Morpheus project experience, the MARE NAVIS (NASA Autonomous Vehicle for In-situ Science) lander, and future possible applications. The paper also discusses technology research and development needs for Lox/Methane propulsion systems.

  7. Accent, intelligibility, and comprehensibility in the perception of foreign-accented Lombard speech

    NASA Astrophysics Data System (ADS)

    Li, Chi-Nin

    2003-10-01

    Speech produced in noise (Lombard speech) has been reported to be more intelligible than speech produced in quiet (normal speech). This study examined the perception of non-native Lombard speech in terms of intelligibility, comprehensibility, and degree of foreign accent. Twelve Cantonese speakers and a comparison group of English speakers read simple true and false English statements in quiet and in 70 dB of masking noise. Lombard and normal utterances were mixed with noise at a constant signal-to-noise ratio, and presented along with noise-free stimuli to eight new English listeners who provided transcription scores, comprehensibility ratings, and accent ratings. Analyses showed that, as expected, utterances presented in noise were less well perceived than were noise-free sentences, and that the Cantonese speakers' productions were more accented, but less intelligible and less comprehensible than those of the English speakers. For both groups of speakers, the Lombard sentences were correctly transcribed more often than their normal utterances in noisy conditions. However, the Cantonese-accented Lombard sentences were not rated as easier to understand than was the normal speech in all conditions. The assigned accent ratings were similar throughout all listening conditions. Implications of these findings will be discussed.

  8. Structural design of liquid oxygen/liquid methane robotic lander JANUS

    NASA Astrophysics Data System (ADS)

    Chaidez, Mariana

    As the attempt to send humans to Mars has gained momentum in the last decade, the need to find alternative propellants that are safer, less toxic, and yields a better performance has become apparent [1]. Liquid methane and oxygen have emerged as a suitable alternative. In addition, the incorporation of liquid methane/liquid oxygen into the propulsion system has demonstrated an increase in engine performance, as well as a reduction in the volume, size and complexity of the propulsion system. In an attempt to further understand the technologies that are possible to develop using liquid oxygen (LO 2) and liquid methane (LCH4), a preliminary design of a robotic lander JANUS is being completed by the Center for Space Exploration and Technology Research (cSTER). The structural design of the vehicle is important because it acts as the skeleton of the vehicle and dictates the maneuverability of the robotic lander. To develop the structure of the robotic lander, six different design vehicle concepts with varying tank configurations were considered. Finite Element Analysis (FEA) was completed on each model to optimize each vehicle. Trade studies were completed to choose the best design for JANUS. Upon completion of the trade studies the design for the first prototype of JANUS was initiated in which the tank and thrust modules were designed. This thesis will describe the design process for the structural design of the JANUS.

  9. Agnosia for accents in primary progressive aphasia☆

    PubMed Central

    Fletcher, Phillip D.; Downey, Laura E.; Agustus, Jennifer L.; Hailstone, Julia C.; Tyndall, Marina H.; Cifelli, Alberto; Schott, Jonathan M.; Warrington, Elizabeth K.; Warren, Jason D.

    2013-01-01

    As an example of complex auditory signal processing, the analysis of accented speech is potentially vulnerable in the progressive aphasias. However, the brain basis of accent processing and the effects of neurodegenerative disease on this processing are not well understood. Here we undertook a detailed neuropsychological study of a patient, AA with progressive nonfluent aphasia, in whom agnosia for accents was a prominent clinical feature. We designed a battery to assess AA's ability to process accents in relation to other complex auditory signals. AA's performance was compared with a cohort of 12 healthy age and gender matched control participants and with a second patient, PA, who had semantic dementia with phonagnosia and prosopagnosia but no reported difficulties with accent processing. Relative to healthy controls, the patients showed distinct profiles of accent agnosia. AA showed markedly impaired ability to distinguish change in an individual's accent despite being able to discriminate phonemes and voices (apperceptive accent agnosia); and in addition, a severe deficit of accent identification. In contrast, PA was able to perceive changes in accents, phonemes and voices normally, but showed a relatively mild deficit of accent identification (associative accent agnosia). Both patients showed deficits of voice and environmental sound identification, however PA showed an additional deficit of face identification whereas AA was able to identify (though not name) faces normally. These profiles suggest that AA has conjoint (or interacting) deficits involving both apperceptive and semantic processing of accents, while PA has a primary semantic (associative) deficit affecting accents along with other kinds of auditory objects and extending beyond the auditory modality. Brain MRI revealed left peri-Sylvian atrophy in case AA and relatively focal asymmetric (predominantly right sided) temporal lobe atrophy in case PA. These cases provide further evidence for the

  10. Agnosia for accents in primary progressive aphasia.

    PubMed

    Fletcher, Phillip D; Downey, Laura E; Agustus, Jennifer L; Hailstone, Julia C; Tyndall, Marina H; Cifelli, Alberto; Schott, Jonathan M; Warrington, Elizabeth K; Warren, Jason D

    2013-08-01

    As an example of complex auditory signal processing, the analysis of accented speech is potentially vulnerable in the progressive aphasias. However, the brain basis of accent processing and the effects of neurodegenerative disease on this processing are not well understood. Here we undertook a detailed neuropsychological study of a patient, AA with progressive nonfluent aphasia, in whom agnosia for accents was a prominent clinical feature. We designed a battery to assess AA's ability to process accents in relation to other complex auditory signals. AA's performance was compared with a cohort of 12 healthy age and gender matched control participants and with a second patient, PA, who had semantic dementia with phonagnosia and prosopagnosia but no reported difficulties with accent processing. Relative to healthy controls, the patients showed distinct profiles of accent agnosia. AA showed markedly impaired ability to distinguish change in an individual's accent despite being able to discriminate phonemes and voices (apperceptive accent agnosia); and in addition, a severe deficit of accent identification. In contrast, PA was able to perceive changes in accents, phonemes and voices normally, but showed a relatively mild deficit of accent identification (associative accent agnosia). Both patients showed deficits of voice and environmental sound identification, however PA showed an additional deficit of face identification whereas AA was able to identify (though not name) faces normally. These profiles suggest that AA has conjoint (or interacting) deficits involving both apperceptive and semantic processing of accents, while PA has a primary semantic (associative) deficit affecting accents along with other kinds of auditory objects and extending beyond the auditory modality. Brain MRI revealed left peri-Sylvian atrophy in case AA and relatively focal asymmetric (predominantly right sided) temporal lobe atrophy in case PA. These cases provide further evidence for the

  11. Sequenced subjective accents for brain-computer interfaces

    NASA Astrophysics Data System (ADS)

    Vlek, R. J.; Schaefer, R. S.; Gielen, C. C. A. M.; Farquhar, J. D. R.; Desain, P.

    2011-06-01

    Subjective accenting is a cognitive process in which identical auditory pulses at an isochronous rate turn into the percept of an accenting pattern. This process can be voluntarily controlled, making it a candidate for communication from human user to machine in a brain-computer interface (BCI) system. In this study we investigated whether subjective accenting is a feasible paradigm for BCI and how its time-structured nature can be exploited for optimal decoding from non-invasive EEG data. Ten subjects perceived and imagined different metric patterns (two-, three- and four-beat) superimposed on a steady metronome. With an offline classification paradigm, we classified imagined accented from non-accented beats on a single trial (0.5 s) level with an average accuracy of 60.4% over all subjects. We show that decoding of imagined accents is also possible with a classifier trained on perception data. Cyclic patterns of accents and non-accents were successfully decoded with a sequence classification algorithm. Classification performances were compared by means of bit rate. Performance in the best scenario translates into an average bit rate of 4.4 bits min-1 over subjects, which makes subjective accenting a promising paradigm for an online auditory BCI.

  12. Does a Foreign Accent Sell? The Effect of Foreign Accents in Radio Commercials for Congruent and Non-Congruent Products

    ERIC Educational Resources Information Center

    Hendriks, Berna; van Meurs, Frank; van der Meij, Els

    2015-01-01

    Commercials regularly feature foreign accents. This paper aims to investigate whether the use of foreign accents in radio commercials is more effective for congruent than incongruent products, and whether foreign-accented commercials are evaluated differently than non-accented commercials. In an experiment, a group of 228 Dutch participants rated…

  13. Accent Identification by Adults with Aphasia

    ERIC Educational Resources Information Center

    Newton, Caroline; Burns, Rebecca; Bruce, Carolyn

    2013-01-01

    The UK is a diverse society where individuals regularly interact with speakers with different accents. Whilst there is a growing body of research on the impact of speaker accent on comprehension in people with aphasia, there is none which explores their ability to identify accents. This study investigated the ability of this group to identify the…

  14. Underneath the Phoenix Lander

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Robotic Arm Camera on NASA's Phoenix Mars Lander took this image on Oct. 18, 2008, during the 142nd Martian day, or sol, since landing. The flat patch in the center of the image has the informal name 'Holy Cow,' based on researchers' reaction when they saw the initial image of it only a few days after the May 25, 2008 landing. Researchers first saw this flat patch in an image taken by the Robotic Arm Camera on May 30, the fifth Martian day of the mission.

    The Phoenix mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  15. Phoenix Lander on Mars with Surrounding Terrain, Vertical Projection

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This view is a vertical projection that combines more than 500 exposures taken by the Surface Stereo Imager camera on NASA's Mars Phoenix Lander and projects them as if looking down from above.

    The black circle on the spacecraft is where the camera itself is mounted on the lander, out of view in images taken by the camera. North is toward the top of the image. The height of the lander's meteorology mast, extending toward the southwest, appears exaggerated because that mast is taller than the camera mast.

    This view in approximately true color covers an area about 30 meters by 30 meters (about 100 feet by 100 feet). The landing site is at 68.22 degrees north latitude, 234.25 degrees east longitude on Mars.

    The ground surface around the lander has polygonal patterning similar to patterns in permafrost areas on Earth.

    This view comprises more than 100 different Stereo Surface Imager pointings, with images taken through three different filters at each pointing. The images were taken throughout the period from the 13th Martian day, or sol, after landing to the 47th sol (June 5 through July 12, 2008). The lander's Robotic Arm is cut off in this mosaic view because component images were taken when the arm was out of the frame.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. Disentangling Accent from Comprehensibility

    ERIC Educational Resources Information Center

    Trofimovich, Pavel; Isaacs, Talia

    2012-01-01

    The goal of this study was to determine which linguistic aspects of second language speech are related to accent and which to comprehensibility. To address this goal, 19 different speech measures in the oral productions of 40 native French speakers of English were examined in relation to accent and comprehensibility, as rated by 60 novice raters…

  17. Evaluation of Speakers with Foreign-Accented Speech in Japan: The Effect of Accent Produced by English Native Speakers

    ERIC Educational Resources Information Center

    Tsurutani, Chiharu

    2012-01-01

    Foreign-accented speakers are generally regarded as less educated, less reliable and less interesting than native speakers and tend to be associated with cultural stereotypes of their country of origin. This discrimination against foreign accents has, however, been discussed mainly using accented English in English-speaking countries. This study…

  18. Advanced Space Propulsion

    NASA Technical Reports Server (NTRS)

    Frisbee, Robert H.

    1996-01-01

    This presentation describes a number of advanced space propulsion technologies with the potential for meeting the need for dramatic reductions in the cost of access to space, and the need for new propulsion capabilities to enable bold new space exploration (and, ultimately, space exploitation) missions of the 21st century. For example, current Earth-to-orbit (e.g., low Earth orbit, LEO) launch costs are extremely high (ca. $10,000/kg); a factor 25 reduction (to ca. $400/kg) will be needed to produce the dramatic increases in space activities in both the civilian and government sectors identified in the Commercial Space Transportation Study (CSTS). Similarly, in the area of space exploration, all of the relatively 'easy' missions (e.g., robotic flybys, inner solar system orbiters and landers; and piloted short-duration Lunar missions) have been done. Ambitious missions of the next century (e.g., robotic outer-planet orbiters/probes, landers, rovers, sample returns; and piloted long-duration Lunar and Mars missions) will require major improvements in propulsion capability. In some cases, advanced propulsion can enable a mission by making it faster or more affordable, and in some cases, by directly enabling the mission (e.g., interstellar missions). As a general rule, advanced propulsion systems are attractive because of their low operating costs (e.g., higher specific impulse, ISD) and typically show the most benefit for relatively 'big' missions (i.e., missions with large payloads or AV, or a large overall mission model). In part, this is due to the intrinsic size of the advanced systems as compared to state-of-the-art (SOTA) chemical propulsion systems. Also, advanced systems often have a large 'infrastructure' cost, either in the form of initial R&D costs or in facilities hardware costs (e.g., laser or microwave transmission ground stations for beamed energy propulsion). These costs must then be amortized over a large mission to be cost-competitive with a SOTA

  19. Low Cost Precision Lander for Lunar Exploration

    NASA Astrophysics Data System (ADS)

    Head, J. N.; Gardner, T. G.; Hoppa, G. V.; Seybold, K. G.

    2004-12-01

    For 60 years the US Defense Department has invested heavily in producing small, low mass, precision guided vehicles. The technologies matured under these programs include terrain-aided navigation, closed loop terminal guidance algorithms, robust autopilots, high thrust-to-weight propulsion, autonomous mission management software, sensors, and data fusion. These technologies will aid NASA in addressing New Millennium Science and Technology goals as well as the requirements flowing from the Vision articulated in January 2004. Establishing and resupplying a long term lunar presence will require automated landing precision not yet demonstrated. Precision landing will increase safety and assure mission success. In the DOD world, such technologies are used routinely and reliably. Hence, it is timely to generate a point design for a precise planetary lander useful for lunar exploration. In this design science instruments amount to 10 kg, 16% of the lander vehicle mass. This compares favorably with 7% for Mars Pathfinder and less than 15% for Surveyor. The mission design flies the lander in an inert configuration to the moon, relying on a cruise stage for navigation and TCMs. The lander activates about a minute before impact. A solid booster reduces the vehicle speed to 300-450 m/s. The lander is now about 2 minutes from touchdown and has 600 to 700 m/s delta-v capability, allowing for about 10 km of vehicle divert during terminal descent. This concept of operations is chosen because it closely mimics missile operational timelines used for decades: the vehicle remains inert in a challenging environment, then must execute its mission flawlessly on a moment's notice. The vehicle design consists of a re-plumbed propulsion system, using propellant tanks and thrusters from exoatmospheric programs. A redesigned truss provides hard points for landing gear, electronics, power supply, and science instruments. A radar altimeter and a Digital Scene Matching Area Correlator (DSMAC

  20. Liquid Oxygen/Liquid Methane Propulsion and Cryogenic Advanced Development

    NASA Technical Reports Server (NTRS)

    Klem, Mark D.; Smith, Timothy D.; Wadel, Mary F.; Meyer, Michael L.; Free, James M.; Cikanek, Harry A., III

    2011-01-01

    Exploration Systems Architecture Study conducted by NASA in 2005 identified the liquid oxygen (LOx)/liquid methane (LCH4) propellant combination as a prime candidate for the Crew Exploration Vehicle Service Module propulsion and for later use for ascent stage propulsion of the lunar lander. Both the Crew Exploration Vehicle and Lunar Lander were part the Constellation architecture, which had the objective to provide global sustained lunar human exploration capability. From late 2005 through the end of 2010, NASA and industry matured advanced development designs for many components that could be employed in relatively high thrust, high delta velocity, pressure fed propulsion systems for these two applications. The major investments were in main engines, reaction control engines, and the devices needed for cryogenic fluid management such as screens, propellant management devices, thermodynamic vents, and mass gauges. Engine and thruster developments also included advanced high reliability low mass igniters. Extensive tests were successfully conducted for all of these elements. For the thrusters and engines, testing included sea level and altitude conditions. This advanced development provides a mature technology base for future liquid oxygen/liquid methane pressure fed space propulsion systems. This paper documents the design and test efforts along with resulting hardware and test results.

  1. Resource Prospector Propulsion Cold Flow Test

    NASA Technical Reports Server (NTRS)

    Williams, Hunter; Pederson, Kevin; Dervan, Melanie; Holt, Kimberly; Jernigan, Frankie; Trinh, Huu; Flores, Sam

    2014-01-01

    For the past year, NASA Marshall Space Flight Center and Johnson Space Center have been working on a government version of a lunar lander design for the Resource Prospector Mission. A propulsion cold flow test system, representing an early flight design of the propulsion system, has been fabricated. The primary objective of the cold flow test is to simulate the Resource Prospector propulsion system operation through water flow testing and obtain data for anchoring analytical models. This effort will also provide an opportunity to develop a propulsion system mockup to examine hardware integration to a flight structure. This paper will report the work progress of the propulsion cold flow test system development and test preparation. At the time this paper is written, the initial waterhammer testing is underway. The initial assessment of the test data suggests that the results are as expected and have a similar trend with the pretest prediction. The test results will be reported in a future conference.

  2. Processing changes when listening to foreign-accented speech

    PubMed Central

    Romero-Rivas, Carlos; Martin, Clara D.; Costa, Albert

    2015-01-01

    This study investigates the mechanisms responsible for fast changes in processing foreign-accented speech. Event Related brain Potentials (ERPs) were obtained while native speakers of Spanish listened to native and foreign-accented speakers of Spanish. We observed a less positive P200 component for foreign-accented speech relative to native speech comprehension. This suggests that the extraction of spectral information and other important acoustic features was hampered during foreign-accented speech comprehension. However, the amplitude of the N400 component for foreign-accented speech comprehension decreased across the experiment, suggesting the use of a higher level, lexical mechanism. Furthermore, during native speech comprehension, semantic violations in the critical words elicited an N400 effect followed by a late positivity. During foreign-accented speech comprehension, semantic violations only elicited an N400 effect. Overall, our results suggest that, despite a lack of improvement in phonetic discrimination, native listeners experience changes at lexical-semantic levels of processing after brief exposure to foreign-accented speech. Moreover, these results suggest that lexical access, semantic integration and linguistic re-analysis processes are permeable to external factors, such as the accent of the speaker. PMID:25859209

  3. Mars Surface near Viking Lander 1 Footpad

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image, which has been flipped horizontally, was taken by Viking Lander 1 on August 1, 1976, 12 sols after landing. Much like images that have returned from Phoenix, the soil beneath Viking 1 has been exposed due to exhaust from thruster engines during descent. This is visible to the right of the struts of Viking's surface-sampler arm housing, seen on the left.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  4. Phoenix Mars Lander in Testing

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's next Mars-bound spacecraft, the Phoenix Mars Lander, was partway through assembly and testing at Lockheed Martin Space Systems, Denver, in September 2006, progressing toward an August 2007 launch from Florida. In this photograph, spacecraft specialists work on the lander after its fan-like circular solar arrays have been spread open for testing. The arrays will be in this configuration when the spacecraft is active on the surface of Mars.

    Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. It will dig into the surface, test scooped-up samples for carbon-bearing compounds and serve as NASA's first exploration of a potential modern habitat on Mars.

    Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

  5. Viking Lander 2 Anniversary

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    This portion of a daytime IR image covers the Viking 2 landing site (shown with the X). The second landing on Mars took place September 3, 1976 in Utopia Planitia. The exact location of Lander 2 is not as well established as Lander 1 because there were no clearly identifiable features in the lander images as there were for the site of Lander 1. The Utopia landing site region contains pedestal craters, shallow swales and gentle ridges. The crater Goldstone was named in honor of the Tracking Station in the desert of California. The two Viking Landers operated for over 6 years (nearly four martian years) after landing. This one band IR (band 9 at 12.6 microns) image shows bright and dark textures, which are primarily due to differences in the abundance of rocks on the surface. The relatively cool (dark) regions during the day are rocky or indurated materials, fine sand and dust are warmer (bright). Many of the temperature variations are due to slope effects, with sun-facing slopes warmer than shaded slopes. The dark rings around several of the craters are due to the presence of rocky (cool) material ejected from the crater. These rocks are well below the resolution of any existing Mars camera, but THEMIS can detect the temperature variations they produce. Daytime temperature variations are produced by a combination of topographic (solar heating) and thermophysical (thermal inertia and albedo) effects. Due to topographic heating the surface morphologies seen in THEMIS daytime IR images are similar to those seen in previous imagery and MOLA topography.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected

  6. A Neural Marker for Social Bias Toward In-group Accents.

    PubMed

    Bestelmeyer, Patricia E G; Belin, Pascal; Ladd, D Robert

    2015-10-01

    Accents provide information about the speaker's geographical, socio-economic, and ethnic background. Research in applied psychology and sociolinguistics suggests that we generally prefer our own accent to other varieties of our native language and attribute more positive traits to it. Despite the widespread influence of accents on social interactions, educational and work settings the neural underpinnings of this social bias toward our own accent and, what may drive this bias, are unexplored. We measured brain activity while participants from two different geographical backgrounds listened passively to 3 English accent types embedded in an adaptation design. Cerebral activity in several regions, including bilateral amygdalae, revealed a significant interaction between the participants' own accent and the accent they listened to: while repetition of own accents elicited an enhanced neural response, repetition of the other group's accent resulted in reduced responses classically associated with adaptation. Our findings suggest that increased social relevance of, or greater emotional sensitivity to in-group accents, may underlie the own-accent bias. Our results provide a neural marker for the bias associated with accents, and show, for the first time, that the neural response to speech is partly shaped by the geographical background of the listener. © The Author 2014. Published by Oxford University Press.

  7. A Neural Marker for Social Bias Toward In-group Accents

    PubMed Central

    Bestelmeyer, Patricia E.G.; Belin, Pascal; Ladd, D. Robert

    2015-01-01

    Accents provide information about the speaker's geographical, socio-economic, and ethnic background. Research in applied psychology and sociolinguistics suggests that we generally prefer our own accent to other varieties of our native language and attribute more positive traits to it. Despite the widespread influence of accents on social interactions, educational and work settings the neural underpinnings of this social bias toward our own accent and, what may drive this bias, are unexplored. We measured brain activity while participants from two different geographical backgrounds listened passively to 3 English accent types embedded in an adaptation design. Cerebral activity in several regions, including bilateral amygdalae, revealed a significant interaction between the participants' own accent and the accent they listened to: while repetition of own accents elicited an enhanced neural response, repetition of the other group's accent resulted in reduced responses classically associated with adaptation. Our findings suggest that increased social relevance of, or greater emotional sensitivity to in-group accents, may underlie the own-accent bias. Our results provide a neural marker for the bias associated with accents, and show, for the first time, that the neural response to speech is partly shaped by the geographical background of the listener. PMID:25452578

  8. Rock Moved by Mars Lander Arm

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The robotic arm on NASA's Phoenix Mars Lander slid a rock out of the way during the mission's 117th Martian day (Sept. 22, 2008) to gain access to soil that had been underneath the rock.The lander's Surface Stereo Imager took the two images for this stereo view later the same day, showing the rock, called 'Headless,' after the arm pushed it about 40 centimeters (16 inches) from its previous location.

    'The rock ended up exactly where we intended it to,' said Matt Robinson of NASA's Jet Propulsion Laboratory, robotic arm flight software lead for the Phoenix team.

    The arm had enlarged the trench near Headless two days earlier in preparation for sliding the rock into the trench. The trench was dug to about 3 centimeters (1.2 inches) deep. The ground surface between the rock's prior position and the lip of the trench had a slope of about 3 degrees downward toward the trench. Headless is about the size and shape of a VHS videotape.

    The Phoenix science team sought to move the rock in order to study the soil and the depth to subsurface ice underneath where the rock had been.

    This image was taken at about 12:30 p.m., local solar time on Mars. The view is to the north northeast of the lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  9. Linguistic Processing of Accented Speech Across the Lifespan

    PubMed Central

    Cristia, Alejandrina; Seidl, Amanda; Vaughn, Charlotte; Schmale, Rachel; Bradlow, Ann; Floccia, Caroline

    2012-01-01

    In most of the world, people have regular exposure to multiple accents. Therefore, learning to quickly process accented speech is a prerequisite to successful communication. In this paper, we examine work on the perception of accented speech across the lifespan, from early infancy to late adulthood. Unfamiliar accents initially impair linguistic processing by infants, children, younger adults, and older adults, but listeners of all ages come to adapt to accented speech. Emergent research also goes beyond these perceptual abilities, by assessing links with production and the relative contributions of linguistic knowledge and general cognitive skills. We conclude by underlining points of convergence across ages, and the gaps left to face in future work. PMID:23162513

  10. The Evaluation of Second Language Fluency and Foreign Accent

    ERIC Educational Resources Information Center

    Wu, Chen-Huei

    2011-01-01

    What is second language fluency? What is a foreign accent? Is it possible for an adult second language learner to speak fluently with a heavy accent or vice versa? What factors contribute to the perception of fluency and a foreign accent? What acoustic attributes correlate with the perception of fluency and a foreign accent? To answer these…

  11. Combining Solar Electric Propulsion and Chemical Propulsion for Crewed Missions to Mars

    NASA Technical Reports Server (NTRS)

    Percy, Tom; McGuire, Melissa; Polsgrove, Tara

    2015-01-01

    This paper documents the results of an investigation of human Mars mission architectures that leverage near-term technology investments and infrastructures resulting from the planned Asteroid Redirect Robotic Mission (ARRM), including high-power Solar Electric Propulsion (SEP) and a human presence in Lunar Distant Retrograde Orbit (LDRO). The architectures investigated use a combination of SEP and chemical propulsion elements. Through this combination of propulsion technologies, these architectures take advantage of the high efficiency SEP propulsion system to deliver cargo, while maintaining the faster trip times afforded by chemical propulsion for crew transport. Evolved configurations of the Asteroid Redirect Vehicle (ARV) are considered for cargo delivery. Sensitivities to SEP system design parameters, including power level and propellant quantity, are presented. For the crew delivery, liquid oxygen and methane stages were designed using engines common to future human Mars landers. Impacts of various Earth departure orbits, Mars loiter orbits, and Earth return strategies are presented. The use of the Space Launch System for delivery of the various architecture elements was also investigated and launch vehicle manifesting, launch scheduling and mission timelines are also discussed. The study results show that viable Mars architecture can be constructed using LDRO and SEP in order to take advantage of investments made in the ARRM mission.

  12. Color Image of Phoenix Lander on Mars Surface

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an enhanced-color image from Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera. It shows the Phoenix lander with its solar panels deployed on the Mars surface. The spacecraft appears more blue than it would in reality.

    The blue/green and red filters on the HiRISE camera were used to make this picture.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  13. Lunar surface base propulsion system study, volume 1

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The efficiency, capability, and evolution of a lunar base will be largely dependent on the transportation system that supports it. Beyond Space Station in low Earth orbit (LEO), a Lunar-derived propellant supply could provide the most important resource for the transportation infrastructure. The key to an efficient Lunar base propulsion system is the degree of Lunar self-sufficiency (from Earth supply) and reasonable propulsion system performance. Lunar surface propellant production requirements must be accounted in the measurement of efficiency of the entire space transportation system. Of all chemical propellant/propulsion systems considered, hydrogen/oxygen (H/O) OTVs appear most desirable, while both H/O and aluminum/oxygen propulsion systems may be considered for the lander. Aluminized-hydrogen/oxygen and Silane/oxygen propulsion systems are also promising candidates. Lunar propellant availability and processing techniques, chemical propulsion/vehicle design characteristics, and the associated performance of the total transportation infrastructure are reviewed, conceptual propulsion system designs and vehicle/basing concepts, and technology requirements are assessed in context of a Lunar Base mission scenario.

  14. Loss of regional accent after damage to the speech production network.

    PubMed

    Berthier, Marcelo L; Dávila, Guadalupe; Moreno-Torres, Ignacio; Beltrán-Corbellini, Álvaro; Santana-Moreno, Daniel; Roé-Vellvé, Núria; Thurnhofer-Hemsi, Karl; Torres-Prioris, María José; Massone, María Ignacia; Ruiz-Cruces, Rafael

    2015-01-01

    Lesion-symptom mapping studies reveal that selective damage to one or more components of the speech production network can be associated with foreign accent syndrome, changes in regional accent (e.g., from Parisian accent to Alsatian accent), stronger regional accent, or re-emergence of a previously learned and dormant regional accent. Here, we report loss of regional accent after rapidly regressive Broca's aphasia in three Argentinean patients who had suffered unilateral or bilateral focal lesions in components of the speech production network. All patients were monolingual speakers with three different native Spanish accents (Cordobés or central, Guaranítico or northeast, and Bonaerense). Samples of speech production from the patient with native Córdoba accent were compared with previous recordings of his voice, whereas data from the patient with native Guaranítico accent were compared with speech samples from one healthy control matched for age, gender, and native accent. Speech samples from the patient with native Buenos Aires's accent were compared with data obtained from four healthy control subjects with the same accent. Analysis of speech production revealed discrete slowing in speech rate, inappropriate long pauses, and monotonous intonation. Phonemic production remained similar to those of healthy Spanish speakers, but phonetic variants peculiar to each accent (e.g., intervocalic aspiration of /s/ in Córdoba accent) were absent. While basic normal prosodic features of Spanish prosody were preserved, features intrinsic to melody of certain geographical areas (e.g., rising end F0 excursion in declarative sentences intoned with Córdoba accent) were absent. All patients were also unable to produce sentences with different emotional prosody. Brain imaging disclosed focal left hemisphere lesions involving the middle part of the motor cortex, the post-central cortex, the posterior inferior and/or middle frontal cortices, insula, anterior putamen and

  15. Loss of regional accent after damage to the speech production network

    PubMed Central

    Berthier, Marcelo L.; Dávila, Guadalupe; Moreno-Torres, Ignacio; Beltrán-Corbellini, Álvaro; Santana-Moreno, Daniel; Roé-Vellvé, Núria; Thurnhofer-Hemsi, Karl; Torres-Prioris, María José; Massone, María Ignacia; Ruiz-Cruces, Rafael

    2015-01-01

    Lesion-symptom mapping studies reveal that selective damage to one or more components of the speech production network can be associated with foreign accent syndrome, changes in regional accent (e.g., from Parisian accent to Alsatian accent), stronger regional accent, or re-emergence of a previously learned and dormant regional accent. Here, we report loss of regional accent after rapidly regressive Broca’s aphasia in three Argentinean patients who had suffered unilateral or bilateral focal lesions in components of the speech production network. All patients were monolingual speakers with three different native Spanish accents (Cordobés or central, Guaranítico or northeast, and Bonaerense). Samples of speech production from the patient with native Córdoba accent were compared with previous recordings of his voice, whereas data from the patient with native Guaranítico accent were compared with speech samples from one healthy control matched for age, gender, and native accent. Speech samples from the patient with native Buenos Aires’s accent were compared with data obtained from four healthy control subjects with the same accent. Analysis of speech production revealed discrete slowing in speech rate, inappropriate long pauses, and monotonous intonation. Phonemic production remained similar to those of healthy Spanish speakers, but phonetic variants peculiar to each accent (e.g., intervocalic aspiration of /s/ in Córdoba accent) were absent. While basic normal prosodic features of Spanish prosody were preserved, features intrinsic to melody of certain geographical areas (e.g., rising end F0 excursion in declarative sentences intoned with Córdoba accent) were absent. All patients were also unable to produce sentences with different emotional prosody. Brain imaging disclosed focal left hemisphere lesions involving the middle part of the motor cortex, the post-central cortex, the posterior inferior and/or middle frontal cortices, insula, anterior putamen and

  16. Phoenix Lander on Mars

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Phoenix Mars Lander monitors the atmosphere overhead and reaches out to the soil below in this artist's depiction of the spacecraft fully deployed on the surface of Mars.

    Phoenix has been assembled and tested for launch in August 2007 from Cape Canaveral Air Force Station, Fla., and for landing in May or June 2008 on an arctic plain of far-northern Mars. The mission responds to evidence returned from NASA's Mars Odyssey orbiter in 2002 indicating that most high-latitude areas on Mars have frozen water mixed with soil within arm's reach of the surface.

    Phoenix will use a robotic arm to dig down to the expected icy layer. It will analyze scooped-up samples of the soil and ice for factors that will help scientists evaluate whether the subsurface environment at the site ever was, or may still be, a favorable habitat for microbial life. The instruments on Phoenix will also gather information to advance understanding about the history of the water in the icy layer. A weather station on the lander will conduct the first study Martian arctic weather from ground level.

    The vertical green line in this illustration shows how the weather station on Phoenix will use a laser beam from a lidar instrument to monitor dust and clouds in the atmosphere. The dark 'wings' to either side of the lander's main body are solar panels for providing electric power.

    The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems, Denver. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen (Denmark), the Max Planck Institute (Germany) and the Finnish Meteorological institute. JPL is a division of the California Institute of Technology in Pasadena.

  17. Attention, Awareness, and Accents in L2 French

    ERIC Educational Resources Information Center

    Sturm, Jessica L.

    2013-01-01

    The present research applies the concepts of attention, awareness, and noticing to a previously unresolved strand of inquiry: accent marks in L2 (second language) French. Previous research found that learners who typed accented words had better recall of the accent marks than those who wrote the same words by hand. Sturm suggested that it may have…

  18. Spaceship Discovery's Crew and Cargo Lander Module Designs for Human Exploration of Mars

    NASA Astrophysics Data System (ADS)

    Benton, Mark G.

    2008-01-01

    The Spaceship Discovery design was first presented at STAIF 2006. This conceptual design space vehicle architecture for human solar system exploration includes two types of Mars exploration lander modules: A piloted crew lander, designated Lander Module 2 (LM2), and an autonomous cargo lander, designated Lander Module 3 (LM3). The LM2 and LM3 designs were first presented at AIAA Space 2007. The LM2 and LM3 concepts have recently been extensively redesigned. The specific objective of this paper is to present these revised designs. The LM2 and LM3 landers are based on a common design that can be configured to carry either crew or cargo. They utilize a combination of aerodynamic reentry, parachutes, and propulsive braking to decelerate from orbital velocity to a soft landing. The LM2 crew lander provides two-way transportation for a nominal three-person crew between Mars orbit and the surface, and provides life support for a 30-day contingency mission. It contains an ascent section to return the crew to orbit after completion of surface operations. The LM3 cargo lander provides one-way, autonomous transportation of cargo from Mars orbit to the surface and can be configured to carry a mix of consumables and equipment, or equipment only. Lander service life and endurance is based on the Spaceship Discovery conjunction-class Design Reference Mission 2. The LM3 is designed to extend the surface stay for three crew members in an LM2 crew lander such that two sets of crew and cargo landers enable human exploration of the surface for the bulk of the 454 day wait time at Mars, in two shifts of three crew members each. Design requirements, mission profiles, mass properties, performance data, and configuration layouts are presented for the LM2 crew and LM3 cargo landers. These lander designs are a proposed solution to the problem of safely transporting a human crew from Mars orbit to the surface, sustaining them for extended periods of time on the surface, and returning them

  19. MARS PATHFINDER LANDER REMOVED FROM SHIPPING CONTAINER IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the SAEF-2 spacecraft checkout facility at Kennedy Space Center, engineers and technicians from Jet Propulsion Laboratory remove the Mars Pathfinder lander from its shipping container, still covered in protective wrapping. Pictured from L-R, Linda Robeck, Jerry Gutierrez, Lorraine Garcia, Chuck Foehlinger of JPL. The arrival of the spacecraft at KSC from Pasadena, CA occurred on Aug. 13, 1996. Launch of Mars Pathfinder aboard a McDonnell Douglas Delta II rocket will occur from Pad B at Complex 17 on Dec. 2.

  20. Acoustic Sources of Accent in Second Language Japanese Speech.

    PubMed

    Idemaru, Kaori; Wei, Peipei; Gubbins, Lucy

    2018-05-01

    This study reports an exploratory analysis of the acoustic characteristics of second language (L2) speech which give rise to the perception of a foreign accent. Japanese speech samples were collected from American English and Mandarin Chinese speakers ( n = 16 in each group) studying Japanese. The L2 participants and native speakers ( n = 10) provided speech samples modeling after six short sentences. Segmental (vowels and stops) and prosodic features (rhythm, tone, and fluency) were examined. Native Japanese listeners ( n = 10) rated the samples with regard to degrees of foreign accent. The analyses predicting accent ratings based on the acoustic measurements indicated that one of the prosodic features in particular, tone (defined as high and low patterns of pitch accent and intonation in this study), plays an important role in robustly predicting accent rating in L2 Japanese across the two first language (L1) backgrounds. These results were consistent with the prediction based on phonological and phonetic comparisons between Japanese and English, as well as Japanese and Mandarin Chinese. The results also revealed L1-specific predictors of perceived accent in Japanese. The findings of this study contribute to the growing literature that examines sources of perceived foreign accent.

  1. Accents in the workplace: their effects during a job interview.

    PubMed

    Deprez-Sims, Anne-Sophie; Morris, Scott B

    2010-12-01

    As the workplace becomes increasingly global, organizations are more likely to employ persons from other countries whose accents clearly identify them as different from the local workforce. Understanding the impact of accents in the workplace is important because accents can be salient in the same way as ethnicity, age, gender, and skin color and may be a source of employment discrimination. The present study looked at the influence of accents on the evaluation of job applicants during an interview for a human resource manager position. Participants from the US were asked to evaluate an applicant with one of three accents (Midwestern US, French, Colombian) by listening to an audiofile. The results showed that the applicant with the Midwestern US accent was evaluated more positively than the applicant with the French accent; however, the applicant with the Colombian accent did not receive an evaluation that differed significantly from those given to the applicants with either the French or the Midwestern US accent. Analyses of process variables indicated that the bias against the French-accented applicant was mediated by perceived lower similarity. These results are consistent with the similarity-attraction hypothesis, which states that demographic variables will impact judgments to the extent to which they make the decision-maker view the applicant as similar or dissimilar. The ability of accent to trigger bias highlights the importance of considering the full array of characteristics that can lead to discrimination in employment settings. Research on employment discrimination has traditionally focused on visual cues such as gender and ethnicity, but in an interview situation, the way the applicant speaks is also important.

  2. Viking Lander Model

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Viking Project found a place in history when it became the first mission to land a spacecraft successfully on the surface of another planet and return both imaging and non-imaging data over an extended time period. Two identical spacecraft, each consisting of a lander and an orbiter, were built. Each orbiter-lander pair flew together and entered Mars orbit; the landers then separated and descended to the planet's surface.

    The Viking 1 Lander touched down on the western slope of Chryse Planitia (the Plains of Gold) on July 20, 1976, while the Viking 2 lander settled down at Utopia Planitia on September 3, 1976.

    Besides taking photographs and collecting other science data on the Martian surface, the two landers conducted three biology experiments designed to look for possible signs of life. These experiments discovered unexpected and enigmatic chemical activity in the Martian soil, but provided no clear evidence for the presence of living microorganisms in soil near the landing sites. According to scientists, Mars is self-sterilizing. They believe the combination of solar ultraviolet radiation that saturates the surface, the extreme dryness of the soil and the oxidizing nature of the soil chemistry prevent the formation of living organisms in the Martian soil.

    The Viking mission was planned to continue for 90 days after landing. Each orbiter and lander operated far beyond its design lifetime. Viking Orbiter 1 functioned until July 25, 1978, while Viking Orbiter 2 continued for four years and 1,489 orbits of Mars, concluding its mission August 7, 1980. Because of the variations in available sunlight, both landers were powered by radioisotope thermoelectric generators -- devices that create electricity from heat given off by the natural decay of plutonium. That power source allowed long-term science investigations that otherwise would not have been possible. The last data from Viking Lander 2 arrived at Earth on April 11, 1980. Viking Lander

  3. Intonation in Neurogenic Foreign Accent Syndrome

    ERIC Educational Resources Information Center

    Kuschmann, Anja; Lowit, Anja; Miller, Nick; Mennen, Ineke

    2012-01-01

    Foreign accent syndrome (FAS) is a motor speech disorder in which changes to segmental as well as suprasegmental aspects lead to the perception of a foreign accent in speech. This paper focuses on one suprasegmental aspect, namely that of intonation. It provides an in-depth analysis of the intonation system of four speakers with FAS with the aim…

  4. An ERP Investigation of Regional and Foreign Accent Processing

    ERIC Educational Resources Information Center

    Goslin, Jeremy; Duffy, Hester; Floccia, Caroline

    2012-01-01

    This study used event-related potentials (ERPs) to examine whether we employ the same normalisation mechanisms when processing words spoken with a regional accent or foreign accent. Our results showed that the Phonological Mapping Negativity (PMN) following the onset of the final word of sentences spoken with an unfamiliar regional accent was…

  5. The influence of talker and foreign-accent variability on spoken word identification.

    PubMed

    Bent, Tessa; Holt, Rachael Frush

    2013-03-01

    In spoken word identification and memory tasks, stimulus variability from numerous sources impairs performance. In the current study, the influence of foreign-accent variability on spoken word identification was evaluated in two experiments. Experiment 1 used a between-subjects design to test word identification in noise in single-talker and two multiple-talker conditions: multiple talkers with the same accent and multiple talkers with different accents. Identification performance was highest in the single-talker condition, but there was no difference between the single-accent and multiple-accent conditions. Experiment 2 further explored word recognition for multiple talkers in single-accent versus multiple-accent conditions using a mixed design. A detriment to word recognition was observed in the multiple-accent condition compared to the single-accent condition, but the effect differed across the language backgrounds tested. These results demonstrate that the processing of foreign-accent variation may influence word recognition in ways similar to other sources of variability (e.g., speaking rate or style) in that the inclusion of multiple foreign accents can result in a small but significant performance decrement beyond the multiple-talker effect.

  6. Children's comprehension of an unfamiliar speaker accent: a review.

    PubMed

    Harte, Jennifer; Oliveira, Ana; Frizelle, Pauline; Gibbon, Fiona

    2016-05-01

    The effect of speaker accent on listeners' comprehension has become a key focus of research given the increasing cultural diversity of society and the increased likelihood of an individual encountering a clinician with an unfamiliar accent. To review the studies exploring the effect of an unfamiliar accent on language comprehension in typically developing (TD) children and in children with speech and language difficulties. This review provides a methodological analysis of the relevant studies by exploring the challenges facing this field of research and highlighting the current gaps in the literature. A total of nine studies were identified using a systematic search and organized under studies investigating the effect of speaker accent on language comprehension in (1) TD children and (2) children with speech and/or language difficulties. This review synthesizes the evidence that an unfamiliar speaker accent may lead to a breakdown in language comprehension in TD children and in children with speech difficulties. Moreover, it exposes the inconsistencies found in this field of research and highlights the lack of studies investigating the effect of speaker accent in children with language deficits. Overall, research points towards a developmental trend in children's ability to comprehend accent-related variations in speech. Vocabulary size, language exposure, exposure to different accents and adequate processing resources (e.g. attention) seem to play a key role in children's ability to understand unfamiliar accents. This review uncovered some inconsistencies in the literature that highlight the methodological issues that must be considered when conducting research in this field. It explores how such issues may be controlled in order to increase the validity and reliability of future research. Key clinical implications are also discussed. © 2016 Royal College of Speech and Language Therapists.

  7. Accent Detection and Social Cognition: Evidence of Protracted Learning

    ERIC Educational Resources Information Center

    Creel, Sarah C.

    2018-01-01

    How and when do children become aware that speakers have different accents? While adults readily make a variety of subtle social inferences based on speakers' accents, findings from children are more mixed: while one line of research suggests that even infants may be acutely sensitive to accent unfamiliarity, other studies suggest that 5-year-olds…

  8. Human Missions to Mars Orbit, Phobos, and Mars Surface Using 100-kWe-Class Solar Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Price, Humphrey W.; Woolley, Ryan C.; Strange, Nathan J.; Baker, John D.

    2014-01-01

    Solar electric propulsion (SEP) tugs in the 100-kWe range, may be utilized to preposition cargo in the Mars system to enable more affordable human missions to Phobos and to the surface of Mars. The SEP tug, a high heritage follow-on to the 50-kWe SEP spacecraft proposed for the Asteroid Redirect Robotic Mission (ARRM), would have the same structure, tankage, electric propulsion components, and avionics as the ARRM version, But with double the number of solar arrays, Hall thrusters, and power processor units (PPUs) and would be accommodated within the same launch envelope defined for ARRM. As a feasibility study, a 950-day human mission to Phobos using a conjunction class trajectory, such as the 2033 opportunity, was developed using two 100-kWe SEP vehicles to preposition a habitat at Phobos and propulsion stages in high Mars orbit (HMO). An architecture concept for a crewed Mars surface lander mission was also developed as a reference to build on the Phobos mission architecture, adding a lander element that could be delivered using chemical propulsion and aerocapture.

  9. Is Language a Factor in the Perception of Foreign Accent Syndrome?

    PubMed

    Jose, Linda; Read, Jennifer; Miller, Nick

    2016-06-01

    Neurogenic foreign accent syndrome (FAS) is diagnosed when listeners perceive speech associated with motor speech impairments as foreign rather than disordered. Speakers with foreign accent syndrome typically have aphasia. It remains unclear how far language changes might contribute to the perception of foreign accent syndrome independent of accent. Judges with and without training in language analysis rated orthographic transcriptions of speech from people with foreign accent syndrome, speech-language disorder and no foreign accent syndrome, foreign accent without neurological impairment and healthy controls on scales of foreignness, normalness and disorderedness. Control speakers were judged as significantly more normal, less disordered and less foreign than other groups. Foreign accent syndrome speakers' transcriptions consistently profiled most closely to those of foreign speakers and significantly different to speakers with speech-language disorder. On normalness and foreignness ratings there were no significant differences between foreign and foreign accent syndrome speakers. For disorderedness, foreign accent syndrome participants fell midway between foreign speakers and those with speech-language impairment only. Slower rate, more hesitations, pauses within and between utterances influenced judgments, delineating control scripts from others. Word-level syntactic and morphological deviations and reduced syntactic and semantic repertoire linked strongly with foreignness perceptions. Greater disordered ratings related to word fragments, poorly intelligible grammatical structures and inappropriate word selection. Language changes influence foreignness perception. Clinical and theoretical issues are addressed.

  10. Phoenix Mars Lander with Solar Arrays Open

    NASA Technical Reports Server (NTRS)

    2006-01-01

    NASA's next Mars-bound spacecraft, the Phoenix Mars Lander, was partway through assembly and testing at Lockheed Martin Space Systems, Denver, in September 2006, progressing toward an August 2007 launch from Florida. In this photograph, spacecraft specialists work on the lander after its fan-like circular solar arrays have been spread open for testing. The arrays will be in this configuration when the spacecraft is active on the surface of Mars.

    Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. It will dig into the surface, test scooped-up samples for carbon-bearing compounds and serve as NASA's first exploration of a potential modern habitat on Mars.

    The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

  11. Phoenix Lander on Mars (Stereo)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Phoenix Mars Lander monitors the atmosphere overhead and reaches out to the soil below in this stereo illustration of the spacecraft fully deployed on the surface of Mars. The image appears three-dimensional when viewed through red-green stereo glasses.

    Phoenix has been assembled and tested for launch in August 2007 from Cape Canaveral Air Force Station, Fla., and for landing in May or June 2008 on an arctic plain of far-northern Mars. The mission responds to evidence returned from NASA's Mars Odyssey orbiter in 2002 indicating that most high-latitude areas on Mars have frozen water mixed with soil within arm's reach of the surface.

    Phoenix will use a robotic arm to dig down to the expected icy layer. It will analyze scooped-up samples of the soil and ice for factors that will help scientists evaluate whether the subsurface environment at the site ever was, or may still be, a favorable habitat for microbial life. The instruments on Phoenix will also gather information to advance understanding about the history of the water in the icy layer. A weather station on the lander will conduct the first study Martian arctic weather from ground level.

    The vertical green line in this illustration shows how the weather station on Phoenix will use a laser beam from a lidar instrument to monitor dust and clouds in the atmosphere. The dark 'wings' to either side of the lander's main body are solar panels for providing electric power.

    The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems, Denver. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen (Denmark), the Max Planck Institute (Germany) and the Finnish Meteorological institute. JPL is a division of the California

  12. Listening with an accent: speech perception in a second language by late bilinguals.

    PubMed

    Leikin, Mark; Ibrahim, Raphiq; Eviatar, Zohar; Sapir, Shimon

    2009-10-01

    The goal of the present study was to examine functioning of late bilinguals in their second language. Specifically, we asked how native and non-native Hebrew speaking listeners perceive accented and native-accented Hebrew speech. To achieve this goal we used the gating paradigm to explore the ability of healthy late fluent bilinguals (Russian and Arabic native speakers) to recognize words in L2 (Hebrew) when they were spoken in an accent like their own, a native accent (Hebrew speakers), or another foreign accent (American accent). The data revealed that for Hebrew speakers, there was no effect of accent, whereas for the two bilingual groups (Russian and Arabic native speakers), stimuli with an accent like their own and the native Hebrew accent, required significantly less phonological information than the other foreign accents. The results support the hypothesis that phonological assimilation works in a similar manner in these two different groups.

  13. Does a Regional Accent Perturb Speech Processing?

    ERIC Educational Resources Information Center

    Floccia, Caroline; Goslin, Jeremy; Girard, Frederique; Konopczynski, Gabrielle

    2006-01-01

    The processing costs involved in regional accent normalization were evaluated by measuring differences in lexical decision latencies for targets placed at the end of sentences with different French regional accents. Over a series of 6 experiments, the authors examined the time course of comprehension disruption by manipulating the duration and…

  14. Shibboleth: An Automated Foreign Accent Identification Program

    ERIC Educational Resources Information Center

    Frost, Wende

    2013-01-01

    The speech of non-native (L2) speakers of a language contains phonological rules that differentiate them from native speakers. These phonological rules characterize or distinguish accents in an L2. The Shibboleth program creates combinatorial rule-sets to describe the phonological pattern of these accents and classifies L2 speakers into their…

  15. When pitch Accents Encode Speaker Commitment: Evidence from French Intonation.

    PubMed

    Michelas, Amandine; Portes, Cristel; Champagne-Lavau, Maud

    2016-06-01

    Recent studies on a variety of languages have shown that a speaker's commitment to the propositional content of his or her utterance can be encoded, among other strategies, by pitch accent types. Since prior research mainly relied on lexical-stress languages, our understanding of how speakers of a non-lexical-stress language encode speaker commitment is limited. This paper explores the contribution of the last pitch accent of an intonation phrase to convey speaker commitment in French, a language that has stress at the phrasal level as well as a restricted set of pitch accents. In a production experiment, participants had to produce sentences in two pragmatic contexts: unbiased questions (the speaker had no particular belief with respect to the expected answer) and negatively biased questions (the speaker believed the proposition to be false). Results revealed that negatively biased questions consistently exhibited an additional unaccented F0 peak in the preaccentual syllable (an H+!H* pitch accent) while unbiased questions were often realized with a rising pattern across the accented syllable (an H* pitch accent). These results provide evidence that pitch accent types in French can signal the speaker's belief about the certainty of the proposition expressed in French. It also has implications for the phonological model of French intonation.

  16. Perception of Foreign Accent Syndrome Speech and Its Relation to Segmental Characteristics

    ERIC Educational Resources Information Center

    Dankovicova, Jana; Hunt, Claire

    2011-01-01

    Foreign accent syndrome (FAS) is an acquired neurogenic disorder characterized by altered speech that sounds foreign-accented. This study presents a British subject perceived to speak with an Italian (or Greek) accent after a brainstem (pontine) stroke. Native English listeners rated the strength of foreign accent and impairment they perceived in…

  17. Malaysian University Students' Attitudes towards Six Varieties of Accented Speech in English

    ERIC Educational Resources Information Center

    Ahmed, Zainab Thamer; Abdullah, Ain Nadzimah; Heng, Chan Swee

    2014-01-01

    Previous language attitude studies indicated that in many countries all over the world, English language learners perceived native accents, either American or British, more positively than the non-native accents such as the Japanese, Korean, and Austrian accents. However, in Malaysia it is still unclear which accent Malaysian learners of English…

  18. Two French-Speaking Cases of Foreign Accent Syndrome: An Acoustic-Phonetic Analysis

    ERIC Educational Resources Information Center

    Roy, Johanna-Pascale; Macoir, Joel; Martel-Sauvageau, Vincent; Boudreault, Carol-Ann

    2012-01-01

    Foreign accent syndrome (FAS) is an acquired neurologic disorder in which an individual suddenly and unintentionally speaks with an accent which is perceived as being different from his/her usual accent. This study presents an acoustic-phonetic description of two Quebec French-speaking cases. The first speaker presents a perceived accent shift to…

  19. Testing Phoenix Mars Lander Parachute in Idaho

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Lander, Spirit, and Opportunity, ensuring that lessons learned from past programs were incorporated into the Phoenix system.

