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At least 523 records · Page 29

A reply from earth? - A proposed approach to developing a message from humankind to extraterrestrial intelligence after we detect them

The question of the formulation of a proper response to the detection of an extraterrestrial civilization is considered. It is proposed that an international agreement or declaration of principles establishing procedures enabling international participation in the making of such decisions be developed and that the SETI Committee of the International Academy of Aeronautics, in cooperation with other interested bodies, draft an agreement or declaration of principles that would set up these procedures; and that the draft be presented to the United Nations for consideration through the Committee on Peaceful Uses of Outer Space. A suggested outline of the agreement or declaration is presented and proposes that a response to the detection of extraterrestrial intelligence should be on behalf of all humankind; that this decision should be made by an appropriately representative international body; and that the content of the reply should reflect an international consensus.

Michaud, Michael↗

Long term integrity for space station power systems

A study was made of the High Temperature Design Codes ASME N47, British R5, and the French RCC-MR Rules. It is concluded that all these codes provide a good basis of design for space application. The new British R5 is the most complete since it deals with the problem of defects. The ASME N47 was subjected longer to practical application and scrutiny. A draft code is introduced, and a proposed draft for high temperature design in which attempts were made to identify gaps and improvements is suggested. The design is limited by creep characteristics. In these circumstances, life is strongly affected by the selected value of the factor of safety. The factor of safety of primary loads adopted in the codes is 1.5. Maybe a lower value of 1.25 is permissible for use in space. Long term creep rupture data for HAYNES 188 is deficient and it is suggested that extrapolation methods be investigated.

Leckie, F. A.↗

Computed potential energy surfaces for chemical reactions

The work on the NH + NO system which was described in the last progress report was written up and a draft of the manuscript is included in the appendix. The appendix also contains a draft of a manuscript on an Ar + H + H surface. New work which was completed in the last six months includes the following: (1) calculations on the (1)CH2 + H2O, H2 + HCOH, and H2 + H2CO product channels in the CH3 + OH reaction; (2) calculations for the NH2 + O reaction; (3) calculations for the CH3 + O2 reaction; and (4) calculations for CH3O and the two decomposition channels--CH2OH and H + H2CO. Detailed descriptions of this work will be given in manuscripts; however, brief descriptions of the CH3 + OH and CH3 + O2 projects are given.

Heinemann, K.↗

Guideline requirements for serviceable spacecraft grasping/berthing/docking interfaces based on simulations and flight experience

The described efforts support a NASA Space Assembly and Servicing Working Group activity to draft guideline interface standards. The general requirements are to provide a simple, reliable, and durable system. Interface requirements developed include lateral position offset, axial and lateral velocities, and angular misalignment. A survey of concepts and simulation studies of spacecraft docking, existing docking/end effector performance criteria, and space proven, qualified docking data was conducted and evaluated, in order to provide recommended mechanical interface guidelines and interface tolerances for manual and autonomous capture operations. The criterion for the selection of the guidelines was maximum capability to handle malfunctions. Originally the guidelines for a zero velocity docking were considered to be covered within the grasping/berthing definition. It is acknowledged that perhaps a separate category needs to be established for this operation. The draft standard was delivered to the AIAA for review, revision, and issuance as the first U.S. national standard guideline on interfaces. The intent is to develop the guidelines into an International Standards Organization standard.

Thompson, Allen B.↗

Knowledge-based systems in Japan

This report summarizes a study of the state-of-the-art in knowledge-based systems technology in Japan, organized by the Japanese Technology Evaluation Center (JTEC) under the sponsorship of the National Science Foundation and the Advanced Research Projects Agency. The panel visited 19 Japanese sites in March 1992. Based on these site visits plus other interactions with Japanese organizations, both before and after the site visits, the panel prepared a draft final report. JTEC sent the draft to the host organizations for their review. The final report was published in May 1993.

Feigenbaum, Edward↗

Robust stability of second-order systems

This progress report gives current progress of the research in nonlinear robust control using positive real concept. The progress is documented in a draft paper. In the paper, the manipulator dynamics is reformulated differently from the existing equations of motion for free base robots. This new formulation gives a compact form of the dynamic equations for easy computation. The nonlinear terms are now considered. The results show that for an additional nonlinear friction term, the feedback controller designed using passivity concept works quite well. Although design of such a controller requires simulation of the dynamics for the example shown in the following draft, this design procedure is feasible.

