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At least 361 records · Page 20

Managing Meetings...Remotely

Remote meetings are best for updates and information sharing, but it is possible to effectively facilitate decisions with a little planning. Generally, the meeting leader needs to clearly state the proposed decision and then separately poll each participant for concurrence. Normally, there will be a range of responses, requiring the facilitator to restate the proposal and repeat the process. Several iterations may be required before a consensus is achieved. I usually confirm decisions by restating the conclusion as it will appear in the meeting notes and asking the participants to express any objections. Gaining commitment to follow-up actions is never easy, of course, but tends to be particularly tricky in remote meetings. The ideal solution is to use collaboration software with a whiteboard as a means of recording the follow-up actions and responsibilities. (A Word or Excel document viewed through NetMeeting works equally well.) But if the meeting is being conducted without collaboration software, the leader must review each follow-up action explicitly, even painstakingly. I generally note follow-up actions throughout the meeting and use the last few minutes to confirm and finalize. I read each action and name the person I think owns the responsibility. When the person accepts, I validate by asking for a completion date. All the normal rules for assigning follow-up actions apply, of course. One, and only one, person must be responsible for each action, and assigning an action to somebody not present is akin to assigning it to nobody.

Woodward, Hugh↗

Let's Orbit Mars: A Proposal to Explore Mars Now

Mars is an exciting target for the human exploration; the next destination toward the ultimate human colonization of the solar system. But the price of proposed missions to Mars is a daunting barrier. Expensive missions make it a slow and difficult process to achieve the political consensus to make a commitment to exploration. In today's deficit-conscious era (and what era is not?), it is as difficult-- perhaps impossible-- task to justify to a skeptical and cost-conscious public the need to invest in exploration. It seems far too easy to postpone exploration into a future that never seems to arrive. It would be terrific to explore Mars in small steps, where each step makes progress toward human exploration and settlement, and each step also is not only exciting to the public, but also justifiable on its own scientific merits.

Landis, Geoffrey A.↗

Basic Research on the Composition of Heavy Cosmic Rays: The Trans-Iron Galactic Element Recorder Experiment (TIGER)

Among the most fundamental astrophysical problems is understanding the mechanism by which particles are accelerated to the enormous energies observed in the cosmic rays. That problem can be conveniently divided into two questions: (1) What is the source of the energy and the mechanism for converting the energy of that source into the energy of individual cosmic-ray nuclei, and (2) what is the source of the material that is accelerated and the mechanism for injecting that material into the cosmic-ray accelerator? There is a general consensus that the answer to the first of these questions, for nuclei with energy eV, is that the source of their energy is almost certainly from supernova explosions (e.g., Ginzburg & Syrovatskii, 1964). The answer to the second question is still uncertain, although evidence in favor of a superbubble origin of cosmic rays is becoming quite significant (Higdon et al, 2203 and Binns, 2005 (Submitted to ApJ). There are several ways of interpreting available data that lead to quite different models for the source of the material and its injection mechanism. With the The Trans-Iron Galactic Element Recorder Experiment (TIGER) instrument we have obtained data that will help to distinguish among these possible models. In the report, the TIGER flights, the instrument itself, results, and a publication list as a result of the work are presented.

Binns, W. Robert↗

The Plunge Phase of Friction Stir Welding

The many advantages of Friction Stir Welding have led to a relatively rapid acceptance in the often conservative welding community. Because the process is so different from traditional fusion welding, with which most investigators are most familiar, there remain many aspects of FSW for which there is no clear consensus. For example, the well known onion rings seen in transverse sections have been variously interpreted as grain size variations, variation in density of second phase particles and parts of the carousel of material rotating with the pin that have been shed from the carousel. Using Orientation Imaging Microscopy, Schneider has recently noted that the onion rings have a different orientation (and hence etch differently) than the surrounding material, and this orientation is consistent with slip plane orientations at the edge of the carousel. Likewise, the forces and torque exerted by the FSW tool on the work piece largely remain unaccounted for. Although these forces are routinely measured by investigators with commercial instrumented welders, they are rarely reported or even qualitatively analyzed. This paper will introduce a model based on a carousel or disk of material that rotates with the tool to estimate the torque and plunge force required to plunge a tool into the work piece. A stationary tool is modeled rather than the moving tool because effects such as thermal transients and metallurgical changes in the sample (primarily aging in aluminum) can be more easily accounted for. It is believed, however, that with some modifications the model should be applicable to a moving tool also.