    During the first 25 seconds of the three-minute period when Phoenix descends on its parachute, the spacecraft will cast away its heat shield and extend its three legs. About 43 seconds before reaching the surface of Mars, the lander will shed the parachute by separating from the backshell. The lander will begin firing its descent thrusters half a second after the separation from the backshell and continue using them until touchdown.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  20. Rock Moved by Mars Lander Arm, Stereo View

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The robotic arm on NASA's Phoenix Mars Lander slid a rock out of the way during the mission's 117th Martian day (Sept. 22, 2008) to gain access to soil that had been underneath the rock.The lander's Surface Stereo Imager took the two images for this stereo view later the same day, showing the rock, called 'Headless,' after the arm pushed it about 40 centimeters (16 inches) from its previous location.

    'The rock ended up exactly where we intended it to,' said Matt Robinson of NASA's Jet Propulsion Laboratory, robotic arm flight software lead for the Phoenix team.

    The arm had enlarged the trench near Headless two days earlier in preparation for sliding the rock into the trench. The trench was dug to about 3 centimeters (1.2 inches) deep. The ground surface between the rock's prior position and the lip of the trench had a slope of about 3 degrees downward toward the trench. Headless is about the size and shape of a VHS videotape.

    The Phoenix science team sought to move the rock in order to study the soil and the depth to subsurface ice underneath where the rock had been.

    This left-eye and right-eye images for this stereo view were taken at about 12:30 p.m., local solar time on Mars. The scene appears three-dimensional when seen through blue-red glasses.The view is to the north northeast of the lander.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  1. Mars pathfinder lander deployment mechanisms

    NASA Technical Reports Server (NTRS)

    Gillis-Smith, Greg R.

    1996-01-01

    The Mars Pathfinder Lander employs numerous mechanisms, as well as autonomous mechanical functions, during its Entry, Descent and Landing (EDL) Sequence. This is the first US lander of its kind, since it is unguided and airbag-protected for hard landing using airbags, instead of retro rockets, to soft land. The arrival condition, location, and orientation of the Lander will only be known by the computer on the Lander. The Lander will then autonomously perform the appropriate sequence to retract the airbags, right itself, and open, such that the Lander is nearly level with no airbag material covering the solar cells. This function uses two different types of mechanisms - the Airbag Retraction Actuators and the Lander Petal Actuators - which are designed for the high torque, low temperature, dirty environment and for limited life application. The development of these actuators involved investigating low temperature lubrication, Electrical Discharge Machining (EDM) to cut gears, and gear design for limited life use.

  2. What makes a rhythm complex? The influence of musical training and accent type on beat perception

    PubMed Central

    Burgoyne, J. Ashley; Odijk, Daan; Honing, Henkjan; Grahn, Jessica A.

    2018-01-01

    Perception of a regular beat in music is inferred from different types of accents. For example, increases in loudness cause intensity accents, and the grouping of time intervals in a rhythm creates temporal accents. Accents are expected to occur on the beat: when accents are “missing” on the beat, the beat is more difficult to find. However, it is unclear whether accents occurring off the beat alter beat perception similarly to missing accents on the beat. Moreover, no one has examined whether intensity accents influence beat perception more or less strongly than temporal accents, nor how musical expertise affects sensitivity to each type of accent. In two experiments, we obtained ratings of difficulty in finding the beat in rhythms with either temporal or intensity accents, and which varied in the number of accents on the beat as well as the number of accents off the beat. In both experiments, the occurrence of accents on the beat facilitated beat detection more in musical experts than in musical novices. In addition, the number of accents on the beat affected beat finding more in rhythms with temporal accents than in rhythms with intensity accents. The effect of accents off the beat was much weaker than the effect of accents on the beat and appeared to depend on musical expertise, as well as on the number of accents on the beat: when many accents on the beat are missing, beat perception is quite difficult, and adding accents off the beat may not reduce beat perception further. Overall, the different types of accents were processed qualitatively differently, depending on musical expertise. Therefore, these findings indicate the importance of designing ecologically valid stimuli when testing beat perception in musical novices, who may need different types of accent information than musical experts to be able to find a beat. Furthermore, our findings stress the importance of carefully designing rhythms for social and clinical applications of beat perception, as

  3. What makes a rhythm complex? The influence of musical training and accent type on beat perception.

    PubMed

    Bouwer, Fleur L; Burgoyne, J Ashley; Odijk, Daan; Honing, Henkjan; Grahn, Jessica A

    2018-01-01

    Perception of a regular beat in music is inferred from different types of accents. For example, increases in loudness cause intensity accents, and the grouping of time intervals in a rhythm creates temporal accents. Accents are expected to occur on the beat: when accents are "missing" on the beat, the beat is more difficult to find. However, it is unclear whether accents occurring off the beat alter beat perception similarly to missing accents on the beat. Moreover, no one has examined whether intensity accents influence beat perception more or less strongly than temporal accents, nor how musical expertise affects sensitivity to each type of accent. In two experiments, we obtained ratings of difficulty in finding the beat in rhythms with either temporal or intensity accents, and which varied in the number of accents on the beat as well as the number of accents off the beat. In both experiments, the occurrence of accents on the beat facilitated beat detection more in musical experts than in musical novices. In addition, the number of accents on the beat affected beat finding more in rhythms with temporal accents than in rhythms with intensity accents. The effect of accents off the beat was much weaker than the effect of accents on the beat and appeared to depend on musical expertise, as well as on the number of accents on the beat: when many accents on the beat are missing, beat perception is quite difficult, and adding accents off the beat may not reduce beat perception further. Overall, the different types of accents were processed qualitatively differently, depending on musical expertise. Therefore, these findings indicate the importance of designing ecologically valid stimuli when testing beat perception in musical novices, who may need different types of accent information than musical experts to be able to find a beat. Furthermore, our findings stress the importance of carefully designing rhythms for social and clinical applications of beat perception, as not

  4. Recognition memory reveals just how CONTRASTIVE contrastive accenting really is

    PubMed Central

    Fraundorf, Scott H.; Watson, Duane G.; Benjamin, Aaron S.

    2010-01-01

    The effects of pitch accenting on memory were investigated in three experiments. Participants listened to short recorded discourses that contained contrast sets with two items (e.g. British scientists and French scientists); a continuation specified one item from the set. Pitch accenting on the critical word in the continuation was manipulated between non-contrastive (H* in the ToBI system) and contrastive (L+H*). On subsequent recognition memory tests, the L+H* accent increased hits to correct statements and correct rejections of the contrast item (Experiments 1–3), but did not impair memory for other parts of the discourse (Experiment 2). L+H* also did not facilitate correct rejections of lures not in the contrast set (Experiment 3), indicating that contrastive accents do not simply strengthen the representation of the target item. These results suggest comprehenders use pitch accenting to encode and update information about multiple elements in a contrast set. PMID:20835405

  5. Structural Influences on Initial Accent Placement in French

    ERIC Educational Resources Information Center

    Astesano, Corine; Bard, Ellen Gurman; Turk, Alice

    2007-01-01

    In addition to the phrase-final accent (FA), the French phonological system includes a phonetically distinct Initial Accent (IA). The present study tested two proposals: that IA marks the onset of phonological phrases, and that it has an independent rhythmic function. Eight adult native speakers of French were instructed to read syntactically…

  6. Scandinavian Accents in Their Relation to One Another

    ERIC Educational Resources Information Center

    Liberman, A. S.

    1975-01-01

    This paper is concerned with four Scandinavian prosodemes: accent 1, accent 2, stoed, and no stoed. The aim is to establish the function of each of them, i.e., the role they play in the system of each Scandinavian language. Available from Liber Laeromedel, Box 1205, S-22105 Lund, Sweden. (Author/TL)

  7. Relative Difficulty of Understanding Foreign Accents as a Marker of Proficiency

    ERIC Educational Resources Information Center

    Lev-Ari, Shiri; van Heugten, Marieke; Peperkamp, Sharon

    2017-01-01

    Foreign-accented speech is generally harder to understand than native-accented speech. This difficulty is reduced for non-native listeners who share their first language with the non-native speaker. It is currently unclear, however, how non-native listeners deal with foreign-accented speech produced by speakers of a different language. We show…

  8. Phonological and Phonetic Marking of Information Status in Foreign Accent Syndrome

    ERIC Educational Resources Information Center

    Kuschmann, Anja; Lowit, Anja

    2012-01-01

    Background: Foreign Accent Syndrome (FAS) is a motor speech disorder in which a variety of segmental and suprasegmental errors lead to the perception of a new accent in speech. Whilst changes in intonation have been identified to contribute considerably to the perceived alteration in accent, research has rarely focused on how these changes impact…

  9. Solar System Exploration Augmented by In-Situ Resource Utilization: Mercury and Saturn Propulsion Investigations

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan

    2016-01-01

    Human and robotic missions to Mercury and Saturn are presented and analyzed with a range of propulsion options. Historical studies of space exploration, in-situ resource utilization (ISRU), and industrialization all point to the vastness of natural resources in the solar system. Advanced propulsion benefitted from these resources in many ways. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal and nuclear pulse propulsion as well as advanced chemical propulsion can significantly enhance these scenarios. Updated analyses based on these historical visions will be presented. Nuclear thermal propulsion and ISRU enhanced chemical propulsion landers are assessed for Mercury missions. At Saturn, nuclear pulse propulsion with alternate propellant feed systems and Titan exploration with chemical propulsion options are discussed. In-situ resource utilization was found to be critical in making Mercury missions more amenable for human visits. At Saturn, refueling using local atmospheric mining was found to be difficult to impractical, while refueling the Saturn missions from Uranus was more practical and less complex.

  10. Native Speakers' Perceptions of Fluency and Accent in L2 Speech

    ERIC Educational Resources Information Center

    Pinget, Anne-France; Bosker, Hans Rutger; Quené, Hugo; de Jong, Nivja H.

    2014-01-01

    Oral fluency and foreign accent distinguish L2 from L1 speech production. In language testing practices, both fluency and accent are usually assessed by raters. This study investigates what exactly native raters of fluency and accent take into account when judging L2. Our aim is to explore the relationship between objectively measured temporal,…

  11. Perception and analysis of Spanish accents in English speech

    NASA Astrophysics Data System (ADS)

    Chism, Cori; Lass, Norman

    2002-05-01

    The purpose of the present study was to determine what relates most closely to the degree of perceived foreign accent in the English speech of native Spanish speakers: intonation, vowel length, stress, voice onset time (VOT), or segmental accuracy. Nineteen native English speaking listeners rated speech samples from 7 native English speakers and 15 native Spanish speakers for comprehensibility and degree of foreign accent. The speech samples were analyzed spectrographically and perceptually to obtain numerical values for each variable. Correlation coefficients were computed to determine the relationship beween these values and the average foreign accent scores. Results showed that the average foreign accent scores were statistically significantly correlated with three variables: the length of stressed vowels (r=-0.48, p=0.05), voice onset time (r =-0.62, p=0.01), and segmental accuracy (r=0.92, p=0.001). Implications of these findings and suggestions for future research are discussed.

  12. Strength of German accent under altered auditory feedback

    PubMed Central

    HOWELL, PETER; DWORZYNSKI, KATHARINA

    2007-01-01

    Borden’s (1979, 1980) hypothesis that speakers with vulnerable speech systems rely more heavily on feedback monitoring than do speakers with less vulnerable systems was investigated. The second language (L2) of a speaker is vulnerable, in comparison with the native language, so alteration to feedback should have a detrimental effect on it, according to this hypothesis. Here, we specifically examined whether altered auditory feedback has an effect on accent strength when speakers speak L2. There were three stages in the experiment. First, 6 German speakers who were fluent in English (their L2) were recorded under six conditions—normal listening, amplified voice level, voice shifted in frequency, delayed auditory feedback, and slowed and accelerated speech rate conditions. Second, judges were trained to rate accent strength. Training was assessed by whether it was successful in separating German speakers speaking English from native English speakers, also speaking English. In the final stage, the judges ranked recordings of each speaker from the first stage as to increasing strength of German accent. The results show that accents were more pronounced under frequency-shifted and delayed auditory feedback conditions than under normal or amplified feedback conditions. Control tests were done to ensure that listeners were judging accent, rather than fluency changes caused by altered auditory feedback. The findings are discussed in terms of Borden’s hypothesis and other accounts about why altered auditory feedback disrupts speech control. PMID:11414137

  13. Factors affecting the perception of Korean-accented American English

    NASA Astrophysics Data System (ADS)

    Cho, Kwansun; Harris, John G.; Shrivastav, Rahul

    2005-09-01

    This experiment examines the relative contribution of two factors, intonation and articulation errors, on the perception of foreign accent in Korean-accented American English. Ten native speakers of Korean and ten native speakers of American English were asked to read ten English sentences. These sentences were then modified using high-quality speech resynthesis techniques [STRAIGHT Kawahara et al., Speech Commun. 27, 187-207 (1999)] to generate four sets of stimuli. In the first two sets of stimuli, the intonation patterns of the Korean speakers and American speakers were switched with one another. The articulatory errors for each speaker were not modified. In the final two sets, the sentences from the Korean and American speakers were resynthesized without any modifications. Fifteen listeners were asked to rate all the stimuli for the degree of foreign accent. Preliminary results show that, for native speakers of American English, articulation errors may play a greater role in the perception of foreign accent than errors in intonation patterns. [Work supported by KAIM.

  14. Psychogenic Foreign Accent Syndrome: A New Case

    PubMed Central

    Keulen, Stefanie; Verhoeven, Jo; De Page, Louis; Jonkers, Roel; Bastiaanse, Roelien; Mariën, Peter

    2016-01-01

    This paper presents the case of a 33-year-old, right-handed, French-speaking Belgian lady who was involved in a car accident as a pedestrian. Six months after the incident she developed a German/Flemish-like accent. The patient's medical history, the onset of the FAS and the possible psychological causes of the accent change are analyzed. Relevant neuropsychological, neurolinguistic, and psychodiagnostic test results are presented and discussed. The psychodiagnostic interview and testing will receive special attention, because these have been underreported in previous FAS case reports. Furthermore, an accent rating experiment was carried out in order to assess the foreign quality of the patient's speech. Pre- and post-morbid spontaneous speech samples were analyzed phonetically to identify the pronunciation characteristics associated with this type of FAS. Several findings were considered essential in the diagnosis of psychogenic FAS: the psychological assessments as well as the clinical interview confirmed the presence of psychological problems, while neurological damage was excluded by means of repeated neuroimaging and neurological examinations. The type and nature of the speech symptoms and the accent fluctuations associated with the patient's psychological state cannot be explained by a neurological disorder. Moreover, the indifference of the patient toward her condition may also suggest a psychogenic etiology, as the opposite is usually observed in neurogenic FAS patients. PMID:27148003

  15. Network science landers for Mars

    NASA Astrophysics Data System (ADS)

    Harri, A.-M.; Marsal, O.; Lognonne, P.; Leppelmeier, G. W.; Spohn, T.; Glassmeier, K.-H.; Angrilli, F.; Banerdt, W. B.; Barriot, J. P.; Bertaux, J.-L.; Berthelier, J. J.; Calcutt, S.; Cerisier, J. C.; Crisp, D.; Dehant, V.; Giardini, D.; Jaumann, R.; Langevin, Y.; Menvielle, M.; Musmann, G.; Pommereau, J. P.; di Pippo, S.; Guerrier, D.; Kumpulainen, K.; Larsen, S.; Mocquet, A.; Polkko, J.; Runavot, J.; Schumacher, W.; Siili, T.; Simola, J.; Tillman, J. E.

    1999-01-01

    The NetLander Mission will deploy four landers to the Martian surface. Each lander includes a network science payload with instrumentation for studying the interior of Mars, the atmosphere and the subsurface, as well as the ionospheric structure and geodesy. The NetLander Mission is the first planetary mission focusing on investigations of the interior of the planet and the large-scale circulation of the atmosphere. A broad consortium of national space agencies and research laboratories will implement the mission. It is managed by CNES (the French Space Agency), with other major players being FMI (the Finnish Meteorological Institute), DLR (the German Space Agency), and other research institutes. According to current plans, the NetLander Mission will be launched in 2005 by means of an Ariane V launch, together with the Mars Sample Return mission. The landers will be separated from the spacecraft and targeted to their locations on the Martian surface several days prior to the spacecraft's arrival at Mars. The landing system employs parachutes and airbags. During the baseline mission of one Martian year, the network payloads will conduct simultaneous seismological, atmospheric, magnetic, ionospheric, geodetic measurements and ground penetrating radar mapping supported by panoramic images. The payloads also include entry phase measurements of the atmospheric vertical structure. The scientific data could be combined with simultaneous observations of the atmosphere and surface of Mars by the Mars Express Orbiter that is expected to be functional during the NetLander Mission's operational phase. Communication between the landers and the Earth would take place via a data relay onboard the Mars Express Orbiter.

  16. Pitch structure, but not selective attention, affects accent weightings in metrical grouping.

    PubMed

    Prince, Jon B

    2014-10-01

    Among other cues, pitch and temporal accents contribute to grouping in musical sequences. However, exactly how they combine remains unclear, possibly because of the role of structural organization. In 3 experiments, participants rated the perceived metrical grouping of sequences that either adhered to the rules of tonal Western musical pitch structure (musical key) or did not (atonal). The tonal status of sequences did not provide any grouping cues and was irrelevant to the task. Experiment 1 established equally strong levels of pitch leap accents and duration accents in baseline conditions, which were then recombined in subsequent experiments. Neither accent type was stronger or weaker for tonal and atonal contexts. In Experiment 2, pitch leap accents dominated over duration accents, but the extent of this advantage was greater when sequences were tonal. Experiment 3 ruled out an attentional origin of this effect by replicating this finding while explicitly manipulating attention to pitch or duration accents between participant groups. Overall, the presence of tonal pitch structure made the dimension of pitch more salient at the expense of time. These findings support a dimensional salience framework in which the presence of organizational structure prioritizes the processing of the more structured dimension regardless of task relevance, independent from psychophysical difficulty, and impervious to attentional allocation.

  17. Foreign-Accented Speech Perception Ratings: A Multifactorial Case Study

    ERIC Educational Resources Information Center

    Kraut, Rachel; Wulff, Stefanie

    2013-01-01

    Seventy-eight native English speakers rated the foreign-accented speech (FAS) of 24 international students enrolled in an Intensive English programme at a public university in Texas on degree of accent, comprehensibility and communicative ability. Variables considered to potentially impact listeners' ratings were the sex of the speaker, the first…

  18. Measuring Implicit and Explicit Attitudes toward Foreign-Accented Speech

    ERIC Educational Resources Information Center

    Pantos, Andrew J.

    2010-01-01

    The purpose of this research was to investigate the nature of listeners' attitudes toward foreign-accented speech and the manner in which those attitudes are formed. This study measured 165 participants' implicit and explicit attitudes toward US- and foreign-accented audio stimuli. Implicit attitudes were measured with an audio Implicit…

  19. Effects of age and hearing loss on recognition of unaccented and accented multisyllabic words.

    PubMed

    Gordon-Salant, Sandra; Yeni-Komshian, Grace H; Fitzgibbons, Peter J; Cohen, Julie I

    2015-02-01

    The effects of age and hearing loss on recognition of unaccented and accented words of varying syllable length were investigated. It was hypothesized that with increments in length of syllables, there would be atypical alterations in syllable stress in accented compared to native English, and that these altered stress patterns would be sensitive to auditory temporal processing deficits with aging. Sets of one-, two-, three-, and four-syllable words with the same initial syllable were recorded by one native English and two Spanish-accented talkers. Lists of these words were presented in isolation and in sentence contexts to younger and older normal-hearing listeners and to older hearing-impaired listeners. Hearing loss effects were apparent for unaccented and accented monosyllabic words, whereas age effects were observed for recognition of accented multisyllabic words, consistent with the notion that altered syllable stress patterns with accent are sensitive for revealing effects of age. Older listeners also exhibited lower recognition scores for moderately accented words in sentence contexts than in isolation, suggesting that the added demands on working memory for words in sentence contexts impact recognition of accented speech. The general pattern of results suggests that hearing loss, age, and cognitive factors limit the ability to recognize Spanish-accented speech.

  20. Effects of age and hearing loss on recognition of unaccented and accented multisyllabic words

    PubMed Central

    Gordon-Salant, Sandra; Yeni-Komshian, Grace H.; Fitzgibbons, Peter J.; Cohen, Julie I.

    2015-01-01

    The effects of age and hearing loss on recognition of unaccented and accented words of varying syllable length were investigated. It was hypothesized that with increments in length of syllables, there would be atypical alterations in syllable stress in accented compared to native English, and that these altered stress patterns would be sensitive to auditory temporal processing deficits with aging. Sets of one-, two-, three-, and four-syllable words with the same initial syllable were recorded by one native English and two Spanish-accented talkers. Lists of these words were presented in isolation and in sentence contexts to younger and older normal-hearing listeners and to older hearing-impaired listeners. Hearing loss effects were apparent for unaccented and accented monosyllabic words, whereas age effects were observed for recognition of accented multisyllabic words, consistent with the notion that altered syllable stress patterns with accent are sensitive for revealing effects of age. Older listeners also exhibited lower recognition scores for moderately accented words in sentence contexts than in isolation, suggesting that the added demands on working memory for words in sentence contexts impact recognition of accented speech. The general pattern of results suggests that hearing loss, age, and cognitive factors limit the ability to recognize Spanish-accented speech. PMID:25698021

  1. Effects and modeling of phonetic and acoustic confusions in accented speech.

    PubMed

    Fung, Pascale; Liu, Yi

    2005-11-01

    Accented speech recognition is more challenging than standard speech recognition due to the effects of phonetic and acoustic confusions. Phonetic confusion in accented speech occurs when an expected phone is pronounced as a different one, which leads to erroneous recognition. Acoustic confusion occurs when the pronounced phone is found to lie acoustically between two baseform models and can be equally recognized as either one. We propose that it is necessary to analyze and model these confusions separately in order to improve accented speech recognition without degrading standard speech recognition. Since low phonetic confusion units in accented speech do not give rise to automatic speech recognition errors, we focus on analyzing and reducing phonetic and acoustic confusability under high phonetic confusion conditions. We propose using likelihood ratio test to measure phonetic confusion, and asymmetric acoustic distance to measure acoustic confusion. Only accent-specific phonetic units with low acoustic confusion are used in an augmented pronunciation dictionary, while phonetic units with high acoustic confusion are reconstructed using decision tree merging. Experimental results show that our approach is effective and superior to methods modeling phonetic confusion or acoustic confusion alone in accented speech, with a significant 5.7% absolute WER reduction, without degrading standard speech recognition.

  2. Atmospheric Mining in the Outer Solar System: Outer Planet Orbital Transfer and Lander Analyses

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan

    2016-01-01

    Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. Analyses of orbital transfer vehicles (OTVs), landers, and the issues with in-situ resource utilization (ISRU) mining factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points. For analyses of round trip OTV flights from Uranus to Miranda or Titania, a 10-Megawatt electric (MWe) OTV power level and a 200-metric ton (MT) lander payload were selected based on a relative short OTV trip time and minimization of the number of lander flights. A similar optimum power level is suggested for OTVs flying from low orbit around Neptune to Thalassa or Triton. Several moon base sites at Uranus and Neptune and the OTV requirements to support them are also addressed.

  3. Atmospheric Mining in the Outer Solar System: Outer Planet Orbital Transfer and Lander Analyses

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan

    2016-01-01

    Atmospheric mining in the outer solar system has been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and deuterium can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and deuterium were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of atmospheric mining in the outer solar system. This included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. Analyses of orbital transfer vehicles (OTVs), landers, and the issues with in-situ resource utilization (ISRU) mining factories are included. Preliminary observations are presented on near-optimal selections of moon base orbital locations, OTV power levels, and OTV and lander rendezvous points. For analyses of round trip OTV flights from Uranus to Miranda or Titania, a 10- Megawatt electric (MWe) OTV power level and a 200 metricton (MT) lander payload were selected based on a relative short OTV trip time and minimization of the number of lander flights. A similar optimum power level is suggested for OTVs flying from low orbit around Neptune to Thalassa or Triton. Several moon base sites at Uranus and Neptune and the OTV requirements to support them are also addressed.

  4. Cold Helium Pressurization for Liquid Oxygen / Liquid Methane Propulsion Systems: Fully-Integrated Initial Hot-Fire Test Results

    NASA Technical Reports Server (NTRS)

    Morehead, R. L.; Atwell, M. J.; Melcher, J. C.; Hurlbert, E. A.

    2016-01-01

    A prototype cold helium active pressurization system was incorporated into an existing liquid oxygen (LOX) / liquid methane (LCH4) prototype planetary lander and hot-fire tested to collect vehicle-level performance data. Results from this hot-fire test series were used to validate integrated models of the vehicle helium and propulsion systems and demonstrate system effectiveness for a throttling lander. Pressurization systems vary greatly in complexity and efficiency between vehicles, so a pressurization performance metric was also developed as a means to compare different active pressurization schemes. This implementation of an active repress system is an initial sizing draft. Refined implementations will be tested in the future, improving the general knowledge base for a cryogenic lander-based cold helium system.

  5. Plug nozzles - The ultimate customer driven propulsion system. [applied to manned lunar and Martian landers

    NASA Technical Reports Server (NTRS)

    Aukerman, Carl A.

    1991-01-01

    This paper presents the results of a study applying the plug cluster nozzle concept to the propulsion system for a typical lunar excursion vehicle. Primary attention for the design criteria is given to user defined factors such as reliability, low volume, and ease of propulsion system development. Total thrust and specific impulse are held constant in the study while other parameters are explored to minimize the design chamber pressure. A brief history of the plug nozzle concept is included to point out the advanced level of technology of the concept and the feasibility of exploiting the variables considered in the study. The plug cluster concept looks very promising as a candidate for consideration for the ultimate customer driven propulsion system.

  6. Feasibility of a Dragon-Derived Mars Lander for Scientific and Human-Precursor Missions

    NASA Technical Reports Server (NTRS)

    Karcz, John S.; Davis, Sanford S.; Allen, Gary A.; Glass, Brian J.; Gonzales, Andrew; Heldmann, Jennifer Lynne; Lemke, Lawrence G.; McKay, Chris; Stoker, Carol R.; Wooster, Paul Douglass; hide

    2013-01-01

    A minimally-modified SpaceX Dragon capsule launched on a Falcon Heavy rocket presents the possibility of a new low-cost, high-capacity Mars lander for robotic missions. We have been evaluating such a "Red Dragon" platform as an option for the Icebreaker Discovery Program mission concept. Dragon is currently in service ferrying cargo to and from the International Space Station, and a crew transport version is in development. The upcoming version, unlike other Earth-return vehicles, exhibits most of the capabilities necessary to land on Mars. In particular, it has a set of high-thrust, throttleable, storable bi-propellant "SuperDraco" engines integrated directly into the capsule that are intended for launch abort and powered landings on Earth. These thrusters provide the possibility of a parachute-free, fully-propulsive deceleration at Mars from supersonic speeds to the surface, a descent approach which would also scale well to larger future human landers. We will discuss the motivations for exploring a Red Dragon lander, the current results of our analysis of its feasibility and capabilities, and the implications of the platform for the Icebreaker mission concept. In particular, we will examine entry, descent, and landing (EDL) in detail. We will also describe the modifications to Dragon necessary for interplanetary cruise, EDL, and operations on the Martian surface. Our analysis to date indicates that a Red Dragon lander is feasible and that it would be capable of delivering more than 1000 kg of payload to sites at elevations three kilometers below the Mars Orbiter Laser Altimeter (MOLA) reference, which includes sites throughout most of the northern plains and Hellas.

  7. Mars atmospheric circulation - Aspects from Viking Landers

    NASA Technical Reports Server (NTRS)

    Ryan, J. A.

    1985-01-01

    Winds measured by the two Viking Landers have been filtered and then compared with predictions from the general circulation model and to Orbiter observations of clouds and surface phenomena that indicate wind direction. This was done to determine the degree to which filtered winds may represent aspects of the general circulation. Excellent agreement was found between wind direction data from Lander 1 and the model predictions and Orbiter observations. For Lander 2, agreement was generally good, but there were periods of disagreement which indicate that the filtering did not remove other extraneous effects. It is concluded that Lander 1 gives a good representation of the general circulation at 22.5 deg N latitude but that Lander 2 is suspect. Most wind data from Lander 1 have yet to be analyzed. It appears that when analyzed these Lander 1 data (covering 3.5 Mars years) can provide information about interannual variations in the general circulation at the Lander latitude.

  8. MITEE-B: A Compact Ultra Lightweight Bi-Modal Nuclear Propulsion Engine for Robotic Planetary Science Missions

    NASA Astrophysics Data System (ADS)

    Powell, James; Maise, George; Paniagua, John; Borowski, Stanley

    2003-01-01

    Nuclear thermal propulsion (NTP) enables unique new robotic planetary science missions that are impossible with chemical or nuclear electric propulsion systems. A compact and ultra lightweight bi-modal nuclear engine, termed MITEE-B (MInature ReacTor EnginE - Bi-Modal) can deliver 1000's of kilograms of propulsive thrust when it operates in the NTP mode, and many kilowatts of continuous electric power when it operates in the electric generation mode. The high propulsive thrust NTP mode enables spacecraft to land and takeoff from the surface of a planet or moon, to hop to multiple widely separated sites on the surface, and virtually unlimited flight in planetary atmospheres. The continuous electric generation mode enables a spacecraft to replenish its propellant by processing in-situ resources, provide power for controls, instruments, and communications while in space and on the surface, and operate electric propulsion units. Six examples of unique and important missions enabled by the MITEE-B engine are described, including: (1) Pluto lander and sample return; (2) Europa lander and ocean explorer; (3) Mars Hopper; (4) Jupiter atmospheric flyer; (5) SunBurn hypervelocity spacecraft; and (6) He3 mining from Uranus. Many additional important missions are enabled by MITEE-B. A strong technology base for MITEE-B already exists. With a vigorous development program, it could be ready for initial robotic science and exploration missions by 2010 AD. Potential mission benefits include much shorter in-space times, reduced IMLEO requirements, and replenishment of supplies from in-situ resources.

  9. Novel Accent Perception in Typically-Developing School-Aged Children

    ERIC Educational Resources Information Center

    Newton, Caroline; Ridgway, Samuel

    2016-01-01

    Many schools in Western countries like the United Kingdom have become increasingly diverse communities in recent years, and children are likely to be exposed to a variety of accents that are different from their own. While there is a wide body of research exploring accent comprehension in the adult population and in infancy, little has been done…

  10. Event-related potential evidence of processing lexical pitch-accent in auditory Japanese sentences.

    PubMed

    Koso, Ayumi; Hagiwara, Hiroko

    2009-09-23

    Neural mechanisms that underlie the processing of lexical pitch-accent in auditory Japanese were investigated by using event-related potentials. Native speakers of Japanese listened to two types of short sentences, both consisting of a noun and a verb. The sentences ended with a verb with either congruous or incongruous pitch-accent pattern, where pitch-accent violations occur at the verb in the incongruent condition. The event-related potentials of the incongruent condition showed an increased widespread negativity that started 400 ms after the onset of the deviant lexical item and lasted for about 400 ms. These results suggest that the negativity evoked by violations in lexical-pitch accent indicates electrophysiological evidence for the online processing of lexical-pitch accent in auditory Japanese.

  11. A Market of Accents

    ERIC Educational Resources Information Center

    Blommaert, Jan

    2009-01-01

    This paper describes the cultural semantics of internet courses in American accent. Such courses are offered by corporate providers to specific groups of customers: people in search of success in the globalized business environment. The core of such courses is an order of indexicality which stresses uniformity and homogeneity, producing an…

  12. Life Support Systems for Lunar Landers

    NASA Technical Reports Server (NTRS)

    Anderson, Molly

    2008-01-01

    Engineers designing life support systems for NASA s next Lunar Landers face unique challenges. As with any vehicle that enables human spaceflight, the needs of the crew drive most of the lander requirements. The lander is also a key element of the architecture NASA will implement in the Constellation program. Many requirements, constraints, or optimization goals will be driven by interfaces with other projects, like the Crew Exploration Vehicle, the Lunar Surface Systems, and the Extravehicular Activity project. Other challenges in the life support system will be driven by the unique location of the vehicle in the environments encountered throughout the mission. This paper examines several topics that may be major design drivers for the lunar lander life support system. There are several functional requirements for the lander that may be different from previous vehicles or programs and recent experience. Some of the requirements or design drivers will change depending on the overall Lander configuration. While the configuration for a lander design is not fixed, designers can examine how these issues would impact their design and be prepared for the quick design iterations required to optimize a spacecraft.

  13. Lunar lander conceptual design

    NASA Technical Reports Server (NTRS)

    Lee, Joo Ahn; Carini, John; Choi, Andrew; Dillman, Robert; Griffin, Sean J.; Hanneman, Susan; Mamplata, Caesar; Stanton, Edward

    1989-01-01

    A conceptual design is presented of a Lunar Lander, which can be the primary vehicle to transport the equipment necessary to establish a surface lunar base, the crew that will man the base, and the raw materials which the Lunar Station will process. A Lunar Lander will be needed to operate in the regime between the lunar surface and low lunar orbit (LLO), up to 200 km. This lander is intended for the establishment and operation of a manned surface base on the moon and for the support of the Lunar Space Station. The lander will be able to fulfill the requirements of 3 basic missions: A mission dedicated to delivering maximum payload for setting up the initial lunar base; Multiple missions between LLO and lunar surface dedicated to crew rotation; and Multiple missions dedicated to cargo shipments within the regime of lunar surface and LLO. A complete set of structural specifications is given.

  14. NEXT-Lunar Lander -an Opportunity for a Close Look at the Lunar South Pole

    NASA Astrophysics Data System (ADS)

    Homeister, Maren; Thaeter, Joachim; Scheper, Marc; Apeldoorn, Jeffrey; Koebel, David

    The NEXT-Lunar Lander mission, as contracted by ESA and investigated by OHB-System and its industrial study team, has two main purposes. The first is technology demonstration for enabling technologies like propulsion-based soft precision landing for future planetary landing missions. This involves also enabling technology experiments, like fuel cell, life science and life support, which are embedded in the stationary payload of the lander. The second main and equally important aspect is the in-situ investigation of the surface of the Moon at the lunar South Pole by stationary payload inside the Lander, deployable payload to be placed in the vicinity of the lander and mobile payload carried by a rover. The currently assessed model payload includes 15 instruments on the lander and additional five on the rover. They are addressing the fields geophysics, geochemistry, geology and radio astronomy preparation. The mission is currently under investigation in frame of a phase A mission study contract awarded by ESA to two independent industrial teams, of which one is led by OHB-System. The phase A activities started in spring 2008 and were conducted until spring 2010. A phase B is expected shortly afterwards. The analysed mission architectures range from a Soyuz-based mission to a Shared-Ariane V class mission via different transfer trajectories. Depending on the scenario payload masses including servicing of 70 to 150 kg can be delivered to the lunar surface. The lander can offer different services to the payload. The stationary payload is powered and conditioned by the lander. Examples for embarked payloads are an optical camera system, a Radio Science Experiment and a radiation monitor. The lander surface payload is deployed to the lunar surface by a 5 DoF robotic arm and will be powered by the Lander. To this group of payloads belong seismometers, a magnetometer and an instrumented Mole. The mobile payload will be carried by a rover. The rover is equipped with its own

  15. ROSETTA lander Philae: Touch-down reconstruction

    NASA Astrophysics Data System (ADS)

    Roll, Reinhard; Witte, Lars

    2016-06-01

    The landing of the ROSETTA-mission lander Philae on November 12th 2014 on Comet 67 P/Churyumov-Gerasimenko was planned as a descent with passive landing and anchoring by harpoons at touch-down. Actually the lander was not fixed at touch-down to the ground due to failing harpoons. The lander internal damper was actuated at touch-down for 42.6 mm with a speed of 0.08 m/s while the lander touch-down speed was 1 m/s. The kinetic energy before touch-down was 50 J, 45 J were dissipated by the lander internal damper and by ground penetration at touch-down, and 5 J kinetic energy are left after touch-down (0.325 m/s speed). Most kinetic energy was dissipated by ground penetration (41 J) while only 4 J are dissipated by the lander internal damper. Based on these data, a value for a constant compressive soil-strength of between 1.55 kPa and 1.8 kPa is calculated. This paper focuses on the reconstruction of the touch-down at Agilkia over a period of around 20 s from first ground contact to lift-off again. After rebound Philae left a strange pattern on ground documented by the OSIRIS Narrow Angle Camera (NAC). The analysis shows, that the touch-down was not just a simple damped reflection on the surface. Instead the lander had repeated contacts with the surface over a period of about 20 s±10 s. This paper discusses scenarios for the reconstruction of the landing sequence based on the data available and on computer simulations. Simulations are performed with a dedicated mechanical multi-body model of the lander, which was validated previously in numerous ground tests. The SIMPACK simulation software was used, including the option to set forces at the feet to the ground. The outgoing velocity vector is mostly influenced by the timing of the ground contact of the different feet. It turns out that ground friction during damping has strong impact on the lander outgoing velocity, on its rotation, and on its nutation. After the end of damping, the attitude of the lander can be

  16. A Short Note on Accent-Bias, Social Identity and Ethnocentrism

    ERIC Educational Resources Information Center

    Chakraborty, Rahul

    2017-01-01

    This paper discusses the interrelations among accent-based biases, social identity and ethnocentrism. Construction of social identity creates a set of ethnocentric values within a person, which indirectly or directly plays a pivotal role in generating accent related biases. Starting with Tajfel's (1959) social identity theory and then the…

  17. Entry Vehicle Control System Design for the Mars Smart Lander

    NASA Technical Reports Server (NTRS)

    Calhoun, Philip C.; Queen, Eric M.

    2002-01-01

    The NASA Langley Research Center, in cooperation with the Jet Propulsion Laboratory, participated in a preliminary design study of the Entry, Descent and Landing phase for the Mars Smart Lander Project. This concept utilizes advances in Guidance, Navigation and Control technology to significantly reduce uncertainty in the vehicle landed location on the Mars surface. A candidate entry vehicle controller based on the Reaction Control System controller for the Apollo Lunar Excursion Module digital autopilot is proposed for use in the entry vehicle attitude control. A slight modification to the phase plane controller is used to reduce jet-firing chattering while maintaining good control response for the Martian entry probe application. The controller performance is demonstrated in a six-degree-of-freedom simulation with representative aerodynamics.

  18. Altair Lunar Lander Consumables Management

    NASA Technical Reports Server (NTRS)

    Polsgrove, Tara; Button, Robert; Linne, Diane

    2009-01-01

    The Altair lunar lander is scheduled to return humans to the moon in the year 2020. Keeping the crew of 4 and the vehicle functioning at their best while minimizing lander mass requires careful budgeting and management of consumables and cooperation with other constellation elements. Consumables discussed here include fluids, gasses, and energy. This paper presents the lander's missions and constraints as they relate to consumables and the design solutions that have been employed in recent Altair conceptual designs.

  19. Does seeing an Asian face make speech sound more accented?

    PubMed

    Zheng, Yi; Samuel, Arthur G

    2017-08-01

    Prior studies have reported that seeing an Asian face makes American English sound more accented. The current study investigates whether this effect is perceptual, or if it instead occurs at a later decision stage. We first replicated the finding that showing static Asian and Caucasian faces can shift people's reports about the accentedness of speech accompanying the pictures. When we changed the static pictures to dubbed videos, reducing the demand characteristics, the shift in reported accentedness largely disappeared. By including unambiguous items along with the original ambiguous items, we introduced a contrast bias and actually reversed the shift, with the Asian-face videos yielding lower judgments of accentedness than the Caucasian-face videos. By changing to a mixed rather than blocked design, so that the ethnicity of the videos varied from trial to trial, we eliminated the difference in accentedness rating. Finally, we tested participants' perception of accented speech using the selective adaptation paradigm. After establishing that an auditory-only accented adaptor shifted the perception of how accented test words are, we found that no such adaptation effect occurred when the adapting sounds relied on visual information (Asian vs. Caucasian videos) to influence the accentedness of an ambiguous auditory adaptor. Collectively, the results demonstrate that visual information can affect the interpretation, but not the perception, of accented speech.

  20. The neural processing of foreign-accented speech and its relationship to listener bias

    PubMed Central

    Yi, Han-Gyol; Smiljanic, Rajka; Chandrasekaran, Bharath

    2014-01-01

    Foreign-accented speech often presents a challenging listening condition. In addition to deviations from the target speech norms related to the inexperience of the nonnative speaker, listener characteristics may play a role in determining intelligibility levels. We have previously shown that an implicit visual bias for associating East Asian faces and foreignness predicts the listeners' perceptual ability to process Korean-accented English audiovisual speech (Yi et al., 2013). Here, we examine the neural mechanism underlying the influence of listener bias to foreign faces on speech perception. In a functional magnetic resonance imaging (fMRI) study, native English speakers listened to native- and Korean-accented English sentences, with or without faces. The participants' Asian-foreign association was measured using an implicit association test (IAT), conducted outside the scanner. We found that foreign-accented speech evoked greater activity in the bilateral primary auditory cortices and the inferior frontal gyri, potentially reflecting greater computational demand. Higher IAT scores, indicating greater bias, were associated with increased BOLD response to foreign-accented speech with faces in the primary auditory cortex, the early node for spectrotemporal analysis. We conclude the following: (1) foreign-accented speech perception places greater demand on the neural systems underlying speech perception; (2) face of the talker can exaggerate the perceived foreignness of foreign-accented speech; (3) implicit Asian-foreign association is associated with decreased neural efficiency in early spectrotemporal processing. PMID:25339883

  1. A Multi-Perspective Investigation of Attitudes towards English Accents in Hong Kong: Implications for Pronunciation Teaching

    ERIC Educational Resources Information Center

    Chan, Jim Y. H.

    2016-01-01

    The study reported in this article examined Hong Kong students' attitudes towards English accents from three interrelated perspectives: (1) their awareness of accents, (2) their perception of accents in relation to the dimensions of status and solidarity, and (3) their choice of accents in various local language-using contexts. By means of the…

  2. Interpreting Pitch Accents in Online Comprehension: H* vs. L+H*

    ERIC Educational Resources Information Center

    Watson, Duane G.; Tanenhaus, Michael K.; Gunlogson, Christine A.

    2008-01-01

    Although the presence or absence of a pitch accent clearly can play an important role in signaling the discourse and information structure of an utterance, whether the form of an accent determines the type of information it conveys is more controversial. We used an eye-tracking paradigm to investigate whether H*, which has been argued to signal…

  3. Accent modulates access to word meaning: Evidence for a speaker-model account of spoken word recognition.

    PubMed

    Cai, Zhenguang G; Gilbert, Rebecca A; Davis, Matthew H; Gaskell, M Gareth; Farrar, Lauren; Adler, Sarah; Rodd, Jennifer M

    2017-11-01

    Speech carries accent information relevant to determining the speaker's linguistic and social background. A series of web-based experiments demonstrate that accent cues can modulate access to word meaning. In Experiments 1-3, British participants were more likely to retrieve the American dominant meaning (e.g., hat meaning of "bonnet") in a word association task if they heard the words in an American than a British accent. In addition, results from a speeded semantic decision task (Experiment 4) and sentence comprehension task (Experiment 5) confirm that accent modulates on-line meaning retrieval such that comprehension of ambiguous words is easier when the relevant word meaning is dominant in the speaker's dialect. Critically, neutral-accent speech items, created by morphing British- and American-accented recordings, were interpreted in a similar way to accented words when embedded in a context of accented words (Experiment 2). This finding indicates that listeners do not use accent to guide meaning retrieval on a word-by-word basis; instead they use accent information to determine the dialectic identity of a speaker and then use their experience of that dialect to guide meaning access for all words spoken by that person. These results motivate a speaker-model account of spoken word recognition in which comprehenders determine key characteristics of their interlocutor and use this knowledge to guide word meaning access. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Mars Polar Lander: The Search Begins

    NASA Technical Reports Server (NTRS)

    1999-01-01

    [figure removed for brevity, see original site]

    Beginning Thursday, December 16, 1999, the Mars Global Surveyor (MGS) spacecraft initiated a search for visible evidence of the fate of the missing Mars Polar Lander using the high resolution Mars Orbiter Camera (MOC) operated by Malin Space Science Systems of San Diego, California. Mars Polar Lander was lost during its landing attempt near 76.3oS, 195.0oW on the martian south polar layered terrain on December 3, 1999. Although the likelihood of seeing the lander is quite small, the MOC effort might provide some clues that shed light on what happened to the lander. The problem, however, is one of 'pixels'--those little square boxes of different shades of gray that comprise a digital image.

    The two pictures above illustrate the difficulty of finding the lander in MOC images. The picture at the top of the page is the first of the images that were acquired to look for the lander--this one was snapped by MOC around 3:36 p.m. Greenwich time on December 16th. Local time on Mars was about 2 p.m. Portions of this image are shown at 1/4th scale (left), full-scale (1.5 meters, or 5 feet, per pixel--middle), and 10 times enlarged (right). Because the landing site is very far south (at this latitude on Earth, you would be in Antarctica), the Sun illumination is not ideal for taking high resolution pictures with MOC. Thus, the full-resolution MOC data for this region show a large amount of 'salt and pepper' noise, which arises from statistical fluctuations in how light falling on the MOC charge-coupled-device (CCD) detector is converted to electricity. Other aspects of the MOC electronics also introduce noise. These effects are greatly reduced when taking pictures of portions of Mars that have better, more direct sunlight, or when the images are taken at reduced resolution to, in effect, 'average-out' the noise.

    The lower picture shows a model of the Mars Polar Lander sitting on a carpet in a conference room at Malin

  5. Processing and Comprehension of Accented Speech by Monolingual and Bilingual Children

    ERIC Educational Resources Information Center

    McDonald, Margarethe; Gross, Megan; Buac, Milijana; Batko, Michelle; Kaushanskaya, Margarita

    2018-01-01

    This study tested the effect of Spanish-accented speech on sentence comprehension in children with different degrees of Spanish experience. The hypothesis was that earlier acquisition of Spanish would be associated with enhanced comprehension of Spanish-accented speech. Three groups of 5-6-year-old children were tested: monolingual…

  6. Contextual Evidence for the Representation of Pitch Accents in Standard Serbian

    ERIC Educational Resources Information Center

    Zsiga, Elizabeth; Zec, Draga

    2013-01-01

    This paper reports the results of an experiment that elicits contextual effects on Rising and Falling accents in Standard Serbian, with the goal of determining their acoustic correlates and their phonological representation. Materials systematically vary the distance between pitch accents, inducing "tone crowding," in order to identify the…

  7. Descent Assisted Split Habitat Lunar Lander Concept

    NASA Technical Reports Server (NTRS)

    Mazanek, Daniel D.; Goodliff, Kandyce; Cornelius, David M.

    2008-01-01

    The Descent Assisted Split Habitat (DASH) lunar lander concept utilizes a disposable braking stage for descent and a minimally sized pressurized volume for crew transport to and from the lunar surface. The lander can also be configured to perform autonomous cargo missions. Although a braking-stage approach represents a significantly different operational concept compared with a traditional two-stage lander, the DASH lander offers many important benefits. These benefits include improved crew egress/ingress and large-cargo unloading; excellent surface visibility during landing; elimination of the need for deep-throttling descent engines; potentially reduced plume-surface interactions and lower vertical touchdown velocity; and reduced lander gross mass through efficient mass staging and volume segmentation. This paper documents the conceptual study on various aspects of the design, including development of sortie and outpost lander configurations and a mission concept of operations; the initial descent trajectory design; the initial spacecraft sizing estimates and subsystem design; and the identification of technology needs

  8. Lander Trajectory Reconstruction computer program

    NASA Technical Reports Server (NTRS)

    Adams, G. L.; Bradt, A. J.; Ferguson, J. B.; Schnelker, H. J.

    1971-01-01

    The Lander Trajectory Reconstruction (LTR) computer program is a tool for analysis of the planetary entry trajectory and atmosphere reconstruction process for a lander or probe. The program can be divided into two parts: (1) the data generator and (2) the reconstructor. The data generator provides the real environment in which the lander or probe is presumed to find itself. The reconstructor reconstructs the entry trajectory and atmosphere using sensor data generated by the data generator and a Kalman-Schmidt consider filter. A wide variety of vehicle and environmental parameters may be either solved-for or considered in the filter process.

  9. Audiovisual cues benefit recognition of accented speech in noise but not perceptual adaptation

    PubMed Central

    Banks, Briony; Gowen, Emma; Munro, Kevin J.; Adank, Patti

    2015-01-01

    Perceptual adaptation allows humans to recognize different varieties of accented speech. We investigated whether perceptual adaptation to accented speech is facilitated if listeners can see a speaker’s facial and mouth movements. In Study 1, participants listened to sentences in a novel accent and underwent a period of training with audiovisual or audio-only speech cues, presented in quiet or in background noise. A control group also underwent training with visual-only (speech-reading) cues. We observed no significant difference in perceptual adaptation between any of the groups. To address a number of remaining questions, we carried out a second study using a different accent, speaker and experimental design, in which participants listened to sentences in a non-native (Japanese) accent with audiovisual or audio-only cues, without separate training. Participants’ eye gaze was recorded to verify that they looked at the speaker’s face during audiovisual trials. Recognition accuracy was significantly better for audiovisual than for audio-only stimuli; however, no statistical difference in perceptual adaptation was observed between the two modalities. Furthermore, Bayesian analysis suggested that the data supported the null hypothesis. Our results suggest that although the availability of visual speech cues may be immediately beneficial for recognition of unfamiliar accented speech in noise, it does not improve perceptual adaptation. PMID:26283946

  10. Audiovisual cues benefit recognition of accented speech in noise but not perceptual adaptation.

    PubMed

    Banks, Briony; Gowen, Emma; Munro, Kevin J; Adank, Patti

    2015-01-01

    Perceptual adaptation allows humans to recognize different varieties of accented speech. We investigated whether perceptual adaptation to accented speech is facilitated if listeners can see a speaker's facial and mouth movements. In Study 1, participants listened to sentences in a novel accent and underwent a period of training with audiovisual or audio-only speech cues, presented in quiet or in background noise. A control group also underwent training with visual-only (speech-reading) cues. We observed no significant difference in perceptual adaptation between any of the groups. To address a number of remaining questions, we carried out a second study using a different accent, speaker and experimental design, in which participants listened to sentences in a non-native (Japanese) accent with audiovisual or audio-only cues, without separate training. Participants' eye gaze was recorded to verify that they looked at the speaker's face during audiovisual trials. Recognition accuracy was significantly better for audiovisual than for audio-only stimuli; however, no statistical difference in perceptual adaptation was observed between the two modalities. Furthermore, Bayesian analysis suggested that the data supported the null hypothesis. Our results suggest that although the availability of visual speech cues may be immediately beneficial for recognition of unfamiliar accented speech in noise, it does not improve perceptual adaptation.

  11. Radiation Testing at Sandia National Laboratories: Sandia – JPL Collaboration for Europa Lander

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hattar, Khalid Mikhiel; Olszewska-Wasiolek, Maryla Aleksandra

    Sandia National Laboratories (SNL) is assisting Jet Propulsion Laboratory in undertaking feasibility studies and performance assessments for the Planetary Protection aspect of the Europa Lander mission. The specific areas of interest for this project are described by task number. This white paper presents the evaluation results for Task 2, Radiation Testing, which was stated as follows: Survey SNL facilities and capabilities for simulating the Europan radiation environment and assess suitability for: A. Testing batteries, electronics, and other component and subsystems B. Exposing biological organisms to assess their survivability metrics. The radiation environment the Europa Lander will encounter on route andmore » in orbit upon arrival at its destination consists primarily of charged particles, energetic protons and electrons with the energies up to 1 GeV. The charged particle environments can be simulated using the accelerators at the Ion Beam Laboratory. The Gamma Irradiation Facility and its annex, the Low Dose Rate Irradiation Facility, offer irradiations using Co-60 gamma sources (1.17 and 1.33 MeV), as well as Cs-137 gamma (0.661 MeV) AmBe neutron (0-10 MeV) sources.« less

  12. Lunar lander ground support system

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The design of the Lunar Lander Ground Support System (LLGSS) is examined. The basic design time line is around 2010 to 2030 and is referred to as a second generation system, as lunar bases and equipment would have been present. Present plans for lunar colonization call for a phased return of personnel and materials to the moons's surface. During settlement of lunar bases, the lunar lander is stationary in a very hostile environment and would have to be in a state of readiness for use in case of an emergency. Cargo and personnel would have to be removed from the lander and transported to a safe environment at the lunar base. An integrated system is required to perform these functions. These needs are addressed which center around the design of a lunar lander servicing system. The servicing system could perform several servicing functions to the lander in addition to cargo servicing. The following were considered: (1) reliquify hydrogen boiloff; (2) supply power; and (3) remove or add heat as necessary. The final design incorporates both original designs and existing vehicles and equipment on the surface of the moon at the time considered. The importance of commonality is foremost in the design of any lunar machinery.