Chuang, C.-H.↗

Supporting Research and Technology Activities for a Microwave Observing Program to Search for Extraterrestrial Intelligence

Curriculum materials based on the search for extraterrestrial intelligence (SETI) were developed for grades 3 through 9 science classes. The project was supported in part by NASA. Six teacher's guides, plus ancillary visuals, addressing topics in astronomy, biology, chemistry, geosciences, and physics as well as mathematics, social sciences, and language arts, were designed by a team of teachers, scientists. curriculum developers, and artists. First drafts were piloted by 10 design team teachers; revised drafts were field tested by 109 teachers in 30 states. Extensive feedback from these teachers and their students and reviews by scientists were used to revise materials prior to submission to the publisher. The field test teachers overall ranking of all guides (data from individual lesson feedback forms) was 431 on a one low to five high scale; 85% found the content appropriate to course and grade level and 75% indicated they had no reservations about using the materials again or recommending them to colleagues. The ratio of liked to disliked student responses (from 1305 student letters) was 70:30. Most recommendations from the teachers, students, and science reviewers were incorporated in the final versions for the guides, published by Libraries Unlimited/Teacher Ideas Press, 1995.

Tarter, Jill↗

Next-Generation Design and Simulation Tools

Thirty years ago, the CAD industry was created as electronic drafting tools were developed to move people from the traditional two-dimensional drafting boards. While these tools provided an improvement in accuracy (true perpendicular lines, etc.), they did offer a significant improvement in productivity or impact development times. They electronically captured a manual process.

Weber, Tod A.↗

X-33 Environmental Impact Statement: A Fast Track Approach

NASA is required by the National Environmental Policy Act (NEPA) to prepare an appropriate level environmental analysis for its major projects. Development of the X-33 Technology Demonstrator and its associated flight test program required an environmental impact statement (EIS) under the NEPA. The EIS process is consists of four parts: the "Notice of Intent" to prepare an EIS and scoping; the draft EIS which is distributed for review and comment; the final ETS; and the "Record of Decision." Completion of this process normally takes from 2 - 3 years, depending on the complexity of the proposed action. Many of the agency's newest fast track, technology demonstration programs require NEPA documentation, but cannot sustain the lengthy time requirement between program concept development to implementation. Marshall Space Flight Center, in cooperation with Kennedy Space Center, accomplished the NEPA process for the X-33 Program in 13 months from Notice of Intent to Record of Decision. In addition, the environmental team implemented an extensive public involvement process, conducting a total of 23 public meetings for scoping and draft EIS comment along with numerous informal meetings with public officials, civic organizations, and Native American Indians. This paper will discuss the fast track approach used to successfully accomplish the NEPA process for X-33 on time.

McCaleb, Rebecca C.↗

Phase 111A Crew Interface Specifications Development for Inflight Maintenance and Stowage Functions

This report presents the findings and data products developed during the Phase IIIA Crew Interface Specification Study for Inflight Maintenance and Stowage Functions, performed by General Electric for the NASA, Johnson Space Center with a set of documentation that can be used as definitive guidelines to improve the present process of defining, controlling and managing flight crew interface requirements that are related to inflight maintenance (including assembly and servicing) and stowage functions. During the Phase IIIA contract period, the following data products were developed: 1) Projected NASA Crew Procedures/Flight Data File Development Process. 2) Inflight Maintenance Management Process Description. 3) Preliminary Draft, General Specification, Inflight Maintenance Management Requirements. 4) Inflight Maintenance Operational Process Description. 5) Preliminary Draft, General Specification, Inflight Maintenance Task and Support Requirements Analysis. 6) Suggested IFM Data Processing Reports for Logistics Management The above Inflight Maintenance data products have been developed during the Phase IIIA study after review of Space Shuttle Program Documentation, including the Level II Integrated Logistics Requirements and other DOD and NASA data relative to Payloads Accommodations and Satellite On-Orbit Servicing. These Inflight Maintenance data products were developed to be in consonance with Space Shuttle Program technical and management requirements.

Carl, John G.↗

The Civil Aviation Sector in Lebanon: Institutional Reforms - Part 1

Civil aviation is one of the key contributors to a successful economic system. This has been recognized within Lebanon, which is undertaking developing a new civil aviation strategy encompassing a program of organizational reform, coordinated internationally, to meet the challenges of the new century. Such strategy is vital, as it will provide a coherent vision for the sector, compliment the extensive investments deployed by Lebanon in its aviation infrastructure, and guide future planning and investments. The proposed Civil Aviation Strategy for Lebanon has two major components: (1) institutional reform aiming at creating effective overall legal and regulatory frameworks in-line with current international best practice; and (2) implementation of liberalization measures and open skies policy. This paper aims to: (1) present Lebanon's current institutional arrangements; (2) review the institutional arrangements in key select countries (in order to define current trends in best institutional practice); (3) discuss the proposed institutional reform (which are at the basis of Lebanon's Draft Civil Aviation Reform Law) while showing that they conform with the identified best institutional trends; and (4) outline an implementation plan. The Draft Law has been approved by the Council of Ministers and now awaits Parliamentary endorsement.