McClure, John C.↗

Simulation of the Genesis of Hurricane Javier (2004) in the Eastern Pacific

NASA is preparing for the Tropical Cloud Systems and Processes (TCSP) field experiment in July 2005, a joint effort with NOAA to study tropical cloud systems and tropical cyclone genesis in the Eastern Pacific. A major thrust of the TCSP program is the improvement of the understanding and prediction of tropical cyclone genesis, intensity, motion, rainfall potential, and landfall impacts using remote sensing and in-situ data, as well as numerical modeling, particularly as they relate to the three phases of water. The Eastern Pacific has the highest frequency of genesis events per unit area of any region worldwide. African easterly waves, mesoscale convective systems (MCSs), and orographic effects are thought to play roles in the genesis of tropical cyclones there. The general consensus is that tropical depressions form in association with one or more mid-level, mesoscale cyclonic vortices that are generated within the stratiform region of the MCS precursors. To create the warm core tropical depression vortex, however, the midlevel cyclonic circulation must somehow extend down to the surface and the tangential winds must attain sufficient strength (-10 m s- ) to enable the wind-induced surface heat exchange to increase the potential energy of the boundary layer air.

Braun, Scott↗

JSC Orbital Debris Website Description

Purpose: The website provides information about the NASA Orbital Debris Program Office at JSC, which is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth. Major Contents: Orbital Debris research is divided into the following five broad efforts. Each area of research contains specific information as follows: 1) Modeling - NASA scientists continue to develop and upgrade orbital debris models to describe and characterize the current and future debris environment. Evolutionary and engineering models are described in detail. Downloadable items include a document in PDF format and executable software. 2) Measurements - Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. The data from these sources provide validation of the environment models and identify the presence of new sources. Radar, optical and surface examinations are described. External links to related topics are provided. 3) Protection - Orbital debris protection involves conducting hypervelocity impact measurements to assess the risk presented by orbital debris to operating spacecraft and developing new materials and new designs to provide better protection from the environment with less weight penalty. The data from this work provides the link between the environment defined by the models and the risk presented by that environment to operating spacecraft and provides recommendations on design and operations procedures to reduce the risk as required. These data also help in the analysis and interpretation of impact features on returned spacecraft surfaces. 4) Mitigation - Controlling the growth of the orbital debris population is a high priority for NASA, the United States, and the major space-faring nations of the world to preserve near-Earth space for future generations. Mitigation measures can take the form of curtailing or preventing the creation of new debris, designing satellites to withstand impacts by small debris, and implementing operational procedures ranging from utilizing orbital regimes with less debris, adopting specific spacecraft attitudes, and even maneuvering to avoid collisions with debris. Downloadable items include several documents in PDF format and executable software.and 5) Reentry - Because of the increasing number of objects in space, NASA has adopted guidelines and assessment procedures to reduce the number of non-operational spacecraft and spent rocket upper stages orbiting the Earth. One method of postmission disposal is to allow reentry of these spacecraft, either from orbital decay (uncontrolled entry) or with a controlled entry. Orbital decay may be achieved by firing engines to lower the perigee altitude so that atmospheric drag will eventually cause the spacecraft to enter. However, the surviving debris impact footprint cannot be guaranteed to avoid inhabited landmasses. Controlled entry normally occurs by using a larger amount of propellant with a larger propulsion system to drive the spacecraft to enter the atmosphere at a steeper flight path angle. It will then enter at a more precise latitude, longitude, and footprint in a nearly uninhabited impact region, generally located in the ocean.

Johnson, Nicholas L.↗

Second NASA Technical Interchange Meeting (TIM): Advanced Technology Lifecycle Analysis System (ATLAS) Technology Tool Box (TTB)

The Advanced Technology Lifecycle Analysis System (ATLAS), a spreadsheet analysis tool suite, applies parametric equations for sizing and lifecycle cost estimation. Performance, operation, and programmatic data used by the equations come from a Technology Tool Box (TTB) database. In this second TTB Technical Interchange Meeting (TIM), technologists, system model developers, and architecture analysts discussed methods for modeling technology decisions in spreadsheet models, identified specific technology parameters, and defined detailed development requirements. This Conference Publication captures the consensus of the discussions and provides narrative explanations of the tool suite, the database, and applications of ATLAS within NASA s changing environment.