  13. Viking lander spacecraft battery

    NASA Technical Reports Server (NTRS)

    Newell, D. R.

    1976-01-01

    The Viking Lander was the first spacecraft to fly a sterilized nickel-cadmium battery on a mission to explore the surface of a planet. The significant results of the battery development program from its inception through the design, manufacture, and test of the flight batteries which were flown on the two Lander spacecraft are documented. The flight performance during the early phase of the mission is also presented.

  14. Do College Instructors Have Implicit Bias toward Latino-Accented English Speakers?

    ERIC Educational Resources Information Center

    Na, Eunkyung

    2016-01-01

    The purpose of this study was to examine the implicit attitudes of college-level instructors toward Latino-accented English and the effects of gender, teaching experience, home language, race/ethnicity, and rank on those attitudes. The auditory Implicit Association Test (IAT) was used to measure the implicit accent preferences. Participants (N =…

  15. Children's Use of Semantic Context in Perception of Foreign-Accented Speech

    ERIC Educational Resources Information Center

    Holt, Rachael Frush; Bent, Tessa

    2017-01-01

    Purpose: The purpose of this study is to evaluate children's use of semantic context to facilitate foreign-accented word recognition in noise. Method: Monolingual American English speaking 5- to 7-year-olds (n = 168) repeated either Mandarin- or American English-accented sentences in babble, half of which contained final words that were highly…

  16. Utterance-Final Lengthening Is Predictive of Infants' Discrimination of English Accents

    ERIC Educational Resources Information Center

    White, Laurence; Floccia, Caroline; Goslin, Jeremy; Butler, Joseph

    2014-01-01

    Infants in their first year manifest selective patterns of discrimination between languages and between accents of the same language. Prosodic differences are held to be important in whether languages can be discriminated, together with the infant's familiarity with one or both of the accents heard. However, the nature of the prosodic cues that…

  17. Combining Solar Electric and Chemical Propulsion for Crewed Missions to Mars

    NASA Technical Reports Server (NTRS)

    Percy, Tom; McGuire, Melissa; Polsgrove, Tara

    2015-01-01

    This paper documents the results of an investigation of human Mars mission architectures that leverage near-term technology investments and infrastructures resulting from the planned Asteroid Redirect Mission, including high-power Solar Electric Propulsion (SEP) and a human presence in Lunar Distant Retrograde Orbit (LDRO). The architectures investigated use a combination of SEP and chemical propulsion elements. Through this combination of propulsion technologies, these architectures take advantage of the high efficiency SEP propulsion system to deliver cargo, while maintaining the faster trip times afforded by chemical propulsion for crew transport. Evolved configurations of the Asteroid Redirect Vehicle (ARV) are considered for cargo delivery. Sensitivities to SEP system design parameters, including power level and propellant quantity, are presented. For the crew delivery, liquid oxygen and methane stages were designed using engines common to future human Mars landers. Impacts of various Earth departure orbits, Mars loiter orbits, and Earth return strategies are presented. The use of the Space Launch System for delivery of the various architecture elements was also investigated and launch vehicle manifesting, launch scheduling and mission timelines are also discussed. The study results show that viable Mars architecture can be constructed using LDRO and SEP in order to take advantage of investments made in the ARM mission.

  18. Viking Lander 2 Anniversary

    NASA Image and Video Library

    2002-12-13

    This portion of NASA Mars Odyssey image covers NASA Viking 2 landing site shown with the X. The second landing on Mars took place September 3, 1976 in Utopia Planitia. The exact location of Lander 2 is not as well established as Lander 1 because there were no clearly identifiable features in the lander images as there were for the site of Lander 1. The Utopia landing site region contains pedestal craters, shallow swales and gentle ridges. The crater Goldstone was named in honor of the Tracking Station in the desert of California. The two Viking Landers operated for over 6 years (nearly four martian years) after landing. This one band IR (band 9 at 12.6 microns) image shows bright and dark textures, which are primarily due to differences in the abundance of rocks on the surface. The relatively cool (dark) regions during the day are rocky or indurated materials, fine sand and dust are warmer (bright). Many of the temperature variations are due to slope effects, with sun-facing slopes warmer than shaded slopes. The dark rings around several of the craters are due to the presence of rocky (cool) material ejected from the crater. These rocks are well below the resolution of any existing Mars camera, but THEMIS can detect the temperature variations they produce. Daytime temperature variations are produced by a combination of topographic (solar heating) and thermophysical (thermal inertia and albedo) effects. Due to topographic heating the surface morphologies seen in THEMIS daytime IR images are similar to those seen in previous imagery and MOLA topography. http://photojournal.jpl.nasa.gov/catalog/PIA04023

  19. The Lunar Lander "HabiTank" Concept

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.

    2007-01-01

    This paper will summarize the study that was conducted under the auspices of the National Aeronautics and Space Administration (NASA), lead by Johnson Space Center s Engineering Directorate in support of the Lunar Lander Preparatory Study (LLPS) as sponsored by the Constellation Program Office (CxPO), Advanced Projects Office (APO). The lunar lander conceptual design and analysis is intended to provide an understanding of requirements for human space exploration of the Moon using the Advanced Projects Office Pre-Lander Project Office selected "HabiTank" Lander concept. In addition, these analyses help identify system "drivers," or significant sources of cost, performance, risk, and schedule variation along with areas needing technology development. Recommendations, results, and conclusions in this paper do not reflect NASA policy or programmatic decisions. This paper is an executive summary of this study.

  20. Mercury Lander Mission Concept Study Summary

    NASA Astrophysics Data System (ADS)

    Eng, D. A.

    2018-05-01

    Provides a summary of the Mercury Lander Mission Concept Study performed as part of the last Planetary Decadal Survey. The presentation will focus on engineering trades and the challenges of developing a Mercury lander mission.

  1. Adaptation to novel foreign-accented speech and retention of benefit following training: Influence of aging and hearing loss

    PubMed Central

    Bieber, Rebecca E.; Gordon-Salant, Sandra

    2017-01-01

    Adaptation to speech with a foreign accent is possible through prior exposure to talkers with that same accent. For young listeners with normal hearing, short term, accent-independent adaptation to a novel foreign accent is also facilitated through exposure training with multiple foreign accents. In the present study, accent-independent adaptation is examined in younger and older listeners with normal hearing and older listeners with hearing loss. Retention of training benefit is additionally explored. Stimuli for testing and training were HINT sentences recorded by talkers with nine distinctly different accents. Following two training sessions, all listener groups showed a similar increase in speech perception for a novel foreign accent. While no group retained this benefit at one week post-training, results of a secondary reaction time task revealed a decrease in reaction time following training, suggesting reduced listening effort. Examination of listeners' cognitive skills reveals a positive relationship between working memory and speech recognition ability. The present findings indicate that, while this no-feedback training paradigm for foreign-accented English is successful in promoting short term adaptation for listeners, this paradigm is not sufficient in facilitation of perceptual learning with lasting benefits for younger or older listeners. PMID:28464671

  2. Resource Prospector Lander: Architecture and Trade Studies

    NASA Technical Reports Server (NTRS)

    Moore, Josh; Calvert, Derek; Frady, Greg; Chavers, Greg; Wayne, Andrew; Hull, Patrick; Lowery, Eric; Farmer, Jeff; Trinh, Huu; Rojdev, Kristina; hide

    2014-01-01

    NASA's Resource Prospector (RP) is a multi-center and multi-institution collaborative project to investigate the polar regions of the Moon in search of volatiles. The mission is rated Class D and is approximately 10 days. The RP vehicle comprises three elements: the Lander, the Rover, and the Payload. The Payload is housed on the Rover and the Rover is on top of the Lander. The focus of this paper is on the Lander element for the RP vehicle. The design of the Lander was requirements driven and focused on a low-cost approach. To arrive at the final configuration, several trade studies were conducted. Of those trade studies, there were six primary trade studies that were instrumental in determining the final design. This paper will discuss each of these trades in further detail and show how these trades led to the final architecture of the RP Lander.

  3. Intonation in neurogenic foreign accent syndrome.

    PubMed

    Kuschmann, Anja; Lowit, Anja; Miller, Nick; Mennen, Ineke

    2012-01-01

    Foreign accent syndrome (FAS) is a motor speech disorder in which changes to segmental as well as suprasegmental aspects lead to the perception of a foreign accent in speech. This paper focuses on one suprasegmental aspect, namely that of intonation. It provides an in-depth analysis of the intonation system of four speakers with FAS with the aim of establishing the intonational changes that have taken place as well as their underlying origin. Using the autosegmental-metrical framework of intonational analysis, four different levels of intonation, i.e., inventory, distribution, realisation and function, were examined in short sentences. Results revealed that the speakers with FAS had the same structural inventory at their disposal as the control speakers, but that they differed from the latter in relation to the distribution, implementation and functional use of their inventory. The current results suggest that these intonational changes cannot be entirely attributed to an underlying intonation deficit but reflect secondary manifestations of physiological constraints affecting speech support systems and compensatory strategies. These findings have implications for the debate surrounding intonational deficits in FAS, advocating a reconsideration of current assumptions regarding the underlying nature of intonation impairment in FAS. The reader will be able to (1) explain the relevance of intonation in defining foreign accent syndrome; (2) describe the process of intonation analysis within the autosegmental-metrical (AM) framework; and (3) discuss the manifestation of intonation changes in FAS at the different levels of intonation and their potential underlying nature. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Preparing the Phoenix Lander for Mars

    NASA Image and Video Library

    2005-06-01

    The Phoenix lander, housed in a 100,000-class clean room at Lockheed Martin Space Systems facilities near Denver, Colo. Shown here, the lander is contained inside the backshell portion of the aeroshell with the heat shield removed.

  5. Robotic Lunar Landers for Science and Exploration

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara A.

    2012-01-01

    The MSFC/APL Robotic Lunar Landing Project (RLLDP) team has developed lander concepts encompassing a range of mission types and payloads for science, exploration, and technology demonstration missions: (1) Developed experience and expertise in lander systems, (2) incorporated lessons learned from previous efforts to improve the fidelity of mission concepts, analysis tools, and test beds Mature small and medium lander designs concepts have been developed: (1) Share largely a common design architecture. (2) Flexible for a large number of mission and payload options. High risk development areas have been successfully addressed Landers could be selected for a mission with much of the concept formulation phase work already complete

  6. Factors Affecting Accent Acquisition: The Case of Russian Immigrants in Israel

    ERIC Educational Resources Information Center

    Abu-Rabia, Salim; Iliyan, Salman

    2011-01-01

    A debate centers on whether the native accent is acquired early in life or whether it can be acquired at any time. This study investigated factors that may affect native accent acquisition in a second language. Participants in this study were 50 Russians who immigrated to Israel, 17 males and 33 females. Their age on arrival was 5 to 25 years.…

  7. Chemistry Lab for Phoenix Mars Lander

    NASA Image and Video Library

    2007-08-02

    The targeted landing site for NASA Phoenix Mars Lander is at about 68 degrees north latitude, 233 degrees east longitude in the Martian arctic. The Phoenix lander, which landed May 25, 2008 ceased its operations about six months later.

  8. The role of accent imitation in sensorimotor integration during processing of intelligible speech

    PubMed Central

    Adank, Patti; Rueschemeyer, Shirley-Ann; Bekkering, Harold

    2013-01-01

    Recent theories on how listeners maintain perceptual invariance despite variation in the speech signal allocate a prominent role to imitation mechanisms. Notably, these simulation accounts propose that motor mechanisms support perception of ambiguous or noisy signals. Indeed, imitation of ambiguous signals, e.g., accented speech, has been found to aid effective speech comprehension. Here, we explored the possibility that imitation in speech benefits perception by increasing activation in speech perception and production areas. Participants rated the intelligibility of sentences spoken in an unfamiliar accent of Dutch in a functional Magnetic Resonance Imaging experiment. Next, participants in one group repeated the sentences in their own accent, while a second group vocally imitated the accent. Finally, both groups rated the intelligibility of accented sentences in a post-test. The neuroimaging results showed an interaction between type of training and pre- and post-test sessions in left Inferior Frontal Gyrus, Supplementary Motor Area, and left Superior Temporal Sulcus. Although alternative explanations such as task engagement and fatigue need to be considered as well, the results suggest that imitation may aid effective speech comprehension by supporting sensorimotor integration. PMID:24109447

  9. Life Support Systems for a New Lunar Lander

    NASA Technical Reports Server (NTRS)

    Anderson, Molly; Rotter, Henry; Stambaugh, Imelda; Yagoda, Evan

    2012-01-01

    A life support system concept has been developed for a new NASA lunar lander concept. The ground rules and assumptions driving the design of this vehicle are different from the Constellation Altair vehicle, and have led to a different design solution. For example, this concept assumes that the lander vehicle arrives in lunar orbit independently of the crew. It loiters in lunar orbit for months before rendezvousing with the Orion Multi-Purpose Crew Vehicle (MPCV), resulting in the use of solar power for this new lander, rather than fuel cells that provided product water to the life support system in the Altair vehicle. Without the need to perform a single Lunar Orbit Insertion burn for both the lander and the MPCV, the modules do not have to be centered in the same way, so the new lander has a smaller ascent module than Altair and a large habitat rather than a small airlock. This new lander utilizes suitport technology to perform EVAs from the habitat, which leads to significantly different requirements for the pressure control system. This paper describes the major trades and resulting concept design for the life support system of a new lunar lander concept. I

  10. Life Support Systems for a New Lunar Lander

    NASA Technical Reports Server (NTRS)

    Anderson, Molly; Rotter, Henry; Stambaugh, Imelda; Yagoda, Evan

    2011-01-01

    A life support system concept has been developed for a new NASA lunar lander concept. The ground rules and assumptions driving the design of this vehicle are different from the Constellation Altair vehicle, and have led to a different design solution. For example, this concept assumes that the lander vehicle arrives in lunar orbit independently of the crew. It loiters in lunar orbit for months before rendezvousing with the Orion Multi-Purpose Crew Vehicle (MPCV), resulting in the use of solar power for this new lander, rather than fuel cells that provided product water to the life support system in the Altair vehicle. Without the need to perform a single Lunar Orbit Insertion burn for both the lander and the MPCV, the modules do not have to be centered in the same way, so the new lander has a smaller ascent module than Altair and a large habitat rather than a small airlock. This new lander utilizes suitport technology to perform EVAs from the habitat, which leads to significantly different requirements for the pressure control system. This paper describes the major trades and resulting concept design for the life support system of a new lunar lander concept.

  11. Science Education and Public Outreach in Asia - experiences in ACCENT

    NASA Astrophysics Data System (ADS)

    Schuepbach, E.

    2006-12-01

    ACCENT is the European Network of Excellence in Atmospheric Composition Change (www.accent- network.org). Its Task Training and Education aims at disseminating ACCENT results to a variety of target groups, including emerging countries. Until now, fellowships have been offered for early-career scientists to participate in European science training events. A teacher training workshop has concentrated on cross- cultural aspects of PhD supervision. The involvement of new Associated Partners from Asia has triggered reflections on science education and outreach to politicians and the public in this part of the world. Joint educational and outreach programmes and products are currently developed with China and Mongolia for training activities scheduled in autumn 2006 and autumn 2007. First experiences in joint science education programmes for early-career scientists will be presented, and the challenges associated with communicating science to non-scientists in Asia will be discussed.

  12. Perception of intelligibility and qualities of non-native accented speakers.

    PubMed

    Fuse, Akiko; Navichkova, Yuliya; Alloggio, Krysteena

    To provide effective treatment to clients, speech-language pathologists must be understood, and be perceived to demonstrate the personal qualities necessary for therapeutic practice (e.g., resourcefulness and empathy). One factor that could interfere with the listener's perception of non-native speech is the speaker's accent. The current study explored the relationship between how accurately listeners could understand non-native speech and their perceptions of personal attributes of the speaker. Additionally, this study investigated how listeners' familiarity and experience with other languages may influence their perceptions of non-native accented speech. Through an online survey, native monolingual and bilingual English listeners rated four non-native accents (i.e., Spanish, Chinese, Russian, and Indian) on perceived intelligibility and perceived personal qualities (i.e., professionalism, intelligence, resourcefulness, empathy, and patience) necessary for speech-language pathologists. The results indicated significant relationships between the perception of intelligibility and the perception of personal qualities (i.e., professionalism, intelligence, and resourcefulness) attributed to non-native speakers. However, these findings were not supported for the Chinese accent. Bilingual listeners judged the non-native speech as more intelligible in comparison to monolingual listeners. No significant differences were found in the ratings between bilingual listeners who share the same language background as the speaker and other bilingual listeners. Based on the current findings, greater perception of intelligibility was the key to promoting a positive perception of personal qualities such as professionalism, intelligence, and resourcefulness, important for speech-language pathologists. The current study found evidence to support the claim that bilinguals have a greater ability in understanding non-native accented speech compared to monolingual listeners. The results

  13. The environs of viking 2 lander.

    PubMed

    Shorthill, R W; Moore, H J; Hutton, R E; Scott, R F; Spitzer, C R

    1976-12-11

    Forty-six days after Viking 1 landed, Viking 2 landed in Utopia Planitia, about 6500 kilometers away from the landing site of Viking 1. Images show that in the immediate vicinity of the Viking 2 landing site the surface is covered with rocks, some of which are partially buried, and fine-grained materials. The surface sampler, the lander cameras, engineering sensors, and some data from the other lander experiments were used to investigate the properties of the surface. Lander 2 has a more homogeneous surface, more coarse-grained material, an extensive crust, small rocks or clods which seem to be difficult to collect, and more extensive erosion by the retro-engine exhaust gases than lander 1. A report on the physical properties of the martian surface based on data obtained through sol 58 on Viking 2 and a brief description of activities on Viking 1 after sol 36 are given.

  14. The Role of Prosody in a Case of Foreign Accent Syndrome (FAS)

    ERIC Educational Resources Information Center

    Katz, William F.; Garst, Diane M.; Levitt, June

    2008-01-01

    Foreign accent syndrome (FAS) is a rare disorder characterized by the emergence of a perceived foreign accent following brain damage. The symptomotology, functional bases, and neural substrates of this disorder are still being elucidated. In this case study, acoustic analyses were performed on the speech of a 46-year old monolingual female who…

  15. Cross-Linguistic Expression of Contrastive Accent: Clinical Assessment in Spanish and English

    ERIC Educational Resources Information Center

    Martinez-Castilla, Pastora; Peppe, Sue

    2010-01-01

    Well-documented Romance-Germanic differences in the use of accent in speech to convey information-structure and focus cause problems for the assessment of prosodic skills in populations with clinical disorders. The strategies for assessing the ability to use lexical and contrastive accent in English and Spanish are reviewed, and studies in the…

  16. Low-cost unmanned lunar lander

    NASA Technical Reports Server (NTRS)

    Daniel, Walter K.

    1992-01-01

    Two student groups designed unmanned landers to deliver 200 kilogram payloads to the lunar surface. Payloads could include astronomical telescopes, small lunar rovers, and experiments related to future human exploration. Requirements include the use of existing hardware where possible, use of a medium-class launch vehicle, an unobstructed view of the sky for the payload, and access to the lunar surface for the payload. The projects were modeled after Artemis, a project that the NASA Office of Exploration is pursuing with a planned first launch in 1996. The Lunar Scout design uses a Delta 2 launch vehicle with a Star 48 motor for insertion into the trans-lunar trajectory. During the transfer, the solar panels will be folded inward and the spacecraft will be powered by rechargeable nickel-cadmium batteries. The lander will use a combination of a solid rocket motor and hydrazine thrusters for the descent to the lunar surface. The solar arrays will be deployed after landing. The lander will provide power for operations to the payload during the lunar day; batteries will provide 'stay-alive' power during the lunar night. A horn antenna on the lander will provide communications between the payload and the earth.

  17. Airbags to Martian Landers: Analyses at Sandia National Laboratories

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gwinn, K.W.

    1994-03-01

    A new direction for the national laboratories is to assist US business with research and development, primarily through cooperative research and development agreements (CRADAs). Technology transfer to the private sector has been very successful as over 200 CRADAs are in place at Sandia. Because of these cooperative efforts, technology has evolved into some new areas not commonly associated with the former mission of the national laboratories. An example of this is the analysis of fabric structures. Explicit analyses and expertise in constructing parachutes led to the development of a next generation automobile airbag; which led to the construction, testing, andmore » analysis of the Jet Propulsion Laboratory Mars Environmental Survey Lander; and finally led to the development of CAD based custom garment designs using 3D scanned images of the human body. The structural analysis of these fabric structures is described as well as a more traditional example Sandia with the test/analysis correlation of the impact of a weapon container.« less

  18. Speaker and Accent Variation Are Handled Differently: Evidence in Native and Non-Native Listeners

    PubMed Central

    Kriengwatana, Buddhamas; Terry, Josephine; Chládková, Kateřina; Escudero, Paola

    2016-01-01

    Listeners are able to cope with between-speaker variability in speech that stems from anatomical sources (i.e. individual and sex differences in vocal tract size) and sociolinguistic sources (i.e. accents). We hypothesized that listeners adapt to these two types of variation differently because prior work indicates that adapting to speaker/sex variability may occur pre-lexically while adapting to accent variability may require learning from attention to explicit cues (i.e. feedback). In Experiment 1, we tested our hypothesis by training native Dutch listeners and Australian-English (AusE) listeners without any experience with Dutch or Flemish to discriminate between the Dutch vowels /I/ and /ε/ from a single speaker. We then tested their ability to classify /I/ and /ε/ vowels of a novel Dutch speaker (i.e. speaker or sex change only), or vowels of a novel Flemish speaker (i.e. speaker or sex change plus accent change). We found that both Dutch and AusE listeners could successfully categorize vowels if the change involved a speaker/sex change, but not if the change involved an accent change. When AusE listeners were given feedback on their categorization responses to the novel speaker in Experiment 2, they were able to successfully categorize vowels involving an accent change. These results suggest that adapting to accents may be a two-step process, whereby the first step involves adapting to speaker differences at a pre-lexical level, and the second step involves adapting to accent differences at a contextual level, where listeners have access to word meaning or are given feedback that allows them to appropriately adjust their perceptual category boundaries. PMID:27309889

  19. Performance Optimization of the Gasdynamic Mirror Propulsion System

    NASA Technical Reports Server (NTRS)

    Emrich, William J., Jr.; Kammash, Terry

    1999-01-01

    Nuclear fusion appears to be a most promising concept for producing extremely high specific impulse rocket engines. Engines such as these would effectively open up the solar system to human exploration and would virtually eliminate launch window restrictions. A preliminary vehicle sizing and mission study was performed based on the conceptual design of a Gasdynamic Mirror (GDM) fusion propulsion system. This study indicated that the potential specific impulse for this engine is approximately 142,000 sec. with about 22,100 N of thrust using a deuterium-tritium fuel cycle. The engine weight inclusive of the power conversion system was optimized around an allowable engine mass of 1500 Mg assuming advanced superconducting magnets and a Field Reversed Configuration (FRC) end plug at the mirrors. The vehicle habitat, lander, and structural weights are based on a NASA Mars mission study which assumes the use of nuclear thermal propulsion' Several manned missions to various planets were analyzed to determine fuel requirements and launch windows. For all fusion propulsion cases studied, the fuel weight remained a minor component of the total system weight regardless of when the missions commenced. In other words, the use of fusion propulsion virtually eliminates all mission window constraints and effectively allows unlimited manned exploration of the entire solar system. It also mitigates the need to have a large space infrastructure which would be required to support the transfer of massive amounts of fuel and supplies to lower a performing spacecraft.

  20. How native-like can you possibly get: fMRI evidence for processing accent

    PubMed Central

    Ghazi-Saidi, Ladan; Dash, Tanya; Ansaldo, Ana I.

    2015-01-01

    Introduction: If ever attained, adopting native-like accent is achieved late in the learning process. Resemblance between L2 and mother tongue can facilitate L2 learning. In particular, cognates (phonologically and semantically similar words across languages), offer the opportunity to examine the issue of foreign accent in quite a unique manner. Methods: Twelve Spanish speaking (L1) adults learnt French (L2) cognates and practiced their native-like pronunciation by means of a computerized method. After consolidation, they were tested on L1 and L2 oral picture- naming during fMRI scanning. Results and Discussion: The results of the present study show that there is a specific impact of accent on brain activation, even if L2 words are cognates, and belong to a pair of closely related languages. Results point that the insula is a key component of accent processing, which is in line with reports from patients with foreign accent syndrome following damage to the insula (e.g., Katz et al., 2012; Moreno-Torres et al., 2013; Tomasino et al., 2013), and healthy L2 learners (Chee et al., 2004). Thus, the left insula has been consistently related to the integration of attentional and working memory abilities, together with fine-tuning of motor programming to achieve optimal articulation. PMID:26578931

  1. Speaker-independent factors affecting the perception of foreign accent in a second languagea)

    PubMed Central

    Levi, Susannah V.; Winters, Stephen J.; Pisoni, David B.

    2012-01-01

    Previous research on foreign accent perception has largely focused on speaker-dependent factors such as age of learning and length of residence. Factors that are independent of a speaker’s language learning history have also been shown to affect perception of second language speech. The present study examined the effects of two such factors—listening context and lexical frequency—on the perception of foreign-accented speech. Listeners rated foreign accent in two listening contexts: auditory-only, where listeners only heard the target stimuli, and auditory+orthography, where listeners were presented with both an auditory signal and an orthographic display of the target word. Results revealed that higher frequency words were consistently rated as less accented than lower frequency words. The effect of the listening context emerged in two interactions: the auditory +orthography context reduced the effects of lexical frequency, but increased the perceived differences between native and non-native speakers. Acoustic measurements revealed some production differences for words of different levels of lexical frequency, though these differences could not account for all of the observed interactions from the perceptual experiment. These results suggest that factors independent of the speakers’ actual speech articulations can influence the perception of degree of foreign accent. PMID:17471745

  2. A lighting metric for quantitative evaluation of accent lighting systems

    NASA Astrophysics Data System (ADS)

    Acholo, Cyril O.; Connor, Kenneth A.; Radke, Richard J.

    2014-09-01

    Accent lighting is critical for artwork and sculpture lighting in museums, and subject lighting for stage, Film and television. The research problem of designing effective lighting in such settings has been revived recently with the rise of light-emitting-diode-based solid state lighting. In this work, we propose an easy-to-apply quantitative measure of the scene's visual quality as perceived by human viewers. We consider a well-accent-lit scene as one which maximizes the information about the scene (in an information-theoretic sense) available to the user. We propose a metric based on the entropy of the distribution of colors, which are extracted from an image of the scene from the viewer's perspective. We demonstrate that optimizing the metric as a function of illumination configuration (i.e., position, orientation, and spectral composition) results in natural, pleasing accent lighting. We use a photorealistic simulation tool to validate the functionality of our proposed approach, showing its successful application to two- and three-dimensional scenes.

  3. In-Space Propulsion: Where We Stand and What's Next

    NASA Technical Reports Server (NTRS)

    Sackheim, Robert L.

    2003-01-01

    The focus of this paper will be on the three stages of in-space transportation propulsion systems, now commonly referred to as in-space propulsion (ISP); i.e., the transfer of payloads from low-Earth orbits into higher orbits or into trajectories for planetary encounters, including planetary landers and sample return launchers, if required. Functions required at the operational location where ISP must provide thrust for orbit include maintenance, position control, stationkeeping, and spacecraft altitude control; i.e., proper pointing and dynamic stability in inertial space; and the third function set to enable operations at various planetary locations, such as atmospheric entry and capture, descent to the surface and ascent, back to rendezvous orbit. The discussion will concentrate on where ISP stands today and some observations of what might be next in line for new ISP technologies and systems for near-term and future flight applications. The architectural choices that are applicable for ISP will also be described and discussed in detail.

  4. Business and Technology Students' Preferences for English-Language Accents: Implications for Business Communication.

    ERIC Educational Resources Information Center

    Scott, James Calvert; Green, Diana J.; Rosewarne, David

    1997-01-01

    Multiple recordings of a message in various accents were heard by 218 college students, including 26 nonnative English speakers. Ranked English accents in descending order were General American, British, Australian, Indian, Estuary, and Japanese. Perceptual differences were related to gender, ethnicity, nationality, and region. Implications for…

  5. Perceptual Accent Rating and Attribution in Psychogenic FAS: Some Further Evidence Challenging Whitaker’s Operational Definition

    PubMed Central

    Keulen, Stefanie; Verhoeven, Jo; Bastiaanse, Roelien; Mariën, Peter; Jonkers, Roel; Mavroudakis, Nicolas; Paquier, Philippe

    2016-01-01

    A 40-year-old, non-aphasic, right-handed, and polyglot (L1: French, L2: Dutch, and L3: English) woman with a 12-year history of addiction to opiates and psychoactive substances, and clear psychiatric problems, presented with a foreign accent of sudden onset in L1. Speech evolved toward a mostly fluent output, despite a stutter-like behavior and a marked grammatical output disorder. The psychogenic etiology of the accent foreignness was construed based on the patient’s complex medical history and psychodiagnostic, neuropsychological, and neurolinguistic assessments. The presence of a foreign accent was affirmed by a perceptual accent rating and attribution experiment. It is argued that this patient provides additional evidence demonstrating the outdatedness of Whitaker’s (1982) definition of foreign accent syndrome, as only one of the four operational criteria was unequivocally applicable to our patient: her accent foreignness was not only recognized by her relatives and the medical staff but also by a group of native French-speaking laymen. However, our patient defied the three remaining criteria, as central nervous system damage could not conclusively be demonstrated, psychodiagnostic assessment raised the hypothesis of a conversion disorder, and the patient was a polyglot whose newly gained accent was associated with a range of foreign languages, which exceeded the ones she spoke. PMID:26973488

  6. Viking 75 project: Viking lander system primary mission performance report

    NASA Technical Reports Server (NTRS)

    Cooley, C. G.

    1977-01-01

    Viking Lander hardware performance during launch, interplanetary cruise, Mars orbit insertion, preseparation, separation through landing, and the primary landed mission, with primary emphasis on Lander engineering and science hardware operations, the as-flown mission are described with respect to Lander system performance and anomalies during the various mission phases. The extended mission and predicted Lander performance is discussed along with a summary of Viking goals, mission plans, and description of the Lander, and its subsystem definitions.

  7. Decision Lists for Lexical Ambiguity Resolution: Application to Accent Restoration in Spanish and French

    DTIC Science & Technology

    1994-06-01

    and compute a table of accent pa t tern distributions as follows: De -accented Form Accent Pat tern cesse cesse cessd cout cofit couta coute...c6td du laisser de cote faute de temps (1) c6td appeler l’ autre cote de l’ at lantique (1) c6td passe de notre cote de la frontiere (2) cSte...vivre sur notre cote ouest toujours verte (2) c6te creer sur la cote du labrador des (2) cSte travaillaient cote a cote , ils avaient The training

  8. The invisible minority: revisiting the debate on foreign-accented speakers and upward mobility in the workplace.

    PubMed

    Akomolafe, Soji

    2013-01-01

    Of some of the major types of discrimination, the one that gets the least attention is national origin discrimination and in particular, accent discrimination, especially when it comes to upward mobility in the workplace. Yet, unlike other forms of discrimination, accent discrimination is rarely a subject of any robust public debate. This paper is a modest attempt to help establish a framework for understanding the relative neglect to which the discourse on accent discrimination has been subjected vis-a-vis the overall national debate on diversity. Hopefully, in the process, it will stimulate a more robust conversation on the plight of foreign-accented speakers.

  9. From One to Multiple Accents on a Test of L2 Listening Comprehension

    ERIC Educational Resources Information Center

    Ockey, Gary J.; French, Robert

    2016-01-01

    Concerns about the need for assessing multidialectal listening skills for global contexts are becoming increasingly prevalent. However, the inclusion of multiple accents on listening assessments may threaten test fairness because it is not practical to include every accent that may be encountered in the language use domain on these tests. Given…

  10. Perception of contrastive bi-syllabic lexical stress in unaccented and accented words by younger and older listeners.

    PubMed

    Gordon-Salant, Sandra; Yeni-Komshian, Grace H; Pickett, Erin J; Fitzgibbons, Peter J

    2016-03-01

    This study examined the ability of older and younger listeners to perceive contrastive syllable stress in unaccented and Spanish-accented cognate bi-syllabic English words. Younger listeners with normal hearing, older listeners with normal hearing, and older listeners with hearing impairment judged recordings of words that contrasted in stress that conveyed a noun or verb form (e.g., CONduct/conDUCT), using two paradigms differing in the amount of semantic support. The stimuli were spoken by four speakers: one native English speaker and three Spanish-accented speakers (one moderately and two mildly accented). The results indicate that all listeners showed the lowest accuracy scores in responding to the most heavily accented speaker and the highest accuracy in judging the productions of the native English speaker. The two older groups showed lower accuracy in judging contrastive lexical stress than the younger group, especially for verbs produced by the most accented speaker. This general pattern of performance was observed in the two experimental paradigms, although performance was generally lower in the paradigm without semantic support. The findings suggest that age-related difficulty in adjusting to deviations in contrastive bi-syllabic lexical stress produced with a Spanish accent may be an important factor limiting perception of accented English by older people.

  11. Perception of contrastive bi-syllabic lexical stress in unaccented and accented words by younger and older listeners

    PubMed Central

    Gordon-Salant, Sandra; Yeni-Komshian, Grace H.; Pickett, Erin J.; Fitzgibbons, Peter J.

    2016-01-01

    This study examined the ability of older and younger listeners to perceive contrastive syllable stress in unaccented and Spanish-accented cognate bi-syllabic English words. Younger listeners with normal hearing, older listeners with normal hearing, and older listeners with hearing impairment judged recordings of words that contrasted in stress that conveyed a noun or verb form (e.g., CONduct/conDUCT), using two paradigms differing in the amount of semantic support. The stimuli were spoken by four speakers: one native English speaker and three Spanish-accented speakers (one moderately and two mildly accented). The results indicate that all listeners showed the lowest accuracy scores in responding to the most heavily accented speaker and the highest accuracy in judging the productions of the native English speaker. The two older groups showed lower accuracy in judging contrastive lexical stress than the younger group, especially for verbs produced by the most accented speaker. This general pattern of performance was observed in the two experimental paradigms, although performance was generally lower in the paradigm without semantic support. The findings suggest that age-related difficulty in adjusting to deviations in contrastive bi-syllabic lexical stress produced with a Spanish accent may be an important factor limiting perception of accented English by older people. PMID:27036250

  12. Entry System Design Considerations for Mars Landers

    NASA Technical Reports Server (NTRS)

    Lockwood, Mary Kae; Powell, Richard W.; Graves, Claude A.; Carman, Gilbert L.

    2001-01-01

    The objective for the next generation or Mars landers is to enable a safe landing at specific locations of scientific interest. The 1st generation entry, descent and landing systems, ex. Viking and Pathfinder, provided successful landing on Mars but by design were limited to large scale, 100s of km, landing sites with minimal local hazards. The 2 nd generation landers, or smart landers, will provide scientists with access to previously unachievable landing sites by providing precision landing to less than 10 km of a target landing site, with the ability to perform local hazard avoidance, and provide hazard tolerance. This 2nd generation EDL system can be utilized for a range of robotic missions with vehicles sized for science payloads from the small 25-70 kg, Viking, Pathfinder, Mars Polar Lander and Mars Exploration Rover-class, to the large robotic Mars Sample Return, 300 kg plus, science payloads. The 2nd generation system can also be extended to a 3nd generation EDL system with pinpoint landing, 10's of meters of landing accuracy, for more capable robotic or human missions. This paper will describe the design considerations for 2nd generation landers. These landers are currently being developed by a consortium of NASA centers, government agencies, industry and academic institutions. The extension of this system and additional considerations required for a 3nd generation human mission to Mars will be described.

  13. Facilitation of creative performance by using blue and red accent lighting in work and learning areas.

    PubMed

    Kombeiz, Olga; Steidle, Anna

    2018-03-01

    Research has shown that colours influence motivation and cognitive performance. In achievement contexts, red evokes avoidance motivation that hinders creativity, while blue elicits an approach motivation that facilitates creativity. However, due to their position and mode of presentation, colours may convey a different message. Red accent lighting creates a cosy, friendly room atmosphere that may, even in an achievement context, elicit an approach rather than an avoidance motivation. Results (N = 146) showed that both blue and red accent light increased strategic approach motivation compared to white accent light. Moreover, through the heightened approach motivation, colourful accent light indirectly improved creative performance. Implications for future research on colour and practical implications for colour usage are discussed. Practitioner Summary: Designing work environments for creativity is a new topic in ergonomics research and practice. The present study demonstrates indirect effects of coloured accent light on creativity providing interesting possibilities for the design of workplaces for knowledge workers, classrooms and all other rooms in which people work on new ideas.

  14. Listening with an Accent: Speech Perception in a Second Language by Late Bilinguals

    ERIC Educational Resources Information Center

    Leikin, Mark; Ibrahim, Raphiq; Eviatar, Zohar; Sapir, Shimon

    2009-01-01

    The goal of the present study was to examine functioning of late bilinguals in their second language. Specifically, we asked how native and non-native Hebrew speaking listeners perceive accented and native-accented Hebrew speech. To achieve this goal we used the gating paradigm to explore the ability of healthy late fluent bilinguals (Russian and…

  15. Advanced Hall Electric Propulsion for Future In-space Transportation

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; Sankovic, John M.

    2001-01-01

    The Hall thruster is an electric propulsion device used for multiple in-space applications including orbit raising, on-orbit maneuvers, and de-orbit functions. These in-space propulsion functions are currently performed by toxic hydrazine monopropellant or hydrazine derivative/nitrogen tetroxide bi-propellant thrusters. The Hall thruster operates nominally in the 1500 sec specific impulse regime. It provides greater thrust to power than conventional gridded ion engines, thus reducing trip times and operational life when compared to that technology in Earth orbit applications. The technology in the far term, by adding a second acceleration stage, has shown promise of providing over 4000s Isp, the regime of the gridded ion engine and necessary for deep space applications. The Hall thruster system consists of three parts, the thruster, the power processor, and the propellant system. The technology is operational and commercially available at the 1.5 kW power level and 5 kW application is underway. NASA is looking toward 10 kW and eventually 50 kW-class engines for ambitious space transportation applications. The former allows launch vehicle step-down for GEO missions and demanding planetary missions such as Europa Lander, while the latter allows quick all-electric propulsion LEO to GEO transfers and non-nuclear transportation human Mars missions.

  16. Cold Helium Pressurization for Liquid Oxygen/Liquid Methane Propulsion Systems: Fully-Integrated Hot-Fire Test Results

    NASA Technical Reports Server (NTRS)

    Morehead, R. L.; Atwell, M. J.; Melcher, J. C.; Hurlbert, E. A.

    2016-01-01

    Hot-fire test demonstrations were successfully conducted using a cold helium pressurization system fully integrated into a liquid oxygen (LOX) / liquid methane (LCH4) propulsion system (Figure 1). Cold helium pressurant storage at near liquid nitrogen (LN2) temperatures (-275 F and colder) and used as a heated tank pressurant provides a substantial density advantage compared to ambient temperature storage. The increased storage density reduces helium pressurant tank size and mass, creating payload increases of 35% for small lunar-lander sized applications. This degree of mass reduction also enables pressure-fed propulsion systems for human-rated Mars ascent vehicle designs. Hot-fire test results from the highly-instrumented test bed will be used to demonstrate system performance and validate integrated models of the helium and propulsion systems. A pressurization performance metric will also be developed as a means to compare different active pressurization schemes.

  17. A lander mission to probe subglacial water on Saturn's moon Enceladus for life

    NASA Astrophysics Data System (ADS)

    Konstantinidis, Konstantinos; Flores Martinez, Claudio L.; Dachwald, Bernd; Ohndorf, Andreas; Dykta, Paul; Bowitz, Pascal; Rudolph, Martin; Digel, Ilya; Kowalski, Julia; Voigt, Konstantin; Förstner, Roger

    2015-01-01

    signatures of life. The general mission concept is to place the Lander at a safe distance from an active plume. The IceMole would then be deployed to melt its way through the ice crust to an aquiferous fracture at a depth of 100 m or more for an in situ examination for the presence of microorganisms. The driving requirement for the mission is the high energy demand by the IceMole to melt through the cold Enceladan ices. This requirement is met by a nuclear reactor providing 5 kW of electrical power. The nuclear reactor and the IceMole are placed on a pallet lander platform. An Orbiter element is also foreseen, with the main function of acting as a communications relay between Lander and Earth. After launch, the Lander and Orbiter will perform the interplanetary transfer to Saturn together, using the on-board nuclear reactor to power electric thrusters. After Saturn orbit insertion, the Combined Spacecraft will continue using Nuclear Electric Propulsion to reach the orbit of Enceladus. After orbit insertion at Enceladus, the Orbiter will perform a detailed reconnaissance of the South-Polar Terrain. At the end of the reconnaissance phase, the Lander will separate from the Orbiter and an autonomously guided landing sequence will place it near one of the active vapor plumes. Once landed, the IceMole will be deployed and start melting through the ice, while navigating around hazards and towards a target subglacial aquiferous fracture. An initial estimation of the mission's cost is given, as well as recommendations on the further development of enabling technologies. The planetary protection challenges posed by such a mission are also addressed.

  18. The Conflation of /l/ and /r/: New Zealand Perceptions of Japanese-Accented English

    ERIC Educational Resources Information Center

    Watanabe, Yutai

    2017-01-01

    As a case study of non-linguists' perceptions of accent, this paper investigates how accurately and on what basis Japanese-accented English (JAE) is discernible from other L2 varieties of English in New Zealand (NZ). The paper sheds light on how a feature salient in speech is associated with the perceived sociolinguistic identity of speakers. An…

  19. Mobile Payload Element (MPE): Concept study for a sample fetching rover for the ESA Lunar Lander Mission

    NASA Astrophysics Data System (ADS)

    Haarmann, R.; Jaumann, R.; Claasen, F.; Apfelbeck, M.; Klinkner, S.; Richter, L.; Schwendner, J.; Wolf, M.; Hofmann, P.

    2012-12-01

    In late 2010, the DLR Space Administration invited the German industry to submit a proposal for a study about a Mobile Payload Element (MPE), which could be a German national contribution to the ESA Lunar Lander Mission. Several spots in the south polar region of the moon come into consideration as landing site for this mission. All possible spots provide sustained periods of solar illumination, interrupted by darkness periods of several 10 h. The MPE is outlined to be a small, autonomous, innovative vehicle in the 10 kg class for scouting and sampling the environment in the vicinity of the lunar landing site. The novel capabilities of the MPE will be to acquire samples of lunar regolith from surface, subsurface as well as shadowed locations, define their geological context and bring them back to the lander. This will enable access to samples that are not contaminated by the lander descent propulsion system plumes to increase the chances of detecting any indigenous lunar volatiles contained within the samples. Kayser-Threde, as prime industrial contractor for Phase 0/A, has assembled for this study a team of German partners with relevant industrial and institutional competence in space robotics and lunar science. The primary scientific objective of the MPE is to acquire clearly documented samples and to bring them to the lander for analysis with the onboard Lunar Dust Analysis Package (L-DAP) and Lunar Volatile Resources Analysis Package (L-VRAP). Due to the unstable nature of volatiles, which are of particular scientific interest, the MPE design needs to provide a safe storage and transportation of the samples to the lander. The proposed MPE rover concept has a four-wheeled chassis configuration with active suspension, being a compromise between innovation and mass efficiency. The suspension chosen allows a compact stowage of the MPE on the lander as well as precise alignment of the solar generators and instruments. Since therefore no further complex mechanics are

  20. Plasticity in speech production and perception: A study of accent change in young adults

    NASA Astrophysics Data System (ADS)

    Evans, Bronwen G.; Iverson, Paul

    2005-04-01

    This study investigated plasticity in speech production and perception among university students, as individuals change their accent from regional to educated norms. Subjects were tested before beginning university, 3 months later and on completion of their first year of study. At each stage they were recorded reading a set of test words and a short passage. They also completed two perceptual tasks; they found best exemplar locations for vowels embedded in carrier sentences and identified words in noise. The results demonstrated that subjects changed their spoken accent after attending university. The changes were linked to sociolinguistic factors; subjects who were highly motivated to fit in with their university community changed their accent more. There was some evidence for a link between production and perception; between-subject differences in production and perception were correlated. However, this relationship was weaker for within-subject changes in accent over time. The results suggest that there were limitations in the ability of these subjects to acquire new phonological rules.

  1. Perceptions about Representative English-Language Accents from Prospective and Practicing Providers of Business-Related Language Services in Argentina

    ERIC Educational Resources Information Center

    Scott, James Calvert; Green, Diana J.; Rosewarne, David D.

    2004-01-01

    The purposes of the study were (a) to identify perceptions about representative English-language accents from prospective and practicing providers of business-related language services residing in Argentina and (b) to examine the differences in their perceptions of these English-language accents. The respondents ranked the accents in this order:…

  2. Northeast View from Pathfinder Lander

    NASA Image and Video Library

    1997-11-04

    This panorama of the region to the northeast of the lander was constructed to support the Sojourner Rover Team's plans to conduct an "autonomous traverse" to explore the terrain away from the lander after science objectives in the lander vicinity had been met. The large, relatively bright surface in the foreground, about 10 meters (33 feet) from the spacecraft, in this scene is "Baker's Bench." The large, elongated rock left of center in the middle distance is "Zaphod." This view was produced by combining 8 individual "Superpan" scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be. http://photojournal.jpl.nasa.gov/catalog/PIA01000

  3. One Mars year: viking lander imaging observations.

    PubMed

    Jones, K L; Arvidson, R E; Guinness, E A; Bragg, S L; Wall, S D; Carlston, C E; Pidek, D G

    1979-05-25

    Throughout the complete Mars year during which they have been on the planet, the imaging systems aboard the two Viking landers have documented a variety of surface changes. Surface condensates, consisting of both solid H(2)O and CO(2), formed at the Viking 2 lander site during the winter. Additional observations suggest that surface erosion rates due to dust redistribution may be substantially less than those predicted on the basis of pre-Viking observations. The Viking 1 lander will continue to acquire and transmit a predetermined sequence of imaging and meteorology data as long as it is operative.

  4. Frost at the Viking Lander 2 Site

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Photo from Viking Lander 2 shows late-winter frost on the ground on Mars around the lander. The view is southeast over the top of Lander 2, and shows patches of frost around dark rocks. The surface is reddish-brown; the dark rocks vary in size from 10 centimeters (four inches) to 76 centimeters (30 inches) in diameter. This picture was obtained Sept. 25, 1977. The frost deposits were detected for the first time 12 Martian days (sols) earlier in a black-and-white image. Color differences between the white frost and the reddish soil confirm that we are observing frost. The Lander Imaging Team is trying to determine if frost deposits routinely form due to cold night temperatures, then disappear during the warmer daytime. Preliminary analysis, however, indicates the frost was on the ground for some time and is disappearing over many days. That suggests to scientists that the frost is not frozen carbon dioxide (dry ice) but is more likely a carbon dioxide clathrate (six parts water to one part carbon dioxide). Detailed studies of the frost formation and disappearance, in conjunction with temperature measurements from the lander's meteorology experiment, should be able to confirm or deny that hypothesis, scientists say.

  5. Talker and accent variability effects on spoken word recognition

    NASA Astrophysics Data System (ADS)

    Nyang, Edna E.; Rogers, Catherine L.; Nishi, Kanae

    2003-04-01

    A number of studies have shown that words in a list are recognized less accurately in noise and with longer response latencies when they are spoken by multiple talkers, rather than a single talker. These results have been interpreted as support for an exemplar-based model of speech perception, in which it is assumed that detailed information regarding the speaker's voice is preserved in memory and used in recognition, rather than being eliminated via normalization. In the present study, the effects of varying both accent and talker are investigated using lists of words spoken by (a) a single native English speaker, (b) six native English speakers, (c) three native English speakers and three Japanese-accented English speakers. Twelve /hVd/ words were mixed with multi-speaker babble at three signal-to-noise ratios (+10, +5, and 0 dB) to create the word lists. Native English-speaking listeners' percent-correct recognition for words produced by native English speakers across the three talker conditions (single talker native, multi-talker native, and multi-talker mixed native and non-native) and three signal-to-noise ratios will be compared to determine whether sources of speaker variability other than voice alone add to the processing demands imposed by simple (i.e., single accent) speaker variability in spoken word recognition.

  6. The Effects of Language Experience and Speech Context on the Phonetic Accommodation of English-accented Spanish Voicing.

    PubMed

    Llanos, Fernando; Francis, Alexander L

    2017-03-01

    Native speakers of Spanish with different amounts of experience with English classified stop-consonant voicing (/b/ versus /p/) across different speech accents: English-accented Spanish, native Spanish, and native English. While listeners with little experience with English classified target voicing with an English- or Spanish-like voice onset time (VOT) boundary, predicted by contextual VOT, listeners familiar with English relied on an English-like VOT boundary in an English-accented Spanish context even in the absence of clear contextual cues to English VOT. This indicates that Spanish listeners accommodated English-accented Spanish voicing differently depending on their degree of familiarization with the English norm.

  7. Foreign Accent Syndrome: An Organic Disorder?

    ERIC Educational Resources Information Center

    Van Borsel, John; Janssens, Leen; Santens, Patrick

    2005-01-01

    This paper reports the case of a 32-year-old Dutch speaking woman who presented with foreign accent syndrome (FAS). There are good reasons to believe that the speech disturbance in this patient was of psychogenic origin. This case suggests that attested brain damage is not a prerequisite for a speech disorder to qualify as FAS and that FAS is not…

  8. Sojourner Rover View of Pathfinder Lander

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Image of Pathfinder Lander on Mars taken from Sojourner Rover left front camera on sol 33. The IMP (on the lattice mast) is looking at the rover. Airbags are prominent, and the meteorology mast is shown to the right. Lowermost rock is Ender, with Hassock behind it and Yogi on the other side of the lander.

    NOTE: original caption as published in Science Magazine

  9. Seeking an Anchorage. Stability and Variability in Tonal Alignment of Rising Prenuclear Pitch Accents in Cypriot Greek.

    PubMed

    Themistocleous, Charalambos

    2016-12-01

    Although tonal alignment constitutes a quintessential property of pitch accents, its exact characteristics remain unclear. This study, by exploring the timing of the Cypriot Greek L*+H prenuclear pitch accent, examines the predictions of three hypotheses about tonal alignment: the invariance hypothesis, the segmental anchoring hypothesis, and the segmental anchorage hypothesis. The study reports on two experiments: the first of which manipulates the syllable patterns of the stressed syllable, and the second of which modifies the distance of the L*+H from the following pitch accent. The findings on the alignment of the low tone (L) are illustrative of the segmental anchoring hypothesis predictions: the L persistently aligns inside the onset consonant, a few milliseconds before the stressed vowel. However, the findings on the alignment of the high tone (H) are both intriguing and unexpected: the alignment of the H depends on the number of unstressed syllables that follow the prenuclear pitch accent. The 'wandering' of the H over multiple syllables is extremely rare among languages, and casts doubt on the invariance hypothesis and the segmental anchoring hypothesis, as well as indicating the need for a modified version of the segmental anchorage hypothesis. To address the alignment of the H, we suggest that it aligns within a segmental anchorage-the area that follows the prenuclear pitch accent-in such a way as to protect the paradigmatic contrast between the L*+H prenuclear pitch accent and the L+H* nuclear pitch accent.

  10. Prototype Lithium-Ion Battery Developed for Mars 2001 Lander

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle A.