Baaj, M. Hadi↗

Detection of the Near-IR Cosmic Infrared Background Using Alternative Models of Near-IR Galactic Emission in the DIRBE Data

The analysis portion of this task has been completed. New models were developed for the removal of the near-infrared emission of Galactic stars in the DIRBE data. Subtraction of these models from the observed emission attempted to achieve a better detection of the Cosmic Infrared Background at near-infrared wavelengths. The new models were found to provide a large improvement in the isotropy of the residual emission, however constraints on the intensity of the emission are not significantly improved. A paper detailing the procedures and results has been drafted, and will be completed next year. The draft of this paper is included as the final report on the contract.

Arendt, Richard G.↗

Over-Luminous Elliptical Galaxies

We have completed a first draft of a paper on the galaxy group ES03060170, the hottest known fossil group. We have submitted a first draft of the paper but the final completion is delayed due to several issues mentioned by the referee that we wish to revisit and discuss in more detail. The XMM data was combined with Chandra data which allowed a rich set of projects. The paper discusses the north-south elongation which is similar to that of the central dominant galaxy as well as the galaxy distribution. We detect an X-ray "finger" or small tail emanating from the central galaxy to the north, suggesting motion of the galaxy within the elongated gravitational potential. The overall agreement between XMM and Chandra data are excellent (although the XMM data extend to larger radii). Both data sets show a cool core centered on the dominant galaxy. Surprisingly, the temperature maps and detailed spectra indicate that the finger of gas is NOT cool, but has the same temperature as the ambient gas. We extracted surface brightness profiles, deprojected gas density profiles, cooling time profiles, and entropy profiles. There is a sharp discontinuity in gas temperature where the surface brightness profile starts to rise rapidly at 10 kpc. This produces a decrease in the cooling time and the gas entropy within 10 kpc. The central cooling time (within 10 kpc) is less than l0(exp 9) years and falls to almost half that value in the inner 5 kpc. Despite the very short cooling time, we find no evidence (even with the excellent statistics from XMM-Newton) for multi-phased gas, i.e., a cooling flow. We find two "edges" associated with the gas distribution (common in peaked X-ray groups and galaxies). On large scales, the temperature profile is flat and disagrees with the profile predicted by Loken et al. (2003) from detailed numerical simulations. We studied the galaxy distribution within one virial radius. The galaxy concentration associated with the group is detectable only within 0.3 of the virial radius (450 kpc) given the available depth of the optical galaxy catalogs at present. We have derived total mass and gas mass distributions (from the X- ray data) and find the gas fraction approaches a constant 8% (for Ho = 70).

Mushotzky, Richard↗

Over-Luminous Elliptical Galaxies

We have completed a first draft of a paper on the galaxy group ESO3060170, the hottest known fossil group. We have submitted a first draft of the paper but the final completion is delayed due to several issues mentioned by the referee that we wish to revisit and discuss in more detail. The XMM data was combined with Chandra data which allowed a rich set of projects. The paper discusses the north-south elongation which is similar to that of the central dominant galaxy as well as the galaxy distribution. We detect an X-ray 'finger' or small tail emanating from the central galaxy to the north, suggesting motion of the galaxy within the elongated gravitational potential. The overall agreement between XMM and Chandra data are excellent (although the XMM data extend to larger radii). Both data sets show a cool core centered on the dominant galaxy. Surprisingly, - the temperature maps and detailed spectra indicate that the finger of gas is NOT cool, but has the same temperature as the ambient gas. We extracted surface brightness profiles, deprojected gas density profiles, cooling time profiles, and entropy profiles. There is a sharp discontinuity in gas temperature where the surface brightness profile starts to rise rapidly at 10 kpc. This produces a decrease in the cooling time and the gas entropy within 10 kpc. The central cooling time (within 10 kpc) is less than 109 years and falls to almost half that value in the inner 5 kpc. Despite the very short cooling time, we find no evidence (even with the excellent statistics from XMM-Newton) for multi-phased gas, i.e., a cooling flow. We find two 'edges' associated with the gas distribution (common in peaked X-ray groups and galaxies). On large scales, the temperature profile is flat and disagrees with the profile predicted by Loken et al. (2003) from detailed numerical simulations. We studied the galaxy distribution within one virial radius. The galaxy concentration associated with the group is detectable only within 0.3 of the virial radius (450 kpc) given the available depth of the optical galaxy catalogs at present. We have derived total mass and gas mass distributions (from the X-ray data) and find the gas fraction approaches a constant 8% (for H0 = 70).