ONeil, D. A.↗

Science Overview: The LTTG Technology Review Meeting March 2006 Summary Report

This report presents an overview of the latest scientific consensus understanding of the effect of aviation emissions on the atmosphere for both local air quality and climate change in order to provide a contextual framework for raising future questions to help assess the environmental benefits of technology goals. Although studies of the two issues share a common framework (of quantifying the emissions, the change in concentrations in the atmosphere, and the environmental impacts), the communities of practitioners are distinctly different. The scientific community will continue to provide guidelines on trade-off among different contributors to a specific environmental impact, such as global climate, or local air quality. Ultimately, monetization of the costs and benefits of mitigation actions is the proper tool for quantifying and analyzing trade-offs between the two issues. Scientific assessment of the impacts and their uncertainties are critical inputs to these analyses. Until environmental effects of aviation emerge as a policy driven issue, there is little incentive within the scientific community to focus on research efforts specific to trade-off studies between local and global impacts.

Bruning, Claus↗

Solar Probe: Close Encounter with the Sun

The Solar Probe Science and Technology Definition Team (STDT) recently completed a detailed study of the Solar Probe Mission based on an earliest launch date of October 2014. Solar Probe, when implemented, will be the first close encounter by a spacecraft with a star (i.e., 3 Rs above the Sun s photosphere). The report and its executive summary were published by NASA (NASA/TM-2005-212786) in September 2005 and can be found at the website http://solarprobe.gsfc.nasa.gov/. A description of the science is being prepared for publication in Reviews of Geophysics by McComas et al. [2006]. For this talk, we will be presenting the consensus view of the STDT including a brief description of the scientific goals, a description of the overall mission, including trajectory scenarios, spacecraft description and proposed scientific payload. We will discuss all these topics and the importance of flying the Solar Probe mission both with regard to understanding fundamental issues of solar wind acceleration and coronal heating near the Sun and Solar Probe s unique role in understanding the acceleration of Solar Energetic Particles (SEPs), which is critical to future Human Exploration.

Sittler, E. C., Jr.↗

Prebiotic materials from on and off the early Earth

One of the great puzzles of all time is how did life arise? It has been universally presumed that life arose in a soup rich in compounds made mostly of carbon, the kind of which we are currently composed. Where did these organic molecules come from? In this talk I will review proposed contributions to pre-biotic organic chemistry from both terrestrial processes (i.e., hydrothermal vents, Miller-Urey syntheses) and also from space. While the former is perhaps better known and more commonly taught in school, we now know that comet and asteroid dust deliver tons of organics to the Earth every day, and there is a growing consensus among scientists that molecules from space played an important role in making the Earth habitable, and perhaps even provided specific compounds that were directly related to the origin of life.

Bernstein, Max↗

A Description of the "Crow's Foot" Tunnel Concept

NASA Langley Research Center has actively pursued the development and the use of pictorial or three-dimensional perspective displays of tunnel-, pathway- or highway-in-the-sky concepts for presenting flight path information to pilots in all aircraft categories (e.g., transports, General Aviation, rotorcraft) since the late 1970s. Prominent among these efforts has been the development of the crow s foot tunnel concept. The crow's foot tunnel concept emerged as the consensus pathway concept from a series of interactive workshops that brought together government and industry display designers, test pilots, and airline pilots to iteratively design, debate, and fly various pathway concepts. Over years of use in many simulation and flight test activities at NASA and elsewhere, modifications have refined and adapted the tunnel concept for different applications and aircraft categories (i.e., conventional transports, High Speed Civil Transport, General Aviation). A description of those refinements follows the definition of the original tunnel concept.

Parrish, Russell V.↗

Mars Sample Handling Protocol Workshop Series: Workshop 4

In preparation for missions to Mars that will involve the return of samples to Earth, it will be necessary to prepare for the receiving, handling, testing, distributing, and archiving of martian materials here on Earth. Previous groups and committees have studied selected aspects of sample return activities, but specific detailed protocols for the handling and testing of returned samples must still be developed. To further refine the requirements for sample hazard testing and to develop the criteria for subsequent release of sample materials from quarantine, the NASA Planetary Protection Officer convened a series of workshops in 2000-2001. The overall objective of the Workshop Series was to produce a Draft Protocol by which returned martian sample materials can be assessed for biological hazards and examined for evidence of life (extant or extinct) while safeguarding the purity of the samples from possible terrestrial contamination. This report also provides a record of the proceedings of Workshop 4, the final Workshop of the Series, which was held in Arlington, Virginia, June 5-7, 2001. During Workshop 4, the sub-groups were provided with a draft of the protocol compiled in May 2001 from the work done at prior Workshops in the Series. Then eight sub-groups were formed to discuss the following assigned topics: Review and Assess the Draft Protocol for Physical/Chemical Testing Review and Assess the Draft Protocol for Life Detection Testing Review and Assess the Draft Protocol for Biohazard Testing Environmental and Health/Monitoring and Safety Issues Requirements of the Draft Protocol for Facilities and Equipment Contingency Planning for Different Outcomes of the Draft Protocol Personnel Management Considerations in Implementation of the Draft Protocol Draft Protocol Implementation Process and Update Concepts This report provides the first complete presentation of the Draft Protocol for Mars Sample Handling to meet planetary protection needs. This Draft Protocol, which was compiled from deliberations and recommendations from earlier Workshops in the Series, represents a consensus that emerged from the discussions of all the sub-groups assembled over the course of the five Workshops of the Series. These discussions converged on a conceptual approach to sample handling, as well as on specific analytical requirements. Discussions also identified important issues requiring attention, as well as research and development needed for protocol implementation.