    2000-01-01

    In fiscal year 1997, NASA, the Jet Propulsion Laboratory, and the U.S. Air Force established a joint program to competitively develop high-power, rechargeable lithium-ion battery technology for aerospace applications. The goal was to address Department of Defense and NASA requirements not met by commercial battery developments. Under this program, contracts have been awarded to Yardney Technical Products, Eagle- Picher Technologies, LLC, BlueStar Advanced Technology Corporation, and SAFT America, Inc., to develop cylindrical and prismatic cell and battery systems for a variety of NASA and U.S. Air Force applications. The battery systems being developed range from low-capacity (7 to 20 A-hr) and low-voltage (14 to 28 V) systems for planetary landers and rovers to systems for aircraft that require up to 270 V and for Unmanned Aerial Vehicles that require capacities up to 200 A-hr. Low-Earth-orbit and geosynchronousorbit spacecraft pose additional challenges to system operation with long cycle life (>30,000 cycles) and long calendar life (>10 years), respectively.

  11. Viking Lander Atlas of Mars

    NASA Technical Reports Server (NTRS)

    Liebes, S., Jr.

    1982-01-01

    Half size reproductions are presented of the extensive set of systematic map products generated for the two Mars Viking landing sites from stereo pairs of images radioed back to Earth. The maps span from the immediate foreground to the remote limits of ranging capability, several hundred meters from the spacecraft. The maps are of two kinds - elevation contour and vertical profile. Background and explanatory material important for understanding and utilizing the map collection included covers the Viking Mission, lander locations, lander cameras, the stereo mapping system and input images to this system.

  12. Imaging experiment: The Viking Lander

    USGS Publications Warehouse

    Mutch, T.A.; Binder, A.B.; Huck, F.O.; Levinthal, E.C.; Morris, E.C.; Sagan, C.; Young, A.T.

    1972-01-01

    The Viking Lander Imaging System will consist of two identical facsimile cameras. Each camera has a high-resolution mode with an instantaneous field of view of 0.04??, and survey and color modes with instantaneous fields of view of 0.12??. Cameras are positioned one meter apart to provide stereoscopic coverage of the near-field. The Imaging Experiment will provide important information about the morphology, composition, and origin of the Martian surface and atmospheric features. In addition, lander pictures will provide supporting information for other experiments in biology, organic chemistry, meteorology, and physical properties. ?? 1972.

  13. Development of Liquid Propulsion Systems Testbed at MSFC

    NASA Technical Reports Server (NTRS)

    Alexander, Reginald; Nelson, Graham

    2016-01-01

    As NASA, the Department of Defense and the aerospace industry in general strive to develop capabilities to explore near-Earth, Cis-lunar and deep space, the need to create more cost effective techniques of propulsion system design, manufacturing and test is imperative in the current budget constrained environment. The physics of space exploration have not changed, but the manner in which systems are developed and certified needs to change if there is going to be any hope of designing and building the high performance liquid propulsion systems necessary to deliver crew and cargo to the further reaches of space. To further the objective of developing these systems, the Marshall Space Flight Center is currently in the process of formulating a Liquid Propulsion Systems testbed, which will enable rapid integration of components to be tested and assessed for performance in integrated systems. The manifestation of this testbed is a breadboard engine configuration (BBE) with facility support for consumables and/or other components as needed. The goal of the facility is to test NASA developed elements, but can be used to test articles developed by other government agencies, industry or academia. Joint government/private partnership is likely the approach that will be required to enable efficient propulsion system development. MSFC has recently tested its own additively manufactured liquid hydrogen pump, injector, and valves in a BBE hot firing. It is rapidly building toward testing the pump and a new CH4 injector in the BBE configuration to demonstrate a 22,000 lbf, pump-fed LO2/LCH4 engine for the Mars lander or in-space transportation. The value of having this BBE testbed is that as components are developed they may be easily integrated in the testbed and tested. MSFC is striving to enhance its liquid propulsion system development capability. Rapid design, analysis, build and test will be critical to fielding the next high thrust rocket engine. With the maturity of the

  14. Viking Lander spacecraft battery. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Newell, D.R.

    1976-09-01

    The Viking Lander was the first spacecraft to fly a sterilized nickel--cadmium battery on a mission to explore the surface of a planet. The significant results of the battery development program from its inception through the design, manufacture, and test of the flight batteries which were flown on the two Lander spacecraft are documented. The flight performance during the early phase of the mission is also presented.

  15. Self-unloading, reusable, lunar lander project

    NASA Technical Reports Server (NTRS)

    Arseculeratne, Ruwan; Cavazos, Melissa; Euker, John; Ghavidel, Fred; Hinkel, Todd J.; Hitzfelder, John; Leitner, Jesse; Nevik, James; Paynter, Scott; Zolondek, Allen

    1990-01-01

    In the early 21st century, NASA will return to the Moon and establish a permanent base. To achieve this goal safely and economically, B&T Engineering has designed an unmanned, reusable, self-unloading lunar lander. The lander is designed to deliver 15,000 kg payloads from an orbit transfer vehicle (OTV) in a low lunar polar orbit and an altitude of 200 km to any location on the lunar surface.

  16. CECE: A Deep Throttling Demonstrator Cryogenic Engine for NASA's Lunar Lander

    NASA Technical Reports Server (NTRS)

    Giuliano, Victor J.; Leonard, Timothy G.; Adamski, Walter M.; Kim, Tony S.

    2007-01-01

    As one of the first technology development programs awarded under NASA's Vision for Space Exploration, the Pratt & Whitney Rocketdyne (PWR) Deep Throttling, Common Extensible Cryogenic Engine (CECE) program was selected by NASA in November 2004 to begin technology development and demonstration toward a deep throttling, cryogenic Lunar Lander engine for use across multiple human and robotic lunar exploration mission segments with extensibility to Mars. The CECE program leverages the maturity and previous investment of a flight-proven hydrogen/oxygen expander cycle engine, the RL10, to develop and demonstrate an unprecedented combination of reliability, safety, durability, throttlability, and restart capabilities in a high-energy, cryogenic engine. NASA Marshall Space Flight Center and NASA Glenn Research Center personnel were integral design and analysis team members throughout the requirements assessment, propellant studies and the deep throttling demonstrator elements of the program. The testbed selected for the initial deep throttling demonstration phase of this program was a minimally modified RL10 engine, allowing for maximum current production engine commonality and extensibility with minimum program cost. In just nine months from technical program start, CECE Demonstrator No. 1 engine testing in April/May 2006 at PWR's E06 test stand successfully demonstrated in excess of 10:1 throttling of the hydrogen/oxygen expander cycle engine. This test provided an early demonstration of a viable, enabling cryogenic propulsion concept with invaluable system-level technology data acquisition toward design and development risk mitigation for both the subsequent CECE Demonstrator No. 2 program and to the future Lunar Lander Design, Development, Test and Evaluation effort.

  17. Sea-Level Flight Demonstration and Altitude Characterization of a LO2/LCH4 Based Accent Propulsion Lander

    NASA Technical Reports Server (NTRS)

    Collins, Jacob; Hurlbert, Eric; Romig, Kris; Melcher, John; Hobson, Aaron; Eaton, Phil

    2009-01-01

    A 1,500 lbf thrust-class liquid oxygen (LO2)/Liquid Methane (LCH4) rocket engine was developed and tested at both sea-level and simulated altitude conditions. The engine was fabricated by Armadillo Aerospace (AA) in collaboration with NASA Johnson Space Center. Sea level testing was conducted at Armadillo Aerospace facilities at Caddo Mills, TX. Sea-level tests were conducted using both a static horizontal test bed and a vertical take-off and landing (VTOL) test bed capable of lift-off and hover-flight in low atmosphere conditions. The vertical test bed configuration is capable of throttling the engine valves to enable liftoff and hover-flight. Simulated altitude vacuum testing was conducted at NASA Johnson Space Center White Sands Test Facility (WSTF), which is capable of providing altitude simulation greater than 120,000 ft equivalent. The engine tests demonstrated ignition using two different methods, a gas-torch and a pyrotechnic igniter. Both gas torch and pyrotechnic ignition were demonstrated at both sea-level and vacuum conditions. The rocket engine was designed to be configured with three different nozzle configurations, including a dual-bell nozzle geometry. Dual-bell nozzle tests were conducted at WSTF and engine performance data was achieved at both ambient pressure and simulated altitude conditions. Dual-bell nozzle performance data was achieved over a range of altitude conditions from 90,000 ft to 50,000 ft altitude. Thrust and propellant mass flow rates were measured in the tests for specific impulse (Isp) and C* calculations.

  18. Rest In Peace Mars Polar Lander

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site]

    Three years ago (December 3, 1999) Mars Polar Lander (MPL) was set to touchdown on the enigmatic layered terrain located near the South Pole. Unfortunately, communications with the spacecraft were lost and never regained. The Mars Program Independent Assessment Team concluded that this loss was most likely due to premature retrorocket shutdown resulting in the crash of the lander. The image primarily shows what appears to be a ridged surface with some small isolated hills.

    Historically, exploration has and will continue to be a very hard and risky endeavor and sometimes you lose. But the spirit of exploration and discovery has served mankind well throughout the ages and it has now driven us to the far reaches of space. Therefore, with this in mind the THEMIS Team today is releasing an image of the region where MPL was set to land in memory of this mission and the unquenchable spirit of exploration. It is hoped that in the near future we will once again attempt another landing in the Martian polar regions.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the

  19. Phonetic Parameters and Perceptual Judgments of Accent in English by American and Japanese Listeners

    ERIC Educational Resources Information Center

    Riney, Timothy J.; Takagi, Naoyuki; Inutsuka, Kumiko

    2005-01-01

    In this study we identify some of the phonetic parameters that correlate with nonnative speakers' (NNSs) perceptual judgments of accent in English and investigate NNS listener perceptions of English from a World Englishes point of view. Our main experiment involved 3,200 assessments of the perceived degree of accent in English of two speaker…

  20. Photogrammetry of the Viking Lander imagery

    NASA Technical Reports Server (NTRS)

    Wu, S. S. C.; Schafer, F. J.

    1982-01-01

    The problem of photogrammetric mapping which uses Viking Lander photography as its basis is solved in two ways: (1) by converting the azimuth and elevation scanning imagery to the equivalent of a frame picture, using computerized rectification; and (2) by interfacing a high-speed, general-purpose computer to the analytical plotter employed, so that all correction computations can be performed in real time during the model-orientation and map-compilation process. Both the efficiency of the Viking Lander cameras and the validity of the rectification method have been established by a series of pre-mission tests which compared the accuracy of terrestrial maps compiled by this method with maps made from aerial photographs. In addition, 1:10-scale topographic maps of Viking Lander sites 1 and 2 having a contour interval of 1.0 cm have been made to test the rectification method.

  1. Identification of the Beagle 2 lander on Mars.

    PubMed

    Bridges, J C; Clemmet, J; Croon, M; Sims, M R; Pullan, D; Muller, J-P; Tao, Y; Xiong, S; Putri, A R; Parker, T; Turner, S M R; Pillinger, J M

    2017-10-01

    The 2003 Beagle 2 Mars lander has been identified in Isidis Planitia at 90.43° E, 11.53° N, close to the predicted target of 90.50° E, 11.53° N. Beagle 2 was an exobiology lander designed to look for isotopic and compositional signs of life on Mars, as part of the European Space Agency Mars Express (MEX) mission. The 2004 recalculation of the original landing ellipse from a 3-sigma major axis from 174 km to 57 km, and the acquisition of Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE) imagery at 30 cm per pixel across the target region, led to the initial identification of the lander in 2014. Following this, more HiRISE images, giving a total of 15, including red and blue-green colours, were obtained over the area of interest and searched, which allowed sub-pixel imaging using super high-resolution techniques. The size (approx. 1.5 m), distinctive multilobed shape, high reflectivity relative to the local terrain, specular reflections, and location close to the centre of the planned landing ellipse led to the identification of the Beagle 2 lander. The shape of the imaged lander, although to some extent masked by the specular reflections in the various images, is consistent with deployment of the lander lid and then some or all solar panels. Failure to fully deploy the panels-which may have been caused by damage during landing-would have prohibited communication between the lander and MEX and commencement of science operations. This implies that the main part of the entry, descent and landing sequence, the ejection from MEX, atmospheric entry and parachute deployment, and landing worked as planned with perhaps only the final full panel deployment failing.

  2. Identification of the Beagle 2 lander on Mars

    PubMed Central

    Clemmet, J.; Croon, M.; Sims, M. R.; Pullan, D.; Muller, J.-P.; Tao, Y.; Xiong, S.; Putri, A. R.; Parker, T.; Turner, S. M. R.; Pillinger, J. M.

    2017-01-01

    The 2003 Beagle 2 Mars lander has been identified in Isidis Planitia at 90.43° E, 11.53° N, close to the predicted target of 90.50° E, 11.53° N. Beagle 2 was an exobiology lander designed to look for isotopic and compositional signs of life on Mars, as part of the European Space Agency Mars Express (MEX) mission. The 2004 recalculation of the original landing ellipse from a 3-sigma major axis from 174 km to 57 km, and the acquisition of Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE) imagery at 30 cm per pixel across the target region, led to the initial identification of the lander in 2014. Following this, more HiRISE images, giving a total of 15, including red and blue-green colours, were obtained over the area of interest and searched, which allowed sub-pixel imaging using super high-resolution techniques. The size (approx. 1.5 m), distinctive multilobed shape, high reflectivity relative to the local terrain, specular reflections, and location close to the centre of the planned landing ellipse led to the identification of the Beagle 2 lander. The shape of the imaged lander, although to some extent masked by the specular reflections in the various images, is consistent with deployment of the lander lid and then some or all solar panels. Failure to fully deploy the panels—which may have been caused by damage during landing—would have prohibited communication between the lander and MEX and commencement of science operations. This implies that the main part of the entry, descent and landing sequence, the ejection from MEX, atmospheric entry and parachute deployment, and landing worked as planned with perhaps only the final full panel deployment failing. PMID:29134081

  3. Identification of the Beagle 2 lander on Mars

    NASA Astrophysics Data System (ADS)

    Bridges, J. C.; Clemmet, J.; Croon, M.; Sims, M. R.; Pullan, D.; Muller, J.-P.; Tao, Y.; Xiong, S.; Putri, A. R.; Parker, T.; Turner, S. M. R.; Pillinger, J. M.

    2017-10-01

    The 2003 Beagle 2 Mars lander has been identified in Isidis Planitia at 90.43° E, 11.53° N, close to the predicted target of 90.50° E, 11.53° N. Beagle 2 was an exobiology lander designed to look for isotopic and compositional signs of life on Mars, as part of the European Space Agency Mars Express (MEX) mission. The 2004 recalculation of the original landing ellipse from a 3-sigma major axis from 174 km to 57 km, and the acquisition of Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment (HiRISE) imagery at 30 cm per pixel across the target region, led to the initial identification of the lander in 2014. Following this, more HiRISE images, giving a total of 15, including red and blue-green colours, were obtained over the area of interest and searched, which allowed sub-pixel imaging using super high-resolution techniques. The size (approx. 1.5 m), distinctive multilobed shape, high reflectivity relative to the local terrain, specular reflections, and location close to the centre of the planned landing ellipse led to the identification of the Beagle 2 lander. The shape of the imaged lander, although to some extent masked by the specular reflections in the various images, is consistent with deployment of the lander lid and then some or all solar panels. Failure to fully deploy the panels-which may have been caused by damage during landing-would have prohibited communication between the lander and MEX and commencement of science operations. This implies that the main part of the entry, descent and landing sequence, the ejection from MEX, atmospheric entry and parachute deployment, and landing worked as planned with perhaps only the final full panel deployment failing.

  4. The surface of Mars: the view from the viking 2 lander.

    PubMed

    Mutch, T A; Grenander, S U; Jones, K L; Patterson, W; Arvidson, R E; Guinness, E A; Avrin, P; Carlston, C E; Binder, A B; Sagan, C; Dunham, E W; Fox, P L; Pieri, D C; Huck, F O; Rowland, C W; Taylor, G R; Wall, S D; Kahn, R; Levinthal, E C; Liebes, S; Tucker, R B; Morris, E C; Pollack, J B; Saunders, R S; Wolf, M R

    1976-12-11

    Viking 2 lander began imaging the surface of Mars at Utopia Planitia on 3 September 1976. The surface is a boulder-strewn reddish desert cut by troughs that probably form a polygonal network. A plateau can be seen to the east of the spacecraft, which for the most probable lander location is approximately the direction of a tongue of ejecta from the crater Mie. Boulders at the lander 2 site are generally more vesicular than those near lander i. Fines at both lander sites appear to be very fine-grained and to be bound in a duricrust. The pinkish color of the sky, similar to that observed at the lander I site, indicates suspension of surface material. However, the atmospheric optical depth is less than that at the lander I site. After dissipation of a cloud of dust stirred during landing, no changes other than those stemming from sampling activities have been detected in the landscape. No signs of large organisms are apparent at either landing site.

  5. The surface of Mars - The view from the Viking 2 lander

    NASA Technical Reports Server (NTRS)

    Mutch, T. A.; Grenander, S. U.; Jones, K. L.; Patterson, W.; Arvidson, R. E.; Guinness, E. A.; Avrin, P.; Carlston, C. E.; Binder, A. B.; Sagan, C.

    1976-01-01

    Viking 2 lander began imaging the surface of Mars at Utopia Planitia on September 3, 1976. The surface is a boulder-strewn reddish desert cut by troughs that probably form a polygonal network. A plateau can be seen to the east of the spacecraft, which for the most probable lander location is approximately the dirction of a tongue of ejecta from the crater Mie. Boulders at the lander 2 site are generally more vesicular than those near lander 1. Fines at both lander sites appear to be very fine-grained and to be bound in a duricrust. The pinkish color of the sky, similar to that observed at the lander 1 site, indicates suspension of surface material. However, the atmospheric optical depth is less than that at the lander 1 site. After dissipation of a cloud of dust stirred during landing, no changes other than those stemming from sampling activities have been detected in the landscape. No signs of large organisms are apparent at either landing site.

  6. Investigating Attitudes towards an Emerging Standard of English: Evaluations of Newscasters' Accents in Trinidad

    ERIC Educational Resources Information Center

    Deuber, Dagmar; Leung, Glenda-Alicia

    2013-01-01

    This paper addresses the issue of the emergence of new standards of English in the postcolonial world by means of a language attitude study conducted in the Caribbean island of Trinidad that involved rating the accents of newscasters. Accents represented in the clips played to respondents comprised various local as well as non-local ones. The…

  7. Planetary Seismology : Lander- and Wind-Induced Seismic Signals

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph

    2016-10-01

    Seismic measurements are of interest for future geophysical exploration of ocean worlds such as Europa or Titan, as well as Venus, Mars and the Moon. Even when a seismometer is deployed away from a lander (as in the case of Apollo) lander-generated disturbances are apparent. Such signatures may be usefully diagnostic of lander operations (at least for outreach), and may serve as seismic excitation for near-field propagation studies. The introduction of these 'spurious' events may also influence the performance of event detection and data compression algorithms.Examples of signatures in the Viking 2 seismometer record of lander mechanism operations are presented. The coherence of Viking seismometer noise levels and wind forcing is well-established : some detailed examples are examined. Wind noise is likely to be significant on future Mars missions such as InSight, as well as on Titan and Venus.

  8. THE BACON not the bacon: How children and adults understand accented and unaccented noun phrases

    PubMed Central

    Arnold, Jennifer E.

    2008-01-01

    Two eye-tracking experiments examine whether adults and 4 and 5 year old children use the presence or absence of accenting to guide their interpretation of noun phrases (e.g., the bacon) with respect to the discourse context. Unaccented nouns tend to refer to contextually accessible referents, while accented variants tend to be used for less accessible entities. Experiment 1 confirms that accenting is informative for adults, who show a bias toward previously-mentioned objects beginning 300 msec after the onset of unaccented nouns and pronouns. But contrary to findings in the literature, accented words produced no observable bias. In Experiment 2, 4 and 5 year olds were also biased toward previously-mentioned objects with unaccented nouns and pronouns. This builds on findings of limits on children’s on-line reference comprehension (Arnold, Brown-Schmidt, & Trueswell, in press), showing that children’s interpretation of unaccented nouns and pronouns is constrained in contexts with one single highly accessible object. PMID:18358460

  9. Boundary Layer Transition Correlations and Aeroheating Predictions for Mars Smart Lander

    NASA Technical Reports Server (NTRS)

    Hollis, Brian R.; Liechty, Derek S.

    2002-01-01

    Laminar and turbulent perfect-gas air, Navier-Stokes computations have been performed for a proposed Mars Smart Lander entry vehicle at Mach 6 over a free stream Reynolds number range of 6.9 x 10(exp 6)/m to 2.4 x 10(exp 7)/m (2.1 x 10(exp 6)/ft to 7.3 x 10(exp 6)/ft) for angles-of-attack of 0-deg, 11-deg, 16-deg, and 20-deg, and comparisons were made to wind tunnel heating data obtained a t the same conditions. Boundary layer edge properties were extracted from the solutions and used to correlate experimental data on the effects of heat-shield penetrations (bolt-holes where the entry vehicle would be attached to the propulsion module during transit to Mars) on boundary-layer transition. A non-equilibrium Martian-atmosphere computation was performed for the peak heating point on the entry trajectory in order to determine if the penetrations would produce boundary-layer transition by using this correlation.

  10. Boundary Layer Transition Correlations and Aeroheating Predictions for Mars Smart Lander

    NASA Technical Reports Server (NTRS)

    Hollis, Brian R.; Liechty, Derek S.

    2002-01-01

    Laminar and turbulent perfect-gas air, Navier-Stokes computations have been performed for a proposed Mars Smart Lander entry vehicle at Mach 6 over a free stream Reynolds number range of 6.9 x 10(exp 6/m to 2.4 x 10(exp 7)m(2.1 x 10(exp 6)/ft to 7.3 x 10(exp 6)ft) for angles-of-attack of 0-deg, 11-deg, 16-deg, and 20-deg, and comparisons were made to wind tunnel heating data obtained at the same conditions. Boundary layer edge properties were extracted from the solutions and used to correlate experimental data on the effects of heat-shield penetrations (bolt-holes where the entry vehicle would be attached to the propulsion module during transit to Mars) on boundary-layer transition. A non-equilibrium Martian-atmosphere computation was performed for the peak heating point on the entry trajectory in order to determine if the penetrations would produce boundary-layer transition by using this correlation.

  11. Shhh… I Need Quiet! Children's Understanding of American, British, and Japanese-accented English Speakers.

    PubMed

    Bent, Tessa; Holt, Rachael Frush

    2018-02-01

    Children's ability to understand speakers with a wide range of dialects and accents is essential for efficient language development and communication in a global society. Here, the impact of regional dialect and foreign-accent variability on children's speech understanding was evaluated in both quiet and noisy conditions. Five- to seven-year-old children ( n = 90) and adults ( n = 96) repeated sentences produced by three speakers with different accents-American English, British English, and Japanese-accented English-in quiet or noisy conditions. Adults had no difficulty understanding any speaker in quiet conditions. Their performance declined for the nonnative speaker with a moderate amount of noise; their performance only substantially declined for the British English speaker (i.e., below 93% correct) when their understanding of the American English speaker was also impeded. In contrast, although children showed accurate word recognition for the American and British English speakers in quiet conditions, they had difficulty understanding the nonnative speaker even under ideal listening conditions. With a moderate amount of noise, their perception of British English speech declined substantially and their ability to understand the nonnative speaker was particularly poor. These results suggest that although school-aged children can understand unfamiliar native dialects under ideal listening conditions, their ability to recognize words in these dialects may be highly susceptible to the influence of environmental degradation. Fully adult-like word identification for speakers with unfamiliar accents and dialects may exhibit a protracted developmental trajectory.

  12. Predicting English Word Accent on Morphological Grounds

    ERIC Educational Resources Information Center

    Salmani Nodoushan, Mohammad Ali

    2007-01-01

    Learners of English as a foreign/Second Language (EFL/ESL) can easily learn the correct pronunciation of English words, some linguists have tried to simplify English phonology in general, and English accent in particular, over the past 50 years or so; some scholars have talked about four degrees of primary, secondary, tertiary and weak stress…

  13. Visual Enhancement of Illusory Phenomenal Accents in Non-Isochronous Auditory Rhythms

    PubMed Central

    2016-01-01

    Musical rhythms encompass temporal patterns that often yield regular metrical accents (e.g., a beat). There have been mixed results regarding perception as a function of metrical saliency, namely, whether sensitivity to a deviant was greater in metrically stronger or weaker positions. Besides, effects of metrical position have not been examined in non-isochronous rhythms, or with respect to multisensory influences. This study was concerned with two main issues: (1) In non-isochronous auditory rhythms with clear metrical accents, how would sensitivity to a deviant be modulated by metrical positions? (2) Would the effects be enhanced by multisensory information? Participants listened to strongly metrical rhythms with or without watching a point-light figure dance to the rhythm in the same meter, and detected a slight loudness increment. Both conditions were presented with or without an auditory interference that served to impair auditory metrical perception. Sensitivity to a deviant was found greater in weak beat than in strong beat positions, consistent with the Predictive Coding hypothesis and the idea of metrically induced illusory phenomenal accents. The visual rhythm of dance hindered auditory detection, but more so when the latter was itself less impaired. This pattern suggested that the visual and auditory rhythms were perceptually integrated to reinforce metrical accentuation, yielding more illusory phenomenal accents and thus lower sensitivity to deviants, in a manner consistent with the principle of inverse effectiveness. Results were discussed in the predictive framework for multisensory rhythms involving observed movements and possible mediation of the motor system. PMID:27880850

  14. NASA's 2004 In-Space Propulsion Refocus Studies for New Frontiers Class Missions

    NASA Technical Reports Server (NTRS)

    Witzberger, Kevin E.; Manzella, David; Oh, David; Cupples, Mike

    2006-01-01

    The New Frontiers (NF) program is designed to provide opportunities to fulfill the science objectives for top priority, medium class missions identified in the Decadal Solar System Exploration Survey. This paper assesses the applicability of the In-Space Propulsion s (ISP) Solar Electric Propulsion (SEP) technologies for representative NF class missions that include a Jupiter Polar Orbiter with Probes (JPOP), Comet Surface Sample Return (CSSR), and two different Titan missions. The SEP technologies evaluated include the 7-kW, 4,100-second NASA's Evolutionary Xenon Thruster (NEXT), the 3-kW, 2,700-second Hall thruster, and two different NASA Solar Electric Propulsion Technology Readiness (NSTAR) thrusters that are variants of the Deep Space 1 (DS1) thruster. One type of NSTAR, a 2.6-kW, 3,100-second thruster, will be the primary propulsion system for the DAWN mission that is scheduled to launch in 2006; the other is an "enhanced", higher power variant (3.8-kW, 4,100-second) and is so-called because it uses NEXT system components such as the NEXT power processing unit (PPU). The results show that SEP is applicable for the CSSR mission and a Titan Lander mission. In addition, NEXT has improved its applicability for these types of missions by modifying its thruster performance relative to its performance at the beginning of this study.

  15. The Effect of Perceived Regional Accents on Individual Economic Behavior: A Lab Experiment on Linguistic Performance, Cognitive Ratings and Economic Decisions

    PubMed Central

    Heblich, Stephan; Lameli, Alfred; Riener, Gerhard

    2015-01-01

    Does it matter if you speak with a regional accent? Speaking immediately reveals something of one’s own social and cultural identity, be it consciously or unconsciously. Perceiving accents involves not only reconstructing such imprints but also augmenting them with particular attitudes and stereotypes. Even though we know much about attitudes and stereotypes that are transmitted by, e.g. skin color, names or physical attractiveness, we do not yet have satisfactory answers how accent perception affects human behavior. How do people act in economically relevant contexts when they are confronted with regional accents? This paper reports a laboratory experiment where we address this question. Participants in our experiment conduct cognitive tests where they can choose to either cooperate or compete with a randomly matched male opponent identified only via his rendering of a standardized text in either a regional accent or standard accent. We find a strong connection between the linguistic performance and the cognitive rating of the opponent. When matched with an opponent who speaks the accent of the participant’s home region—the in-group opponent –, individuals tend to cooperate significantly more often. By contrast, they are more likely to compete when matched with an accent speaker from outside their home region, the out-group opponent. Our findings demonstrate, firstly, that the perception of an out-group accent leads not only to social discrimination but also influences economic decisions. Secondly, they suggest that this economic behavior is not necessarily attributable to the perception of a regional accent per se, but rather to the social rating of linguistic distance and the in-group/out-group perception it evokes. PMID:25671607

  16. The effect of perceived regional accents on individual economic behavior: a lab experiment on linguistic performance, cognitive ratings and economic decisions.

    PubMed

    Heblich, Stephan; Lameli, Alfred; Riener, Gerhard

    2015-01-01

    Does it matter if you speak with a regional accent? Speaking immediately reveals something of one's own social and cultural identity, be it consciously or unconsciously. Perceiving accents involves not only reconstructing such imprints but also augmenting them with particular attitudes and stereotypes. Even though we know much about attitudes and stereotypes that are transmitted by, e.g. skin color, names or physical attractiveness, we do not yet have satisfactory answers how accent perception affects human behavior. How do people act in economically relevant contexts when they are confronted with regional accents? This paper reports a laboratory experiment where we address this question. Participants in our experiment conduct cognitive tests where they can choose to either cooperate or compete with a randomly matched male opponent identified only via his rendering of a standardized text in either a regional accent or standard accent. We find a strong connection between the linguistic performance and the cognitive rating of the opponent. When matched with an opponent who speaks the accent of the participant's home region--the in-group opponent--, individuals tend to cooperate significantly more often. By contrast, they are more likely to compete when matched with an accent speaker from outside their home region, the out-group opponent. Our findings demonstrate, firstly, that the perception of an out-group accent leads not only to social discrimination but also influences economic decisions. Secondly, they suggest that this economic behavior is not necessarily attributable to the perception of a regional accent per se, but rather to the social rating of linguistic distance and the in-group/out-group perception it evokes.

  17. Selection and Characterization of Landing Sites for Chandrayaan-2 Lander

    NASA Astrophysics Data System (ADS)

    Gopala Krishna, Barla; Amitabh, Amitabh; Srinivasan, T. P.; Karidhal, Ritu; Nagesh, G.; Manjusha, N.

    2016-07-01

    Indian Space Research Organisation has planned the second mission to moon known as Chandrayaan-2, which consists of an Orbiter, a Lander and a Rover. This will be the first soft landing mission of India on lunar surface. The Orbiter, Lander and Rover individually will carry scientific payloads that enhance the scientific objectives of Chandrayaan-2. The Lander soft lands on the lunar surface and subsequently Lander & Rover will carry on with the payload activities on the moon surface. Landing Site identification based on the scientific and engineering constrains of lander plays an important role in success of a mission. The Lander poses some constraints because of its engineering design for the selection of the landing site and on the other hand the landing site / region imparts some constrain on the Lander. The various constraints that have to be considered for the study of the landing site are Local slope, Sun illumination during mission life, Radio communication with the Earth, Global slope towards equator, Boulders size, Crater density and boulder distribution. This paper describes the characterization activities of the different landing locations which have been studied for Chandrayaan-2 Lander. The sites have been studied both in the South Polar and North Polar regions of the moon on the near side. The Engineering Constraints at the sites due to the Lander, Factors that affect mission life (i.e. illumination at the location), Factors influencing communication to earth (i.e. RF visibility) & Shadow movements have been studied at these locations and zones that are favourable for landing have been short listed. This paper gives methodology of these studies along with the results of the characteristics of all the sites and the recommendations for further action in finalizing the landing area.

  18. Predicting English Word Accent on Morphological Grounds

    ERIC Educational Resources Information Center

    Salmani-Nodoushan, Mohammad Ali

    2007-01-01

    Learners of English as a foreign/Second Language (EFL/ESL) can easily learn the correct pronunciation of English words. Linguists have tried to simplify English phonology in general, and English accent in particular, over the past 50 years or so; some scholars have talked about four degrees of primary, secondary, tertiary and weak stress (e.g.,…

  19. The influence of speech rate and accent on access and use of semantic information.

    PubMed

    Sajin, Stanislav M; Connine, Cynthia M

    2017-04-01

    Circumstances in which the speech input is presented in sub-optimal conditions generally lead to processing costs affecting spoken word recognition. The current study indicates that some processing demands imposed by listening to difficult speech can be mitigated by feedback from semantic knowledge. A set of lexical decision experiments examined how foreign accented speech and word duration impact access to semantic knowledge in spoken word recognition. Results indicate that when listeners process accented speech, the reliance on semantic information increases. Speech rate was not observed to influence semantic access, except in the setting in which unusually slow accented speech was presented. These findings support interactive activation models of spoken word recognition in which attention is modulated based on speech demands.

  20. Viking lander: Creating the science teams

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The teams of scientists and the contractors involved in designing and fabricating the Viking lander spacecraft for Mars exploration are discussed. The requirements established for each member of the research teams are enumerated and the personnel selection process is described. Two instruments for the lander, a gas chromatograph-mass spectrometer and a biology life detection instrument, are addressed in terms of costs, design, planning, and subcontractors. The challenges and ultimate success of the research management efforts are related in detail.

  1. Location of Viking 1 Lander on the surface of Mars

    USGS Publications Warehouse

    Morris, E.C.; Jones, K.L.; Berger, J.P.

    1978-01-01

    A location of the Viking 1 Lander on the surface of Mars has been determined by correlating topographic features in the lander pictures with similar features in the Viking orbiter pictures. Radio tracking data narrowed the area of search for correlating orbiter and lander features and an area was found on the orbiter pictures in which there is good agreement with topographic features on the lander pictures. This location, when plotted on the 1:250,000 scale photomosaic of the Yorktown Region of Mars (U.S. Geological Survey, 1977) is at 22.487??N latitude and 48.041??W longitude. ?? 1978.

  2. Active Collision Avoidance for Planetary Landers

    NASA Technical Reports Server (NTRS)

    Rickman, Doug; Hannan, Mike; Srinivasan, Karthik

    2014-01-01

    Present day robotic missions to other planets require precise, a priori knowledge of the terrain to pre-determine a landing spot that is safe. Landing sites can be miles from the mission objective, or, mission objectives may be tailored to suit landing sites. Future robotic exploration missions should be capable of autonomously identifying a safe landing target within a specified target area selected by mission requirements. Such autonomous landing sites must (1) 'see' the surface, (2) identify a target, and (3) land the vehicle. Recent advances in radar technology have resulted in small, lightweight, low power radars that are used for collision avoidance and cruise control systems in automobiles. Such radar systems can be adapted for use as active hazard avoidance systems for planetary landers. The focus of this CIF proposal is to leverage earlier work on collision avoidance systems for MSFC's Mighty Eagle lander and evaluate the use of automotive radar systems for collision avoidance in planetary landers.

  3. Lunar lander stage requirements based on the Civil Needs Data Base

    NASA Technical Reports Server (NTRS)

    Mulqueen, John A.

    1992-01-01

    This paper examines the lunar lander stages that will be necessary for the future exploration and development of the Moon. Lunar lander stage sizing is discussed based on the projected lunar payloads listed in the Civil Needs Data Base. Factors that will influence the lander stage design are identified and discussed. Some of these factors are (1) lunar orbiting and lunar surface lander bases; (2) implications of direct landing trajectories and landing from a parking orbit; (3) implications of landing site and parking orbit; (4) implications of landing site and parking orbit selection; (5) the use of expendable and reusable lander stages; and (6) the descent/ascent trajectories. Data relating the lunar lander stage design requirements to each of the above factors and others are presented in parametric form. These data will provide useful design data that will be applicable to future mission model modifications and design studies.

  4. Viking 1 Lander on the surface of Mars - Revised location

    NASA Technical Reports Server (NTRS)

    Morris, E. C.; Jones, K. L.

    1980-01-01

    The method used to pinpoint the location of the Viking 1 Lander is described. The higher resolution of pictures taken by the Viking Orbiter at a lower periapsis altitude facilitated the correlation of topographical features with the same features in the Lander pictures. The new areographic coordinates of the Lander are 22.483 deg N latitude and 47.968 deg W longitude.

  5. Native and Nonnative Processing of Japanese Pitch Accent

    ERIC Educational Resources Information Center

    Wu, Xianghua; Tu, Jung-Yueh; Wang, Yue

    2012-01-01

    The theoretical framework of this study is based on the prevalent debate of whether prosodic processing is influenced by higher level linguistic-specific circuits or reflects lower level encoding of physical properties. Using the dichotic listening technique, the study investigates the hemispheric processing of Japanese pitch accent by native…

  6. Acquisition of stress and pitch accent in English-Spanish bilingual children

    NASA Astrophysics Data System (ADS)

    Kim, Sahyang; Andruski, Jean; Nathan, Geoffrey S.; Casielles, Eugenia; Work, Richard

    2005-09-01

    Although understanding of prosodic development is considered crucial for understanding of language acquisition in general, few studies have focused on how children develop native-like prosody in their speech production. This study will examine the acquisition of lexical stress and postlexical pitch accent in two English-Spanish bilingual children. Prosodic characteristics of English and Spanish are different in terms of frequent stress patterns (trochaic versus penultimate), phonetic realization of stress (reduced unstressed vowel versus full unstressed vowel), and frequent pitch accent types (H* versus L*+H), among others. Thus, English-Spanish bilingual children's prosodic development may provide evidence of their awareness of language differences relatively early during language development, and illustrate the influence of markedness or input frequency in prosodic acquisition. For this study, recordings from the children's one-word stage are used. Durations of stressed and unstressed syllables and F0 peak alignment are measured, and pitch accent types in different accentual positions (nuclear versus prenuclear) are transcribed using American English ToBI and Spanish ToBI. Prosodic development is compared across ages within each language and across languages at each age. Furthermore, the bilingual children's productions are compared with monolingual English and Spanish parents' productions.

  7. Shades of Cosmopolitanism: EFL Teachers' Perspectives on English Accents and Pronunciation Teaching in the Gulf

    ERIC Educational Resources Information Center

    Buckingham, Louisa

    2015-01-01

    Research suggests that passing for a native English speaker (NES) is often perceived as desirable by teachers of English as a Foreign Language (EFL) and employers, and students may claim to prefer certain NES accents as learning models. While this may be partly motivated by the prevalence of a particular regional accent in ESL contexts or…

  8. The Mars Polar Lander undergoes spin test

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers maneuver the Mars Polar Lander onto a spin table for testing. The lander, which will be launched on Jan. 3, 1999, is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which is due to be launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  9. The Mars Polar Lander undergoes spin test

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), the Mars Polar Lander is lowered toward a spin table for testing. The lander, which will be launched on Jan. 3, 1999, is a solar- powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which is due to be launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  10. Early meteorological results from the viking 2 lander.

    PubMed

    Hess, S L; Henry, R M; Leovy, C B; Mitchell, J L; Ryan, J A; Tillman, J E

    1976-12-11

    Early results from the meteorological instruments on the Viking 2 lander are presented. As on lander 1, the daily patterns of temperature, wind, and pressure have been highly repetitive during the early summer period. The average daily maximum temperature was 241 degrees K and the diurnal minimum was 191 degrees K. The wind has a vector mean of 0.7 meter per second from the southeast with a diurnal amplitude of 3 meters per second. Pressure exhibits both diurnal and semidiurnal oscillations, although of substantially smaller amplitude than those of lander 1. Departures from the repetitive diurnal patterns begin to appear on sol 37.

  11. Report on the Loss of the Mars Polar Lander and Deep Space 2 Missions

    NASA Technical Reports Server (NTRS)

    Albee, Arden; Battel, Steven; Brace, Richard; Burdick, Garry; Casani, John; Lavell, Jeffrey; Leising, Charles; MacPherson, Duncan; Burr, Peter; Dipprey, Duane

    2000-01-01

    NASA's Mars Surveyor Program (MSP) began in 1994 with plans to send spacecraft to Mars every 26 months. Mars Global Surveyor (MGS), a global mapping mission, was launched in 1996 and is currently orbiting Mars. Mars Surveyor '98 consisted of Mars Climate Orbiter (MCO) and Mars Polar Lander (MPL). Lockheed Martin Astronautics (LMA) was the prime contractor for Mars Surveyor '98. The Jet Propulsion Laboratory (JPL), California Institute of Technology, manages the Mars Surveyor Program for NASA's Office of Space Science. MPL was developed under very tight funding constraints. The combined development cost of MPL and MCO, including the cost of the two launch vehicles, was approximately the same as the development cost of the Mars Pathfinder mission, including the cost of its single launch vehicle. The MPL project accepted the challenge to develop effective implementation methodologies consistent with programmatic requirements.

  12. The impact of phonetic dissimilarity on the perception of foreign accented speech

    NASA Astrophysics Data System (ADS)

    Weil, Shawn A.

    2003-10-01

    Non-normative speech (i.e., synthetic speech, pathological speech, foreign accented speech) is more difficult to process for native listeners than is normative speech. Does perceptual dissimilarity affect only intelligibility, or are there other costs to processing? The current series of experiments investigates both the intelligibility and time course of foreign accented speech (FAS) perception. Native English listeners heard single English words spoken by both native English speakers and non-native speakers (Mandarin or Russian). Words were chosen based on the similarity between the phonetic inventories of the respective languages. Three experimental designs were used: a cross-modal matching task, a word repetition (shadowing) task, and two subjective ratings tasks which measured impressions of accentedness and effortfulness. The results replicate previous investigations that have found that FAS significantly lowers word intelligibility. Furthermore, in FAS as well as perceptual effort, in the word repetition task, correct responses are slower to accented words than to nonaccented words. An analysis indicates that both intelligibility and reaction time are, in part, functions of the similarity between the talker's utterance and the listener's representation of the word.

  13. The Mars NetLander panoramic camera

    NASA Astrophysics Data System (ADS)

    Jaumann, Ralf; Langevin, Yves; Hauber, Ernst; Oberst, Jürgen; Grothues, Hans-Georg; Hoffmann, Harald; Soufflot, Alain; Bertaux, Jean-Loup; Dimarellis, Emmanuel; Mottola, Stefano; Bibring, Jean-Pierre; Neukum, Gerhard; Albertz, Jörg; Masson, Philippe; Pinet, Patrick; Lamy, Philippe; Formisano, Vittorio

    2000-10-01

    The panoramic camera (PanCam) imaging experiment is designed to obtain high-resolution multispectral stereoscopic panoramic images from each of the four Mars NetLander 2005 sites. The main scientific objectives to be addressed by the PanCam experiment are (1) to locate the landing sites and support the NetLander network sciences, (2) to geologically investigate and map the landing sites, and (3) to study the properties of the atmosphere and of variable phenomena. To place in situ measurements at a landing site into a proper regional context, it is necessary to determine the lander orientation on ground and to exactly locate the position of the landing site with respect to the available cartographic database. This is not possible by tracking alone due to the lack of on-ground orientation and the so-called map-tie problem. Images as provided by the PanCam allow to determine accurate tilt and north directions for each lander and to identify the lander locations based on landmarks, which can also be recognized in appropriate orbiter imagery. With this information, it will be further possible to improve the Mars-wide geodetic control point network and the resulting geometric precision of global map products. The major geoscientific objectives of the PanCam lander images are the recognition of surface features like ripples, ridges and troughs, and the identification and characterization of different rock and surface units based on their morphology, distribution, spectral characteristics, and physical properties. The analysis of the PanCam imagery will finally result in the generation of precise map products for each of the landing sites. So far comparative geologic studies of the Martian surface are restricted to the timely separated Mars Pathfinder and the two Viking Lander Missions. Further lander missions are in preparation (Beagle-2, Mars Surveyor 03). NetLander provides the unique opportunity to nearly double the number of accessible landing site data by providing

  14. Vehicle-Level Oxygen/Methane Propulsion System Hotfire Testing at Thermal Vacuum Conditions

    NASA Technical Reports Server (NTRS)

    Morehead, Robert L.; Melcher, J. C.; Atwell, Matthew J.; Hurlbert, Eric A.; Desai, Pooja; Werlink, Rudy

    2017-01-01

    A prototype integrated liquid oxygen/liquid methane propulsion system was hot-fire tested at a variety of simulated altitude and thermal conditions in the NASA Glenn Research Center Plum Brook Station In-Space Propulsion Thermal Vacuum Chamber (formerly B2). This test campaign served two purposes: 1) Characterize the performance of the Plum Brook facility in vacuum accumulator mode and 2) Collect the unique data set of an integrated LOX/Methane propulsion system operating in high altitude and thermal vacuum environments (a first). Data from this propulsion system prototype could inform the design of future spacecraft in-space propulsion systems, including landers. The test vehicle for this campaign was the Integrated Cryogenic Propulsion Test Article (ICPTA), which was constructed for this project using assets from the former Morpheus Project rebuilt and outfitted with additional new hardware. The ICPTA utilizes one 2,800 lbf main engine, two 28 lbf and two 7 lbf reaction control engines mounted in two pods, four 48-inch propellant tanks (two each for liquid oxygen and liquid methane), and a cold helium system for propellant tank pressurization. Several hundred sensors on the ICPTA and many more in the test cell collected data to characterize the operation of the vehicle and facility. Multiple notable experiments were performed during this test campaign, many for the first time, including pressure-fed cryogenic reaction control system characterization over a wide range of conditions, coil-on-plug ignition system demonstration at the vehicle level, integrated main engine/RCS operation, and a non-intrusive propellant mass gauging system. The test data includes water-hammer and thermal heat leak data critical to validating models for use in future vehicle design activities. This successful test campaign demonstrated the performance of the updated Plum Brook In-Space Propulsion thermal vacuum chamber and incrementally advanced the state of LOX/Methane propulsion

  15. Testing general relativity with Landers on the Martian satellite Phobos

    NASA Technical Reports Server (NTRS)

    Anderson, J. D.; Borderies, N. J.; Campbell, J. K.; Dunne, J. A.; Ellis, J.

    1989-01-01

    A planned experiment to obtain range and Doppler data with the Phobos 2 Lander on the surface of the Martian satellite Phobos is described. With the successful insertion on January 29, 1989 of Phobos 2 into Mars orbit, it is anticipated that the Lander will be placed on the surface of Phobos in April 1989. Depending on the longevity of the Lander, range and Doppler data for a period of from one to several years are expected. Because these data are of value in performing solar-system tests of general relativity, the current accuracy of the relevant relativity tests using Deep Space Network data from the Mariner-9 orbiter of Mars in 1971 and from the Viking Landers in 1976-1982 is reviewed. The expected improvement from data anticipated during the Phobos 2 Lander Mission is also discussed; most important will be an improved sensitivity to any time variation in the gravitational 'constant' as measured in atomic units.

  16. The Mars Polar Lander undergoes spin test

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers in the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2) lift the Mars Polar Lander to move it to a spin table for testing. The lander, which will be launched on Jan. 3, 1999, is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which is due to be launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  17. An Advantage for Age? Self-Concept and Self-Regulation as Teachable Foundations in Second Language Accent

    ERIC Educational Resources Information Center

    Moyer, Alene

    2018-01-01

    Age of onset has long been assumed to predict outcomes in second/foreign language accent. Yet beyond early childhood, acquiring a new accent has much to do with social-affective factors such as learner identity and motivation, as well as cognitive factors such as learning strategies (Pfenninger, 2017). Newer perspectives acknowledge this…

  18. Viking lander battery performance, degradation, and reconditioning

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Britting, A.O. Jr.

    1981-01-01

    On July 20 and September 3, 1976, Viking Landers 1 and 2 touched down on the surface of Mars. Prior to launch each lander, including its batteries was subjected to a sterilization temperature of 233 F for 54 hours. The results of battery performance, degradation and reconditioning are presented, including charge/discharge cycles, reconditioning technique, temperature history, early and current capacity. A brief description of the power system operation is also included.

  19. The Phoenix Mars Lander Robotic Arm

    NASA Technical Reports Server (NTRS)

    Bonitz, Robert; Shiraishi, Lori; Robinson, Matthew; Carsten, Joseph; Volpe, Richard; Trebi-Ollennu, Ashitey; Arvidson, Raymond E.; Chu, P. C.; Wilson, J. J.; Davis, K. R.

    2009-01-01

    The Phoenix Mars Lander Robotic Arm (RA) has operated for over 150 sols since the Lander touched down on the north polar region of Mars on May 25, 2008. During its mission it has dug numerous trenches in the Martian regolith, acquired samples of Martian dry and icy soil, and delivered them to the Thermal Evolved Gas Analyzer (TEGA) and the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The RA inserted the Thermal and Electrical Conductivity Probe (TECP) into the Martian regolith and positioned it at various heights above the surface for relative humidity measurements. The RA was used to point the Robotic Arm Camera to take images of the surface, trenches, samples within the scoop, and other objects of scientific interest within its workspace. Data from the RA sensors during trenching, scraping, and trench cave-in experiments have been used to infer mechanical properties of the Martian soil. This paper describes the design and operations of the RA as a critical component of the Phoenix Mars Lander necessary to achieve the scientific goals of the mission.

  20. The Martian surface as imaged, sampled, and analyzed by the Viking landers

    NASA Technical Reports Server (NTRS)

    Arvidson, Raymond E.; Gooding, James L.; Moore, Henry J.

    1989-01-01

    Data collected by two Viking landers are analyzed. Attention is given to the characteristics of the surface inferred from Lander imaging and meteorology data, physical and magnetic properties experiments, and both inorganic and organic analyses of Martian samples. Viking Lander 1 touched down on Chryse Planitia on July 20, 1976 and continued to operate for 2252 sols, until November 20, 1982. Lander 2 touched down about 6500 km away from Lander 1, on Utopia Planitia on September 3, 1976. The chemical compositions of sediments at the two landing sites are similar, suggesting an aeolian origin. The compositions suggest an iron-rich rock an are matched by various clays and salts.

  1. Planetary Lake Lander - A Robotic Sentinel to Monitor a Remote Lake

    NASA Technical Reports Server (NTRS)

    Pedersen, Liam; Smith, Trey; Lee, Susan; Cabrol, Nathalie; Rose, Kevin

    2012-01-01

    The Planetary Lake Lander Project is studying the impact of rapid deglaciation at a high altitude alpine lake in the Andes, where disrupted environmental, physical, chemical, and biological cycles result in newly emerging natural patterns. The solar powered Lake Lander robot is designed to monitor the lake system and characterize both baseline characteristics and impacts of disturbance events such as storms and landslides. Lake Lander must use an onboard adaptive science-on-the-fly approach to return relevant data about these events to mission control without exceeding limited energy and bandwidth resources. Lake Lander carries weather sensors, cameras and a sonde that is winched up and down the water column to monitor temperature, dissolved oxygen, turbidity and other water quality parameters. Data from Lake Lander is returned via satellite and distributed to an international team of scientists via web-based ground data systems. Here, we describe the Lake Lander Project scientific goals, hardware design, ground data systems, and preliminary data from 2011. The adaptive science-on-the-fly system will be described in future papers.

  2. Identifying a Foreign Accent in an Unfamiliar Language

    ERIC Educational Resources Information Center

    Major, Roy C.

    2007-01-01

    This study explores the question of whether native and nonnative listeners, some familiar with the language and some not, differ in their accent ratings of native speakers (NSs) and nonnative speakers (NNSs). Although a few studies have employed native and nonnative judges to evaluate native and nonnative speech, the present study is perhaps the…

  3. Attitudes towards Foreign Accents among Adult Multilingual Language Users

    ERIC Educational Resources Information Center

    Dewaele, Jean-Marc; McCloskey, James

    2015-01-01

    The present study investigates inter-individual variation (linked to personality traits, multilingualism and sociobiographical variables) in the attitudes that 2035 multilinguals have of their own and others' foreign accent (FA). Data were collected through an online questionnaire. We found that multilinguals who were extraverted, emotionally…

  4. Impact and Crashworthiness Characteristics of Venera Type Landers for Future Venus Missions

    NASA Technical Reports Server (NTRS)

    Schroeder, Kevin; Bayandor, Javid; Samareh, Jamshid

    2016-01-01

    In this paper an in-depth investigation of the structural design of the Venera 9-14 landers is explored. A complete reverse engineering of the Venera lander was required. The lander was broken down into its fundamental components and analyzed. This provided in-sights into the hidden features of the design. A trade study was performed to find the sensitivity of the lander's overall mass to the variation of several key parameters. For the lander's legs, the location, length, configuration, and number are all parameterized. The size of the impact ring, the radius of the drag plate, and other design features are also parameterized, and all of these features were correlated to the change of mass of the lander. A multi-fidelity design tool used for further investigation of the parameterized lander was developed. As a design was passed down from one level to the next, the fidelity, complexity, accuracy, and run time of the model increased. The low-fidelity model was a highly nonlinear analytical model developed to rapidly predict the mass of each design. The medium and high fidelity models utilized an explicit finite element framework to investigate the performance of various landers upon impact with the surface under a range of landing conditions. This methodology allowed for a large variety of designs to be investigated by the analytical model, which identified designs with the optimum structural mass to payload ratio. As promising designs emerged, investigations in the following higher fidelity models were focused on establishing their reliability and crashworthiness. The developed design tool efficiently modelled and tested the best concepts for any scenario based on critical Venusian mission requirements and constraints. Through this program, the strengths and weaknesses inherent in the Venera-Type landers were thoroughly investigated. Key features identified for the design of robust landers will be used as foundations for the development of the next generation of

  5. Self-unloading, unmanned, reusable lunar lander project

    NASA Technical Reports Server (NTRS)

    Cowan, Kevin; Lewis, Ron; Mislinski, Philip; Rivers, Donna; Smith, Solar; Vasicek, Clifford; Verona, Matt

    1991-01-01

    A payload delivery system will be required to support the buildup and operation of a manned lunar base. In response, a self-unloading, unmanned, reusable lunar lander was conceptually designed. The lander will deliver a 7000 kg payload, with the same dimensions as a space station logistics module, from low lunar orbit to any location on the surface of the moon. The technical aspects of the design is introduced as well as the management structure and project cost.