Mushotsky, Richard↗

Update on SLD Engineering Tools Development

The airworthiness authorities (FAA, JAA, Transport Canada) will be releasing a draft rule in the 2006 timeframe concerning the operation of aircraft in a Supercooled Large Droplet (SLD) environment aloft. The draft rule will require aircraft manufacturers to demonstrate that their aircraft can operate safely in an SLD environment for a period of time to facilitate a safe exit from the condition. It is anticipated that aircraft manufacturers will require a capability to demonstrate compliance with this rule via experimental means (icing tunnels or tankers) and by analytical means (ice prediction codes). Since existing icing research facilities and analytical codes were not developed to account for SLD conditions, current engineering tools are not adequate to support compliance activities in SLD conditions. Therefore, existing capabilities need to be augmented to include SLD conditions. In response to this need, NASA and its partners conceived a strategy or Roadmap for developing experimental and analytical SLD simulation tools. Following review and refinement by the airworthiness authorities and other international research partners, this technical strategy has been crystallized into a project plan to guide the SLD Engineering Tool Development effort. This paper will provide a brief overview of the latest version of the project plan and technical rationale, and provide a status of selected SLD Engineering Tool Development research tasks which are currently underway.

Miller, Dean R.↗

Office of Biological and Physical Research: Overview Transitioning to the Vision for Space Exploration

Viewgraphs on NASA's transition to its vision for space exploration is presented. The topics include: 1) Strategic Directives Guiding the Human Support Technology Program; 2) Progressive Capabilities; 3) A Journey to Inspire, Innovate, and Discover; 4) Risk Mitigation Status Technology Readiness Level (TRL) and Countermeasures Readiness Level (CRL); 5) Biological And Physical Research Enterprise Aligning With The Vision For U.S. Space Exploration; 6) Critical Path Roadmap Reference Missions; 7) Rating Risks; 8) Current Critical Path Roadmap (Draft) Rating Risks: Human Health; 9) Current Critical Path Roadmap (Draft) Rating Risks: System Performance/Efficiency; 10) Biological And Physical Research Enterprise Efforts to Align With Vision For U.S. Space Exploration; 11) Aligning with the Vision: Exploration Research Areas of Emphasis; 12) Code U Efforts To Align With The Vision For U.S. Space Exploration; 13) Types of Critical Path Roadmap Risks; and 14) ISS Human Support Systems Research, Development, and Demonstration. A summary discussing the vision for U.S. space exploration is also provided.

Crouch, Roger↗

Teaming for Exploration

A multibillion-dollar NASA contracting effort, the largest since the Apollo, shuttle, and space station developments, is formally underway with the release of the draft request for proposals for the Crew Exploration Vehicle (CEV) to replace the shuttle and eventually return astronauts to the Moon as a stepping-stone to Mars. With guidance from the draft request for proposals (RFP) now in hand, contractors are beginning a flurry of activity to posture for formal bids and to align their earlier in-house concepts with major new exploration program specifics, including strong guidelines on managing cost and risk. And Lockheed Martin will announce this week that it is teaming with EADS Space Transportation for the CEV contract. Should this team win, Europe's largest aerospace contractor would be in line for a key role in developing a replacement for the shuttle and renewed human operations on the lunar surface.

Covault, Craig↗

Test Standard Developed for Determining the Slow Crack Growth of Advanced Ceramics at Ambient Temperature

The service life of structural ceramic components is often limited by the process of slow crack growth. Therefore, it is important to develop an appropriate testing methodology for accurately determining the slow crack growth design parameters necessary for component life prediction. In addition, an appropriate test methodology can be used to determine the influences of component processing variables and composition on the slow crack growth and strength behavior of newly developed materials, thus allowing the component process to be tailored and optimized to specific needs. At the NASA Lewis Research Center, work to develop a standard test method to determine the slow crack growth parameters of advanced ceramics was initiated by the authors in early 1994 in the C 28 (Advanced Ceramics) committee of the American Society for Testing and Materials (ASTM). After about 2 years of required balloting, the draft written by the authors was approved and established as a new ASTM test standard: ASTM C 1368-97, Standard Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress-Rate Flexural Testing at Ambient Temperature. Briefly, the test method uses constant stress-rate testing to determine strengths as a function of stress rate at ambient temperature. Strengths are measured in a routine manner at four or more stress rates by applying constant displacement or loading rates. The slow crack growth parameters required for design are then estimated from a relationship between strength and stress rate. This new standard will be published in the Annual Book of ASTM Standards, Vol. 15.01, in 1998. Currently, a companion draft ASTM standard for determination of the slow crack growth parameters of advanced ceramics at elevated temperatures is being prepared by the authors and will be presented to the committee by the middle of 1998. Consequently, Lewis will maintain an active leadership role in advanced ceramics standardization within ASTM. In addition, the authors have been and are involved with several international standardization organizations including the Versailles Project on Advanced Materials and Standards (VAMAS), the International Energy Agency (IEA), and the International Organization for Standardization (ISO). The associated standardization activities involve fracture toughness, strength, elastic modulus, and the machining of advanced ceramics.

Choi, Sung R.↗