Race Margaret S.↗

System Architecture Modeling for Technology Portfolio Management using ATLAS

Strategic planners and technology portfolio managers have traditionally relied on consensus-based tools, such as Analytical Hierarchy Process (AHP) and Quality Function Deployment (QFD) in planning the funding of technology development. While useful to a certain extent, these tools are limited in the ability to fully quantify the impact of a technology choice on system mass, system reliability, project schedule, and lifecycle cost. The Advanced Technology Lifecycle Analysis System (ATLAS) aims to provide strategic planners a decision support tool for analyzing technology selections within a Space Exploration Architecture (SEA). Using ATLAS, strategic planners can select physics-based system models from a library, configure the systems with technologies and performance parameters, and plan the deployment of a SEA. Key parameters for current and future technologies have been collected from subject-matter experts and other documented sources in the Technology Tool Box (TTB). ATLAS can be used to compare the technical feasibility and economic viability of a set of technology choices for one SEA, and compare it against another set of technology choices or another SEA. System architecture modeling in ATLAS is a multi-step process. First, the modeler defines the system level requirements. Second, the modeler identifies technologies of interest whose impact on an SEA. Third, the system modeling team creates models of architecture elements (e.g. launch vehicles, in-space transfer vehicles, crew vehicles) if they are not already in the model library. Finally, the architecture modeler develops a script for the ATLAS tool to run, and the results for comparison are generated.

Thompson, Robert W.↗

Continual coordination of shared activities

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. For domains with varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently achieve their goals. ShAC (Shared Activity Coordination) is a framework for designing coordination protocols and an algorithm for continually coordinating agents using these protocols during execution. We show how a variety of protocols can be constructed using this framework and describe how ShAC coordinates two rovers and an orbiter in a simulated Mars scenario.

multiple agents coordination planning scheduling M↗

AMOS: Generic Planetary Mission Ops

The spacecraft control community is focusing increasing attention on various forms of architectures. Studies on software architectures and related technologies have been commissioned by DOD programs. The purpose of planning a series of annual workshops is to bring together participants working in the Spacecraft Ground System (SGS) domain. The overall intent of these workshops is to expedite the transition to common consensus-based open software architectures for SGSs.

workshops SGS technologies↗

Participant-Observations of 'Effective Dialogue' at a NASA Center: Toward New Paradigm

Four recently instituted 'dialogic' communication forums at a NASA center are described and analyzed. Their discourse is compared to a (typical) paradigmatic model of dialogic discourse principles. It is argued that dialogue which does not fit the exemplary model may nonetheless be effective for building community, investment, and democratic exchange. The study further suggests that consensus and teamwork may be less evident (and perhaps less effective) than individual voice and oppositional stance.

Effective Dialogue↗

Report of the Microspacecraft Panel

These findings and recommendations are based solely on the material presented during the Microtechnologies and Applications to Space Systems Workshop, 5/27 and 28/92, and the personal knowledge and judgment of the panel members. These findings and recommendations represent the consensus views of the committee. This mission utility of microspacecraft for NASA space science missions was not an issue that the panel addressed. For the purposes of this panel, a microspacecraft was defined to be a fully functional spacecraft, intended for use on NASA space science missions, whose mass is on the order of 10 kg. During the panel discussions the microspacecraft mass definition was used somewhat loosely to be not less than 10 kg but certainly not more than 100, dependent upon the mission requirements.

Jones, Ross M.↗

Argumentation for coordinating shared activities

There is an increasing need for space missions to be able to collaboratively (and competitively) develop plans both within and across missions. In addition, interacting spacecraft that interleave onboard planning and execution must reach consensus on their commitments to each other prior to execution.

scheduling↗