  6. Evolving Best Practice in Learning About Air Quality and Climate Change Science in ACCENT

    NASA Astrophysics Data System (ADS)

    Schuepbach, E.

    2008-12-01

    Learning about air quality and climate change science has developed into a transdisciplinary impact generator, moulded by academic-stakeholder partnerships, where complementary skills and competences lead to a culture of dialogue, mutual learning and decision-making. These sweeping changes are mirrored in the evolving best practice within the European Network of Excellence on Atmospheric Composition Change (ACCENT). The Training and Education Programme in ACCENT pursues an integrated approach and innovative avenues to sharing knowledge and communicating air quality and climate change science to various end-user groups, including teachers, policy makers, stakeholders, and the general public. Early career scientists are involved in the process, and are trained to acquire new knowledge in a variety of learning communities and environments. Here, examples of both the open system of teaching within ACCENT training workshops for early career scientists, and the engagement of non-academic audiences in the joint learning process are presented.

  7. Lunar lander ground support system

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This year's project, like the previous Aerospace Group's project, involves a lunar transportation system. The basic time line will be the years 2010-2030 and will be referred to as a second generation system, as lunar bases would be present. The project design completed this year is referred to as the Lunar Lander Ground Support System (LLGSS). The area chosen for analysis encompasses a great number of vehicles and personnel. The design of certain elements of the overall lunar mission are complete projects in themselves. For this reason the project chosen for the Senior Aerospace Design is the design of specific servicing vehicles and additions or modifications to existing vehicles for the area of concern involving servicing and maintenance of the lunar lander while on the surface.

  8. InSight Lander in Assembly

    NASA Image and Video Library

    2015-05-27

    The Mars lander that NASA's InSight mission will use for investigating how rocky planets formed and evolved is being assembled by Lockheed Martin Space Systems, Denver. In this scene from January 2015, Lockheed Martin spacecraft specialists are working on the lander in a clean room. InSight, for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport, is scheduled for launch in March 2016 and landing in September 2016. Note: After thorough examination, NASA managers have decided to suspend the planned March 2016 launch of the Interior Exploration using Seismic Investigations Geodesy and Heat Transport (InSight) mission. The decision follows unsuccessful attempts to repair a leak in a section of the prime instrument in the science payload. http://photojournal.jpl.nasa.gov/catalog/PIA19402

  9. The Martian surface as imaged, sampled, and analyzed by the Viking landers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Arvidson, R.E.; Gooding, J.L.; Moore, H.J.

    1989-02-01

    Data collected by two Viking landers are analyzed. Attention is given to the characteristics of the surface inferred from Lander imaging and meteorology data, physical and magnetic properties experiments, and both inorganic and organic analyses of Martian samples. Viking Lander 1 touched down on Chryse Planitia on July 20, 1976 and continued to operate for 2252 sols, until November 20, 1982. Lander 2 touched down about 6500 km away from Lander 1, on Utopia Planitia on September 3, 1976. The chemical compositions of sediments at the two landing sites are similar, suggesting an aeolian origin. The compositions suggest an iron-richmore » rock an are matched by various clays and salts. 89 refs.« less

  10. Linear Covariance Analysis for a Lunar Lander

    NASA Technical Reports Server (NTRS)

    Jang, Jiann-Woei; Bhatt, Sagar; Fritz, Matthew; Woffinden, David; May, Darryl; Braden, Ellen; Hannan, Michael

    2017-01-01

    A next-generation lunar lander Guidance, Navigation, and Control (GNC) system, which includes a state-of-the-art optical sensor suite, is proposed in a concept design cycle. The design goal is to allow the lander to softly land within the prescribed landing precision. The achievement of this precision landing requirement depends on proper selection of the sensor suite. In this paper, a robust sensor selection procedure is demonstrated using a Linear Covariance (LinCov) analysis tool developed by Draper.

  11. Efficient Personalized Mispronunciation Detection of Taiwanese-Accented English Speech Based on Unsupervised Model Adaptation and Dynamic Sentence Selection

    ERIC Educational Resources Information Center

    Wu, Chung-Hsien; Su, Hung-Yu; Liu, Chao-Hong

    2013-01-01

    This study presents an efficient approach to personalized mispronunciation detection of Taiwanese-accented English. The main goal of this study was to detect frequently occurring mispronunciation patterns of Taiwanese-accented English instead of scoring English pronunciations directly. The proposed approach quickly identifies personalized…

  12. Lunar lander conceptual design

    NASA Technical Reports Server (NTRS)

    Stecklein, J. M.; Petro, A. J.; Stump, W. R.; Adorjan, A. S.; Chambers, T. V.; Donofrio, M.; Hirasaki, J. K.; Morris, O. G.; Nudd, G.; Rawlings, R. P.

    1992-01-01

    This paper is a first look at the problems of building a lunar lander to support a small lunar surface base. A series of trade studies was performed to define the lander. The initial trades concerned choosing number of stages, payload mass, parking orbit altitude, and propellant type. Other important trades and issues included plane change capability, propellant loading and maintenance location, and reusability considerations. Given a rough baseline, the systems were then reviewed. A conceptual design was then produced. The process was carried through only one iteration. Many more iterations are needed. A transportation system using reusable, aerobraked orbital transfer vehicles (OTV's) is assumed. These OTV's are assumed to be based and maintained at a low Earth orbit (LEO) space station, optimized for transportation functions. Single- and two-stage OTV stacks are considered. The OTV's make the translunar injection (TLI), lunar orbit insertion (LOI), and trans-Earth injection (TEI) burns, as well as midcourse and perigee raise maneuvers.

  13. Foreign Accents Revisited: The English Pronunciation of Russian Immigrants.

    ERIC Educational Resources Information Center

    Thompson, Irene

    1991-01-01

    This study investigated factors associated with the acquisition of second-language pronunciation and methodological problems associated with the study of foreign accents. Thirty-six native speakers of Russian fluent in English read specifically constructed English sentences and a prose passage, and talked spontaneously about their daily routine.…

  14. The Impact of Foreign Accent on Credibility: An Analysis of Cognitive Statement Ratings in a Swiss Context

    ERIC Educational Resources Information Center

    Stocker, Ladina

    2017-01-01

    The present paper reports on a study investigating whether the presence of a foreign accent negatively affects credibility judgments. Previous research suggests that trivia statements recorded by speakers with a foreign accent are judged as less credible than when recorded by native speakers due to increased cognitive demands (Lev-Ari and Keysar…

  15. A fault is born: The Landers-Mojave earthquake line

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nur, A.; Ron, H.

    1993-04-01

    The epicenter and the southern portion of the 1992 Landers earthquake fell on an approximately N-S earthquake line, defined by both epicentral locations and by the rupture directions of four previous M>5 earthquakes in the Mojave: The 1947 Manix; 1975 Galway Lake; 1979 Homestead Valley: and 1992 Joshua Tree events. Another M 5.2 earthquake epicenter in 1965 fell on this line where it intersects the Calico fault. In contrast, the northern part of the Landers rupture followed the NW-SE trending Camp Rock and parallel faults, exhibiting an apparently unusual rupture kink. The block tectonic model (Ron et al., 1984) combiningmore » fault kinematic and mechanics, explains both the alignment of the events, and their ruptures (Nur et al., 1986, 1989), as well as the Landers kink (Nur et al., 1992). Accordingly, the now NW oriented faults have rotated into their present direction away from the direction of maximum shortening, close to becoming locked, whereas a new fault set, optimally oriented relative to the direction of shortening, is developing to accommodate current crustal deformation. The Mojave-Landers line may thus be a new fault in formation. During the transition of faulting from the old, well developed and wak but poorly oriented faults to the strong, but favorably oriented new ones, both can slip simultaneously, giving rise to kinks such as Landers.« less

  16. The Foundations of Accent and Intelligibility in Pronunciation Research

    ERIC Educational Resources Information Center

    Munro, Murray J.; Derwing, Tracey M.

    2011-01-01

    Our goal in developing this timeline was to trace the empirical bases of current approaches to L2 pronunciation teaching, with particular attention to the concepts of "accent" and "intelligibility". The process of identifying suitable works for inclusion challenged us in several ways. First, the number of empirical studies of pronunciation…

  17. The Impact of Foreign Accent on Credibility: An Analysis of Cognitive Statement Ratings in a Swiss Context.

    PubMed

    Stocker, Ladina

    2017-06-01

    The present paper reports on a study investigating whether the presence of a foreign accent negatively affects credibility judgments. Previous research suggests that trivia statements recorded by speakers with a foreign accent are judged as less credible than when recorded by native speakers due to increased cognitive demands (Lev-Ari and Keysar in J Exp Soc Psychol 46(6):1093-1096, 2010. doi: 10.1016/j.jesp.2010.05.025 ). In the present study, 194 French- and 183 Swiss-German-speaking participants were asked to judge the truthfulness of 48 trivia statements recorded by speakers with French, Swiss-German, Italian and English accents by means of an online survey. Before submitting the survey, raters were asked to attribute given labels-including adjectives referring to credibility-to a language group aiming to elicit raters' stereotypes in a direct manner. Although the results of this task indicate that the raters do hold different stereotypes concerning credibility of speech communities, foreign accent does not seem to have an impact on credibility ratings in the Swiss context.

  18. Lander Trench Dug by Opportunity

    NASA Image and Video Library

    2015-01-27

    On March 20, 2004, NASA Mars Exploration Rover Opportunity used a wheel to dig a trench revealing subsurface material beside the lander hardware that carried the rover to the surface of Mars 55 Martian days earlier.

  19. The Prosodic Basis of the Tiberian Hebrew System of Accents.

    ERIC Educational Resources Information Center

    Dresher, Bezalel Elan

    1994-01-01

    It is argued that the Tiberian system of accents that annotate the text of the Hebrew Bible has a prosodic basis. Tiberian representation can best be understood by integrating results of phonological, phonetic, and psycholinguistic research on prosodic structure. (93 references) (Author/LB)

  20. Performance evaluation of a quasi-microscope for planetary landers

    NASA Technical Reports Server (NTRS)

    Burcher, E. E.; Huck, F. O.; Wall, S. D.; Woehrle, S. B.

    1977-01-01

    Spatial resolutions achieved with cameras on lunar and planetary landers have been limited to about 1 mm, whereas microscopes of the type proposed for such landers could have obtained resolutions of about 1 um but were never accepted because of their complexity and weight. The quasi-microscope evaluated in this paper could provide intermediate resolutions of about 10 um with relatively simple optics that would augment a camera, such as the Viking lander camera, without imposing special design requirements on the camera of limiting its field of view of the terrain. Images of natural particulate samples taken in black and white and in color show that grain size, shape, and texture are made visible for unconsolidated materials in a 50- to 500-um size range. Such information may provide broad outlines of planetary surface mineralogy and allow inferences to be made of grain origin and evolution. The mineralogical descriptions of single grains would be aided by the reflectance spectra that could, for example, be estimated from the six-channel multispectral data of the Viking lander camera.

  1. Robotic Lunar Landers for Science and Exploration

    NASA Technical Reports Server (NTRS)

    Cohen, B. A.; Bassler, J. A.; Hammond, M. S.; Harris, D. W.; Hill, L. A.; Kirby, K. W.; Morse, B. J.; Mulac, B. D.; Reed, C. L. B.

    2010-01-01

    The Moon provides an important window into the early history of the Earth, containing information about planetary composition, magmatic evolution, surface bombardment, and exposure to the space environment. Robotic lunar landers to achieve science goals and to provide precursor technology development and site characterization are an important part of program balance within NASA s Science Mission Directorate (SMD) and Exploration Systems Mission Directorate (ESMD). A Robotic Lunar Lan-der mission complements SMD's initiatives to build a robust lunar science community through R&A lines and increases international participation in NASA's robotic exploration of the Moon.

  2. A Comparative Analysis of the English-Language Accent Preferences of Prospective and Practicing Businesspersons from around the World

    ERIC Educational Resources Information Center

    Scott, James C.; Green, Diana J.; Blaszczynski, Carol; Rosewarne, David D.

    2007-01-01

    Problem: The studies of the English-language accent preferences of prospective and practicing businesspersons from around the world have not been integrated. Research Questions: What are the English-language accent preferences of prospective and practicing businesspersons from around the world, and how are those preferences influenced by the…

  3. Composite View from Phoenix Lander

    NASA Image and Video Library

    2009-07-02

    This mosaic of images from the Surface Stereo Imager camera on NASA Phoenix Mars Lander shows several trenches dug by Phoenix, plus a corner of the spacecraft deck and the Martian arctic plain stretching to the horizon.

  4. Enabling technologies for Chinese Mars lander guidance system

    NASA Astrophysics Data System (ADS)

    Jiang, Xiuqiang; Li, Shuang

    2017-04-01

    Chinese first Mars exploration activity, orbiting landing and roaming collaborative mission, has been programmed and started. As a key technology, Mars lander guidance system is intended to serve atmospheric entry, descent and landing (EDL) phases. This paper is to report the formation process of enabling technology road map for Chinese Mars lander guidance system. First, two scenarios of the first-stage of the Chinese Mars exploration project are disclosed in detail. Second, mission challenges and engineering needs of EDL guidance, navigation, and control (GNC) are presented systematically for Chinese Mars exploration program. Third, some useful related technologies developed in China's current aerospace projects are pertinently summarized, especially on entry guidance, parachute descent, autonomous hazard avoidance and safe landing. Finally, an enabling technology road map of Chinese Mars lander guidance is given through technological inheriting and improving.

  5. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1991-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  6. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1992-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  7. A Wind Tunnel Study on the Mars Pathfinder (MPF) Lander Descent Pressure Sensor

    NASA Technical Reports Server (NTRS)

    Soriano, J. Francisco; Coquilla, Rachael V.; Wilson, Gregory R.; Seiff, Alvin; Rivell, Tomas

    2001-01-01

    The primary focus of this study was to determine the accuracy of the Mars Pathfinder lander local pressure readings in accordance with the actual ambient atmospheric pressures of Mars during parachute descent. In order to obtain good measurements, the plane of the lander pressure sensor opening should ideally be situated so that it is parallel to the freestream. However, due to two unfavorable conditions, the sensor was positioned in locations where correction factors are required. One of these disadvantages is due to the fact that the parachute attachment point rotated the lander's center of gravity forcing the location of the pressure sensor opening to be off tangent to the freestream. The second and most troublesome factor was that the lander descends with slight oscillations that could vary the amplitude of the sensor readings. In order to accurately map the correction factors required at each sensor position, an experiment simulating the lander descent was conducted in the Martian Surface Wind Tunnel at NASA Ames Research Center. Using a 115 scale model at Earth ambient pressures, the test settings provided the necessary Reynolds number conditions in which the actual lander was possibly subjected to during the descent. In the analysis and results of this experiment, the readings from the lander sensor were converted to the form of pressure coefficients. With a contour map of pressure coefficients at each lander oscillatory position, this report will provide a guideline to determine the correction factors required for the Mars Pathfinder lander descent pressure sensor readings.

  8. The heat shield for the Mars Polar Lander is attached

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers get ready to lift the heat shield for the Mars Polar Lander off the workstand before attaching it to the lander. Scheduled to be launched on Jan. 3, 1999, the lander is a solar- powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which is due to be launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  9. Europa Lander Mission Concept (Artist Rendering)

    NASA Image and Video Library

    2017-02-08

    This artist's rendering illustrates a conceptual design for a potential future mission to land a robotic probe on the surface of Jupiter's moon Europa. The lander is shown with a sampling arm extended, having previously excavated a small area on the surface. The circular dish on top is a dual-purpose high-gain antenna and camera mast, with stereo imaging cameras mounted on the back of the antenna. Three vertical shapes located around the top center of the lander are attachment points for cables that would lower the rover from a sky crane, which is envisioned as the landing system for this mission concept. http://photojournal.jpl.nasa.gov/catalog/PIA21048

  10. Can You Understand Me? Speaking Robots and Accented Speech

    ERIC Educational Resources Information Center

    Moussalli, Souheila; Cardoso, Walcir

    2017-01-01

    The results of our previous research on the pedagogical use of Speaking Robots (SRs) revealed positive effects on motivating students to practice their oral skills in a stress-free environment. However, our findings indicated that the SR was sometimes unable to understand students' foreign accented speech. In this paper, we report the results of a…

  11. Radiator Study for Stationary Lunar Landers

    NASA Technical Reports Server (NTRS)

    OConnor, Brian; Abel, Elisabeth

    2010-01-01

    This paper provides an overview of a study to identify, select and evaluate potential heat rejection radiators for application to small, low power, stationary lunar landers. While this study supported risk mitigation activities related to the International Lunar Network project, the radiator concepts and performance assessments are applicable to a wide range of lunar lander applications. The radiator concepts identified and evaluated in this study were aimed at providing reliable heat rejection for landers that might be subjected to hot lunar noon conditions at the equator. As a part of the study, a literature search of lunar radiators was performed from which many radiator designs were developed. These designs were compared in a trade study and two of the most promising were used to develop six concepts. These six radiator concepts went through a more detailed thermal analysis using Thermal Desktop. The analysis considered heat rejection capability, and sensitivity to many factors such as dust deposition, latitude, life, and topographical features like landing on a hill, on a rock, or in a hole/crater. From the result of the analysis, two radiator concepts were selected for recommendation: a flat horizontal plate with a dust cover and a stacked vertical radiator with parabolic reflectors and a one degree tilting mechanism.

  12. Mars Relay Lander and Orbiter Overflight Profile Estimation

    NASA Technical Reports Server (NTRS)

    Wallick, Michael N.; Allard, Daniel A.; Gladden, Roy E.; Peterson, Corey L.

    2012-01-01

    This software allows science and mission operations to view graphs of geometric overflights of satellites and landers within the Mars (or other planetary) networks. It improves on the MaROS Web interface within any modern Web browser, in that it adds new capabilities to the MaROS suite. The profile for an overflight is an important element for selecting communication/ overflight opportunities between the landers and orbiters within the Mars network. Unfortunately, determining these estimates is very computationally expensive and difficult to compute by hand. This software allows the user to select different overflights (via the existing MaROS Web interface) and specify the smoothness of the estimation. Estimates for the geometric relationship between a lander and an orbiter are determined based upon the orbital conditions of the orbiter at the moment the orbiter rises above the horizon from the perspective of the lander. It utilizes 2-body orbital equations to propagate the trajectory through the duration of the view period, and returns profiles that represent the range between the two vehicles, and the elevation and azimuth angles of the orbiter as measured from the lander s position. The algorithms assume a 2-body relationship with an ideal, spherical planetary body, so therefore can see errors less than 2% at polar landing sites on Mars. These algorithms are being implemented to provide rough estimates rapidly for the geometry of a geometric view period where more complete data is unavailable, such as for planning purposes. While other software for this task exists, each at the time of this reporting has been contained within a much more complicated package. This tool allows science and mission operations to view the estimates with a few clicks of the mouse.

  13. Mars Polar Lander is mated with Boeing Delta II rocket

    NASA Technical Reports Server (NTRS)

    1998-01-01

    At Launch Complex 17B, Cape Canaveral Air Station, the protective covering on the Mars Polar Lander is lifted up and out of the way. The lander, in the opening below, is being mated to the Boeing Delta II rocket that will launch it on Jan. 3, 1999. The lander is a solar- powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars Surveyor'98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  14. Rocket Propulsion (RP) 21 Steering Committee Meeting - NASA Spacecraft Propulsion Update

    NASA Technical Reports Server (NTRS)

    Klem, Mark

    2016-01-01

    Lander Tech is three separate but synergistic efforts: Lunar CATALYST (Lunar Cargo Transportation and Landing by Soft Touchdown) Support U.S. industry led robotic lunar lander development via three public-private efforts. Support U.S. industry led robotic lunar lander development via three public-private partnerships. Infuse or transfer landing technologies into these public private partnerships. Advanced Exploration Systems-Automated Propellant Loading (APL) -Integrated Ground Operations. Demonstrate LH2 zero loss storage, loading and transfer operations via testing on a large scale in a relevant launch vehicle servicing environment. (KSC, GRC). Game Changing Technology-20 Kelvin -20 Watt Cryocooler Development of a Reverse Turbo-Brayton Cryocooler operating at 20 Kelvin with 20 Watts of refrigeration lift.

  15. Neural Correlates of Infant Accent Discrimination: An fNIRS Study

    ERIC Educational Resources Information Center

    Cristia, Alejandrina; Minagawa-Kawai, Yasuyo; Egorova, Natalia; Gervain, Judit; Filippin, Luca; Cabrol, Dominique; Dupoux, Emmanuel

    2014-01-01

    The present study investigated the neural correlates of infant discrimination of very similar linguistic varieties (Quebecois and Parisian French) using functional Near InfraRed Spectroscopy. In line with previous behavioral and electrophysiological data, there was no evidence that 3-month-olds discriminated the two regional accents, whereas…

  16. Viking Lander Mosaics of Mars

    NASA Technical Reports Server (NTRS)

    Morris, E. C.

    1985-01-01

    The Viking Lander 1 and 2 cameras acquired many high-resolution pictures of the Chryse Planitia and Utopia Planitia landing sites. Based on computer-processed data of a selected number of these pictures, eight high-resolution mosaics were published by the U.S. Geological Survey as part of the Atlas of Mars, Miscellaneous Investigation Series. The mosaics are composites of the best picture elements (pixels) of all the Lander pictures used. Each complete mosaic extends 342.5 deg in azimuth, from approximately 5 deg above the horizon to 60 deg below, and incorporates approximately 15 million pixels. Each mosaic is shown in a set of five sheets. One sheet contains the full panorama from one camera taken in either morning or evening. The other four sheets show sectors of the panorama at an enlarged scale; when joined together they make a panorama approximately 2' X 9'.

  17. International Students' Accented English-Communication Difficulties and Developed Strategies

    ERIC Educational Resources Information Center

    Park, Eunjae; Klieve, Helen; Tsurutani, Chiharu; Harte, Wendy

    2017-01-01

    The purpose of the present investigation is to explore the communication challenges caused by accented English along with strategies of international students in the Australian context. A quantitative approach was employed in order to obtain a comprehensive understanding of the linguistic experience of the students. Participants comprised 182…

  18. Design of a hydrophone for an Ocean World lander

    NASA Astrophysics Data System (ADS)

    Smith, Heather D.; Duncan, Andrew G.

    2017-10-01

    For this presentation we describe the science return, and design of a microphone on- board a Europa lander mission. In addition to the E/PO benefit of a hydrophone to listen to the Europa Ocean, a microphone also provides scientific data on the properties of the subsurface ocean.A hydrophone is a small light-weight instrument that could be used to achieve two of the three Europa Lander mission anticipated science goals of: 1) Asses the habitability (particularly through quantitative compositional measurements of Europa via in situ techniques uniquely available to a landed mission. And 2) Characterize surface properties at the scale of the lander to support future exploration, including the local geologic context.Acoustic properties of the ocean would lead to a better understanding of the water density, currents, seafloor topography and other physical properties of the ocean as well as lead to an understanding of the salinity of the ocean. Sound from water movement (tidal movement, currents, subsurface out-gassing, ocean homogeneity (clines), sub-surface morphology, and biological sounds.The engineering design of the hydrophone instrument will be designed to fit within a portion of the resource allocation of the current best estimates of the Europa lander payload (26.6 Kg, 24,900 cm3, 2,500 W-hrs and 2700 Mbits). The hydrophone package will be designed to ensure planetary protection is maintained and will function under the cur- rent Europa lander mission operations scenario of a two-year cruise phase, and 30-day surface operational phase on Europa.Although the microphone could be used on the surface, it is designed to be lowered into the subsurface ocean. As such, planetary protection (forward contamination) is a primary challenge for a subsurface microphone/ camera. The preliminary design is based on the Navy COTS optical microphone.Reference: Pappalardo, R. T., et al. "Science potential from a Europa lander." Astrobiology 13.8 (2013): 740-773.

  19. Auditory perceptual simulation: Simulating speech rates or accents?

    PubMed

    Zhou, Peiyun; Christianson, Kiel

    2016-07-01

    When readers engage in Auditory Perceptual Simulation (APS) during silent reading, they mentally simulate characteristics of voices attributed to a particular speaker or a character depicted in the text. Previous research found that auditory perceptual simulation of a faster native English speaker during silent reading led to shorter reading times that auditory perceptual simulation of a slower non-native English speaker. Yet, it was uncertain whether this difference was triggered by the different speech rates of the speakers, or by the difficulty of simulating an unfamiliar accent. The current study investigates this question by comparing faster Indian-English speech and slower American-English speech in the auditory perceptual simulation paradigm. Analyses of reading times of individual words and the full sentence reveal that the auditory perceptual simulation effect again modulated reading rate, and auditory perceptual simulation of the faster Indian-English speech led to faster reading rates compared to auditory perceptual simulation of the slower American-English speech. The comparison between this experiment and the data from Zhou and Christianson (2016) demonstrate further that the "speakers'" speech rates, rather than the difficulty of simulating a non-native accent, is the primary mechanism underlying auditory perceptual simulation effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Titan Accent Mark

    NASA Image and Video Library

    2015-10-05

    A coincidence of viewing angle makes Pandora appear to be hovering over Titan, almost like an accent mark. Little Pandora is much closer to Cassini than hazy Titan in this view. (Titan is nearly three times farther away.) Even so, Titan (3,200 miles or 5,150 kilometers across) dwarfs Pandora (50 miles or 81 kilometers across). This gives us some sense of the diversity in sizes, and shapes, of Saturn's many moons. North on Titan is up and rotated 19 degrees to the right. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on July 4, 2015. The view was acquired at a distance of approximately 1.2 million miles (1.9 million kilometers) from Titan. Image scale is 7 miles (12 kilometers) per pixel on Titan. Pandora is at a distance of 436,000 miles (698,000 kilometers) away from the spacecraft. The scale on Pandora is about 3 miles (4 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18338

  1. Accent, Identity, and a Fear of Loss? ESL Students' Perspectives

    ERIC Educational Resources Information Center

    McCrocklin, Shannon; Link, Stephanie

    2016-01-01

    Because many theorists propose a connection between accent and identity, some theorists have justifiably been concerned about the ethical ramifications of L2 pronunciation teaching. However, English-as-a-second-language (ESL) students often state a desire to sound like native speakers. With little research into ESL students' perceptions of links…

  2. Prosodic Transfer: From Chinese Lexical Tone to English Pitch Accent

    ERIC Educational Resources Information Center

    Ploquin, Marie

    2013-01-01

    Chinese tones are associated with a syllable to convey meaning, English pitch accents are prominence markers associated with stressed syllables. As both are created by pitch modulation, their pitch contours can be quite similar. The experiment reported here examines whether native speakers of Chinese produce, when speaking English, the Chinese…

  3. Morphological Make-up as the Predictor of English Word Accent

    ERIC Educational Resources Information Center

    Salmani-Nodoushan, Mohammad Ali

    2009-01-01

    For years, phoneticians have tried to simplify pronunciation for EFL/ESL learners. Some have identified four degrees of primary, secondary, tertiary, and weak stress, and others only three degrees: primary, secondary, and weak. Still others have concentrated on two stress levels: accented versus unaccented, or stressed versus unstressed (Bowen,…

  4. Multibody Modeling and Simulation for the Mars Phoenix Lander Entry, Descent and Landing

    NASA Technical Reports Server (NTRS)

    Queen, Eric M.; Prince, Jill L.; Desai, Prasun N.

    2008-01-01

    A multi-body flight simulation for the Phoenix Mars Lander has been developed that includes high fidelity six degree-of-freedom rigid-body models for the parachute and lander system. The simulation provides attitude and rate history predictions of all bodies throughout the flight, as well as loads on each of the connecting lines. In so doing, a realistic behavior of the descending parachute/lander system dynamics can be simulated that allows assessment of the Phoenix descent performance and identification of potential sensitivities for landing. This simulation provides a complete end-to-end capability of modeling the entire entry, descent, and landing sequence for the mission. Time histories of the parachute and lander aerodynamic angles are presented. The response of the lander system to various wind models and wind shears is shown to be acceptable. Monte Carlo simulation results are also presented.

  5. Location and Geologic Setting for the Three U.S. Mars Landers

    NASA Technical Reports Server (NTRS)

    Parker, T. J.; Kirk, R. L.

    1999-01-01

    Super resolution of the horizon at both Viking landing sites has revealed "new" features we use for triangulation, similar to the approach used during the Mars Pathfinder Mission. We propose alternative landing site locations for both landers for which we believe the confidence is very high. Super resolution of VL-1 images also reveals some of the drift material at the site to consist of gravel-size deposits. Since our proposed location for VL-2 is NOT on the Mie ejecta blanket, the blocky surface around the lander may represent the meter-scale texture of "smooth palins" in the region. The Viking Lander panchromatic images typically offer more repeat coverage than does the IMP on Mars Pathfinder, due to the longer duration of these landed missions. Sub-pixel offsets, necessary for super resolution to work, appear to be attributable to thermal effects on the lander and settling of the lander over time. Due to the greater repeat coverage (particularly in the near and mid-fields) and all-panchromatic images, the gain in resolution by super resolution processing is better for Viking than it is with most IMP image sequences. This enhances the study of textural details near the lander and enables the identification rock and surface textures at greater distances from the lander. Discernment of stereo in super resolution im-ages is possible to great distances from the lander, but is limited by the non-rotating baseline between the two cameras and the shorter height of the cameras above the ground compared to IMP. With super resolution, details of horizon features, such as blockiness and crater rim shapes, may be better correlated with Orbiter images. A number of horizon features - craters and ridges - were identified at VL-1 during the misison, and a few hils and subtle ridges were identified at VL-2. We have added a few "new" horizon features for triangulation at the VL-2 landing site in Utopia Planitia. These features were used for independent triangulation with features

  6. Rapid scientific response to Landers quake

    NASA Astrophysics Data System (ADS)

    Mori, J.; Hudnut, K.; Jones, L.; Hauksson, E.; Hutton, K.

    Early on the morning of June 28, 1992, millions of people in southern California were awakened by the largest earthquake (Ms 7.5, Mw 7.4) in the western U.S. in the past 40 years. The quake initiated near the town of Landers, Calif., at 11:57 (GMT) and ruptured to the north and then the northwest along a 70-km stretch of the Mojave Shear Zone. Fortunately, the strongest shaking occurred in uninhabited regions of the Mojave desert, but one child was killed in Yucca Valley and 400 people were injured in the surrounding area. The communities of Landers, Yucca Valley, and Joshua Tree in San Bernardino County sustained significant ($100 million) damage to buildings and roads. Damage to water and power lines also caused problems in many of the desert areas.

  7. The Developmental Trajectory of Toddlers' Comprehension of Unfamiliar Regional Accents

    ERIC Educational Resources Information Center

    van Heugten, Marieke; Krieger, Dena R.; Johnson, Elizabeth K.

    2015-01-01

    Efficient language use involves the capacity to flexibly adjust to varied pronunciations of words. Although children can contend with some accent variability before their second birthday, it is currently unclear when and how this ability reaches its mature state. In a series of five experiments, we examine the developmental trajectory of toddlers'…

  8. Mars Polar Lander Mission Distributed Operations

    NASA Technical Reports Server (NTRS)

    Norris, J.; Backes, P.; Slostad, J.; Bonitz, R.; Tharp, G.; Tso, K.

    2000-01-01

    The Mars Polar Lander (MPL) mission is the first planetary mission to use Internet-based distributed ground operations where scientists and engineers collaborate in daily mission operations from multiple geographically distributed locations via the Internet.

  9. The role of beat gesture and pitch accent in semantic processing: an ERP study.

    PubMed

    Wang, Lin; Chu, Mingyuan

    2013-11-01

    The present study investigated whether and how beat gesture (small baton-like hand movements used to emphasize information in speech) influences semantic processing as well as its interaction with pitch accent during speech comprehension. Event-related potentials were recorded as participants watched videos of a person gesturing and speaking simultaneously. The critical words in the spoken sentences were accompanied by a beat gesture, a control hand movement, or no hand movement, and were expressed either with or without pitch accent. We found that both beat gesture and control hand movement induced smaller negativities in the N400 time window than when no hand movement was presented. The reduced N400s indicate that both beat gesture and control movement facilitated the semantic integration of the critical word into the sentence context. In addition, the words accompanied by beat gesture elicited smaller negativities in the N400 time window than those accompanied by control hand movement over right posterior electrodes, suggesting that beat gesture has a unique role for enhancing semantic processing during speech comprehension. Finally, no interaction was observed between beat gesture and pitch accent, indicating that they affect semantic processing independently. © 2013 Elsevier Ltd. All rights reserved.

  10. Brake Failure from Residual Magnetism in the Mars Exploration Rover Lander Petal Actuator

    NASA Technical Reports Server (NTRS)

    Jandura, Louise

    2004-01-01

    In January 2004, two Mars Exploration Rover spacecraft arrived at Mars. Each safely delivered an identical rover to the Martian surface in a tetrahedral lander encased in airbags. Upon landing, the airbags deflated and three Lander Petal Actuators opened the three deployable Lander side petals enabling the rover to exit the Lander. Approximately nine weeks prior to the scheduled launch of the first spacecraft, one of these mission-critical Lander Petal Actuators exhibited a brake stuck-open failure during its final flight stow at Kennedy Space Center. Residual magnetism was the definitive conclusion from the failure investigation. Although residual magnetism was recognized as an issue in the design, the lack of an appropriately specified lower bound on brake drop-out voltage inhibited the discovery of this problem earlier in the program. In addition, the brakes had more unit-to-unit variation in drop-out voltage than expected, likely due to a larger than expected variation in the magnetic properties of the 15-5 PH stainless steel brake plates. Failure analysis and subsequent rework of two other Lander Petal Actuators with marginal brakes was completed in three weeks, causing no impact to the launch date.

  11. The mosaics of Mars: As seen by the Viking Lander cameras

    NASA Technical Reports Server (NTRS)

    Levinthal, E. C.; Jones, K. L.

    1980-01-01

    The mosaics and derivative products produced from many individual high resolution images acquired by the Viking Lander Camera Systems are described: A morning and afternoon mosaic for both cameras at the Lander 1 Chryse Planitia site, and a morning, noon, and afternoon camera pair at Utopia Planitia, the Lander 11 site. The derived products include special geometric projections of the mosaic data sets, polar stereographic (donut), stereoscopic, and orthographic. Contour maps and vertical profiles of the topography were overlaid on the mosaics from which they were derived. Sets of stereo pairs were extracted and enlarged from stereoscopic projections of the mosaics.

  12. Design and Development of a Methane Cryogenic Propulsion Stage for Human Mars Exploration

    NASA Technical Reports Server (NTRS)

    Percy, Thomas K.; Polsgrove, Tara; Turpin, Jason; Alexander, Leslie

    2016-01-01

    of operations introduces several challenges, specifically related to propellant storage and engine reliability. These challenges and some potential solutions are discussed. Specific focus is provided on two key technology areas; propulsion and cryogenic fluid management. In the area of propulsion development, the development of an integrated methane propulsion system that combines both main propulsion and reaction control is discussed. This includes an overview of potential development paths, areas where development for Mars applications are complementary to development efforts underway in other parts of the aerospace industry, and commonality between the MCPS methane propulsion applications and other Mars elements, including the Mars lander systems. This commonality is a key affordability aspect of the Evolvable Mars Campaign. A similar discussion is provided for cryogenic fluid management technologies including a discussion of how using cryo-propulsion in the Mars transportation application not only provides performance benefits but also leverages decades of technology development investments made by NASA and its aerospace contractor community.

  13. Science potential from a Europa lander.

    PubMed

    Pappalardo, R T; Vance, S; Bagenal, F; Bills, B G; Blaney, D L; Blankenship, D D; Brinckerhoff, W B; Connerney, J E P; Hand, K P; Hoehler, T M; Leisner, J S; Kurth, W S; McGrath, M A; Mellon, M T; Moore, J M; Patterson, G W; Prockter, L M; Senske, D A; Schmidt, B E; Shock, E L; Smith, D E; Soderlund, K M

    2013-08-01

    The prospect of a future soft landing on the surface of Europa is enticing, as it would create science opportunities that could not be achieved through flyby or orbital remote sensing, with direct relevance to Europa's potential habitability. Here, we summarize the science of a Europa lander concept, as developed by our NASA-commissioned Science Definition Team. The science concept concentrates on observations that can best be achieved by in situ examination of Europa from its surface. We discuss the suggested science objectives and investigations for a Europa lander mission, along with a model planning payload of instruments that could address these objectives. The highest priority is active sampling of Europa's non-ice material from at least two different depths (0.5-2 cm and 5-10 cm) to understand its detailed composition and chemistry and the specific nature of salts, any organic materials, and other contaminants. A secondary focus is geophysical prospecting of Europa, through seismology and magnetometry, to probe the satellite's ice shell and ocean. Finally, the surface geology can be characterized in situ at a human scale. A Europa lander could take advantage of the complex radiation environment of the satellite, landing where modeling suggests that radiation is about an order of magnitude less intense than in other regions. However, to choose a landing site that is safe and would yield the maximum science return, thorough reconnaissance of Europa would be required prior to selecting a scientifically optimized landing site.

  14. Patient satisfaction and efficacy of accent radiofrequency for facial skin wrinkle reduction

    PubMed Central

    Jaffary, Fariba; Nilforoushzadeh, Mohammad Ali; Zarkoob, Hajar

    2013-01-01

    Background: Radiofrequency (RF) is a new technique to treat facial wrinkles. This study was designed to assess the efficacy of Accent RF in wrinkle reduction of different areas of the face. Materials and Methods: Patients with mild to severe facial wrinkles were treated with Accent using RF energies of 35-145 W. The average energy used in this study was 83.11 W. Patients received four subsequent weekly RF sessions. Wrinkle improvement was rated by two physicians comparing 6-month post treatment photographs with pretreatment photos. Moreover, patient satisfaction was assessed at 1 and 6 months after the last session of the treatment. Results: A total of 45 women participated in this study. In terms of patient satisfaction one month after the last treatment, 8.9% of the patients declared their dissatisfaction, 53.3% were somehow satisfied, 33.3% were satisfied, and 4.4% were very satisfied. At 6 months, patient satisfaction was as follows: 4.4% dissatisfied, 31.1% somehow satisfied, 46.7% satisfied, and 17.8% very satisfied. Patient satisfaction 6 months after the last treatment was significantly higher than 1 month post treatment (P = 0.006). At 6 months, patient satisfaction was not more than 75% in any treatment areas of the face. Conclusion: The results of this study suggest that Accent RF may be considered as a possible effective option for facial skin rejuvenation although its efficacy and safety needs to be evaluated further in randomized controlled trials. PMID:24523783

  15. Dynamic analysis of lunar lander during soft landing using explicit finite element method

    NASA Astrophysics Data System (ADS)

    Zheng, Guang; Nie, Hong; Chen, Jinbao; Chen, Chuanzhi; Lee, Heow Pueh

    2018-07-01

    In this paper, the soft-landing analysis of a lunar lander spacecraft under three loading case was carried out in ABAQUS, using the Explicit Finite Element method. To ensure the simulation result's accuracy and reliability, the energy and mass balance criteria of the model was presented along with the theory and calculation method, and the results were benchmarked with other software (LS-DYNA) to get a validated model. The results from three loading case showed that the energy and mass of the models were conserved during soft landing, which satisfies the energy and mass balance criteria. The overloading response, structure steady state, and the crushing stroke of this lunar lander all met the design requirements of the lunar lander. The buffer energy-absorbing properties in this model have a good energy-absorbing capability, in which up to 84% of the initial energy could be dissipated. The design parameters of the model could guide the design of future manned landers or larger lunar landers.

  16. Viking lander camera geometry calibration report. Volume 1: Test methods and data reduction techniques

    NASA Technical Reports Server (NTRS)

    Wolf, M. B.

    1981-01-01

    The determination and removal of instrument signature from Viking Lander camera geometric data are described. All tests conducted as well as a listing of the final database (calibration constants) used to remove instrument signature from Viking Lander flight images are included. The theory of the geometric aberrations inherent in the Viking Lander camera is explored.

  17. Lander, Airbags, & Martian Terrain

    NASA Image and Video Library

    1997-07-05

    Several objects have been imaged by the Imager for Mars Pathfinder (IMP) during the spacecraft's first day on Mars. Portions of the deflated airbags, part of one the lander's petals, soil, and several rocks are visible. The furrows in the soil were artificially produced by the retraction of the airbags after landing, which occurred at 10:07 a.m. PDT. http://photojournal.jpl.nasa.gov/catalog/PIA00616

  18. Phoenix Lander Amid Disappearing Spring Ice

    NASA Image and Video Library

    2010-01-11

    NASA Phoenix Mars Lander, its backshell and heatshield visible within this enhanced-color image of the Phoenix landing site taken on Jan. 6, 2010 by the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter.

  19. Liquid Oxygen/Liquid Methane Integrated Power and Propulsion

    NASA Technical Reports Server (NTRS)

    Banker, Brian; Ryan, Abigail

    2016-01-01

    previously wasted mass. Such is the case for human and robotic planetary landers. Although many potential benefits through integrated power & propulsion exist, integrated operations have yet to be successfully demonstrated and many challenges have already been identified the most obvious of which is the large temperature gradient. SOFC chemistry is exothermic with operating temperatures in excess of 1,000 K; however, any shared commodities will be undoubtedly stored at cryogenic temperatures (90-112 K) for mass efficiency reasons. Spacecraft packaging will drive these two subsystems in close proximity thus heat leak into the commodity tankage must be minimized and/or mitigated. Furthermore, commodities must be gasified prior to consumption by the SOFC. Excess heat generated by the SOFC could be used to perform this phase change; however, this has yet to be demonstrated. A further identified challenge is the ability of the SOFC to handle the sudden power spikes created by the propulsion system. A power accumulator (battery) will likely be necessary to handle these sudden demands while the SOFC thermally adjusts. JSC's current SOFC test system consists of a 1 kW fuel cell designed by Delphi. The fuel cell is currently undergoing characterization testing at the NASA JSC Energy Systems Test Area (ESTA) after which a Steam Methane Reformer (SMR) will be integrated and the combined system tested in closed-loop. The propulsion brassboard is approximately the size of what could be flown on a sounding rocket. It consists of one 100 lbf thrust "main" engine developed for NASA by Aerojet and two 10 lbf thrusters to simulate a reaction control system developed at NASA JSC. This system is also under development and initial testing at ESTA. After initial testing, combined testing will occur which will provide data on the fuel cell's ability to sufficiently handle the power spikes created by the propulsion system. These two systems will also be modeled using General-Use Nodal Network

  20. Non-Cooled Power System for Venus Lander

    NASA Technical Reports Server (NTRS)

    Salazar, Denise; Landis, Geoffrey A.; Colozza, Anthony J.

    2014-01-01

    The Planetary Science Decadal Survey of 2013-2022 stated that the exploration of Venus is of significant interest. Studying the seismic activity of the planet is of particular importance because the findings can be compared to the seismic activity of Earth. Further, the geological and atmospheric properties of Venus will shed light into the past and future of Earth. This paper presents a radioisotope power system (RPS) design for a small low-power Venus lander. The feasibility of the new power system is then compared to that of primary batteries. A requirement for the power source system is to avoid moving parts in order to not interfere with the primary objective of the mission - to collect data about the seismic activity of Venus using a seismometer. The target mission duration of the lander is 117 days, a significant leap from Venera 13, the longest-lived lander on the surface of Venus, which survived for 2 hours. One major assumption for this mission design is that the power source system will not provide cooling to the other components of the lander. This assumption is based on high-temperature electronics technology that will enable the electronics and components of the lander to operate at Venus surface temperature. For the proposed RPS, a customized General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHSRTG) is designed and analyzed. The GPHS-RTG is chosen primarily because it has no moving parts and it is capable of operating for long duration missions on the order of years. This power system is modeled as a spherical structure for a fundamental thermal analysis. The total mass and electrical output of the system are calculated to be 24 kilograms and 26 Watts, respectively. An alternative design for a battery-based power system uses Sodium Sulfur batteries. To deliver a similar electrical output for 117 days, the battery mass is calculated to be 234 kilograms. Reducing mission duration or power required will reduce the required battery mass

  1. LANDER program manual: A lunar ascent and descent simulation

    NASA Technical Reports Server (NTRS)

    1988-01-01

    LANDER is a computer program used to predict the trajectory and flight performance of a spacecraft ascending or descending between a low lunar orbit of 15 to 500 nautical miles (nm) and the lunar surface. It is a three degree-of-freedom simulation which is used to analyze the translational motion of the vehicle during descent. Attitude dynamics and rotational motion are not considered. The program can be used to simulate either an ascent from the Moon or a descent to the Moon. For an ascent, the spacecraft is initialized at the lunar surface and accelerates vertically away from the ground at full thrust. When the local velocity becomes 30 ft/s, the vehicle turns downrange with a pitch-over maneuver and proceeds to fly a gravity turn until Main Engine Cutoff (MECO). The spacecraft then coasts until it reaches the requested holding orbit where it performs an orbital insertion burn. During a descent simulation, the lander begins in the holding orbit and performs a deorbit burn. It then coasts to pericynthion, where it reignites its engines and begins a gravity turn descent. When the local horizontal velocity becomes zero, the lander pitches up to a vertical orientation and begins to hover in search of a landing site. The lander hovers for a period of time specified by the user, and then lands.

  2. On the Thermal Protection Systems of Landers for Venus Exploration

    NASA Astrophysics Data System (ADS)

    Ekonomov, A. P.; Ksanfomality, L. V.

    2018-01-01

    The landers of the Soviet Venera series—from Venera-9 to Venera-14—designed at the Lavochkin Association are a man-made monument to spectacular achievements of Soviet space research. For more than 40 years, they have remained the uneclipsed Soviet results in space studies of the Solar System. Within the last almost half a century, the experiments carried out by the Venera-9 to Venera-14 probes for studying the surface of the planet have not been repeated by any space agency in the world, mainly due to quite substantial technical problems. Since that time, no Russian missions with landers have been sent to Venus either. On Venus, there is an anoxic carbon dioxide atmosphere, where the pressure is 9.2 MPa and the temperature is 735 K near the surface. A long-lived lander should experience these conditions for an appreciable length of time. What technical solutions could provide a longer operation time for a new probe investigating the surface of Venus, if its thermal scheme is constructed similar to that of the Venera series? Onboard new landers, there should be a sealed module, where the physical conditions required for operating scientific instruments are maintained for a long period. At the same time, new high-temperature electronic equipment that remains functional under the above-mentioned conditions have appeared. In this paper, we consider and discuss different variants of the system for a long-lived sealed lander, in particular, the absorption of the penetrating heat due to water evaporation and the thermal protection construction for the instruments with intermediate characteristics.

  3. The Effect of Vocal Training Methods on Improving Turkish Accent Defects

    ERIC Educational Resources Information Center

    Aycan, Kivanc; Evren, Gul Fahriye

    2016-01-01

    Problem Statement: Despite analyses of how vocal training methods can correct or improve Turkish-language accent defects, for most voice educators, the most important methods continue to be breathe management control and correct vocalization exercises. We therefore sought to demonstrate the relationship of song lyrics to breathe control, accent…

  4. Battery and Fuel Cell Development Goals for the Lunar Surface and Lander

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.

    2008-01-01

    NASA is planning a return to the moon and requires advances in energy storage technology for its planned lunar lander and lunar outpost. This presentation describes NASA s overall mission goals and technical goals for batteries and fuel cells to support the mission. Goals are given for secondary batteries for the lander s ascent stage and suits for extravehicular activity on the lunar surface, and for fuel cells for the lander s descent stage and regenerative fuel cells for outpost power. An overall approach to meeting these goals is also presented.

  5. Viking lander location and spin axis of Mars: determination from radio tracking data.

    PubMed

    Michael, W H; Tolson, R H; Mayo, A P; Blackshear, W T; Kelly, G M; Cain, D L; Brenkle, J P; Shapiro, I I; Reasenberg, R D

    1976-08-27

    Radio tracking data from the Viking lander have been used to determine the lander position and the orientation of the spin axis of Mars. The areocentric coordinates of the lander are 22.27 degrees N, 48.00 degrees W, and 3389.5 kilometers from the center of mass; the spin axis orientation, referred to Earth's mean equator and equinox of 1950.0, is 317.35 degrees right ascension and 52.71 degrees declination.

  6. Positioning for the Chang'E-3 lander and rover using Earth-based Observations

    NASA Astrophysics Data System (ADS)

    Li, P.; Huang, Y.; Hu, X.; Shengqi, C.

    2016-12-01

    The Chinese first lunar lander, Chang'E-3, performed a lunar soft-landing on 14 Dec, 2013. Precise positioning for the lander and rover was the most important precondition and guarantee for a successful lunar surface exploration. In this study, first, the tracking system, measurement models and positioning method are discussed in detail. Second, the location of the CE-3 lander was determined: 44.1206°N, -19.5124°E, -2632 m (altitude was relative to the assumed lunar surface with a height of 1737.4 km), and the analysis showed the VLBI Very Long Base Interferometry data were able to significantly improve the positioning accuracy. Furthermore, the positioning error was evaluated in various ways; the result was better than 50 m. Finally, the relative positioning of the rover and lander using earth-based observations was studied and compared with the optical positioning method using photographs taken by the lander and rover. The method applied in this study was not limited by the visible range of the lander, and the relative positioning accuracy did not decrease as the distance between the lander and rover increased. The results indicated that under the current tracking and measuring conditions, the relative positioning accuracy was about 100 m using the same beam VLBI group delay data with ns nanosecond level noise. Furthermore, using the same beam VLBI phase delay data with ps picosecond level noise it was possible to significantly improve the relative positioning accuracy to the order of 1 m.

  7. The heat shield for the Mars Polar Lander is attached

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers lower the heat shield onto the Mars Polar Lander. Scheduled to be launched on Jan. 3, 1999, the lander is a solar- powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which is due to be launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  8. Mars Polar Lander mated with third stage of rocket

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers mate the Mars Polar Lander to the third stage of the Boeing Delta II rocket before it is transported to Launch Pad 17B, Cape Canaveral Air Station. The lander, which will be launched on Jan. 3, 1999, is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  9. Mars Polar Lander mated with third stage of rocket

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), the Mars Polar Lander is lowered onto the third stage of the Boeing Delta II rocket before it is transported to Launch Pad 17B, Cape Canaveral Air Station. The lander, which will be launched on Jan. 3, 1999, is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  10. Mars Polar Lander arrives at Pad 17B, CCAS

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Mars Polar Landerspacecraft is lifted off the trailer of that transported it to the gantry at Launch Complex 17B, Cape Canaveral Air Station. The lander, which will be launched aboard a Boeing Delta II rocket on Jan. 3, 1999, is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  11. The Landers earthquake; preliminary instrumental results

    USGS Publications Warehouse

    Jones, L.; Mori, J.; Hauksson, E.

    1992-01-01

    Early on the morning of June 28, 1992, millions of people in southern California were awakened by the largest earthquake to occur in the western United States in the past 40 yrs. At 4:58 a.m PDT (local time), faulting associated with the magnitude 7.3 earthquake broke through to earth's surface near the town of Landers, California. the surface rupture then propagated 70km (45 mi) to the north and northwest along a band of faults passing through the middle of the Mojave Desert. Fortunately, the strongest shaking occurred in uninhabited regions of the Mojave Desert. Still one child was killed in Yucca Valley, and about 400 people were injured in the surrounding area. the desert communities of Landers, Yucca Valley, and Joshua Tree in San Bernardino Country suffered considerable damage to buildings and roads. Damage to water and power lines caused problems in many areas. 

  12. Hazard detection and avoidance sensor for NASA's planetary landers

    NASA Technical Reports Server (NTRS)

    Lau, Brian; Chao, Tien-Hsin

    1992-01-01

    An optical terrain analysis based sensor system specifically designed for landing hazard detection as required for NASA's autonomous planetary landers is introduced. This optical hazard detection and avoidance (HDA) sensor utilizes an optoelectronic wedge-and-ting (WRD) filter for Fourier transformed feature extraction and an electronic neural network processor for pattern classification. A fully implemented optical HDA sensor would assure safe landing of the planetary landers. Computer simulation results of a successful feasibility study is reported. Future research for hardware system implementation is also provided.

  13. Vowel normalization for accent: An investigation of perceptual plasticity in young adults

    NASA Astrophysics Data System (ADS)

    Evans, Bronwen G.; Iverson, Paul

    2004-05-01

    Previous work has emphasized the role of early experience in the ability to accurately perceive and produce foreign or foreign-accented speech. This study examines how listeners at a much later stage in language development-early adulthood-adapt to a non-native accent within the same language. A longitudinal study investigated whether listeners who had had no previous experience of living in multidialectal environments adapted their speech perception and production when attending university. Participants were tested before beginning university and then again 3 months later. An acoustic analysis of production was carried out and perceptual tests were used to investigate changes in word intelligibility and vowel categorization. Preliminary results suggest that listeners are able to adjust their phonetic representations and that these patterns of adjustment are linked to the changes in production that speakers typically make due to sociolinguistic factors when living in multidialectal environments.

  14. Benthic long-term Observatories based on Lander Technology

    NASA Astrophysics Data System (ADS)

    Linke, P.; Pfannkuche, O.; Sommer, S.; Gubsch, S.; Gust, G.

    2003-04-01

    Landers are autonomous carrier systems for a wide range of scientific applications. The GEOMAR Lander System is based on a tripod-shaped platform for various scientific payloads to monitor, measure and experiment at the deep sea floor. These landers can be deployed using hybrid fibre optical or coaxial cables with a special launching device or in the conventional free falling mode. The launcher enables accurate positioning on meter scale, soft deployment and rapid disconnection of lander and launcher by an electric release. The bi-directional video and data telemetry provides on line video transmission, power supply and surface control of various relay functions. Within the collaborative project LOTUS novel long-term observatories have been developed and integrated into the GEOMAR Lander System. An overview of the recent developments is presented. Two new observatories are presented in detail to study the temporal variability of physico-chemical and biogeochemical mechanisms, flux- and turnover rates related to the decomposition and formation of near surface gas hydrates embedded in their original sedimentary matrix. With the Biogeochemical Observatory, BIGO, the temporal variability of the biologically facilitated methane turnover in the sediment and fluxes across the sediment water interface is studied in two mesocosms. Inside the mesocosms the oxygen content can be maintained by a chemostat. The in situ flow regime is measured outside the mesocosms and is reproduced within the chamber with an intelligent stirring system. This approach represents a major step in the development of benthic chambers from stationary to dynamic systems. The Fluid-Flux Observatory (FLUFO) measures the different types of fluid fluxes at the benthic boundary layer of sediments overlying near surface gas hydrates and monitors relevant environmental parameters as temperature, pressure and near bottom currents. FLUFO consists of two chamber units. Both units separate the gas phase from the

  15. Viking Lander 1's U.S. Flag on Mars Surface

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The flag of the United States with the rocky Martian surface in the background is seen in this color picture taken on the sixth day of Viking Lander 1 on Mars (July 26). The flag is on the RTG (Radioisotope Thermoelectric Generator) wind screen. Below the flag is the bicentennial logo and the Viking symbol which shows an ancient Viking ship. This Viking symbol was designed by Peter Purol of Baltimore, winner of the Viking logo contest open to high school science students. To the right is the Reference Test Chart used for color balancing of the color images. At the bottom is the GCMS Processor Distribution Assembly with the wind screens unfurled demonstrating that the GCMS cover was deployed properly. The scene in the background is looking almost due west on Mars. The lighter zone at the far horizon is about 3 km (nearly 2 miles) from the Lander. The darker line below this is a hill crest much closer to the Lander (about 200 m or about 650 feet). The picture was taken at local Mars Time of 7:18 A.M., hence the relatively dark sky and the far horizon illuminated by the sun just rising behind the Lander.

  16. Performance Characteristics of Lithium-Ion Prototype Batteries for Mars Surveyor Program 2001 Lander

    NASA Technical Reports Server (NTRS)

    Smart, M. C.; Ratnakumar, B. V.; Whitcanack, L.; Surampudi, S.; Byers, J.; Marsh, R. A.

    2000-01-01

    A viewgraph presentation outlines the scientific payload, expected launch date and tasks, and an image of the Mars Surveyor 2001 Lander components. The Lander's battery specifications are given. The program objectives for the Li-ion cells for the Lander are listed, and results performance evaluation and cycle life performance tests are outlined for different temperatures. Cell charge characteristics are described, and test data is presented for charge capacity at varying temperatures. Capacity retention and storage characteristics tests are described and results are shown.

  17. Mars Polar Lander undergoes testing in SAEF-2

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians lower the Mars Polar Lander onto a workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The Lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

  18. Mars Polar Lander undergoes testing in SAEF-2

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians look over the Mars Polar Lander. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. Targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, the solar-powered spacecraft is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The Lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

  19. Mars Polar Lander undergoes testing in SAEF-2

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), a KSC technician takes part in testing science instruments and basic spacecraft subsystems on the Mars Polar Lander. The solar- powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

  20. Life Sciences Investigations for ESA's First Lunar Lander

    NASA Astrophysics Data System (ADS)

    Carpenter, J. D.; Angerer, O.; Durante, M.; Linnarson, D.; Pike, W. T.

    2010-12-01

    Preparing for future human exploration of the Moon and beyond is an interdisciplinary exercise, requiring new technologies and the pooling of knowledge and expertise from many scientific areas. The European Space Agency is working to develop a Lunar Lander, as a precursor to future human exploration activities. The mission will demonstrate new technologies and perform important preparatory investigations. In the biological sciences the two major areas requiring investigation in advance of human exploration are radiation and its effects on human physiology and the potential toxicity of lunar dust. This paper summarises the issues associated with these areas and the investigations planned for the Lunar Lander to address them.

  1. Design and Development of a Methane Cryogenic Propulsion Stage for Human Mars Exploration

    NASA Technical Reports Server (NTRS)

    Percy, Thomas K.; Polsgrove, Tara; Turpin, Jason; Alexander, Leslie

    2016-01-01

    unique aspect to the concept of operations introduces several challenges, specifically related to propellant storage and engine reliability. These challenges and some potential solutions are discussed. Specific focus is provided on two key technology areas; propulsion and cryogenic fluid management. In the area of propulsion development, the development of an integrated methane propulsion system that combines both main propulsion and reaction control is discussed. This includes an overview of potential development paths, areas where development for Mars applications are complementary to development efforts underway in other parts of the aerospace industry, and commonality between the MCPS methane propulsion applications and other Mars elements, including the Mars lander systems. This commonality is a key affordability aspect of the Evolvable Mars Campaign. A similar discussion is provided for cryogenic fluid management technologies including a discussion of how using cryo propulsion in the Mars transportation application not only provides performance benefits but also leverages decades of technology development investments made by NASA and its aerospace contractor community.

  2. Automatic control of a mobile Viking lander on the surface of Mars

    NASA Technical Reports Server (NTRS)

    Moore, J.; Scofield, W.; Tobey, W.

    1976-01-01

    A mobile lander system is being considered for use in a possible follow-on mission to the Viking '75 landings on Mars. A mobile Viking lander, which could be launched as early as the 1979 opportunity, would be capable of traversing 100 m to 1 km per day on a commanded heading while sensing hazards and performing avoidance maneuvers. The degree of autonomous control, and consequently the daily traverse range, is still under study. The mobility concept requires the addition of: (1) track-laying or wheel units in place of the Viking Lander footpads, (2) a set of hazard and navigation sensors, and (3) a mobility control computer capability. The technology required to develop these three subsystems is available today. The principal objective of current design studies, as described in this paper, is to define a mobile lander system that will demonstrate high reliability and fail-safe hazard avoidance while achieving range- and terrain-handling capabilities which satisfy the Mars exploration science requirements.

  3. Effects of Noise and Proficiency on Intelligibility of Chinese-Accented English

    ERIC Educational Resources Information Center

    Rogers, Catherine L.; Dalby, Jonathan; Nishi, Kanae

    2004-01-01

    This study compared the intelligibility of native and foreign-accented English speech presented in quiet and mixed with three different levels of background noise. Two native American English speakers and four native Mandarin Chinese speakers for whom English is a second language each read a list of 50 phonetically balanced sentences (Egan, 1948).…

  4. Accent Priority in a Thai University Context: A Common Sense Revisited

    ERIC Educational Resources Information Center

    Jindapitak, Naratip; Teo, Adisa

    2013-01-01

    In Thailand, there has been much debate regarding what accents should be prioritized and adopted as models for learning and use in the context of English language education. However, it is not a debate in which the voices of English learners have sufficiently been heard. Several world Englishes scholars have maintained that being a denationalized…

  5. Design of a Thermal and Micrometeorite Protection System for an Unmanned Lunar Cargo Lander

    NASA Technical Reports Server (NTRS)

    Hernandez, Carlos A.; Sunder, Sankar; Vestgaard, Baard

    1989-01-01

    The first vehicles to land on the lunar surface during the establishment phase of a lunar base will be unmanned lunar cargo landers. These landers will need to be protected against the hostile lunar environment for six to twelve months until the next manned mission arrives. The lunar environment is characterized by large temperature changes and periodic micrometeorite impacts. An automatically deployable and reconfigurable thermal and micrometeorite protection system was designed for an unmanned lunar cargo lander. The protection system is a lightweight multilayered material consisting of alternating layers of thermal and micrometeorite protection material. The protection system is packaged and stored above the lander common module. After landing, the system is deployed to cover the lander using a system of inflatable struts that are inflated using residual fuel (liquid oxygen) from the fuel tanks. Once the lander is unloaded and the protection system is no longer needed, the protection system is reconfigured as a regolith support blanket for the purpose of burying and protecting the common module, or as a lunar surface garage that can be used to sort and store lunar surface vehicles and equipment. A model showing deployment and reconfiguration of the protection system was also constructed.

  6. Mars Polar Lander is mated with Boeing Delta II rocket

    NASA Technical Reports Server (NTRS)

    1998-01-01

    At Launch Complex 17B, Cape Canaveral Air Station, workers get ready to remove the protective wrapping on the Mars Polar Lander to be launched aboard a Boeing Delta II rocket on Jan. 3, 1999. The lander is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars Surveyor'98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  7. Mars Polar Lander is mated with Boeing Delta II rocket

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Workers mate the Mars Polar Lander (top) to the Boeing Delta II rocket at Launch Complex 17B, Cape Canaveral Air Station. The rocket is scheduled to launch Jan. 3, 1999. The lander is a solar-powered spacecraft designed to touch down on the Martian surface near the northern- most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars Surveyor '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  8. Mars Polar Lander mated with third stage of rocket

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Mars Polar Lander is suspended from a crane in the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2) before being lowered to a workstand. There it will be mated to the third stage of the Boeing Delta II rocket before it is transported to Launch Pad 17B, Cape Canaveral Air Station. The lander, which will be launched on Jan. 3, 1999, is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  9. Artist Concept of InSight Lander on Mars

    NASA Image and Video Library

    2015-08-18

    This artist's concept from August 2015 depicts NASA's InSight Mars lander fully deployed for studying the deep interior of Mars. This illustration updates the correct placement and look of Insight's main instruments. For an earlier artist rendition, see PIA17358. InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, will investigate processes that formed and shaped Mars. Its findings will improve understanding about the evolution of our inner solar system's rocky planets, including Earth. The lander will be the first mission to permanently deploy instruments directly onto Martian ground using a robotic arm. The two instruments to be placed into a work area in front of the lander are a seismometer (contributed by the French space agency Centre National d'Études Spatiales, or CNES) to measure the microscopic ground motions from distant marsquakes providing information about the interior structure of Mars, and a heat-flow probe (contributed by the German Aerospace Center, or DLR) designed to hammer itself 3 to 5 meters (about 16 feet) deep and monitor heat coming from the planet's interior. The mission will also track the lander's radio to measure wobbles in the planet's rotation that relate to the size of its core and a suite of environmental sensors to monitor the weather and variations in the magnetic field. Two cameras will aid in instrument deployment and monitoring the local environment. Note: After thorough examination, NASA managers have decided to suspend the planned March 2016 launch of the Interior Exploration using Seismic Investigations Geodesy and Heat Transport (InSight) mission. The decision follows unsuccessful attempts to repair a leak in a section of the prime instrument in the science payload. http://photojournal.jpl.nasa.gov/catalog/PIA19811

  10. Lander, Airbags, & Martian terrain

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Several objects have been imaged by the Imager for Mars Pathfinder (IMP) during the spacecraft's first day on Mars. Portions of the deflated airbags, part of one the lander's petals, soil, and several rocks are visible. The furrows in the soil were artificially produced by the retraction of the airbags after landing, which occurred at 10:07 a.m. PDT.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.

  11. ExoMars Lander Radioscience LaRa, a Space Geodesy Experiment to Mars.

    NASA Astrophysics Data System (ADS)

    Dehant, Veronique; Le Maistre, Sebastien; Yseboodt, Marie; Peters, Marie-Julie; Karatekin, Ozgur; Van Hove, Bart; Rivoldini, Attilio; Baland, Rose-Marie; Van Hoolst, Tim

    2017-04-01

    The LaRa (Lander Radioscience) experiment is designed to obtain coherent two-way Doppler measurements from the radio link between the ExoMars lander and Earth over at least one Martian year. The instrument life time is thus almost twice the one Earth year of nominal mission duration. The Doppler measurements will be used to observe the orientation and rotation of Mars in space (precession, nutations, and length-of-day variations), as well as polar motion. The ultimate objective is to obtain information / constraints on the Martian interior, and on the sublimation / condensation cycle of atmospheric CO2. Rotational variations will allow us to constrain the moment of inertia of the entire planet, including its mantle and core, the moment of inertia of the core, and seasonal mass transfer between the atmosphere and the ice caps. The LaRa experiment will be combined with other ExoMars experiments, in order to retrieve a maximum amount of information on the interior of Mars. Specifically, combining LaRa's Doppler measurements with similar data from the Viking landers, Mars Pathfinder, Mars Exploration Rovers landers, and the forthcoming InSight-RISE lander missions, will allow us to improve our knowledge on the interior of Mars with unprecedented accuracy, hereby providing crucial information on the formation and evolution of the red planet.

  12. Mars Polar Lander undergoes testing in SAEF-2

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), KSC technicians check underneath the Mars Polar Lander as it sits on a workstand. The spacecraft is undergoing testing of science instruments and basic spacecraft subsystems. The solar-powered spacecraft, targeted for launch from Cape Canaveral Air Station aboard a Delta II rocket on Jan. 3, 1999, is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere.

  13. Long-Lived Venus Lander Conceptual Design: How To Keep It Cool

    NASA Technical Reports Server (NTRS)

    Dyson, Ridger W.; Schmitz, Paul C.; Penswick, L. Barry; Bruder, Geoffrey A.

    2009-01-01

    Surprisingly little is known about Venus, our neighboring sister planet in the solar system, due to the challenges of operating in its extremely hot, corrosive, and dense environment. For example, after over two dozen missions to the planet, the longest-lived lander was the Soviet Venera 13, and it only survived two hours on the surface. Several conceptual Venus mission studies have been formulated in the past two decades proposing lander architectures that potentially extend lander lifetime. Most recently, the Venus Science and Technology Definition Team (STDT) was commissioned by NASA to study a Venus Flagship Mission potentially launching in the 2020- 2025 time-frame; the reference lander of this study is designed to survive for only a few hours more than Venera 13 launched back in 1981! Since Cytherean mission planners lack a viable approach to a long-lived surface architecture, specific scientific objectives outlined in the National Science Foundation Decadal Survey and Venus Exploration Advisory Group final report cannot be completed. These include: mapping the mineralogy and composition of the surface on a planetary scale determining the age of various rock samples on Venus, searching for evidence of changes in interior dynamics (seismometry) and its impact on climate and many other key observations that benefit with time scales of at least a full Venus day (Le. daylight/night cycle). This report reviews those studies and recommends a hybrid lander architecture that can survive for at least one Venus day (243 Earth days) by incorporating selective Stirling multi-stage active cooling and hybrid thermoacoustic power.

  14. Perceptual Judgments of Accented Speech by Listeners from Different First Language Backgrounds

    ERIC Educational Resources Information Center

    Kang, Okim; Vo, Son Ca Thanh; Moran, Meghan Kerry

    2016-01-01

    Research in second language speech has often focused on listeners' accent judgment and factors that affect their perception. However, the topic of listeners' application of specific sound categories in their own perceptual judgments has not been widely investigated. The current study explored how listeners from diverse language backgrounds weighed…

  15. Instructor Accents in Online Education and Their Effect on Learning and Attitudes

    ERIC Educational Resources Information Center

    Sanchez, C. A.; Khan, S.

    2016-01-01

    Reductions in perceptual fluency have been shown to negatively impact attitudes towards learning material, but not learning itself. The current study extends this work to spoken presentations and examines whether the presence of a foreign accent negatively affects learners' experience in an online learning environment. Results indicate that the…

  16. Acoustic and perceptual effects of overall F0 range in a lexical pitch accent distinction

    NASA Astrophysics Data System (ADS)

    Wade, Travis

    2002-05-01

    A speaker's overall fundamental frequency range is generally considered a variable, nonlinguistic element of intonation. This study examined the precision with which overall F0 is predictable based on previous intonational context and the extent to which it may be perceptually significant. Speakers of Tokyo Japanese produced pairs of sentences differing lexically only in the presence or absence of a single pitch accent as responses to visual and prerecorded speech cues presented in an interactive manner. F0 placement of high tones (previously observed to be relatively variable in pitch contours) was found to be consistent across speakers and uniformly dependent on the intonation of the different sentences used as cues. In a subsequent perception experiment, continuous manipulation of these same sentences between typical accented and typical non-accent-containing versions were presented to Japanese listeners for lexical identification. Results showed that listeners' perception was not significantly altered in compensation for artificial manipulation of preceding intonation. Implications are discussed within an autosegmental analysis of tone. The current results are consistent with the notion that pitch range (i.e., specific vertical locations of tonal peaks) does not simply vary gradiently across speakers and situations but constitutes a predictable part of the phonetic specification of tones.

  17. Listening with a foreign-accent: The interlanguage speech intelligibility benefit in Mandarin speakers of English

    PubMed Central

    Xie, Xin; Fowler, Carol A.

    2013-01-01

    This study examined the intelligibility of native and Mandarin-accented English speech for native English and native Mandarin listeners. In the latter group, it also examined the role of the language environment and English proficiency. Three groups of listeners were tested: native English listeners (NE), Mandarin-speaking Chinese listeners in the US (M-US) and Mandarin listeners in Beijing, China (M-BJ). As a group, M-US and M-BJ listeners were matched on English proficiency and age of acquisition. A nonword transcription task was used. Identification accuracy for word-final stops in the nonwords established two independent interlanguage intelligibility effects. An interlanguage speech intelligibility benefit for listeners (ISIB-L) was manifest by both groups of Mandarin listeners outperforming native English listeners in identification of Mandarin-accented speech. In the benefit for talkers (ISIB-T), only M-BJ listeners were more accurate identifying Mandarin-accented speech than native English speech. Thus, both Mandarin groups demonstrated an ISIB-L while only the M-BJ group overall demonstrated an ISIB-T. The English proficiency of listeners was found to modulate the magnitude of the ISIB-T in both groups. Regression analyses also suggested that the listener groups differ in their use of acoustic information to identify voicing in stop consonants. PMID:24293741

  18. Orbiting Depot and Reusable Lander for Lunar Transportation

    NASA Technical Reports Server (NTRS)

    Petro, Andrew

    2009-01-01

    A document describes a conceptual transportation system that would support exploratory visits by humans to locations dispersed across the surface of the Moon and provide transport of humans and cargo to sustain one or more permanent Lunar outpost. The system architecture reflects requirements to (1) minimize the amount of vehicle hardware that must be expended while maintaining high performance margins and (2) take advantage of emerging capabilities to produce propellants on the Moon while also enabling efficient operation using propellants transported from Earth. The system would include reusable single- stage lander spacecraft and a depot in a low orbit around the Moon. Each lander would have descent, landing, and ascent capabilities. A crew-taxi version of the lander would carry a pressurized crew module; a cargo version could carry a variety of cargo containers. The depot would serve as a facility for storage and for refueling with propellants delivered from Earth or propellants produced on the Moon. The depot could receive propellants and cargo sent from Earth on a variety of spacecraft. The depot could provide power and orbit maintenance for crew vehicles from Earth and could serve as a safe haven for lunar crews pending transport back to Earth.

  19. Near-field postseismic deformation associated with the 1992 Landers and 1999 Hector Mine, California, earthquakes

    USGS Publications Warehouse

    Savage, J.C.; Svarc, J.L.; Prescott, W.H.

    2003-01-01

    After the Landers earthquake (Mw = 7.3, 1992.489) a linear array of 10 monuments extending about 30 km N50??E on either side of the earthquake rupture plus a nearby offtrend reference monument were surveyed frequently by GPS until 2003.2. The array also spans the rupture of the subsequent Hector Mine earthquake (Mw = 7.1, 1999.792 . The pre-Landers velocities of monuments in the array relative to interior North America were estimated from earlier trilateration and very long baseline interferometry measurements. Except at the reference monument, the post-Landers velocities of the individual monuments in the array relaxed to their preseismic values within 4 years. Following the Hector Mine earthquake the velocities of the monuments relaxed to steady rates within 1 year. Those steady rates for the east components are about equal to the pre-Landers rates as is the steady rate for the north component of the one monument east of the Hector Mine rupture. However, the steady rates for the north components of the 10 monuments west of the rupture are systematically ???10 mm yr1 larger than the pre-Landers rates. The relaxation to a steady rate is approximately exponential with decay times of 0.50 ?? 0.10 year following the Landers earthquake and 0.32 ?? 0.18 year following the Hector Mine earthquake. The postearthquake motions of the Landers array following the Landers earthquake are not well approximated by the viscoelastic-coupling model of Pollitz et al. [2000]. A similar viscoelastic-coupling model [Pollitz et al., 2001] is more successful in representing the deformation after the Hector Mine earthquake.

  20. Digibaro pressure instrument onboard the Phoenix Lander

    NASA Astrophysics Data System (ADS)

    Harri, A.-M.; Polkko, J.; Kahanpää, H. H.; Schmidt, W.; Genzer, M. M.; Haukka, H.; Savijarv1, H.; Kauhanen, J.

    2009-04-01

    The Phoenix Lander landed successfully on the Martian northern polar region. The mission is part of the National Aeronautics and Space Administration's (NASA's) Scout program. Pressure observations onboard the Phoenix lander were performed by an FMI (Finnish Meteorological Institute) instrument, based on a silicon diaphragm sensor head manufactured by Vaisala Inc., combined with MDA data processing electronics. The pressure instrument performed successfully throughout the Phoenix mission. The pressure instrument had 3 pressure sensor heads. One of these was the primary sensor head and the other two were used for monitoring the condition of the primary sensor head during the mission. During the mission the primary sensor was read with a sampling interval of 2 s and the other two were read less frequently as a check of instrument health. The pressure sensor system had a real-time data-processing and calibration algorithm that allowed the removal of temperature dependent calibration effects. In the same manner as the temperature sensor, a total of 256 data records (8.53 min) were buffered and they could either be stored at full resolution, or processed to provide mean, standard deviation, maximum and minimum values for storage on the Phoenix Lander's Meteorological (MET) unit.The time constant was approximately 3s due to locational constraints and dust filtering requirements. Using algorithms compensating for the time constant effect the temporal resolution was good enough to detect pressure drops associated with the passage of nearby dust devils.

  1. Relative Salience of Speech Rhythm and Speech Rate on Perceived Foreign Accent in a Second Language.

    PubMed

    Polyanskaya, Leona; Ordin, Mikhail; Busa, Maria Grazia

    2017-09-01

    We investigated the independent contribution of speech rate and speech rhythm to perceived foreign accent. To address this issue we used a resynthesis technique that allows neutralizing segmental and tonal idiosyncrasies between identical sentences produced by French learners of English at different proficiency levels and maintaining the idiosyncrasies pertaining to prosodic timing patterns. We created stimuli that (1) preserved the idiosyncrasies in speech rhythm while controlling for the differences in speech rate between the utterances; (2) preserved the idiosyncrasies in speech rate while controlling for the differences in speech rhythm between the utterances; and (3) preserved the idiosyncrasies both in speech rate and speech rhythm. All the stimuli were created in intoned (with imposed intonational contour) and flat (with monotonized, constant F0) conditions. The original and the resynthesized sentences were rated by native speakers of English for degree of foreign accent. We found that both speech rate and speech rhythm influence the degree of perceived foreign accent, but the effect of speech rhythm is larger than that of speech rate. We also found that intonation enhances the perception of fine differences in rhythmic patterns but reduces the perceptual salience of fine differences in speech rate.

  2. Development of an Audio Microphone for the Mars Surveyor 98 Lander

    NASA Astrophysics Data System (ADS)

    Delory, G. T.; Luhmann, J. G.; Curtis, D. W.; Friedman, L. D.; Primbsch, J. H.; Mozer, F. S.

    1998-01-01

    In December 1999, the next Mars Surveyor Lander will bring the first microphone to the surface of Mars. The Mars Microphone represents a joint effort between the Planetary Society and the University of California at Berkeley Space Sciences Laboratory and is riding on the lander as part of the LIDAR instrument package provided by the Russian Academy of Sciences in Moscow. The inclusion of a microphone on the Mars Surveyor Lander represents a unique opportunity to sample for the first time the acoustic environment on the surface, including both natural and lander-generated sounds. Sounds produced by martian meteorology are among the signals to be recorded, including wind and impacts of sand particles on the instrument. Photographs from the Viking orbiters as well as Pathfinder images show evidence of small tornado-like vortices that may be acoustically detected, along with noise generated by static discharges possible during sandstorms. Lander-generated sounds that will be measured include the motion and digging of the lander arm as it gathers soil samples for analysis. Along with these scientific objectives, the Mars Microphone represents a powerful tool for public outreach by providing sound samples on the Internet recorded during the mission. The addition of audio capability to the lander brings us one step closer to a true virtual presence on the Mars surface by complementing the visual capabilities of the Mars Surveyor cameras. The Mars Microphone is contained in a 5 x 5 x 1 cm box, weighs less than 50 g, and uses 0.1 W of power during its most active times. The microphone used is a standard hearing-aid electret. The sound sampling and processing system relies on an RSC-164 speech processor chip, which performs 8-bit A/ D sampling and sound compression. An onboard flight program enables several modes for the instrument, including varying sample ranges of 5 kHz and 20 kHz, and a selectable gain setting with 64x dynamic range. The device automatically triggers on

  3. The InSight Mars Lander and Its Effect on the Subsurface Thermal Environment

    NASA Astrophysics Data System (ADS)

    Siegler, Matthew A.; Smrekar, Suzanne E.; Grott, Matthias; Piqueux, Sylvain; Mueller, Nils; Williams, Jean-Pierre; Plesa, Ana-Catalina; Spohn, Tilman

    2017-10-01

    The 2018 InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Mission has the mission goal of providing insitu data for the first measurement of the geothermal heat flow of Mars. The Heat Flow and Physical Properties Package (HP3) will take thermal conductivity and thermal gradient measurements to approximately 5 m depth. By necessity, this measurement will be made within a few meters of the lander. This means that thermal perturbations from the lander will modify local surface and subsurface temperature measurements. For HP3's sensitive thermal gradient measurements, this spacecraft influence will be important to model and parameterize. Here we present a basic 3D model of thermal effects of the lander on its surroundings. Though lander perturbations significantly alter subsurface temperatures, a successful thermal gradient measurement will be possible in all thermal conditions by proper (>3 m depth) placement of the heat flow probe.

  4. Mars Polar Lander is mated with Boeing Delta II rocket

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Inside the gantry at Launch Complex 17B, Cape Canaveral Air Station, the Mars Polar Lander spacecraft is lowered to mate it with the Boeing Delta II rocket that will launch it on Jan. 3, 1999. The lander is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. It is the second spacecraft to be launched in a pair of Mars Surveyor'98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  5. Phoenix Mission Lander on Mars, Artist Concept

    NASA Image and Video Library

    2005-06-01

    NASA Phoenix Mars Lander, landed on May 25, 2008, and explored the history of water and monitored polar climate on Mars until communications ended in November, 2008, about six months after landing, when its solar panels ceased operating in the winter.

  6. International Space Exploration Coordination Group Assessment of Technology Gaps for LOx/Methane Propulsion Systems for the Global Exploration Roadmap

    NASA Technical Reports Server (NTRS)

    Hurlbert, Eric A.; Whitley, Ryan; Klem, Mark D.; Johnson, Wesley; Alexander, Leslie; D'Aversa, Emanuela; Ruault, Jean-Marc; Manfletti, Chiara; Caruana, Jean-Noel; Ueno, Hiroshi; hide

    2016-01-01

    As part of the Global Exploration Roadmap (GER), the International Space Exploration Coordination Group (ISECG) formed two technology gap assessment teams to evaluate topic discipline areas that had not been worked at an international level to date. The participating agencies were ASI, CNES, DLR, ESA, JAXA, and NASA. Accordingly, the ISECG Technology Working Group (TWG) recommended two discipline areas based on Critical Technology Needs reflected within the GER Technology Development Map (GTDM): Dust Mitigation and LOX/Methane Propulsion. LOx/Methane propulsion systems are enabling for future human missions Mars by significantly reducing the landed mass of the Mars ascent stage through the use of in-situ propellant production, for improving common fluids for life support, power and propulion thus allowing for diverse redundancy, for eliminating the corrosive and toxic propellants thereby improving surface operations and resusabilty, and for inceasing the performance of propulsion systems. The goals and objectives of the international team are to determine the gaps in technology that must be closed for LOx/Methane to be used in human exploration missions in cis-lunar, lunar, and Mars mission applications. An emphasis is placed on near term lunar lander applications with extensibility to Mars. Each agency provided a status of the substantial amount of Lox/Methane propulsion system development to date and their inputs on the gaps in the technology that are remaining. The gaps, which are now opportunities for collaboration, are then discussed.

  7. Social dominance orientation, nonnative accents, and hiring recommendations.

    PubMed

    Hansen, Karolina; Dovidio, John F

    2016-10-01

    Discrimination against nonnative speakers is widespread and largely socially acceptable. Nonnative speakers are evaluated negatively because accent is a sign that they belong to an outgroup and because understanding their speech requires unusual effort from listeners. The present research investigated intergroup bias, based on stronger support for hierarchical relations between groups (social dominance orientation [SDO]), as a predictor of hiring recommendations of nonnative speakers. In an online experiment using an adaptation of the thin-slices methodology, 65 U.S. adults (54% women; 80% White; Mage = 35.91, range = 18-67) heard a recording of a job applicant speaking with an Asian (Mandarin Chinese) or a Latino (Spanish) accent. Participants indicated how likely they would be to recommend hiring the speaker, answered questions about the text, and indicated how difficult it was to understand the applicant. Independent of objective comprehension, participants high in SDO reported that it was more difficult to understand a Latino speaker than an Asian speaker. SDO predicted hiring recommendations of the speakers, but this relationship was mediated by the perception that nonnative speakers were difficult to understand. This effect was stronger for speakers from lower status groups (Latinos relative to Asians) and was not related to objective comprehension. These findings suggest a cycle of prejudice toward nonnative speakers: Not only do perceptions of difficulty in understanding cause prejudice toward them, but also prejudice toward low-status groups can lead to perceived difficulty in understanding members of these groups. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  8. Beliefs regarding the Impact of Accent within Speech-Language Pathology Practice Areas

    ERIC Educational Resources Information Center

    Levy, Erika S.; Crowley, Catherine J.

    2012-01-01

    With the demographic shifts in the United States, it is increasingly the case that speech-language pathologists (SLPs) come from different language backgrounds from those of their clients and have nonnative accents in their languages of service. An anonymous web-based survey was completed by students and clinic directors in SLP training programs…

  9. Stronger Accent Following a Stroke: The Case of a Trilingual with Aphasia

    ERIC Educational Resources Information Center

    Levy, Erika S.; Goral, Mira; De Diesbach, Catharine Castelluccio; Law, Franzo, II

    2011-01-01

    This study documents patterns of change in speech production in a multilingual with aphasia following a cerebrovascular accident (CVA). EC, a right-handed Hebrew-English-French trilingual man, had a left fronto-temporo-parietal CVA, after which he reported that his (native) Hebrew accent became stronger in his (second language) English. Recordings…

  10. Using Bona Adaptation to Improve Accent Defects as a Voice Training Method

    ERIC Educational Resources Information Center

    Aycan, Kivanc

    2017-01-01

    Purpose: In this research, it is observed that if solfeggio syllables, consonants, and vowels are spoken properly, voice intensity (accent), duration, pitch (high pitch-low pitch) and intonation (the ability to carry a musical voice) related to proper pitch level. In this study, it is observed that rhythmic structures do not form without…

  11. How to Speak Standard American English without a Foreign Accent. Russian Edition.

    ERIC Educational Resources Information Center

    Catran, Jack

    The transcript of and guide to a two-cassette course designed to assist Russian immigrants in erasure of their foreign accent can be used for either individual or group study. Narrative and taped demonstrations of American English that pinpoint typical phonological barriers and pronunciation difficulties are outlined. The author's own system of…

  12. Rest In Peace Mars Polar Lander

    NASA Image and Video Library

    2002-12-04

    On December 3, 1999) Mars Polar Lander (MPL) was set to touchdown on the enigmatic layered terrain located near the South Pole. Unfortunately, communications with the spacecraft were lost and never regained. The Mars Program Independent Assessment Team concluded that this loss was most likely due to premature retrorocket shutdown resulting in the crash of the lander. The image primarily shows what appears to be a ridged surface with some small isolated hills. Historically, exploration has and will continue to be a very hard and risky endeavor and sometimes you lose. But the spirit of exploration and discovery has served mankind well throughout the ages and it has now driven us to the far reaches of space. Therefore, with this in mind the THEMIS Team today is releasing an image of the region where MPL was set to land in memory of this mission and the unquenchable spirit of exploration. It is hoped that in the near future we will once again attempt another landing in the Martian polar regions. http://photojournal.jpl.nasa.gov/catalog/PIA04016

  13. Thermal and Electrical Conductivity Probe for Phoenix Mars Lander

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Phoenix Mars Lander will assess how heat and electricity move through Martian soil from one spike or needle to another of a four-spike electronic fork that will be pushed into the soil at different stages of digging by the lander's Robotic Arm.

    The four-spike tool, called the thermal and electrical conductivity probe, is in the middle-right of this photo, mounted near the end of the arm near the lander's scoop (upper left).

    In one type of experiment with this tool, a pulse of heat will be put into one spike, and the rate at which the temperature rises on the nearby spike will be recorded, along with the rate at which the heated spike cools. A little bit of ice can make a big difference in how well soil conducts heat. Similarly, soil's electrical conductivity -- also tested with this tool -- is a sensitive

    indicator of moisture in the soil. This device adapts technology used in soil-moisture gauges for irrigation-control systems. The conductivity probe has an additional role besides soil analysis. It will serve as a hunidity sensor when held in the air.

  14. SPE propulsion electrolyzer for NASA's integrated propulsion test article

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Hamilton Standard has delivered a 3000 PSI SPE Propulsion Electrolyzer Stack and Special Test Fixture to the NASA Lyndon B. Johnson Space Center (JSC) Integrated Propulsion Test Article (IPTA) program in June 1990, per contract NAS9-18030. This prototype unit demonstrates the feasibility of SPE-high pressure water electrolysis for future space applications such as Space Station propulsion and Lunar/Mars energy storage. The SPE-Propulsion Electrolyzer has met or exceeded all IPTA program goals. It continues to function as the primary hydrogen and oxygen source for the IPTA test bed at the NASA/JSC Propulsion and Power Division Thermochemical Test Branch.

  15. The Influence of Semantic Context on the Perception of Spanish-Accented American English

    ERIC Educational Resources Information Center

    Behrman, Alison; Akhund, Ali

    2013-01-01

    Purpose: In this article, the authors examine (a) the effect of semantic context on accentedness, comprehensibility, and intelligibility of Spanish-accented American English (AE) as judged by monolingual AE listeners and (b) the interaction of semantic context and accentedness on comprehensibility and intelligibility. Method: Twenty adult native…

  16. Propulsion

    ERIC Educational Resources Information Center

    Air and Space, 1978

    1978-01-01

    An introductory discussion of aircraft propulsion is included along with diagrams and pictures of piston, turbojet, turboprop, turbofan, and jet engines. Also, a table on chemical propulsion is included. (MDR)

  17. Color Image of Phoenix Lander on Mars Surface

    NASA Image and Video Library

    2008-05-27

    This is an enhanced-color image from Mars Reconnaissance Orbiter High Resolution Imaging Science Experiment HiRISE camera. It shows the NASA Mars Phoenix lander with its solar panels deployed on the Mars surface

  18. Beamed energy propulsion

    NASA Technical Reports Server (NTRS)

    Shoji, James M.

    1992-01-01

    Beamed energy concepts offer an alternative for an advanced propulsion system. The use of a remote power source reduces the weight of the propulsion system in flight and this, combined with the high performance, provides significant payload gains. Within the context of this study's baseline scenario, two beamed energy propulsion concepts are potentially attractive: solar thermal propulsion and laser thermal propulsion. The conceived beamed energy propulsion devices generally provide low thrust (tens of pounds to hundreds of pounds); therefore, they are typically suggested for cargo transportation. For the baseline scenario, these propulsion system can provide propulsion between the following nodes: (1) low Earth orbit to geosynchronous Earth orbit; (2) low Earth orbit to low lunar orbit; (3) low lunar orbit to low Mars orbit--only solar thermal; and (4) lunar surface to low lunar orbit--only laser thermal.

  19. Mars Lander Deck of NASA's InSight Mission

    NASA Image and Video Library

    2017-08-28

    This view looks upward toward the InSight Mars lander suspended upside down. It shows the top of the lander's science deck with the mission's two main science instruments -- the Seismic Experiment for Interior Structure (SEIS) and the Heat Flow and Physical Properties Probe (HP3) -- plus the robotic arm and other subsystems installed. The photo was taken Aug. 9, 2017, in a Lockheed Martin clean room facility in Littleton, Colorado. The InSight mission (for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) is scheduled to launch in May 2018 and land on Mars Nov. 26, 2018. It will investigate processes that formed and shaped Mars and will help scientists better understand the evolution of our inner solar system's rocky planets, including Earth. https://photojournal.jpl.nasa.gov/catalog/PIA21847

  20. Do Language Attitudes Determine Accent? A Study of Bilinguals in the USA

    ERIC Educational Resources Information Center

    Moyer, Alene

    2007-01-01

    This study presents new data on the degree of "foreign" accent among immigrant learners of English in the USA (total N = 50) as it correlates to learner orientation to the target language and target language culture. Correlation analyses confirm the significance of age of onset and length of immersion, as well as learner attitudes, including: (a)…

  1. Changes Over Time in Global Foreign Accent and Liquid Identifiability and Accuracy.

    ERIC Educational Resources Information Center

    Riney, Timothy J.; Flege, James E.

    1998-01-01

    Assessed global foreign accent in sentences and production of two English consonants by Japanese college students during their freshman and senior years (T1, T2). Auditory evaluations by native English-speaking listeners were used to determine to what extent the consonants produced could be identified as intended at T1 and T2; and whether the two…

  2. The Processing of the Right-Sided Accent Mark in Left Neglect Dyslexia

    ERIC Educational Resources Information Center

    Cubelli, Roberto; Beschin, Nicoletta

    2005-01-01

    Italian polysyllabic words with stress falling on the last syllable are written with a diacritic sign on the last vowel. It allows discrimination between two words with the same orthographic segments (e.g., papa [pope], papa [dad]). The effect of the accent mark in left neglect dyslexia has never been investigated. In the current study, six…

  3. Wesco Operating Inc., Lander Field NPDES Proposed Permit

    EPA Pesticide Factsheets

    Indian Country, Minor, indust., non-discharge, proposed permit WY-0000221 establishes monitoring and reporting provisions should an unauthorized release of produced water occur from the Wesco Operating, Inc., Lander Field NW Discharge oil production site.

  4. Are the Viking Lander sites representative of the surface of Mars?

    NASA Technical Reports Server (NTRS)

    Jakosky, B. M.; Christensen, P. R.

    1986-01-01

    Global remote sensing data of the Martian surface, collected by earth- and satellite-based instruments, are compared with data from the two Viking Landers to determine if the Lander data are representative of the Martian surface. The landing sites are boulder-strewn and feature abundant fine material and evidence of strong eolian forces. One site (VL-1) is in a plains-covered basin which is associated with volcanic activity; the VL-2 site is in the northern plains. Thermal IR, broadband albedo, color imaging and radar remote sensing has been carried out of the global Martian surface. The VL-1 data do not fit a general correlation observed between increases in 70-cm radar cross-sections and thermal inertia. A better fit is found with 12.5-cm cross sections, implying the presence of a thinner or discontinuous duricrust at the VL-1 site, compared to other higher-inertia regions. A thin dust layer is also present at the VL-2 site, based on the Lander reflectance data. The Lander sites are concluded to be among the three observed regions of anomalous reflectivity, which can be expected in low regions selected for the landings. Recommendations are furnished for landing sites of future surface probes in order to choose sites more typical of the global Martian surface.

  5. The method of landing sites selection for Russian lunar lander missions

    NASA Astrophysics Data System (ADS)

    Mitrofanov, Igor; Djachkova, Maya; Litvak, Maxim; Sanin, Anton

    2016-04-01

    Russian space agency is planning to launch two lunar landers in the upcoming years - Luna-Glob (2018) and Luna-Resurs (2021). Instruments installed on board the landers are designed to study volatiles and water ice, lunar exosphere, dust particles and regolith composition. As primary scientific interest is concentrated in the south polar region, the landing sites for both landers will be selected there. Since rugged terrain, conditions of solar illumination at high altitudes and necessity of direct radio communication with the Earth, it is essential to select an optimal landing site for each lander. We present the method of landing sites selection, which is based on geographical information systems (GIS) technologies to perform analysis, based on the criteria of surface suitability for landing, such as slopes, illumination conditions and Earth visibility. In addition, the estimations of hydrogen concentration in regolith based on LEND/LRO data were used to evaluate landing site candidates on possible water ice presence. The method gave us 6 canditates to land. Four of them are located in the impact craters: Simpelius D, Simpelius E, Boguslawsky C, Boussingault, and the other two are located to the north of Schomberger crater and to the north-west of Boguslawsky C crater and associated with probable basin-related materials. The main parameters of these sites will be presented with possible prioritization based on both technical requirements and scientific interest.

  6. Project UM-HAUL: A self-unloading reusable lunar lander

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The establishment of a lunar base is technologically and financially challenging. Given the necessary resources and political support, it can be done. In addition to the geopolitical obstacles, however, there are logistical problems involved in establishing such bases that can only be overcome with the acquisition of a significant transportation and communications network in the Earth-Moon spatial region. Considering the significant number of payloads that will be required in this process, the mass-specific cost of launching these payloads, and the added risk and cost of human presence in space, it is clearly desirable to automate major parts of such an operation. One very costly and time-consuming factor in this picture is the delivery of payloads to the Moon. Foreseeable payloads would include atmospheric modules, inflatable habitat kits, energy and oxygen plant elements, ground vehicles, laboratory modules, crew supplies, etc. The duration of high-risk human presence on the Moon could be greatly reduced if all such payloads were delivered to the prospective base site in advance of crew arrival. In this view, the idea of a 'Self-Unloading Reusable Lunar Lander' (SURLL) arises naturally. The general scenario depicts the lander being brought to low lunar orbit (LLO) from Earth atop a generic Orbital Transfer Vehicle (OTV). From LLO, the lander shuttles payloads down to the lunar surface, where, by means of some resident, detachable unloading device, it deploys the payloads and returns to orbit. The general goal is for the system to perform with maximum payload capability, automation, and reliability, while also minimizing environmental hazards, servicing needs, and mission costs. Our response to this demand is UM-HAUL, or the UnManned Heavy pAyload Unloader and Lander. The complete study includes a system description, along with a preliminary cost analysis and a design status assessment.

  7. Project UM-HAUL: A self-unloading reusable lunar lander

    NASA Astrophysics Data System (ADS)

    The establishment of a lunar base is technologically and financially challenging. Given the necessary resources and political support, it can be done. In addition to the geopolitical obstacles, however, there are logistical problems involved in establishing such bases that can only be overcome with the acquisition of a significant transportation and communications network in the Earth-Moon spatial region. Considering the significant number of payloads that will be required in this process, the mass-specific cost of launching these payloads, and the added risk and cost of human presence in space, it is clearly desirable to automate major parts of such an operation. One very costly and time-consuming factor in this picture is the delivery of payloads to the Moon. Foreseeable payloads would include atmospheric modules, inflatable habitat kits, energy and oxygen plant elements, ground vehicles, laboratory modules, crew supplies, etc. The duration of high-risk human presence on the Moon could be greatly reduced if all such payloads were delivered to the prospective base site in advance of crew arrival. In this view, the idea of a 'Self-Unloading Reusable Lunar Lander' (SURLL) arises naturally. The general scenario depicts the lander being brought to low lunar orbit (LLO) from Earth atop a generic Orbital Transfer Vehicle (OTV). From LLO, the lander shuttles payloads down to the lunar surface, where, by means of some resident, detachable unloading device, it deploys the payloads and returns to orbit. The general goal is for the system to perform with maximum payload capability, automation, and reliability, while also minimizing environmental hazards, servicing needs, and mission costs. Our response to this demand is UM-HAUL, or the UnManned Heavy pAyload Unloader and Lander. The complete study includes a system description, along with a preliminary cost analysis and a design status assessment.

  8. Recognizing speech in a novel accent: the motor theory of speech perception reframed.

    PubMed

    Moulin-Frier, Clément; Arbib, Michael A

    2013-08-01

    The motor theory of speech perception holds that we perceive the speech of another in terms of a motor representation of that speech. However, when we have learned to recognize a foreign accent, it seems plausible that recognition of a word rarely involves reconstruction of the speech gestures of the speaker rather than the listener. To better assess the motor theory and this observation, we proceed in three stages. Part 1 places the motor theory of speech perception in a larger framework based on our earlier models of the adaptive formation of mirror neurons for grasping, and for viewing extensions of that mirror system as part of a larger system for neuro-linguistic processing, augmented by the present consideration of recognizing speech in a novel accent. Part 2 then offers a novel computational model of how a listener comes to understand the speech of someone speaking the listener's native language with a foreign accent. The core tenet of the model is that the listener uses hypotheses about the word the speaker is currently uttering to update probabilities linking the sound produced by the speaker to phonemes in the native language repertoire of the listener. This, on average, improves the recognition of later words. This model is neutral regarding the nature of the representations it uses (motor vs. auditory). It serve as a reference point for the discussion in Part 3, which proposes a dual-stream neuro-linguistic architecture to revisits claims for and against the motor theory of speech perception and the relevance of mirror neurons, and extracts some implications for the reframing of the motor theory.

  9. Inorganic chemical investigation by X-ray fluorescence analysis - The Viking Mars Lander

    NASA Technical Reports Server (NTRS)

    Toulmin, P., III; Rose, H. J., Jr.; Baird, A. K.; Clark, B. C.; Keil, K.

    1973-01-01

    The inorganic chemical investigation experiment added in August 1972 to the Viking Lander scientific package uses an energy-dispersive X-ray fluorescence spectrometer in which four sealed, gas-filled proportional counters detect X-rays emitted from samples of the Martian surface materials irradiated by X-rays from radioisotope sources (Fe-55 and Cd-109). The instrument is inside the Lander body, and samples are to be delivered to it by the Viking Lander Surface Sampler. Instrument design is described along with details of the data processing and analysis procedures. The results of the investigation will characterize the surface materials of Mars as to elemental composition with accuracies ranging from a few tens of parts per million (at the trace-element level) to a few per cent (for major elements) depending on the element in question.

  10. Human Mars Lander Design for NASA's Evolvable Mars Campaign

    NASA Technical Reports Server (NTRS)

    Polsgrove, Tara; Chapman, Jack; Sutherlin, Steve; Taylor, Brian; Fabisinski, Leo; Collins, Tim; Cianciolo Dwyer, Alicia; Samareh, Jamshid; Robertson, Ed; Studak, Bill; hide

    2016-01-01

    Landing humans on Mars will require entry, descent, and landing capability beyond the current state of the art. Nearly twenty times more delivered payload and an order of magnitude improvement in precision landing capability will be necessary. To better assess entry, descent, and landing technology options and sensitivities to future human mission design variations, a series of design studies on human-class Mars landers has been initiated. This paper describes the results of the first design study in the series of studies to be completed in 2016 and includes configuration, trajectory and subsystem design details for a lander with Hypersonic Inflatable Aerodynamic Decelerator (HIAD) entry technology. Future design activities in this series will focus on other entry technology options.

  11. A Monte Carlo analysis of the Viking lander dynamics at touchdown. [soft landing simulation

    NASA Technical Reports Server (NTRS)

    Muraca, R. J.; Campbell, J. W.; King, C. A.

    1975-01-01

    The performance of the Viking lander has been evaluated by using a Monte Carlo simulation, and all results are presented in statistical form. The primary objectives of this analysis were as follows: (1) to determine the three sigma design values of maximum rigid body accelerations and the minimum clearance of the lander body during landing; (2) to determine the probability of an unstable landing; and (3) to determine the probability of the lander body striking a rock. Two configurations were analyzed with the only difference being in the ability of the primary landing gear struts to carry tension loads.

  12. The accent method of voice therapy: effect of accentuations on FO, SPL, and airflow.

    PubMed

    Kotby, M N; Shiromoto, O; Hirano, M

    1993-12-01

    The effect of the increased flow rate (delta U) in response to the Accent Method exercises on fundamental frequency (FO) and sound pressure level (SPL) was studied in three subjects (professionally trained, trained, and untrained in this method). In all the subjects, the rhythmic accentuated exercises produced a variable degree of increase in FO (delta FO) and SPL (delta SPL). The professionally trained subject showed greater delta FO and delta SPL in response to the delta U in the fastest tempo, which requires higher skills. Both trained subjects showed a greater correlation between delta U and both delta SPL and delta FO, as well as between delta FO and delta SPL, as compared to the untrained subject. The effects of the accentuated exercises on FO and SPL in response to the increased airflow rate (delta U) thus appear to demonstrate the treating effectiveness of the Accent Method.

  13. Advanced Chemical Propulsion

    NASA Technical Reports Server (NTRS)

    Alexander, Leslie, Jr.

    2006-01-01

    Advanced Chemical Propulsion (ACP) provides near-term incremental improvements in propulsion system performance and/or cost. It is an evolutionary approach to technology development that produces useful products along the way to meet increasingly more demanding mission requirements while focusing on improving payload mass fraction to yield greater science capability. Current activities are focused on two areas: chemical propulsion component, subsystem, and manufacturing technologies that offer measurable system level benefits; and the evaluation of high-energy storable propellants with enhanced performance for in-space application. To prioritize candidate propulsion technology alternatives, a variety of propulsion/mission analyses and trades have been conducted for SMD missions to yield sufficient data for investment planning. They include: the Advanced Chemical Propulsion Assessment; an Advanced Chemical Propulsion System Model; a LOx-LH2 small pumps conceptual design; a space storables propellant study; a spacecraft cryogenic propulsion study; an advanced pressurization and mixture ratio control study; and a pump-fed vs. pressure-fed study.

  14. The Influence of Information Structure on the Depth of Semantic Processing: How Focus and Pitch Accent Determine the Size of the N400 Effect

    ERIC Educational Resources Information Center

    Wang, Lin; Bastiaansen, Marcel; Yang, Yufang; Hagoort, Peter

    2011-01-01

    To highlight relevant information in dialogues, both wh-question context and pitch accent in answers can be used, such that focused information gains more attention and is processed more elaborately. To evaluate the relative influence of context and pitch accent on the depth of semantic processing, we measured event-related potentials (ERPs) to…

  15. The development of pyro shock test requirements for Viking Lander Capsule components

    NASA Technical Reports Server (NTRS)

    Barrett, S.

    1975-01-01

    The procedure used to derive component-level pyro shock specifications for the Viking Lander Capsule (VLC) is described. Effects of shock path distance and mechanical joints between the device and the point at which the environment is to be estimated are accounted for in the method. The validity of the prediction technique was verified by a series of shock tests on a full-scale structural model of the lander body.

  16. SIIOS in Alaska - Testing an `In-Vault' Option for a Europa Lander Seismometer.

    NASA Astrophysics Data System (ADS)

    Bray, V. J.; Weber, R. C.; DellaGiustina, D. N.; Bailey, H.; Schmerr, N. C.; Pettit, E. C.; Dahl, P.; Albert, D.; Avenson, B.; Byrne, S.; Siegler, M.; Bland, M. T.; Patterson, G. W.; Selznick, S.

    2017-12-01

    The surface environment of Europa within the radiation-heavy jovian system, poses extreme technical challenges for potential landed missions. The need for radiation shielding and protection from the cold requires instruments to be housed within a thermally insulated and radiation protected `vault'. Unfortunately, this is non-ideal for seismometers as instrument-to-surface coupling is an important factor in the quality of returned data. Delivering a seismic package to an icy world would therefore benefit from the development of a cold-tolerant, radiation-hardened sensor that can survive outside of a protective vault. If such an instrument package were not technologically mature enough, or if lander safety considerations prevent deployment on lander legs, an in-vault location is still a viable option. For such a case, a better understanding of the transmission of seismic signals received through the lander legs is necessary for interpretation of the received signals. The performance, mass, and volume of the `Seismometer to investigate ice and ocean structure' (SIIOS) already meet or exceed flight requirements identified in lander studies for the icy moon Europa. We are testing this flight-candidate in several configurations around and within a lander mock-up, assuming a 1x1 meter vault with extended legs. We compare the received signals from a SIIOS device on the ice with those received by an identical sensor directly above it in the `vault'. We also compare the data from these single-point receivers to that received by two short base-line arrays - A 4-point "in-vault" array and another 4-point array arranged at the ice surface at the base of the lander legs. Our field-testing is performed at Gulkana Glacier, Alaska. The summer melt season provides kilometer-scale regions of coexisting ice, water, and silicate material, thereby providing seismic contrasts analogous to the ice-water layers and possible sub-surface lakes expected at Europa. We demonstrate the

  17. Concept study for a Venus Lander Mission to Analyze Atmospheric and Surface Composition

    NASA Astrophysics Data System (ADS)

    Kumar, K.; Banks, M. E.; Benecchi, S. D.; Bradley, B. K.; Budney, C. J.; Clark, G. B.; Corbin, B. A.; James, P. B.; O'Brien, R. C.; Rivera-Valentin, E. G.; Saltman, A.; Schmerr, N. C.; Seubert, C. R.; Siles, J. V.; Stickle, A. M.; Stockton, A. M.; Taylor, C.; Zanetti, M.; JPL Team X

    2011-12-01

    We present a concept-level study of a New Frontiers class, Venus lander mission that was developed during Session 1 of NASA's 2011 Planetary Science Summer School, hosted by Team X at JPL. Venus is often termed Earth's sister planet, yet they have evolved in strikingly different ways. Venus' surface and atmosphere dynamics, and their complex interaction are poorly constrained. A lander mission to Venus would enable us to address a multitude of outstanding questions regarding the geological evolution of the Venusian atmosphere and crust. Our proposed mission concept, VenUs Lander for Composition ANalysis (VULCAN), is a two-component mission, consisting of a lander and a carrier spacecraft functioning as relay to transmit data to Earth. The total mission duration is 150 days, with primary science obtained during a 1-hour descent through the atmosphere and a 2-hour residence on the Venusian surface. In the atmosphere, the lander will provide new data on atmospheric evolution by measuring dominant and trace gas abundances, light stable isotopes, and noble gas isotopes with a neutral mass spectrometer. It will make important meteorological observations of mid-lower atmospheric dynamics with pressure and temperature sensors and obtain unprecedented, detailed imagery of surface geomorphology and properties with a descent Near-IR/VIS camera. A nepholometer will provide new constraints on the sizes of suspended particulate matter within the lower atmosphere. On the surface, the lander will quantitatively investigate the chemical and mineralogical evolution of the Venusian crust with a LIBS-Raman spectrometer. Planetary differentiation processes recorded in heavy elements will be evaluated using a gamma-ray spectrometer. The lander will also provide the first stereo images for evaluating the geomorphologic/volcanic evolution of the Venusian surface, as well as panoramic views of the sample site using multiple filters, and detailed images of unconsolidated material and rock

  18. The Effect of Intensity and Age on the Perception of Accent in Isochronous Sequences of a Snare Drum Timbre

    NASA Astrophysics Data System (ADS)

    Walls, Kimberly Kyle Curley

    1992-01-01

    Musical expression is largely dependent upon accentuation, yet there have been few attempts to study the perception of dynamic accent in music or to relate the results of psychoacoustical research in intensity to realistic musical situations. The purpose of the experiment was to estimate the relationships among (a) the intensity increment in dB(A) required to meet an 80% correct criterion in the perception of one accented tone embedded within a seven -tone isochronous series of identical 87 dB(A) snare drum timbre stimuli of 333 ms onsets (accent level, or AL), (b) the different limen (DL) for intensity increase to meet a 75% correct criterion in a 2AFC task for pairs for the stimuli, and (c) the age of the subjects, all of whom have normal audiograms. The 51 subjects (N = 51) were female nonmusicians ranging in age from 9 to 33 years (M = 17.98, SD = 5.21). The response tasks involved saying whether the second tone of each pair was louder or softer and circling the accented note in notated quarter notes. The stimuli production, the headphone calibration process, and their rationales were detailed. The global regression model was significant (F(2, 48) = 5.505, p =.007, R^2 =.187), and the relationship between AL and DL was not significant (F(1, 48) = 5.505, p =.197, R^2 change =.029), the relationship between AL and age was significant (F(1, 48) = 5.732, p =.021, R ^2 change =.098) at an alpha level of.05 and power calculated at.66 for a medium ES. It was concluded that accented sounds are easier to perceive in tone pairs than they are in a musical setting and that subject maturation improves performance of intensity judgement tasks. Suggestions for further research include shortening the length of the experimental session for younger subjects and increasing the number of intensity increments as well as using smaller increments to accommodate individual differences in perception.

  19. Novel Architecture for a Long-Life, Lightweight Venus Lander

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bugby, D.; Seghi, S.; Kroliczek, E.

    2009-03-16

    This paper describes a novel concept for an extended lifetime, lightweight Venus lander. Historically, to operate in the 480 deg. C, 90 atm, corrosive, mostly CO{sub 2} Venus surface environment, previous landers have relied on thick Ti spherical outer shells and thick layers of internal insulation. But even the most resilient of these landers operated for only about 2 hours before succumbing to the environment. The goal on this project is to develop an architecture that extends lander lifetime to 20-25 hours and also reduces mass compared to the Pioneer Venus mission architecture. The idea for reducing mass is to:more » (a) contain the science instruments within a spherical high strength lightweight polymer matrix composite (PMC) tank; (b) surround the PMC tank with an annular shell of high performance insulation pre-pressurized to a level that (after landing) will exceed the external Venus surface pressure; and (c) surround the insulation with a thin Ti outer shell that contains only a net internal pressure, eliminating buckling overdesign mass. The combination of the PMC inner tank and thin Ti outer shell is lighter than a single thick Ti outer shell. The idea for extending lifetime is to add the following three features: (i) an expendable water supply that is placed within the insulation or is contained in an additional vessel within the PMC tank; (ii) a thin spherical evaporator shell placed within the insulation a short radial distance from the outer shell; and (iii) a thin heat-intercepting liquid cooled shield placed inboard of the evaporator shell. These features lower the temperature of the insulation below what it would have been with the insulation alone, reducing the internal heat leak and lengthening lifetime. The use of phase change materials (PCMs) inside the PMC tank is also analyzed as a lifetime-extending design option. The paper describes: (1) analytical modeling to demonstrate reduced mass and extended life; (2) thermal conductivity testing

  20. Could This Be the Mars Soviet 3 Lander?

    NASA Image and Video Library

    2013-04-11

    This set of images shows what might be hardware from the Soviet Union 1971 Mars 3 lander, seen in a pair of images from the High Resolution Imaging Science Experiment HiRISE camera on NASA Mars Reconnaissance Orbiter.

  1. Examining differences in nurses' language, accent, and comprehensibility in nursing home settings based on birth origin and country of education.

    PubMed

    Wagner, Laura M; Brush, Barbara L; Castle, Nicholas G; Eaton, Michelle; Capezuti, Elizabeth

    2015-01-01

    As nursing homes turn abroad to fill vacancies, the diverse linguistic backgrounds of nurse hires are creating new challenges in comprehensibility between nurses, providers, and residents. Accents are a natural part of spoken language that may present difficulty even when the parties involved are speaking the same language. We surveyed 1,629 nurses working in 98 nursing homes (NHs) in five U.S. states to determine if and how language difficulties were perceived by nurses and others (e.g. physicians, residents and family members). We found that when participants were asked how often other care team members and residents/families had difficulty understanding them due to language use or accent, foreign born nurses were significantly more likely to report that they experienced difficulty at least some of the time across all groups. This study supports an assessment of nurses' language, accents, and comprehensibility in these settings. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Mars Pathfinder Spacecraft, Lander, and Rover Testing in Simulated Deep Space and Mars Surface Environments

    NASA Technical Reports Server (NTRS)

    Johnson, Kenneth R.

    1997-01-01

    The Mars Pathfinder (MPF) Spacecraft was built and tested at the Jet Propulsion Laboratory during 1995/96. MPF is scheduled to launch in December 1996 and to land on Mars on July 4, 1997. The testing program for MPF required subjecting the mission hardware to both deep space and Mars surface conditions. A series of tests were devised and conducted from 1/95 to 7/96 to study the thermal response of the MPF spacecraft to the environmental conditions in which it will be exposed during the cruise phase (on the way to Mars) and the lander phase (landed on Mars) of the mission. Also, several tests were conducted to study the thermal characteristics of the Mars rover, Sojourner, under Mars surface environmental conditions. For these tests, several special test fixtures and methods were devised to simulate the required environmental conditions. Creating simulated Mars surface conditions was a challenging undertaking since Mars' surface is subjected to diurnal cycling between -20 C and -85 C, with windspeeds to 20 m/sec, occurring in an 8 torr CO2 atmosphere. This paper describes the MPF test program which was conducted at JPL to verify the MPF thermal design.

  3. COMPASS Final Report: Advanced Long-Life Lander Investigating the Venus Environment (ALIVE)

    NASA Technical Reports Server (NTRS)

    Oleson, Steven R.; Paul, Michael

    2016-01-01

    The COncurrent Multi-disciplinary Preliminary Assessment of Space Systems (COMPASS) Team partnered with the Applied Research Laboratory to perform a NASA Innovative Advanced Concepts (NIAC) Program study to evaluate chemical based power systems for keeping a Venus lander alive(power and cooling) and functional for a period of days. The mission class targeted was either a Discovery ($500M) or New Frontiers ($750M to $780M) class mission. Historic Soviet Venus landers have only lasted on the order of 2 hours in the extreme Venus environment: temperatures of 460 C and pressures of 93 bar. Longer duration missions have been studied using plutonium powered systems to operate and cool landers for up to a year. However, the plutonium load is very large. This NIAC study sought to still provide power and cooling but without the plutonium.

  4. Experiments on asteroids using hard landers

    NASA Technical Reports Server (NTRS)

    Turkevich, A.; Economou, T.

    1978-01-01

    Hard lander missions to asteroids are examined using the Westphal penetrator study as a basis. Imagery and chemical information are considered to be the most significant science to be obtained. The latter, particularly a detailed chemical analysis performed on an uncontaminated sample, may answer questions about the relationships of asteroids to meteorites and the place of asteroids in theories of the formation of the solar system.

  5. NASA's International Lunar Network Anchor Nodes and Robotic Lunar Lander Project Update

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara A.; Bassler, Julie A.; Ballard, Benjamin; Chavers, Greg; Eng, Doug S.; Hammond, Monica S.; Hill, Larry A.; Harris, Danny W.; Hollaway, Todd A.; Kubota, Sanae; hide

    2010-01-01

    NASA Marshall Space Flight Center and The Johns Hopkins University Applied Physics Laboratory have been conducting mission studies and performing risk reduction activities for NASA's robotic lunar lander flight projects. Additional mission studies have been conducted to support other objectives of the lunar science and exploration community and extensive risk reduction design and testing has been performed to advance the design of the lander system and reduce development risk for flight projects.

  6. Viking lander camera radiometry calibration report, volume 2

    NASA Technical Reports Server (NTRS)

    Wolf, M. R.; Atwood, D. L.; Morrill, M. E.

    1977-01-01

    The requirements the performance validation, and interfaces for the RADCAM program, to convert Viking lander camera image data to radiometric units were established. A proposed algorithm is described, and an appendix summarizing the planned reduction of camera test data was included.

  7. Synthetic and Enhanced Vision System for Altair Lunar Lander

    NASA Technical Reports Server (NTRS)

    Prinzell, Lawrence J., III; Kramer, Lynda J.; Norman, Robert M.; Arthur, Jarvis J., III; Williams, Steven P.; Shelton, Kevin J.; Bailey, Randall E.

    2009-01-01

    Past research has demonstrated the substantial potential of synthetic and enhanced vision (SV, EV) for aviation (e.g., Prinzel & Wickens, 2009). These augmented visual-based technologies have been shown to significantly enhance situation awareness, reduce workload, enhance aviation safety (e.g., reduced propensity for controlled flight -into-terrain accidents/incidents), and promote flight path control precision. The issues that drove the design and development of synthetic and enhanced vision have commonalities to other application domains; most notably, during entry, descent, and landing on the moon and other planetary surfaces. NASA has extended SV/EV technology for use in planetary exploration vehicles, such as the Altair Lunar Lander. This paper describes an Altair Lunar Lander SV/EV concept and associated research demonstrating the safety benefits of these technologies.

  8. Advanced transportation system studies. Alternate propulsion subsystem concepts: Propulsion database

    NASA Technical Reports Server (NTRS)

    Levack, Daniel

    1993-01-01

    The Advanced Transportation System Studies alternate propulsion subsystem concepts propulsion database interim report is presented. The objective of the database development task is to produce a propulsion database which is easy to use and modify while also being comprehensive in the level of detail available. The database is to be available on the Macintosh computer system. The task is to extend across all three years of the contract. Consequently, a significant fraction of the effort in this first year of the task was devoted to the development of the database structure to ensure a robust base for the following years' efforts. Nonetheless, significant point design propulsion system descriptions and parametric models were also produced. Each of the two propulsion databases, parametric propulsion database and propulsion system database, are described. The descriptions include a user's guide to each code, write-ups for models used, and sample output. The parametric database has models for LOX/H2 and LOX/RP liquid engines, solid rocket boosters using three different propellants, a hybrid rocket booster, and a NERVA derived nuclear thermal rocket engine.

  9. Spectral mixture modeling: Further analysis of rock and soil types at the Viking Lander sites

    NASA Technical Reports Server (NTRS)

    Adams, John B.; Smith, Milton O.

    1987-01-01

    A new image processing technique was applied to Viking Lander multispectral images. Spectral endmembers were defined that included soil, rock and shade. Mixtures of these endmembers were found to account for nearly all the spectral variance in a Viking Lander image.

  10. An Exploratory Study of Undergraduate College Students' Perceptions and Attitudes toward Foreign Accented Faculty

    ERIC Educational Resources Information Center

    Kavas, Aysel; Kavas, Alican

    2008-01-01

    The findings of an exploratory survey related to students' perceptions of factors, including accent and pronunciation, influencing their learning were presented. Data were collected from students through a self-administered questionnaire at one Southeastern University. A big majority (82.4%) of the respondents indicated that instructors'…

  11. Lunar lander conceptual design: Lunar base systems study task 2.2

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This study is a first look at the problem of building a lunar lander to support a small lunar surface base. One lander, which can land 25 metric tons, one way, or take a 6 metric ton crew capsule up and down is desired. A series of trade studies are used to narrow the choices and provide some general guidelines. Given a rough baseline, the systems are then reviewed. A conceptual design is then produced. The process was only carried through one iteration. Many more iterations are needed. Assumptions and groundrules are considered.

  12. Learning to Comprehend Foreign-Accented Speech by Means of Production and Listening Training

    ERIC Educational Resources Information Center

    Grohe, Ann-Kathrin; Weber, Andrea

    2016-01-01

    The effects of production and listening training on the subsequent comprehension of foreign-accented speech were investigated in a training-test paradigm. During training, German nonnative (L2) and English native (L1) participants listened to a story spoken by a German speaker who replaced all English /?/s with /t/ (e.g., *"teft" for…

  13. Policies and Practices regarding Students with Accents in Speech-Language Pathology Training Programs

    ERIC Educational Resources Information Center

    Levy, Erika S.; Crowley, Catherine J.

    2012-01-01

    Speech-language pathology (SLP) training programs are the initial gateway for nonnative speakers of English to join the SLP profession. An anonymous web-based survey in New York State examined policies and practices implemented when SLP students have foreign accents in English or in other languages. Responses were elicited from 530 students and 28…

  14. Jovian Tour Design for Orbiter and Lander Missions to Europa

    NASA Technical Reports Server (NTRS)

    Campagnola, Stefano; Buffington, Brent B.; Petropoulos, Anastassios E.

    2013-01-01

    Europa is one of the most interesting targets for solar system exploration, as its ocean of liquid water could harbor life. Following the recommendation of the Planetary Decadal Survey, NASA commissioned a study for a flyby mission, an orbiter mission, and a lander mission. This paper presents the moon tours for the lander and orbiter concepts. The total delta v and radiation dose would be reduced by exploiting multi-body dynamics and avoiding phasing loops in the Ganymede-to- Europa transfer. Tour 11-O3, 12-L1 and 12-L4 are presented in details and their performaces compared to other tours from previous Europa mission studies.

  15. Planetary protection implementation on future Mars lander missions

    NASA Astrophysics Data System (ADS)

    Howell, Robert; Devincenzi, Donald L.

    1993-06-01

    A workshop was convened to discuss the subject of planetary protection implementation for Mars lander missions. It was sponsored and organized by the Exobiology Implementation Team of the U.S./Russian Joint Working Group on Space Biomedical and Life Support Systems. The objective of the workshop was to discuss planetary protection issues for the Russian Mars '94 mission, which is currently under development, as well as for additional future Mars lander missions including the planned Mars '96 and U.S. MESUR Pathfinder and Network missions. A series of invited presentations was made to ensure that workshop participants had access to information relevant to the planned discussions. The topics summarized in this report include exobiology science objectives for Mars exploration, current international policy on planetary protection, planetary protection requirements developed for earlier missions, mission plans and designs for future U.S. and Russian Mars landers, biological contamination of spacecraft components, and techniques for spacecraft bioload reduction. In addition, the recent recommendations of the U.S. Space Studies Board (SSB) on this subject were also summarized. Much of the discussion focused on the recommendations of the SSB. The SSB proposed relaxing the planetary protection requirements for those Mars lander missions that do not contain life detection experiments, but maintaining Viking-like requirements for those missions that do contain life detection experiments. The SSB recommendations were found to be acceptable as a guide for future missions, although many questions and concerns about interpretation were raised and are summarized. Significant among the concerns was the need for more quantitative guidelines to prevent misinterpretation by project offices and better access to and use of the Viking data base of bio-assays to specify microbial burden targets. Among the questions raised were how will the SSB recommendations be integrated with existing

  16. Planetary protection implementation on future Mars lander missions

    NASA Technical Reports Server (NTRS)

    Howell, Robert; Devincenzi, Donald L.

    1993-01-01

    A workshop was convened to discuss the subject of planetary protection implementation for Mars lander missions. It was sponsored and organized by the Exobiology Implementation Team of the U.S./Russian Joint Working Group on Space Biomedical and Life Support Systems. The objective of the workshop was to discuss planetary protection issues for the Russian Mars '94 mission, which is currently under development, as well as for additional future Mars lander missions including the planned Mars '96 and U.S. MESUR Pathfinder and Network missions. A series of invited presentations was made to ensure that workshop participants had access to information relevant to the planned discussions. The topics summarized in this report include exobiology science objectives for Mars exploration, current international policy on planetary protection, planetary protection requirements developed for earlier missions, mission plans and designs for future U.S. and Russian Mars landers, biological contamination of spacecraft components, and techniques for spacecraft bioload reduction. In addition, the recent recommendations of the U.S. Space Studies Board (SSB) on this subject were also summarized. Much of the discussion focused on the recommendations of the SSB. The SSB proposed relaxing the planetary protection requirements for those Mars lander missions that do not contain life detection experiments, but maintaining Viking-like requirements for those missions that do contain life detection experiments. The SSB recommendations were found to be acceptable as a guide for future missions, although many questions and concerns about interpretation were raised and are summarized. Significant among the concerns was the need for more quantitative guidelines to prevent misinterpretation by project offices and better access to and use of the Viking data base of bioassays to specify microbial burden targets. Among the questions raised were how will the SSB recommendations be integrated with existing

  17. Test of Lander Vision System for Mars 2020

    NASA Image and Video Library

    2016-10-04

    A prototype of the Lander Vision System for NASA Mars 2020 mission was tested in this Dec. 9, 2014, flight of a Masten Space Systems Xombie vehicle at Mojave Air and Space Port in California. http://photojournal.jpl.nasa.gov/catalog/PIA20848

  18. Names Chip Placed on InSight Lander Deck

    NASA Image and Video Library

    2015-12-17

    A spacecraft specialist in a clean room at Lockheed Martin Space Systems in Denver affixes a dime-size chip onto the lander deck in November 2015. This chip carries 826,923 names, submitted by the public online from all over the world.

  19. Navigation Strategy for the Mars 2001 Lander Mission

    NASA Technical Reports Server (NTRS)

    Mase, Robert A.; Spencer, David A.; Smith, John C.; Braun, Robert D.

    2000-01-01

    The Mars Surveyor Program (MSP) is an ongoing series of missions designed to robotically study, map and search for signs of life on the planet Mars. The MSP 2001 project will advance the effort by sending an orbiter, a lander and a rover to the red planet in the 2001 opportunity. Each vehicle will carry a science payload that will Investigate the Martian environment on both a global and on a local scale. Although this mission will not directly search for signs of life, or cache samples to be returned to Earth, it will demonstrate certain enabling technologies that will be utilized by the future Mars Sample Return missions. One technology that is needed for the Sample Return mission is the capability to place a vehicle on the surface within several kilometers of the targeted landing site. The MSP'01 Lander will take the first major step towards this type of precision landing at Mars. Significant reduction of the landed footprint will be achieved through two technology advances. The first, and most dramatic, is hypersonic aeromaneuvering; the second is improved approach navigation. As a result, the guided entry will produce in a footprint that is only tens of kilometers, which is an order of magnitude improvement over the Pathfinder and Mars Polar Lander ballistic entries. This reduction will significantly enhance scientific return by enabling the potential selection of otherwise unreachable landing sites with unique geologic interest and public appeal. A landed footprint reduction from hundreds to tens of kilometers is also a milestone on the path towards human exploration of Mars, where the desire is to place multiple vehicles within several hundred meters of the planned landing site. Hypersonic aeromaneuvering is an extension of the atmospheric flight goals of the previous landed missions, Pathfinder and Mars Polar Lander (MPL), that utilizes aerodynamic lift and an autonomous guidance algorithm while in the upper atmosphere. The onboard guidance algorithm will

  20. InSight Lander Solar Array Test

    NASA Image and Video Library

    2018-01-23

    The solar arrays on NASA's InSight Mars lander were deployed as part of testing conducted Jan. 23, 2018, at Lockheed Martin Space in Littleton, Colorado. Engineers and technicians evaluated the solar arrays and performed an illumination test to confirm that the solar cells were collecting power. The launch window for InSight opens May 5, 2018. A video is available at https://photojournal.jpl.nasa.gov/catalog/PIA22205

  1. The Sound of German: Descriptions of Accent by Native and Non-Native Listeners

    ERIC Educational Resources Information Center

    Wilkerson, Miranda E.

    2013-01-01

    This paper presents a study of factors affecting judgments of native and non-native accent in German. The data suggest that listener status (native or non-native speakers) and degree of experience with German play a role in the aspects of speech which raters cite as salient. Interestingly, the same descriptive terms used by raters were shown to…

  2. Solar Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Gerrish, Harold P., Jr.

    2003-01-01

    This paper presents viewgraphs on Solar Thermal Propulsion (STP). Some of the topics include: 1) Ways to use Solar Energy for Propulsion; 2) Solar (fusion) Energy; 3) Operation in Orbit; 4) Propulsion Concepts; 5) Critical Equations; 6) Power Efficiency; 7) Major STP Projects; 8) Types of STP Engines; 9) Solar Thermal Propulsion Direct Gain Assembly; 10) Specific Impulse; 11) Thrust; 12) Temperature Distribution; 13) Pressure Loss; 14) Transient Startup; 15) Axial Heat Input; 16) Direct Gain Engine Design; 17) Direct Gain Engine Fabrication; 18) Solar Thermal Propulsion Direct Gain Components; 19) Solar Thermal Test Facility; and 20) Checkout Results.

  3. Propulsion Systems Panel deliberations

    NASA Technical Reports Server (NTRS)

    Bianca, Carmelo J.; Miner, Robert; Johnston, Lawrence M.; Bruce, R.; Dennies, Daniel P.; Dickenson, W.; Dreshfield, Robert; Karakulko, Walt; Mcgaw, Mike; Munafo, Paul M.

    1993-01-01

    The Propulsion Systems Panel was established because of the specialized nature of many of the materials and structures technology issues related to propulsion systems. This panel was co-chaired by Carmelo Bianca, MSFC, and Bob Miner, LeRC. Because of the diverse range of missions anticipated for the Space Transportation program, three distinct propulsion system types were identified in the workshop planning process: liquid propulsion systems, solid propulsion systems and nuclear electric/nuclear thermal propulsion systems.

  4. Propulsion Systems Panel deliberations

    NASA Astrophysics Data System (ADS)

    Bianca, Carmelo J.; Miner, Robert; Johnston, Lawrence M.; Bruce, R.; Dennies, Daniel P.; Dickenson, W.; Dreshfield, Robert; Karakulko, Walt; McGaw, Mike; Munafo, Paul M.

    1993-02-01

    The Propulsion Systems Panel was established because of the specialized nature of many of the materials and structures technology issues related to propulsion systems. This panel was co-chaired by Carmelo Bianca, MSFC, and Bob Miner, LeRC. Because of the diverse range of missions anticipated for the Space Transportation program, three distinct propulsion system types were identified in the workshop planning process: liquid propulsion systems, solid propulsion systems and nuclear electric/nuclear thermal propulsion systems.

  5. Martian Meteorological Lander

    NASA Astrophysics Data System (ADS)

    Vorontsov, V.; Pichkhadze, K.; Polyakov, A.

    2002-01-01

    Martian meteorological lander (MML) is dedicated for landing onto the Mars surface with the purpose to carry on the monitoring of Mars atmosphere condition at a landing point during one Martian year. MML is supposed to become the basic element of a global net of meteorological mini stations and will permit to observe the dynamics of Martian atmosphere parameters changes during a long time duration. The main scientific tasks of MML are as follows: -study of vertical structure of Mars atmosphere during MML descending; -meteorological observations on Mars surface during one Martian year. One of the essential factor influencing to the lander design is descent trajectory design. During the preliminary phase of development five (5) options of MML were considered. In our opinion, these variants provide the accomplishment of the above-mentioned tasks with a high effectiveness. Joined into the first group, variants with parachute system and with Inflatable Air Brakes+Inflatable Airbag are similar in arranging of pre-landing braking stage and completely analogous in landing by means of airbags. The usage of additional Inflatable Braking Unit (IBU) in the second variant does not affect the procedure of braking - decreasing of velocity by the moment of touching the surface due to decreasing of ballistic parameter Px. A distinctive feature of MML development variants of other three concepts is the presence of Inflatable Braking Unit (IBU) in their configurations (IBU is rigidly joined with landing module up to the moment of its touching the surface). Besides, in variant with the tore-shaped IBU it acts as a shock- absorbing unit. In two options, Inflatable Braking Shock-Absorbing Unit (IBSAU) (or IBU) releases the surface module after its landing at the moment of IBSAU (or IBU) elastic recoil. Variants of this concept are equal in terms of mass (approximately 15 kg). For variants of concepts with IBU the landing velocity is up to50-70 m/s. Stations of last three options are

  6. Earthquake triggering by seismic waves following the landers and hector mine earthquakes

    USGS Publications Warehouse

    Gomberg, J.; Reasenberg, P.A.; Bodin, P.; Harris, R.A.

    2001-01-01

    The proximity and similarity of the 1992, magnitude 7.3 Landers and 1999, magnitude 7.1 Hector Mine earthquakes in California permit testing of earthquake triggering hypotheses not previously possible. The Hector Mine earthquake confirmed inferences that transient, oscillatory 'dynamic' deformations radiated as seismic waves can trigger seismicity rate increases, as proposed for the Landers earthquake1-6. Here we quantify the spatial and temporal patterns of the seismicity rate changes7. The seismicity rate increase was to the north for the Landers earthquake and primarily to the south for the Hector Mine earthquake. We suggest that rupture directivity results in elevated dynamic deformations north and south of the Landers and Hector Mine faults, respectively, as evident in the asymmetry of the recorded seismic velocity fields. Both dynamic and static stress changes seem important for triggering in the near field with dynamic stress changes dominating at greater distances. Peak seismic velocities recorded for each earthquake suggest the existence of, and place bounds on, dynamic triggering thresholds. These thresholds vary from a few tenths to a few MPa in most places, depend on local conditions, and exceed inferred static thresholds by more than an order of magnitude. At some sites, the onset of triggering was delayed until after the dynamic deformations subsided. Physical mechanisms consistent with all these observations may be similar to those that give rise to liquefaction or cyclic fatigue.

  7. Lunar Lander Offloading Operations Using a Heavy-Lift Lunar Surface Manipulator System

    NASA Technical Reports Server (NTRS)

    Jefferies, Sharon A.; Doggett, William R.; Chrone, Jonathan; Angster, Scott; Dorsey, John T.; Jones, Thomas C.; Haddad, Michael E.; Helton, David A.; Caldwell, Darrell L., Jr.

    2010-01-01

    This study investigates the feasibility of using a heavy-lift variant of the Lunar Surface Manipulator System (LSMS-H) to lift and handle a 12 metric ton payload. Design challenges and requirements particular to handling heavy cargo were examined. Differences between the previously developed first-generation LSMS and the heavy-lift version are highlighted. An in-depth evaluation of the tip-over risk during LSMS-H operations has been conducted using the Synergistic Engineering Environment and potential methods to mitigate that risk are identified. The study investigated three specific offloading scenarios pertinent to current Lunar Campaign studies. The first involved offloading a large element, such as a habitat or logistics module, onto a mobility chassis with a lander-mounted LSMS-H and offloading that payload from the chassis onto the lunar surface with a surface-mounted LSMS-H. The second scenario involved offloading small pressurized rovers with a lander-mounted LSMS-H. The third scenario involved offloading cargo from a third-party lander, such as the proposed ESA cargo lander, with a chassis-mounted LSMS-H. In all cases, the analyses show that the LSMS-H can perform the required operations safely. However, Chariot-mounted operations require the addition of stabilizing outriggers, and when operating from the Lunar surface, LSMS-H functionality is enhanced by adding a simple ground anchoring system.

  8. NASA's Phoenix Lander on Mars, Nearly a Decade Later

    NASA Image and Video Library

    2018-02-20

    This is one of two images taken nearly a decade apart of NASA's Mars Phoenix Lander and related hardware around the mission's May 25, 2008, landing site on far-northern Mars. By late 2017, dust had obscured much of what was visible two months after the landing. Both images were taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The one with three patches of darker ground -- where landing events removed dust -- was taken on July 20, 2008. It is Fig. 1, an excerpt of HiRISE observation PSP_009290_2485. The one with a more even coating of pale dust throughout the area was taken on Dec. 21, 2017. It is Fig. 2, an excerpt of HiRISE observation ESP_053451_2485. Both cover an area roughly 300 meters wide at 68 degrees north latitude, 234 degrees east longitude, and the two are closely matched in viewing and illumination geometry, from about five Martian years apart in northern hemisphere summers. An animation comparing the two images shows a number of changes between mid-2008 and late 2017. The lander (top) appears darker, and is now covered by dust. The dark spot created by the heat shield impact (right) is brighter, again due to dust deposition. The back shell and parachute (bottom) shows a darker parachute and brighter area of impact disturbance, thanks again to deposits of dust. We also see that the parachute has shifted in the wind, moving to the east. In August 2008, Phoenix completed its three-month mission studying Martian ice, soil and atmosphere. The lander worked for two additional months before reduced sunlight caused energy to become insufficient to keep the lander functioning. The solar-powered robot was not designed to survive through the dark and cold conditions of a Martian arctic winter. An animation and both images are available at https://photojournal.jpl.nasa.gov/catalog/PIA22223

  9. 2010 JPC Abstract: Ares I First Stage Propulsion System Status

    NASA Technical Reports Server (NTRS)

    Priskos, Alex S.

    2010-01-01

    In November 2005, NASA created the Constellation Program to develop an entirely new fleet of spacecraft to include the Ares I Crew Launch Vehicle and Ares V Cargo Launch vehicles. This mission architecture included the Orion capsule (which would be used to transport astronauts to low-Earth orbit and beyond), the Altair lunar lander, and an Earth departure stage. The Ares First Stage Team has made significant progress on the design of a propulsion system to meet the objectives of the Constellation Program. Work on a first stage element propulsion system capable of lofting a new fleet of spacecraft is well underway. To minimize technical risks and development costs, the Solid Rocket Boosters (SRBs) of Shuttle served as a starting point in the design of a new motor that would meet the requirements of those new vehicles. This new propulsive element will provide greater total impulse utilizing a fifth segment to loft a safer, more powerful fleet of space flight vehicles. Performance requirements, basic architecture, and obsolescence issues were all factors in determining the new first stage element design and configuration. Early efforts focused on creating designs that would be capable of supporting the requisite loads and environments. While the motor casings are Shuttle legacy, because of Ares I s unique in-line configuration, the first stage will require entirely new forward structures (forward skirt, forward skirt extension, aeroshell, and frustum) and a modified systems tunnel. The use of composites facilitated a change in the geometry, which in turn afforded the ability to focus strength where it was needed without additional mass. The Ares First Stage rocket motor casting tooling was designed and built to achieve a propellant grain geometry that produces the specific required ballistic profile. The new propellant formulation is a polybutadiene acrylonitrile (PBAN) copolymer, which has been modified to attain the desired burn rate and retain adequate tailoring

  10. Breaking Lander-Waterman’s Coverage Bound

    PubMed Central

    Nashta-ali, Damoun; Motahari, Seyed Abolfazl; Hosseinkhalaj, Babak

    2016-01-01

    Lander-Waterman’s coverage bound establishes the total number of reads required to cover the whole genome of size G bases. In fact, their bound is a direct consequence of the well-known solution to the coupon collector’s problem which proves that for such genome, the total number of bases to be sequenced should be O(G ln G). Although the result leads to a tight bound, it is based on a tacit assumption that the set of reads are first collected through a sequencing process and then are processed through a computation process, i.e., there are two different machines: one for sequencing and one for processing. In this paper, we present a significant improvement compared to Lander-Waterman’s result and prove that by combining the sequencing and computing processes, one can re-sequence the whole genome with as low as O(G) sequenced bases in total. Our approach also dramatically reduces the required computational power for the combined process. Simulation results are performed on real genomes with different sequencing error rates. The results support our theory predicting the log G improvement on coverage bound and corresponding reduction in the total number of bases required to be sequenced. PMID:27806058

  11. Observed Changes at Viking Lander 1

    NASA Technical Reports Server (NTRS)

    Moore, H. J.

    1985-01-01

    A local dust storm raged in Chryse Planitia, Mars, in June 1981. The changes wrought in the vicinity of the lander (Mutch Memorial Station) by this storm sometime near Sol 1742 were partly described previously. Here, changes related to the storm are itemized, evidence for wind directions during the peak of the storm are cited, and two observations unrelated to the storm are noted. The observations suggest that the eroding winds of the Sol 1742 storm were more easterly (N. 35 deg to 90 deg E.) than those (N. 5 deg to 11 deg E.) that formed the large wind tails; and fragments in erosional residues are 0.7 cm and larger, but smaller ones may be present. Some fragments 0.4 to 0.5 cm and smaller were somehow removed, at least locally; wind speeds of the 1742 local storm were probably greater than those of a previous local dust storm (25 to 30 m/s) that occurred during the same season on Sol 423 because the earlier storm did not alter the surface; the major, if not entire, amount of erosion by the storm occurred between Sols 1728 and 1757; and erosion chiefly occurred where the surface configuration and material properties were altered by the lander and its sampler.

  12. Acoustic and Perceptual Correlates of Foreign Accent Syndrome with Manic Etiology: A Case Study

    ERIC Educational Resources Information Center

    Lewis, Skye; Ball, Laura J.; Kitten, Suzanna

    2013-01-01

    In foreign accent syndrome (FAS), changes in articulation and prosody cause listeners to perceive the speaker as "foreign-sounding." Fewer than 100 cases of FAS have been described in the literature; commonly associated with brain damage, only a handful of these have been analyzed with respect to acoustic measures. Acoustic and…

  13. Viking Landers and remote sensing

    NASA Technical Reports Server (NTRS)

    Moore, H. J.; Jakosky, B. M.; Christensen, P. R.

    1987-01-01

    Thermal and radar remote sensing signatures of the materials in the lander sample fields can be crudely estimated from evaluations of their physical-mechanical properties, laboratory data on thermal conductivities and dielectric constants, and theory. The estimated thermal inertias and dielectric constants of some of the materials in the sample field are close to modal values estimated from orbital and earth-based observations. This suggests that the mechanical properties of the surface materials of much of Mars will not be significantly different that those of the landing sites.

  14. Triggered seismicity and deformation between the Landers, California, and Little Skull Mountain, Nevada, earthquakes

    USGS Publications Warehouse

    Bodin, Paul; Gomberg, Joan

    1994-01-01

    This article presents evidence for the channeling of strain energy released by the Ms = 7.4 Landers, California, earthquake within the eastern California shear zone (ECSZ). We document an increase in seismicity levels during the 22-hr period starting with the Landers earthquake and culminating 22 hr later with the Ms = 5.4 Little Skull Mountain (LSM), Nevada, earthquake. We evaluate the completeness of regional seismicity catalogs during this period and find that the continuity of post-Landers strain release within the ECSZ is even more pronounced than is evident from the catalog data. We hypothesize that regional-scale connectivity of faults within the ECSZ and LSM region is a critical ingredient in the unprecedented scale and distribution of remotely triggered earthquakes and geodetically manifest strain changes that followed the Landers earthquake. The viability of static strain changes as triggering agents is tested using numerical models. Modeling results illustrate that regional-scale fault connectivity can increase the static strain changes by approximately an order of magnitude at distances of at least 280 km, the distance between the Landers and LSM epicenters. This is possible for models that include both a network of connected faults that slip “sympathetically” and realistic levels of tectonic prestrain. Alternatively, if dynamic strains are a more significant triggering agent than static strains, ECSZ structure may still be important in determining the distribution of triggered seismic and aseismic deformation.

  15. Stress triggering of the 1999 Hector Mine earthquake by transient deformation following the 1992 Landers earthquake

    USGS Publications Warehouse

    Pollitz, F.F.; Sacks, I.S.

    2002-01-01

    The M 7.3 June 28, 1992 Landers and M 7.1 October 16, 1999 Hector Mine earthquakes, California, both right lateral strike-slip events on NNW-trending subvertical faults, occurred in close proximity in space and time in a region where recurrence times for surface-rupturing earthquakes are thousands of years. This suggests a causal role for the Landers earthquake in triggering the Hector Mine earthquake. Previous modeling of the static stress change associated with the Landers earthquake shows that the area of peak Hector Mine slip lies where the Coulomb failure stress promoting right-lateral strike-slip failure was high, but the nucleation point of the Hector Mine rupture was neutrally to weakly promoted, depending on the assumed coefficient of friction. Possible explanations that could account for the 7-year delay between the two ruptures include background tectonic stressing, dissipation of fluid pressure gradients, rate- and state-dependent friction effects, and post-Landers viscoelastic relaxation of the lower crust and upper mantle. By employing a viscoelastic model calibrated by geodetic data collected during the time period between the Landers and Hector Mine events, we calculate that postseismic relaxation produced a transient increase in Coulomb failure stress of about 0.7 bars on the impending Hector Mine rupture surface. The increase is greatest over the broad surface that includes the 1999 nucleation point and the site of peak slip further north. Since stress changes of magnitude greater than or equal to 0.1 bar are associated with documented causal fault interactions elsewhere, viscoelastic relaxation likely contributed to the triggering of the Hector Mine earthquake. This interpretation relies on the assumption that the faults occupying the central Mojave Desert (i.e., both the Landers and Hector Mine rupturing faults) were critically stressed just prior to the Landers earthquake.

  16. Best Practices for In-Situ Sediment-Water Incubations with Benthic Landers

    NASA Astrophysics Data System (ADS)

    Tengberg, Anders; Kononets, Mikhail; Hall, Per; Nilsson, Madeleine; Ekeroth, Nils

    2017-04-01

    Biological, chemical, physical and geological processes that take place at the seafloor are crucial in influencing and regulating many aquatic environments. One method to estimate exchange rates, fluxes, between the sediment and the overlying water is in-situ sediment-water incubations using autonomous chamber landers. As for all field sampling and measurements best practices methods are needed to obtain high quality data. With experiences form many years usage of the Gothenburg autonomous bottom lander systems this presentation will describe some of the experimental work that has been done with focus on quality control and data evaluation methods.

  17. Age Matters, and so May Raters: Rater Differences in the Assessment of Foreign Accents

    ERIC Educational Resources Information Center

    Huang, Becky H.; Jun, Sun-Ah

    2015-01-01

    Research on the age of learning effect on second language learners' foreign accents utilizes human judgments to determine speech production outcomes. Inferences drawn from analyses of these ratings are then used to inform theories. The present study focuses on rater differences in the age of learning effect research. Three groups of raters who…

  18. A Cross-Linguistic Investigation of the Effect of Raters' Accent Familiarity on Speaking Assessment

    ERIC Educational Resources Information Center

    Huang, Becky; Alegre, Analucia; Eisenberg, Ann

    2016-01-01

    The project aimed to examine the effect of raters' familiarity with accents on their judgments of non-native speech. Participants included three groups of raters who were either from Spanish Heritage, Spanish Non-Heritage, or Chinese Heritage backgrounds (n = 16 in each group) using Winke & Gass's (2013) definition of a heritage learner as…

  19. Viking Orbiter completion mission and Viking Lander monitor mission

    NASA Technical Reports Server (NTRS)

    Gillette, R. L.

    1980-01-01

    A brief history of the Viking Missions is presented. The status of the present Viking Orbiter and Landers for the period from February 1, 1980 through March 31, 1980 is discussed, with emphasis on data transmission abilities.

  20. The 1992 Landers earthquake sequence; seismological observations

    USGS Publications Warehouse

    Egill Hauksson,; Jones, Lucile M.; Hutton, Kate; Eberhart-Phillips, Donna

    1993-01-01

    The (MW6.1, 7.3, 6.2) 1992 Landers earthquakes began on April 23 with the MW6.1 1992 Joshua Tree preshock and form the most substantial earthquake sequence to occur in California in the last 40 years. This sequence ruptured almost 100 km of both surficial and concealed faults and caused aftershocks over an area 100 km wide by 180 km long. The faulting was predominantly strike slip and three main events in the sequence had unilateral rupture to the north away from the San Andreas fault. The MW6.1 Joshua Tree preshock at 33°N58′ and 116°W19′ on 0451 UT April 23 was preceded by a tightly clustered foreshock sequence (M≤4.6) beginning 2 hours before the mainshock and followed by a large aftershock sequence with more than 6000 aftershocks. The aftershocks extended along a northerly trend from about 10 km north of the San Andreas fault, northwest of Indio, to the east-striking Pinto Mountain fault. The Mw7.3 Landers mainshock occurred at 34°N13′ and 116°W26′ at 1158 UT, June 28, 1992, and was preceded for 12 hours by 25 small M≤3 earthquakes at the mainshock epicenter. The distribution of more than 20,000 aftershocks, analyzed in this study, and short-period focal mechanisms illuminate a complex sequence of faulting. The aftershocks extend 60 km to the north of the mainshock epicenter along a system of at least five different surficial faults, and 40 km to the south, crossing the Pinto Mountain fault through the Joshua Tree aftershock zone towards the San Andreas fault near Indio. The rupture initiated in the depth range of 3–6 km, similar to previous M∼5 earthquakes in the region, although the maximum depth of aftershocks is about 15 km. The mainshock focal mechanism showed right-lateral strike-slip faulting with a strike of N10°W on an almost vertical fault. The rupture formed an arclike zone well defined by both surficial faulting and aftershocks, with more westerly faulting to the north. This change in strike is accomplished by jumping across

  1. Phobos lander coding system: Software and analysis

    NASA Technical Reports Server (NTRS)

    Cheung, K.-M.; Pollara, F.

    1988-01-01

    The software developed for the decoding system used in the telemetry link of the Phobos Lander mission is described. Encoders and decoders are provided to cover the three possible telemetry configurations. The software can be used to decode actual data or to simulate the performance of the telemetry system. The theoretical properties of the codes chosen for this mission are analyzed and discussed.

  2. Rosetta Lander - Philae: activities after hibernation and landing preparations

    NASA Astrophysics Data System (ADS)

    Ulamec, Stephan; Biele, Jens; Sierks, Holger; Blazquez, Alejandro; Cozzoni, Barbara; Fantinati, Cinzia; Gaudon, Philippe; Geurts, Koen; Jurado, Eric; Paetz, Brigitte.; Maibaum, Michael

    Rosetta is a Cornerstone Mission of the ESA Horizon 2000 programme. It is going to rendezvous with comet 67P/Churyumov-Gerasimenko after a ten year cruise and will study both its nucleus and coma with an orbiting spacecraft as well as with a Lander, Philae. Aboard Philae, a payload consisting of ten scientific instruments will perform in-situ studies of the cometary material. Rosetta and Philae have been in hibernation until January 20, 2014. After the successful wakeup they will undergo a post hibernation commissioning. The orbiter instruments (like e.g. the OSIRIS cameras) are to characterize the target comet to allow landing site selection and the definition of a separation, descent and landing (SDL) strategy for the Lander. By August 2014 our currently very poor knowledge of the characteristics of the nucleus of the comet will have increased dramatically. The paper will report on the latest updates in Separation-Descent-Landing (SDL) planning. Landing is foreseen for November 2014 at a heliocentric distance of 3 AU. Philae will be separated from the mother spacecraft from a dedicated delivery trajectory. It then descends ballistically to the surface of the comet, stabilized with an internal flywheel. At touch-down anchoring harpoons will be fired and a damping mechanism within the landing gear will provide the lander from re-bouncing. The paper will give an overview of the Philae system, the operational activities after hibernation and the latest status on the preparations for landing.

  3. Propulsion Research and Technology: Overview

    NASA Technical Reports Server (NTRS)

    Cole, John; Schmidt, George

    1999-01-01

    Propulsion is unique in being the main delimiter on how far and how fast one can travel in space. It is the lack of truly economical high-performance propulsion systems that continues to limit and restrict the extent of human endeavors in space. Therefore the goal of propulsion research is to conceive and investigate new, revolutionary propulsion concepts. This presentation reviews the development of new propulsion concepts. Some of these concepts are: (1) Rocket-based Combined Cycle (RBCC) propulsion, (2) Alternative combined Cycle engines suc2 as the methanol ramjet , and the liquid air cycle engines, (3) Laser propulsion, (4) Maglifter, (5) pulse detonation engines, (6) solar thermal propulsion, (7) multipurpose hydrogen test bed (MHTB) and other low-G cryogenic fluids, (8) Electric propulsion, (9) nuclear propulsion, (10) Fusion Propulsion, and (11) Antimatter technology. The efforts of the NASA centers in this research is also spotlighted.

  4. The Effects of Lexical Pitch Accent on Infant Word Recognition in Japanese

    PubMed Central

    Ota, Mitsuhiko; Yamane, Naoto; Mazuka, Reiko

    2018-01-01

    Learners of lexical tone languages (e.g., Mandarin) develop sensitivity to tonal contrasts and recognize pitch-matched, but not pitch-mismatched, familiar words by 11 months. Learners of non-tone languages (e.g., English) also show a tendency to treat pitch patterns as lexically contrastive up to about 18 months. In this study, we examined if this early-developing capacity to lexically encode pitch variations enables infants to acquire a pitch accent system, in which pitch-based lexical contrasts are obscured by the interaction of lexical and non-lexical (i.e., intonational) features. Eighteen 17-month-olds learning Tokyo Japanese were tested on their recognition of familiar words with the expected pitch or the lexically opposite pitch pattern. In early trials, infants were faster in shifting their eyegaze from the distractor object to the target object than in shifting from the target to distractor in the pitch-matched condition. In later trials, however, infants showed faster distractor-to-target than target-to-distractor shifts in both the pitch-matched and pitch-mismatched conditions. We interpret these results to mean that, in a pitch-accent system, the ability to use pitch variations to recognize words is still in a nascent state at 17 months. PMID:29375452

  5. Dynamic allocation of attention to metrical and grouping accents in rhythmic sequences.

    PubMed

    Kung, Shu-Jen; Tzeng, Ovid J L; Hung, Daisy L; Wu, Denise H

    2011-04-01

    Most people find it easy to perform rhythmic movements in synchrony with music, which reflects their ability to perceive the temporal periodicity and to allocate attention in time accordingly. Musicians and non-musicians were tested in a click localization paradigm in order to investigate how grouping and metrical accents in metrical rhythms influence attention allocation, and to reveal the effect of musical expertise on such processing. We performed two experiments in which the participants were required to listen to isochronous metrical rhythms containing superimposed clicks and then to localize the click on graphical and ruler-like representations with and without grouping structure information, respectively. Both experiments revealed metrical and grouping influences on click localization. Musical expertise improved the precision of click localization, especially when the click coincided with a metrically strong beat. Critically, although all participants located the click accurately at the beginning of an intensity group, only musicians located it precisely when it coincided with a strong beat at the end of the group. Removal of the visual cue of grouping structures enhanced these effects in musicians and reduced them in non-musicians. These results indicate that musical expertise not only enhances attention to metrical accents but also heightens sensitivity to perceptual grouping.

  6. Improved inflatable landing systems for low cost planetary landers

    NASA Astrophysics Data System (ADS)

    Northey, Dave; Morgan, Chris

    2006-10-01

    Inflatable landing systems have been traditionally perceived as a cost-effective solution to the problem of landing a spacecraft on a planetary surface. To date, the systems used have all employed the approach of surrounding the lander with non-vented airbags where the lander on impact bounces a number of times until the impact energy is dissipated. However, the reliability record of such systems is not at all good. This paper examines the problems involved in the use of non-vented airbags, and how these problems have been overcome by the use of vented airbags in terrestrial systems. Using a specific case study, it is shown that even the basic passive type of venting can give significant mass reductions. It is also shown that actively controlling the venting based on the landing scenario can further enhance the performance of vented airbags.

  7. Improved inflatable landing systems for low cost planetary landers

    NASA Astrophysics Data System (ADS)

    Northey, Dave; Morgan, Chris

    2003-11-01

    Inflatable landing systems have been traditionally perceived as a cost-effective solution to the problem of landing a spacecraft on a planetary surface. To date the systems used have all employed the approach of surrounding the lander with non-vented airbags where the lander bounces on impact a number of times until the impact energy is dissipated. However the reliability record of such systems is not at all good. This paper examines the problems involved in the use of non-vented airbags, and how these problems have been overcome by the use of vented airbags in terrestrial systems. Using a specific case study, it is shown that even the basic passive type of venting can give significant mass reductions. It is also shown that actively controlling the venting based on the landing scenario can further enhance the performance of vented airbags.

  8. Space Propulsion Technology Program Overview

    NASA Technical Reports Server (NTRS)

    Escher, William J. D.

    1991-01-01

    The topics presented are covered in viewgraph form. Focused program elements are: (1) transportation systems, which include earth-to-orbit propulsion, commercial vehicle propulsion, auxiliary propulsion, advanced cryogenic engines, cryogenic fluid systems, nuclear thermal propulsion, and nuclear electric propulsion; (2) space platforms, which include spacecraft on-board propulsion, and station keeping propulsion; and (3) technology flight experiments, which include cryogenic orbital N2 experiment (CONE), SEPS flight experiment, and cryogenic orbital H2 experiment (COHE).

  9. On-Line Smiles: Does Gender Make a Difference in the Use of Graphic Accents?

    ERIC Educational Resources Information Center

    Witmer, Diane; Katzman, Sandra

    1997-01-01

    Examines whether it is possible to determine the gender of a message sender from cues in the message. Finds partial support for the hypothesis that women use more graphic accents than men do in their computer-mediated communication. Finds also that women tend to challenge and "flame" more than men. Discusses implications and poses…

  10. Design and Sizing of the Air Revitalization System for Altair Lunar Lander

    NASA Technical Reports Server (NTRS)

    Allada, Rama Kumar

    2009-01-01

    Designing closed-loop Air Revitalization Systems (ARS) for human spaceflight applications requires a delicate balance between designing for system robustness while minimizing system power and mass requirements. This presentation will discuss the design of the ARS for the Altair Lunar Lander. The presentation will illustrate how dynamic simulations, using Aspen Custom Modeler, were used to develop a system configuration with the ability to control atmospheric conditions under a wide variety of circumstances while minimizing system mass/volume and the impact on overall power requirements for the Lander architecture.

  11. The Ion Propulsion System for the Solar Electric Propulsion Technology Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Herman, Daniel A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard R.; Parker, J. Morgan

    2015-01-01

    The Asteroid Redirect Robotic Mission is a candidate Solar Electric Propulsion Technology Demonstration Mission whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a companion human-crewed mission. The ion propulsion system must be capable of operating over an 8-year time period and processing up to 10,000 kg of xenon propellant. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as a critical part of an affordable, beyond-low-Earth-orbit, manned-exploration architecture. Under the NASA Space Technology Mission Directorate the critical electric propulsion and solar array technologies are being developed. The ion propulsion system being co-developed by the NASA Glenn Research Center and the Jet Propulsion Laboratory for the Asteroid Redirect Vehicle is based on the NASA-developed 12.5 kW Hall Effect Rocket with Magnetic Shielding (HERMeS0 thruster and power processing technologies. This paper presents the conceptual design for the ion propulsion system, the status of the NASA in-house thruster and power processing activity, and an update on flight hardware.

  12. NPDES Permit for Wesco Operating, Inc., Lander Field in Wyoming

    EPA Pesticide Factsheets

    Indian Country, Minor, indust., non-discharge, permit WY-0000221 Wesco Operating, Inc., is directed to have no discharge from the Lander Field NW Discharge oil production site in Fremont County, Wyoming.

  13. Effects of Strength of Accent on an L2 Interactive Lecture Listening Comprehension Test

    ERIC Educational Resources Information Center

    Ockey, Gary J.; Papageorgiou, Spiros; French, Robert

    2016-01-01

    This article reports on a study which aimed to determine the effect of strength of accent on listening comprehension of interactive lectures. Test takers (N = 21,726) listened to an interactive lecture given by one of nine speakers and responded to six comprehension items. The test taker responses were analyzed with the Rasch computer program…

  14. Electric Propulsion Requirements and Mission Analysis Under NASA's In-Space Propulsion Technology Project

    NASA Technical Reports Server (NTRS)

    Dudzinski, Leonard a.; Pencil, Eric J.; Dankanich, John W.

    2007-01-01

    The In-Space Propulsion Technology Project (ISPT) is currently NASA's sole investment in electric propulsion technologies. This project is managed at NASA Glenn Research Center (GRC) for the NASA Headquarters Science Mission Directorate (SMD). The objective of the electric propulsion project area is to develop near-term and midterm electric propulsion technologies to enhance or enable future NASA science missions while minimizing risk and cost to the end user. Systems analysis activities sponsored by ISPT seek to identify future mission applications in order to quantify mission requirements, as well as develop analytical capability in order to facilitate greater understanding and application of electric propulsion and other propulsion technologies in the ISPT portfolio. These analyses guide technology investments by informing decisions and defining metrics for technology development to meet identified mission requirements. This paper discusses the missions currently being studied for electric propulsion by the ISPT project, and presents the results of recent electric propulsion (EP) mission trades. Recent ISPT systems analysis activities include: an initiative to standardize life qualification methods for various electric propulsion systems in order to retire perceived risk to proposed EP missions; mission analysis to identify EP requirements from Discovery, New Frontiers, and Flagship classes of missions; and an evaluation of system requirements for radioisotope-powered electric propulsion. Progress and early results of these activities is discussed where available.

  15. Solar Thermal Propulsion Concept

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Harnessing the Sun's energy through Solar Thermal Propulsion will propel vehicles through space by significantly reducing weight, complexity, and cost while boosting performance over current conventional upper stages. Another solar powered system, solar electric propulsion, demonstrates ion propulsion is suitable for long duration missions. Pictured is an artist's concept of space flight using solar thermal propulsion.

  16. The Meteorological Experiment on the Mars Surveyor '98 Polar Lander

    NASA Technical Reports Server (NTRS)

    Crisp, D.

    1999-01-01

    When it lands on Mars on December 3, 1999, the Mars Surveyor '98 Mars Polar Lander (MPL) will provide the first opportunity to make in-situ measurements of the near-surface weather climate, and volatile inventory in the Martian south polar region. To make the most of this opportunity, the MPL's Mars Volatiles and Climate Surveyor (MVACS) payload includes the most comprehensive complement of meteorological instruments ever sent to Mars. Like the Viking and the Mars Pathfinder Lander, the MVACS Meteorological (Met) package includes sensors for measuring atmospheric pressures, temperatures, and wind velocities. This payload also includes a 2-channel tunable diode laser spectrometer for in-situ measurements of the atmospheric water vapor abundance near the ground, and improved instruments for measuring the relative abundances of oxygen isotopes (in water vapor and CO2) and a surface temperature probe for measuring the surface and sub-surface temperatures. This presentation will provide a brief overview of the environmental conditions anticipated at the surface in the Martian regions. We will then provide an over-view of the MVACS Met instrument and describe the MET sensors in detail, including their principle of operation, range, resolution, accuracy, sampling strategy, heritage, accommodation on the Lander, and their control and data handling system. Finally, we will describe the operational sequences, resource requirements, and the anticipated data volumes for each of the Met instruments.

  17. Status of Propulsion Technology Development Under the NASA In-space Propulsion Technology Program

    NASA Technical Reports Server (NTRS)

    Anderson, David; Kamhawi, Hani; Patterson, Mike; Dankanich, John; Pencil, Eric; Pinero, Luis

    2014-01-01

    Since 2001, the In-Space Propulsion Technology (ISPT) program has been developing and delivering in-space propulsion technologies for NASA's Science Mission Directorate (SMD). These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, Flagship and sample return missions currently under consideration. The ISPT program is currently developing technology in three areas that include Propulsion System Technologies, Entry Vehicle Technologies, and Systems Mission Analysis. ISPT's propulsion technologies include: 1) the 0.6-7 kW NASA's Evolutionary Xenon Thruster (NEXT) gridded ion propulsion system; 2) a 0.3-3.9kW Hall-effect electric propulsion (HEP) system for low cost and sample return missions; 3) the Xenon Flow Control Module (XFCM); 4) ultra-lightweight propellant tank technologies (ULTT); and 5) propulsion technologies for a Mars Ascent Vehicle (MAV). The HEP system is composed of the High Voltage Hall Accelerator (HiVHAc) thruster, a power processing unit (PPU), and the XFCM. NEXT and the HiVHAc are throttle-able electric propulsion systems for planetary science missions. The XFCM and ULTT are two component technologies which being developed with nearer-term flight infusion in mind. Several of the ISPT technologies are related to sample return missions needs like: MAV propulsion and electric propulsion. And finally, one focus of the SystemsMission Analysis area is developing tools that aid the application or operation of these technologies on wide variety of mission concepts. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness.

  18. Propulsion for CubeSats

    NASA Astrophysics Data System (ADS)

    Lemmer, Kristina

    2017-05-01

    At present, very few CubeSats have flown in space featuring propulsion systems. Of those that have, the literature is scattered, published in a variety of formats (conference proceedings, contractor websites, technical notes, and journal articles), and often not available for public release. This paper seeks to collect the relevant publically releasable information in one location. To date, only two missions have featured propulsion systems as part of the technology demonstration. The IMPACT mission from the Aerospace Corporation launched several electrospray thrusters from Massachusetts Institute of Technology, and BricSAT-P from the United States Naval Academy had four micro-Cathode Arc Thrusters from George Washington University. Other than these two missions, propulsion on CubeSats has been used only for attitude control and reaction wheel desaturation via cold gas propulsion systems. As the desired capability of CubeSats increases, and more complex missions are planned, propulsion is required to accomplish the science and engineering objectives. This survey includes propulsion systems that have been designed specifically for the CubeSat platform and systems that fit within CubeSat constraints but were developed for other platforms. Throughout the survey, discussion of flight heritage and results of the mission are included where publicly released information and data have been made available. Major categories of propulsion systems that are in this survey are solar sails, cold gas propulsion, electric propulsion, and chemical propulsion systems. Only systems that have been tested in a laboratory or with some flight history are included.

  19. Listening to Accented Speech in a Second Language: First Language and Age of Acquisition Effects

    ERIC Educational Resources Information Center

    Larraza, Saioa; Samuel, Arthur G.; Oñederra, Miren Lourdes

    2016-01-01

    Bilingual speakers must acquire the phonemic inventory of 2 languages and need to recognize spoken words cross-linguistically; a demanding job potentially made even more difficult due to dialectal variation, an intrinsic property of speech. The present work examines how bilinguals perceive second language (L2) accented speech and where…

  20. The Ion Propulsion System for the Solar Electric Propulsion Technology Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Herman, Daniel A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard; Parker, J. Morgan

    2015-01-01

    The Asteroid Redirect Robotic Mission is a candidate Solar Electric Propulsion Technology Demonstration Mission whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a subsequent human-crewed mission. The ion propulsion subsystem must be capable of operating over an 8-year time period and processing up to 10,000 kg of xenon propellant. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as an enabling element of an affordable beyond low-earth orbit human-crewed exploration architecture. Under the NASA Space Technology Mission Directorate the critical electric propulsion and solar array technologies are being developed. The ion propulsion system for the Asteroid Redirect Vehicle is based on the NASA-developed 12.5 kW Hall Effect Rocket with Magnetic Shielding thruster and power processing technologies. This paper presents the conceptual design for the ion propulsion system, a status on the NASA in-house thruster and power processing is provided, and an update on acquisition for flight provided.

  1. Viking Lander: subsurface water analyzing probe. [Mars subsoil

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Simmons, G.J.

    1969-10-01

    A small terradynamic (soil penetrating) vehicle, to be released from the Viking Lander at an altitude of between 5000 and 6000 feet before the terminal descent on the vernier rockets begins, will implant a sensor package 3 to 5 feet beneath the surface to measure water content of Mars subsoil. As it penetrates the soil, the vehicle separates into a probe which carries the primary instrumentation and a tail section which contains the power supply, secondary sensors, and transmitter and antenna assembly. The two sections remain linked by a hard wire umbilical which provides for power and data flow betweenmore » the sections. After impact, a soil moisture subsystem would be activated to gather approximately 100 milligrams of soil at the depth of the penetrating probe. After the mass of the sample is measured, its water content would be determined by heating in a sealed known volume and measuring the dew point of the resulting water vapor with a specular reflection dew point indicator. The penetrating probe and the tail section each contain a pair of aluminum oxide hygrometer elements and one sensistor temperature sensor which, on request by an on-board programmer will measure temperature and absolute water content of the vapor phase in equilibrium with the surrounding soil. Once each 8 hours, the digitized output of the sensors would be transmitted by the RF link to the Lander. This apparatus is expected to measure the water vapor in equilibrium with the soil water in concentrations as low as 0.01 microgram per liter at --60/sup 0/C and absolute soil water in amounts as small as 10 micrograms per gram of soil. A radioisotope power supply would provide an expected life for this instrumentation package in excess of the proposed 90-day mission for the Mars Viking Lander.« less

  2. Lowering Back Shell onto Stowed InSight Lander

    NASA Image and Video Library

    2015-05-27

    In this photo, the back shell of NASA's InSight spacecraft is being lowered onto the mission's lander, which is folded into its stowed configuration. The back shell and a heat shield form the aeroshell, which will protect the lander as the spacecraft plunges into the upper atmosphere of Mars. The photo was taken on April 29, 2015, in a spacecraft assembly clean room at Lockheed Martin Space Systems, Denver. InSight, for Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport, is scheduled for launch in March 2016 and landing in September 2016. It will study the deep interior of Mars to advance understanding of the early history of all rocky planets, including Earth. Note: After thorough examination, NASA managers have decided to suspend the planned March 2016 launch of the Interior Exploration using Seismic Investigations Geodesy and Heat Transport (InSight) mission. The decision follows unsuccessful attempts to repair a leak in a section of the prime instrument in the science payload. http://photojournal.jpl.nasa.gov/catalog/PIA19666

  3. Compact Low Power DPU for Plasma Instrument LINA on the Russian Luna-Glob Lander

    NASA Astrophysics Data System (ADS)

    Schmidt, Walter; Riihelä, Pekka; Kallio, Esa

    2013-04-01

    The Swedish Institute for Space Physics in Kiruna is bilding a Lunar Ions and Neutrals Analyzer (LINA) for the Russian Luna-Glob lander mission and its orbiter, to be launched around 2016 [1]. The Finnish Meteorological Institute is responsible for designing and building the central data processing units (DPU) for both instruments. The design details were optimized to serve as demonstrator also for a similar instrument on the Jupiter mission JUICE. To accommodate the originally set short development time and to keep the design between orbiter and Lander as similar as possible, the DPU is built around two re-programmable flash-based FPGAs from Actel. One FPGA contains a public-domain 32-bit processor core identical for both Lander and orbiter. The other FPGA handles all interfaces to the spacecraft system and the detectors, somewhat different for both implementations. Monitoring of analog housekeeping data is implemented as an IP-core from Stellamar inside the interface FPGA, saving mass, volume and especially power while simplifying the radiation protection design. As especially on the Lander the data retention before transfer to the orbiter cannot be guaranteed under all conditions, the DPU includes a Flash-PROM containing several software versions and data storage capability. With the memory management implemented inside the interface FPGA, one of the serial links can also be used as test port to verify the system, load the initial software into the Flash-PROM and to control the detector hardware directly without support by the processor and a ready developed operating system and software. Implementation and performance details will be presented. Reference: [1] http://www.russianspaceweb.com/luna_glob_lander.html.

  4. Distributed Propulsion Vehicles

    NASA Technical Reports Server (NTRS)

    Kim, Hyun Dae

    2010-01-01

    Since the introduction of large jet-powered transport aircraft, the majority of these vehicles have been designed by placing thrust-generating engines either under the wings or on the fuselage to minimize aerodynamic interactions on the vehicle operation. However, advances in computational and experimental tools along with new technologies in materials, structures, and aircraft controls, etc. are enabling a high degree of integration of the airframe and propulsion system in aircraft design. The National Aeronautics and Space Administration (NASA) has been investigating a number of revolutionary distributed propulsion vehicle concepts to increase aircraft performance. The concept of distributed propulsion is to fully integrate a propulsion system within an airframe such that the aircraft takes full synergistic benefits of coupling of airframe aerodynamics and the propulsion thrust stream by distributing thrust using many propulsors on the airframe. Some of the concepts are based on the use of distributed jet flaps, distributed small multiple engines, gas-driven multi-fans, mechanically driven multifans, cross-flow fans, and electric fans driven by turboelectric generators. This paper describes some early concepts of the distributed propulsion vehicles and the current turboelectric distributed propulsion (TeDP) vehicle concepts being studied under the NASA s Subsonic Fixed Wing (SFW) Project to drastically reduce aircraft-related fuel burn, emissions, and noise by the year 2030 to 2035.

  5. Lander and rover exploration on the lunar surface: A study for SELENE-B mission

    NASA Astrophysics Data System (ADS)

    Selene-B Rover Science Group; Sasaki, S.; Sugihara, T.; Saiki, K.; Akiyama, H.; Ohtake, M.; Takeda, H.; Hasebe, N.; Kobayashi, M.; Haruyama, J.; Shirai, K.; Kato, M.; Kubota, T.; Kunii, Y.; Kuroda, Y.

    The SELENE-B, a lunar landing mission, has been studied in Japan, where a scientific investigation plan is proposed using a robotic rover and a static lander. The main theme to be investigated is to clarify the lunar origin and evolution, especially for early crustal formation process probably from the ancient magma ocean. The highest priority is placed on a direct in situ geology at a crater central peak, “a window to the interior”, where subcrustal materials are exposed and directly accessed without drilling. As a preliminary study was introduced by Sasaki et al. [Sasaki, S., Kubota, T., Okada, T. et al. Scientific exploration of lunar surface using a rover in Japanse future lunar mission. Adv. Space Res. 30, 1921 1926, 2002.], the rover and lander are jointly used, where detailed analyses of the samples collected by the rover are conducted at the lander. Primary scientific instruments are a multi-band stereo imager, a gamma-ray spectrometer, and a sampling tool on the rover, and a multi-spectral telescopic imager, a sampling system, and a sample analysis package with an X-ray spectrometer/diffractometer, a multi-band microscope as well as a sample cleaning and grinding device on the lander.

  6. Electric Propulsion Applications and Impacts

    NASA Technical Reports Server (NTRS)

    Curran, Frank M.; Wickenheiser, Timothy J.

    1996-01-01

    Most space missions require on-board propulsion systems and these systems are often dominant spacecraft mass drivers. Presently, on-board systems account for more than half the injected mass for commercial communications systems and even greater mass fractions for ambitious planetary missions. Anticipated trends toward the use of both smaller spacecraft and launch vehicles will likely increase pressure on the performance of on-board propulsion systems. The acceptance of arcjet thrusters for operational use on commercial communications satellites ushered in a new era in on-board propulsion and exponential growth of electric propulsion across a broad spectrum of missions is anticipated. NASA recognizes the benefits of advanced propulsion and NASA's Office of Space Access and Technology supports an aggressive On-Board Propulsion program, including a strong electric propulsion element, to assure the availability of high performance propulsion systems to meet the goals of the ambitious missions envisioned in the next two decades. The program scope ranges from fundamental research for future generation systems through specific insertion efforts aimed at near term technology transfer. The On-Board propulsion program is committed to carrying technologies to levels required for customer acceptance and emphasizes direct interactions with the user community and the development of commercial sources. This paper provides a discussion of anticipated missions, propulsion functions, and electric propulsion impacts followed by an overview of the electric propulsion element of the NASA On-Board Propulsion program.

  7. Lunar Sample Return Missions Using a Tele-Robotic Lander

    NASA Astrophysics Data System (ADS)

    Downes, H.; Crawford, I. A.; Alexander, L.

    2018-02-01

    Deep Space Gateway would allow tele-robotic landers and rovers to access regions of the Moon which have not been previously sampled. Scientific questions, e.g., the nature and duration of volcanic activity and the composition of the mantle/lower crust, could be addressed.

  8. Cold Helium Gas Pressurization For Spacecraft Cryogenic Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Morehead, Robert L.; Atwell. Matthew J.; Hurlbert, Eric A.; Melcher, J. C.

    2017-01-01

    To reduce the dry mass of a spacecraft pressurization system, helium pressurant may be stored at low temperature and high pressure to increase mass in a given tank volume. Warming this gas through an engine heat exchanger prior to tank pressurization both increases the system efficiency and simplifies the designs of intermediate hardware such as regulators, valves, etc. since the gas is no longer cryogenic. If this type of cold helium pressurization system is used in conjunction with a cryogenic propellant, though, a loss in overall system efficiency can be expected due to heat transfer from the warm ullage gas to the cryogenic propellant which results in a specific volume loss for the pressurant, interpreted as the Collapse Factor. Future spacecraft with cryogenic propellants will likely have a cold helium system, with increasing collapse factor effects as vehicle sizes decrease. To determine the collapse factor effects and overall implementation strategies for a representative design point, a cold helium system was hotfire tested on the Integrated Cryogenic Propulsion Test Article (ICPTA) in a thermal vacuum environment at the NASA Glenn Research Center Plum Brook Station. The ICPTA vehicle is a small lander-sized spacecraft prototype built at NASA Johnson Space Center utilizing cryogenic liquid oxygen/liquid methane propellants and cryogenic helium gas as a pressurant to operate one 2,800lbf 5:1 throttling main engine, two 28lbf Reaction Control Engines (RCE), and two 7lbf RCEs (Figure 1). This vehicle was hotfire tested at a variety of environmental conditions at NASA Plum Brook, ranging from ambient temperature/simulated high altitude, deep thermal/high altitude, and deep thermal/high vacuum conditions. A detailed summary of the vehicle design and testing campaign may be found in Integrated Cryogenic Propulsion Test Article Thermal Vacuum Hotfire Testing, AIAA JPC 2017.

  9. Status of Propulsion Technology Development Under the NASA In-Space Propulsion Technology Program

    NASA Technical Reports Server (NTRS)

    Anderson, David; Kamhawi, Hani; Patterson, Mike; Pencil, Eric; Pinero, Luis; Falck, Robert; Dankanich, John

    2014-01-01

    Since 2001, the In-Space Propulsion Technology (ISPT) program has been developing and delivering in-space propulsion technologies for NASA's Science Mission Directorate (SMD). These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, Flagship and sample return missions currently under consideration. The ISPT program is currently developing technology in three areas that include Propulsion System Technologies, Entry Vehicle Technologies, and Systems/Mission Analysis. ISPT's propulsion technologies include: 1) the 0.6-7 kW NASA's Evolutionary Xenon Thruster (NEXT) gridded ion propulsion system; 2) a 0.3-3.9kW Halleffect electric propulsion (HEP) system for low cost and sample return missions; 3) the Xenon Flow Control Module (XFCM); 4) ultra-lightweight propellant tank technologies (ULTT); and 5) propulsion technologies for a Mars Ascent Vehicle (MAV). The NEXT Long Duration Test (LDT) recently exceeded 50,000 hours of operation and 900 kg throughput, corresponding to 34.8 MN-s of total impulse delivered. The HEP system is composed of the High Voltage Hall Accelerator (HIVHAC) thruster, a power processing unit (PPU), and the XFCM. NEXT and the HIVHAC are throttle-able electric propulsion systems for planetary science missions. The XFCM and ULTT are two component technologies which being developed with nearer-term flight infusion in mind. Several of the ISPT technologies are related to sample return missions needs: MAV propulsion and electric propulsion. And finally, one focus of the Systems/Mission Analysis area is developing tools that aid the application or operation of these technologies on wide variety of mission concepts. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness.

  10. Prospects of passive radio detection of a subsurface ocean on Europa with a lander

    NASA Astrophysics Data System (ADS)

    Romero-Wolf, Andrew; Schroeder, Dustin M.; Ries, Paul; Bills, Bruce G.; Naudet, Charles; Scott, Bryan R.; Treuhaft, Robert; Vance, Steve

    2016-09-01

    We estimate the sensitivity of a lander-based instrument for the passive radio detection of a subsurface ocean beneath the ice shell of Europa, expected to be between 3 km and 30 km thick, using Jupiter's decametric radiation. A passive technique was previously studied for an orbiter. Using passive detection in a lander platform provides a point measurement with significant improvements due to largely reduced losses from surface roughness effects, longer integration times, and diminished dispersion due to ionospheric effects allowing operation at lower frequencies and a wider band. A passive sounder on-board a lander provides a low resource instrument sensitive to subsurface ocean at Europa up to depths of 6.9 km for high loss ice (16 dB/km two-way attenuation rate) and 69 km for pure ice (1.6 dB/km).

  11. Centralized versus distributed propulsion

    NASA Technical Reports Server (NTRS)

    Clark, J. P.

    1982-01-01

    The functions and requirements of auxiliary propulsion systems are reviewed. None of the three major tasks (attitude control, stationkeeping, and shape control) can be performed by a collection of thrusters at a single central location. If a centralized system is defined as a collection of separated clusters, made up of the minimum number of propulsion units, then such a system can provide attitude control and stationkeeping for most vehicles. A distributed propulsion system is characterized by more numerous propulsion units in a regularly distributed arrangement. Various proposed large space systems are reviewed and it is concluded that centralized auxiliary propulsion is best suited to vehicles with a relatively rigid core. These vehicles may carry a number of flexible or movable appendages. A second group, consisting of one or more large flexible flat plates, may need distributed propulsion for shape control. There is a third group, consisting of vehicles built up from multiple shuttle launches, which may be forced into a distributed system because of the need to add additional propulsion units as the vehicles grow. The effects of distributed propulsion on a beam-like structure were examined. The deflection of the structure under both translational and rotational thrusts is shown as a function of the number of equally spaced thrusters. When two thrusters only are used it is shown that location is an important parameter. The possibility of using distributed propulsion to achieve minimum overall system weight is also examined. Finally, an examination of the active damping by distributed propulsion is described.

  12. Fine particles on mars: Observations with the viking 1 lander cameras

    USGS Publications Warehouse

    Mutch, T.A.; Arvidson, R. E.; Binder, A.B.; Huck, F.O.; Levinthal, E.C.; Liebes, S.; Morris, E.C.; Nummedal, D.; Pollack, James B.; Sagan, C.

    1976-01-01

    Drifts of fine-grained sediment are present in the vicinity of the Viking 1 lander. Many drifts occur in the lees of large boulders. Morphologic analysis indicates that the last dynamic event was one of general deflation for at least some drifts. Particle cohesion implies that there is a distinct small-particle upturn in the threshold velocity-particle size curve; the apparent absence of the most easily moved particles (150 micrometers in diameter) may be due to their preferential transport to other regions or their preferential collisional destruction. A twilight rescan with lander cameras indicates a substantial amount of red dust with mean radius on the order of 1 micrometer in the atmosphere.

  13. Fine particles on Mars: observations with the viking 1 lander cameras.

    PubMed

    Mutch, T A; Arvidson, R E; Binder, A B; Huck, F O; Levinthal, E C; Liebes, S; Morris, E C; Nummedal, D; Pollack, J B; Sagan, C

    1976-10-01

    Drifts of fine-grained sediment are present in the vicinity of the Viking 1 lander. Many drifts occur in the lees of large boulders. Morphologic analysis indicates that the last dynamic event was one of general deflation for at least some drifts. Particle cohesion implies that there is a distinct small-particle upturn in the threshold velocity-particle size curve; the apparent absence of the most easily moved particles (150 micrometers in diameter) may be due to their preferential transport to other regions or their preferential collisional destruction. A twilight rescan with lander cameras indicates a substantial amount of red dust with mean radius on the order of 1 micrometer in the atmosphere.

  14. Seismicity remotely triggered by the magnitude 7.3 landers, california, earthquake

    USGS Publications Warehouse

    Hill, D.P.; Reasenberg, P.A.; Michael, A.; Arabaz, W.J.; Beroza, G.; Brumbaugh, D.; Brune, J.N.; Castro, R.; Davis, S.; Depolo, D.; Ellsworth, W.L.; Gomberg, J.; Harmsen, S.; House, L.; Jackson, S.M.; Johnston, M.J.S.; Jones, L.; Keller, Rebecca Hylton; Malone, S.; Munguia, L.; Nava, S.; Pechmann, J.C.; Sanford, A.; Simpson, R.W.; Smith, R.B.; Stark, M.; Stickney, M.; Vidal, A.; Walter, S.; Wong, V.; Zollweg, J.

    1993-01-01

    The magnitude 7.3 Landers earthquake of 28 June 1992 triggered a remarkably sudden and widespread increase in earthquake activity across much of the western United States. The triggered earthquakes, which occurred at distances up to 1250 kilometers (17 source dimensions) from the Landers mainshock, were confined to areas of persistent seismicity and strike-slip to normal faulting. Many of the triggered areas also are sites of geothermal and recent volcanic activity. Static stress changes calculated for elastic models of the earthquake appear to be too small to have caused the triggering. The most promising explanations involve nonlinear interactions between large dynamic strains accompanying seismic waves from the mainshock and crustal fluids (perhaps including crustal magma).

  15. Thermoacoustic Duplex Technology for Cooling and Powering a Venus Lander

    NASA Astrophysics Data System (ADS)

    Walker, A. R.; Haberbusch, M. S.; Sasson, J.

    2015-04-01

    A Thermoacoustic Stirling Heat Engine (TASHE) is directly coupled to a Pulse Tube Refrigerator (PTR) in a duplex configuration, providing simultaneous cooling and electrical power, thereby suiting the needs of a long-lived Venus lander.

  16. Poro-elastic Rebound Along the Landers 1992 Earthquake Surface Rupture

    NASA Technical Reports Server (NTRS)

    Peltzer, G.; Rosen, P.; Rogez, F.; Hudnut, K.

    1998-01-01

    Maps of post-seismic surface displacement after the 1992, Landers, California earthquake, generated by interferometric processing of ERS-1 Synthetic Aperture Radar (SAR) images, reveal effects of various deformation processes near the 1992 surface rupture.

  17. Identification of propulsion systems

    NASA Technical Reports Server (NTRS)

    Merrill, Walter; Guo, Ten-Huei; Duyar, Ahmet

    1991-01-01

    This paper presents a tutorial on the use of model identification techniques for the identification of propulsion system models. These models are important for control design, simulation, parameter estimation, and fault detection. Propulsion system identification is defined in the context of the classical description of identification as a four step process that is unique because of special considerations of data and error sources. Propulsion system models are described along with the dependence of system operation on the environment. Propulsion system simulation approaches are discussed as well as approaches to propulsion system identification with examples for both air breathing and rocket systems.

  18. Coordination and propulsion and non-propulsion phases in 100 meter breaststroke swimming.

    PubMed

    Strzała, Marek; Krężałek, Piotr; Kucia-Czyszczoń, Katarzyna; Ostrowski, Andrzej; Stanula, Arkadiusz; Tyka, Anna K; Sagalara, Andrzej

    2014-01-01

    The main purpose of this study was to analyze the coordination, propulsion and non-propulsion phases in the 100 meter breaststroke race. Twenty-seven male swimmers (15.7 ± 1.98 years old) with the total body length (TBL) of 247.0 ± 10.60 [cm] performed an all-out 100 m breaststroke bout. The bouts were recorded with an underwater camera installed on a portable trolley. The swimming kinematic parameters, stroke rate (SR) and stroke length (SL), as well as the coordination indices based on propulsive or non-propulsive movement phases of the arms and legs were distinguished. Swimming speed (V100surface breast) was associated with SL (R = 0.41, p < 0.05) and with TBL tending towards statistical significance (R = 0.36, p < 0.07), all relationships between the selected variables in the study were measured using partial correlations with controlled age. SL interplayed negatively with the limbs propulsive phase Overlap indicator (R = -0.46, p < 0.05), but had no significant relationship to the non-propulsion Glide indicator. The propulsion in-sweep (AP3) phase of arms and their non-propulsion partial air recovery (ARair) phase interplayed with V100surface breast (R = 0.51, p < 0.05 and 0.48 p < 0.05) respectively, displaying the importance of proper execution of this phase (AP3) and in reducing the resistance recovery phases in consecutive ones.

  19. Chemistry Lab for Phoenix Mars Lander

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The science payload of NASA's Phoenix Mars Lander includes a multi-tool instrument named the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The instrument's wet chemistry laboratory, prominent in this photograph, will measure a range of chemical properties of Martian soil samples, such as the presence of dissolved salts and the level of acidity or alkalinity. Other tools that are parts of the instrument are microscopes that will examine samples' mineral grains and a probe that will check the soil's thermal and electrical properties.

  20. A stereo-vision hazard-detection algorithm to increase planetary lander autonomy

    NASA Astrophysics Data System (ADS)

    Woicke, Svenja; Mooij, Erwin

    2016-05-01

    For future landings on any celestial body, increasing the lander autonomy as well as decreasing risk are primary objectives. Both risk reduction and an increase in autonomy can be achieved by including hazard detection and avoidance in the guidance, navigation, and control loop. One of the main challenges in hazard detection and avoidance is the reconstruction of accurate elevation models, as well as slope and roughness maps. Multiple methods for acquiring the inputs for hazard maps are available. The main distinction can be made between active and passive methods. Passive methods (cameras) have budgetary advantages compared to active sensors (radar, light detection and ranging). However, it is necessary to proof that these methods deliver sufficiently good maps. Therefore, this paper discusses hazard detection using stereo vision. To facilitate a successful landing not more than 1% wrong detections (hazards that are not identified) are allowed. Based on a sensitivity analysis it was found that using a stereo set-up at a baseline of ≤ 2 m is feasible at altitudes of ≤ 200 m defining false positives of less than 1%. It was thus shown that stereo-based hazard detection is an effective means to decrease the landing risk and increase the lander autonomy. In conclusion, the proposed algorithm is a promising candidate for future landers.

  1. Electrolysis Propulsion for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    deGroot, Wim A.; Arrington, Lynn A.; McElroy, James F.; Mitlitsky, Fred; Weisberg, Andrew H.; Carter, Preston H., II; Myers, Blake; Reed, Brian D.

    1997-01-01

    Electrolysis propulsion has been recognized over the last several decades as a viable option to meet many satellite and spacecraft propulsion requirements. This technology, however, was never used for in-space missions. In the same time frame, water based fuel cells have flown in a number of missions. These systems have many components similar to electrolysis propulsion systems. Recent advances in component technology include: lightweight tankage, water vapor feed electrolysis, fuel cell technology, and thrust chamber materials for propulsion. Taken together, these developments make propulsion and/or power using electrolysis/fuel cell technology very attractive as separate or integrated systems. A water electrolysis propulsion testbed was constructed and tested in a joint NASA/Hamilton Standard/Lawrence Livermore National Laboratories program to demonstrate these technology developments for propulsion. The results from these testbed experiments using a I-N thruster are presented. A concept to integrate a propulsion system and a fuel cell system into a unitized spacecraft propulsion and power system is outlined.

  2. When one person's mistake is another's standard usage: the effect of foreign accent on syntactic processing.

    PubMed

    Hanulíková, Adriana; van Alphen, Petra M; van Goch, Merel M; Weber, Andrea

    2012-04-01

    How do native listeners process grammatical errors that are frequent in non-native speech? We investigated whether the neural correlates of syntactic processing are modulated by speaker identity. ERPs to gender agreement errors in sentences spoken by a native speaker were compared with the same errors spoken by a non-native speaker. In line with previous research, gender violations in native speech resulted in a P600 effect (larger P600 for violations in comparison with correct sentences), but when the same violations were produced by the non-native speaker with a foreign accent, no P600 effect was observed. Control sentences with semantic violations elicited comparable N400 effects for both the native and the non-native speaker, confirming no general integration problem in foreign-accented speech. The results demonstrate that the P600 is modulated by speaker identity, extending our knowledge about the role of speaker's characteristics on neural correlates of speech processing.

  3. The Philae lander mission and science overview.

    PubMed

    Boehnhardt, Hermann; Bibring, Jean-Pierre; Apathy, Istvan; Auster, Hans Ulrich; Ercoli Finzi, Amalia; Goesmann, Fred; Klingelhöfer, Göstar; Knapmeyer, Martin; Kofman, Wlodek; Krüger, Harald; Mottola, Stefano; Schmidt, Walter; Seidensticker, Klaus; Spohn, Tilman; Wright, Ian

    2017-07-13

    The Philae lander accomplished the first soft landing and the first scientific experiments of a human-made spacecraft on the surface of a comet. Planned, expected and unexpected activities and events happened during the descent, the touch-downs, the hopping across and the stay and operations on the surface. The key results were obtained during 12-14 November 2014, at 3 AU from the Sun, during the 63 h long period of the descent and of the first science sequence on the surface. Thereafter, Philae went into hibernation, waking up again in late April 2015 with subsequent communication periods with Earth (via the orbiter), too short to enable new scientific activities. The science return of the mission comes from eight of the 10 instruments on-board and focuses on morphological, thermal, mechanical and electrical properties of the surface as well as on the surface composition. It allows a first characterization of the local environment of the touch-down and landing sites. Unique conclusions on the organics in the cometary material, the nucleus interior, the comet formation and evolution became available through measurements of the Philae lander in the context of the Rosetta mission.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

  4. Integral design method for simple and small Mars lander system using membrane aeroshell

    NASA Astrophysics Data System (ADS)

    Sakagami, Ryo; Takahashi, Ryohei; Wachi, Akifumi; Koshiro, Yuki; Maezawa, Hiroyuki; Kasai, Yasko; Nakasuka, Shinichi

    2018-03-01

    To execute Mars surface exploration missions, spacecraft need to overcome the difficulties of the Mars entry, descent, and landing (EDL) sequences. Previous landing missions overcame these challenges with complicated systems that could only be executed by organizations with mature technology and abundant financial resources. In this paper, we propose a novel integral design methodology for a small, simple Mars lander that is achievable even by organizations with limited technology and resources such as universities or emerging countries. We aim to design a lander (including its interplanetary cruise stage) whose size and mass are under 1 m3 and 150 kg, respectively. We adopted only two components for Mars EDL process: a "membrane aeroshell" for the Mars atmospheric entry and descent sequence and one additional mechanism for the landing sequence. The landing mechanism was selected from the following three candidates: (1) solid thrusters, (2) aluminum foam, and (3) a vented airbag. We present a reasonable design process, visualize dependencies among parameters, summarize sizing methods for each component, and propose the way to integrate these components into one system. To demonstrate the effectiveness, we applied this methodology to the actual Mars EDL mission led by the National Institute of Information and Communications Technology (NICT) and the University of Tokyo. As a result, an 80 kg class Mars lander with a 1.75 m radius membrane aeroshell and a vented airbag was designed, and the maximum landing shock that the lander will receive was 115 G.

  5. Telecommunications Relay Support of the Mars Phoenix Lander Mission

    NASA Technical Reports Server (NTRS)

    Edwards, Charles D., Jr.; Erickson, James K.; Gladden, Roy E.; Guinn, Joseph R.; Ilott, Peter A.; Jai, Benhan; Johnston, Martin D.; Kornfeld, Richard P.; Martin-Mur, Tomas J.; McSmith, Gaylon W.; hide

    2010-01-01

    The Phoenix Lander, first of NASA's Mars Scout missions, arrived at the Red Planet on May 25, 2008. From the moment the lander separated from its interplanetary cruise stage shortly before entry, the spacecraft could no longer communicate directly with Earth, and was instead entirely dependent on UHF relay communications via an international network of orbiting Mars spacecraft, including NASA's 2001 Mars Odyssey (ODY) and Mars Reconnaissance Orbiter (MRO) spacecraft, as well as ESA's Mars Express (MEX) spacecraft. All three orbiters captured critical event telemetry and/or tracking data during Phoenix Entry, Descent and Landing. During the Phoenix surface mission, ODY and MRO provided command and telemetry services, far surpassing the original data return requirements. The availability of MEX as a backup relay asset enhanced the robustness of the surface relay plan. In addition to telecommunications services, Doppler tracking observables acquired on the UHF link yielded an accurate position for the Phoenix landing site.

  6. Lander rocket exhaust effects on Europa regolith nitrogen assays

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.

    2016-08-01

    Soft-landings on large worlds such as Europa or our Moon require near-surface retropropulsion, which leads to impingement of the rocket plume on the surface. Surface modification by such plumes was documented on Apollo and Surveyor, and on Mars by Viking, Curiosity and especially Phoenix. The low temperatures of the Europan regolith may lead to efficient trapping of ammonia, a principal component of the exhaust from monopropellant hydrazine thrusters. Deposited ammonia may react with any trace organics, and may overwhelm the chemical and isotopic signatures of any endogenous nitrogen compounds, which are likely rare on Europa. An empirical correlation of the photometrically-altered regions ('blast zones') around prior lunar and Mars landings is made, indicating A=0.02T1.5, where A is the area in m2 and W is the lander weight (thus, ~thrust) at landing in N: this suggests surface alteration will occur out to a distance of ~9 m from a 200 kg lander on Europa.

  7. The Boeing Delta II rocket with Mars Polar Lander aboard lifts off at Pad 17B, CCAS

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Amid clouds of exhaust, a Boeing Delta II expendable launch vehicle with NASA's Mars Polar Lander clears Launch Complex 17B, Cape Canaveral Air Station, after launch at 3:21:10 p.m. EST. The lander is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south polar cap, which consists of carbon dioxide ice. The lander will study the polar water cycle, frosts, water vapor, condensates and dust in the Martian atmosphere. It is equipped with a robotic arm to dig beneath the layered terrain at the polar cap. In addition, Deep Space 2 microprobes, developed by NASA's New Millennium Program, are installed on the lander's cruise stage. After crashing into the planet's surface, they will conduct two days of soil and water experiments up to 1 meter (3 feet) below the Martian surface, testing new technologies for future planetary descent probes. The lander is the second spacecraft to be launched in a pair of Mars Surveyor '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  8. The Boeing Delta II rocket with Mars Polar Lander aboard lifts off at Pad 17B, CCAS

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Silhouetted against the gray sky, a Boeing Delta II expendable launch vehicle with NASA's Mars Polar Lander lifts off from Launch Complex 17B, Cape Canaveral Air Station, at 3:21:10 p.m. EST. The lander is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south polar cap, which consists of carbon dioxide ice. The lander will study the polar water cycle, frosts, water vapor, condensates and dust in the Martian atmosphere. It is equipped with a robotic arm to dig beneath the layered terrain at the polar cap. In addition, Deep Space 2 microprobes, developed by NASA's New Millennium Program, are installed on the lander's cruise stage. After crashing into the planet's surface, they will conduct two days of soil and water experiments up to 1 meter (3 feet) below the Martian surface, testing new technologies for future planetary descent probes. The lander is the second spacecraft to be launched in a pair of Mars Surveyor '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  9. The Boeing Delta II rocket with Mars Polar Lander aboard lifts off at Pad 17B, CCAS

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Amid clouds of exhaust and into a gray-clouded sky , a Boeing Delta II expendable launch vehicle lifts off with NASA's Mars Polar Lander at 3:21:10 p.m. EST from Launch Complex 17B, Cape Canaveral Air Station. The lander is a solar-powered spacecraft designed to touch down on the Martian surface near the northern- most boundary of the south polar cap, which consists of carbon dioxide ice. The lander will study the polar water cycle, frosts, water vapor, condensates and dust in the Martian atmosphere. It is equipped with a robotic arm to dig beneath the layered terrain at the polar cap. In addition, Deep Space 2 microprobes, developed by NASA's New Millennium Program, are installed on the lander's cruise stage. After crashing into the planet's surface, they will conduct two days of soil and water experiments up to 1 meter (3 feet) below the Martian surface, testing new technologies for future planetary descent probes. The lander is the second spacecraft to be launched in a pair of Mars Surveyor '98 missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  10. The Boeing Delta II rocket with Mars Polar Lander aboard lifts off at Pad 17B, CCAS

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A Boeing Delta II expendable launch vehicle lifts off with NASA's Mars Polar Lander into a cloud-covered sky at 3:21:10 p.m. EST from Launch Complex 17B, Cape Canaveral Air Station. The lander is a solar-powered spacecraft designed to touch down on the Martian surface near the northern-most boundary of the south polar cap, which consists of carbon dioxide ice. The lander will study the polar water cycle, frosts, water vapor, condensates and dust in the Martian atmosphere. It is equipped with a robotic arm to dig beneath the layered terrain at the polar cap. In addition, Deep Space 2 microprobes, developed by NASA's New Millennium Program, are installed on the lander's cruise stage. After crashing into the planet's surface, they will conduct two days of soil and water experiments up to 1 meter (3 feet) below the Martian surface, testing new technologies for future planetary descent probes. The lander is the second spacecraft to be launched in a pair of Mars Surveyor '98missions. The first is the Mars Climate Orbiter, which was launched aboard a Delta II rocket from Launch Complex 17A on Dec. 11, 1998.

  11. Moon Express: Lander Capabilities and Initial Payload and Mission

    NASA Astrophysics Data System (ADS)

    Spudis, P.; Richards, R.; Burns, J. O.

    2013-12-01

    Moon Express Inc. is developing a common lander design to support the commercial delivery of a wide variety of possible payloads to the lunar surface. Significant recent progress has been made on lander design and configuration and a straw man mission concept has been designed to return significant new scientific and resource utilization data from the first mission. The Moon Express lander is derived from designs tested at NASA Ames Research Center over the past decade. The MX-1 version is designed to deliver 26 kg of payload to the lunar surface, with no global restrictions on landing site. The MX-2 lander can carry a payload of 400 kg and can deliver an upper stage (designed for missions that require Earth-return, such as sample retrieval) or a robotic rover. The Moon Express lander is powered by a specially designed engine capable of being operated in either monoprop or biprop mode. The concept for the first mission is a visit to a regional pyroclastic deposit on the lunar near side. We have focused on the Rima Bode dark mantle deposits (east of crater Copernicus, around 13 N, 4 W). These deposits are mature, having been exposed to solar wind for at least 3 Ga, and have high Ti content, suggesting high concentrations of implanted hydrogen. Smooth areas near the vent suggest that the ash beds are several tens of meters thick. The projected payload includes an imaging system to document the geological setting of the landing area, an APX instrument to provide major element composition of the regolith and a neutron spectrometer to measure the bulk hydrogen composition of the regolith at the landing site. Additionally, inclusion of a next generation laser retroreflector would markedly improve measurements of lunar librations and thus, constrain the dimensions of both the liquid and solid inner cores of the Moon, as well as provide tests of General Relativity. Conops are simple, with measurements of the surface composition commencing immediately upon landing. APX

  12. Winter frost at Viking Lander 2 site

    NASA Technical Reports Server (NTRS)

    Svitek, Thomas; Murray, Bruce

    1990-01-01

    This paper presents quantitative evidence for cold trapping (frost redeposition) at the Viking Lander 2 site. This evidence consists of the frost surface coverage and color transition, the timing of this transition, and the limited vertical mixing and horizontal water transport. It is argued that cold trapping must be a general property of seasonal frost and, therefore, must be considered in order to understand the evolution of the surface environment of Mars.

  13. Fine structure of the landers fault zone: Segmentation and the rupture process

    USGS Publications Warehouse

    Li, Y.-G.; Vidale, J.E.; Aki, K.; Marone, C.J.; Lee, W.H.K.

    1994-01-01

    Observations and modeling of 3- to 6-hertz seismic shear waves trapped within the fault zone of the 1992 Landers earthquake series allow the fine structure and continuity of the zone to be evaluated. The fault, to a depth of at least 12 kilometers, is marked by a zone 100 to 200 meters wide where shear velocity is reduced by 30 to 50 percent. This zone forms a seismic waveguide that extends along the southern 30 kilometers of the Landers rupture surface and ends at the fault bend about 18 kilometers north of the main shock epicenter. Another fault plane waveguide, disconnected from the first, exists along the northern rupture surface. These observations, in conjunction with surface slip, detailed seismicity patterns, and the progression of rupture along the fault, suggest that several simple rupture planes were involved in the Landers earthquake and that the inferred rupture front hesitated or slowed at the location where the rupture jumped from one to the next plane. Reduction in rupture velocity can tentatively be attributed to fault plane complexity, and variations in moment release can be attributed to variations in available energy.

  14. Ground simulation of wide frequency band angular vibration for Lander's optic sensors

    NASA Astrophysics Data System (ADS)

    Xing, Zhigang; Xiang, Jianwei; Zheng, Gangtie

    2017-11-01

    To guide a lander of Moon or Mars exploration spacecraft during the stage of descent onto a desired place, optic sensors have been chosen to take the task, which include optic cameras and laser distance meters. However, such optic sensors are sensitive to vibrations, especially angular vibrations, from the lander. To reduce the risk of abnormal function and ensure the performance of optic sensors, ground simulations are necessary. More importantly, the simulations can be used as a method for examining the sensor performance and finding possible improvement on the sensor design. In the present paper, we proposed an angular vibration simulation method during the landing. This simulation method has been realized into product and applied to optic sensor tests for the moon lander. This simulator can generate random angular vibration in a frequency range from 0 to 2000Hz, the control precision is +/-1dB, and the linear translational speed can be set to the required descent speed. The operation and data processing methods of this developed simulator are the same as a normal shake table. The analysis and design methods are studied in the present paper, and test results are also provided.

  15. Photogrammetry of the Viking-Lander imagery.

    USGS Publications Warehouse

    Wu, S.S.C.; Schafer, F.J.

    1982-01-01

    We have solved the problem of photogrammetric mapping from the Viking Lander photography in two ways: 1) by converting the azimuth and elevation scanning imagery to the equivalent of a frame picture by means of computerized rectification; and 2) by interfacing a high-speed, general-purpose computer to the AS-11A analytical plotter so that all computations of corrections can be performed in real time during the process of model orientation and map compilation. Examples are presented of photographs and maps of Earth and Mars. -from Authors

  16. InSight Lander Solar Array Test

    NASA Image and Video Library

    2018-01-23

    While in the landed configuration for the last time before arriving on Mars, NASA's InSight lander was commanded to deploy its solar arrays to test and verify the exact process that it will use on the surface of the Red Planet. During the test on Jan. 23, 2018 from the Lockheed Martin clean room in Littleton, Colorado, engineers and technicians evaluated that the solar arrays fully deployed and conducted an illumination test to confirm that the solar cells were collecting power. A video is available at https://photojournal.jpl.nasa.gov/catalog/PIA22200

  17. InSight Lander Solar Array Test

    NASA Image and Video Library

    2018-01-23

    While in the landed configuration for the last time before arriving on Mars, NASA's InSight lander was commanded to deploy its solar arrays to test and verify the exact process that it will use on the surface of the Red Planet. During the test on Jan. 23, 2018 from the Lockheed Martin clean room in Littleton, Colorado, engineers and technicians evaluated that the solar arrays fully deployed and conducted an illumination test to confirm that the solar cells were collecting power. A video is available at https://photojournal.jpl.nasa.gov/catalog/PIA22203

  18. InSight Lander Solar Array Test

    NASA Image and Video Library

    2018-01-23

    While in the landed configuration for the last time before arriving on Mars, NASA's InSight lander was commanded to deploy its solar arrays to test and verify the exact process that it will use on the surface of the Red Planet. During the test on Jan. 23, 2018 from the Lockheed Martin clean room in Littleton, Colorado, engineers and technicians evaluated that the solar arrays fully deployed and conducted an illumination test to confirm that the solar cells were collecting power. A video is available at https://photojournal.jpl.nasa.gov/catalog/PIA22202

  19. InSight Lander Solar Array Test

    NASA Image and Video Library

    2018-01-23

    While in the landed configuration for the last time before arriving on Mars, NASA's InSight lander was commanded to deploy its solar arrays to test and verify the exact process that it will use on the surface of the Red Planet. During the test on Jan. 23, 2018 from the Lockheed Martin clean room in Littleton, Colorado, engineers and technicians evaluated that the solar arrays fully deployed and conducted an illumination test to confirm that the solar cells were collecting power. A video is available at https://photojournal.jpl.nasa.gov/catalog/PIA22201

  20. InSight Lander Solar Array Test

    NASA Image and Video Library

    2018-01-23

    While in the landed configuration for the last time before arriving on Mars, NASA's InSight lander was commanded to deploy its solar arrays to test and verify the exact process that it will use on the surface of the Red Planet. During the test on Jan. 23, 2018 from the Lockheed Martin clean room in Littleton, Colorado, engineers and technicians evaluated that the solar arrays fully deployed and conducted an illumination test to confirm that the solar cells were collecting power. A video is available at https://photojournal.jpl.nasa.gov/catalog/PIA22204