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At least 289 records · Page 16

Planetary nomenclature

In fiscal 1986, names were chosen for prominent features on the five previously known Uranian satellites and for features on the largest of the 10 satellites discovered by Voyager 2. The names of the five large satellites are taken mostly from Shakespeare, and most are spirits; therefore, Shakespearean and spirit themes were used to choose names for topographic features on the satellites. Crater names and most other feature names on Miranda, Oberon, and Titania are from Shakespeare; features on Ariel are named for bright spirits and those on Umbriel for dark, all taken from universal mythology. Preliminary coordinates for these features are derived from shaded relief maps of the satellites to be published in 1987. Orbital elements have been established for the 10 new satellites, and a paper describing this work is in progress; satellite positions are under review by Commission 16 of the IAU. The moon 1985 U1 is informally designated Puck. The nine small satellites discovered in 1986 are to be named for Shakespearean heroines; these names are to be listed in the 1987 edition of the Annual Gazetteer of Planetary Nomenclature.

Strobell, M. E.↗

Guidelines for noise and vibration levels for the space station

Human habitability noise and vibration guidelines for the Space Station are presented. These were developed by a working group of experts established by the Committee on Hearing, Bioacoustics, and Biomechanics (CHABA) of the National Research Council's Commission on Behavioral and Social Science and Education. Noise exposure limits are suggested that will permit adequate speech communication, sleep, and hearing safety. Vibration exposure limits are suggested which will provide adequate comfort and permit adequate task performance. These are provided for guidance only for setting criteria. The exact criteria will depend on Space Station design and duty cycles.

Source record↗

LEO and GEO missions

The occurrence of the Challenger disaster in early 1986 caused a severe reevaluation of the space program. Plans already established had to be drastically revised and new plans had to be made. NASA created the Space Leadership Planning Group (SLPG) to formulate space mission plans covering a 50 year period based on Agency goals and objectives responsive to the National Commission on Space recommendations. An interim view of the status of SLPG plans for low altitude and geosynchronous missions is presented.

Mercanti, Enrico↗

The history of IUE

The early organizational and development history of the NASA-ESA-SERC International UV Explorer (IUE) satellite observatory is reviewed. Consideration is given to the progress of UV astronomy prior to the launch of the IUE in 1978; the initial feasibility and design studies; preliminary proposals (e.g., UVAS) and the reasons for their rejection; the designs selected for the telescope, spectrographs, detectors, and attitude-control system; the preflight preparations; and the commissioning phase.

Boggess, Albert↗

NASA's post-Challenger safety program - Themes and thrusts

The range of managerial, technical, and procedural initiatives implemented by NASA's post-Challenger safety program is reviewed. The recommendations made by the Rogers Commission, the NASA post-Challenger review of Shuttle design, the Congressional investigation of the accident, the National Research Council, the Aerospace Safety Advisory Panel, and NASA internal advisory panels and studies are summarized. NASA safety initiatives regarding improved organizational accountability for safety, upgraded analytical techniques and methodologies for risk assessment and management, procedural initiatives in problem reporting and corrective-action tracking, ground processing, maintenance documentation, and improved technologies are discussed. Safety issues relevant to the planned Space Station are examined.

Rodney, G. A.↗

Shock tunnel studies of scramjet phenomena

Commissioning of the new T4 shock tunnel at the University of Queensland implied that it was no longer necessary to focus the work of the research group about an annual test series conducted in the T3 shock tunnel in Canberra. Therefore, it has been possible to organize a group for work to proceed along lines such that particular personnel are associated with particular project areas. The format of this report consists of a series of reports on specific project areas, with a brief general introduction commenting on each report. The introduction is structured by project areas, with the title of the relevant report stated under the project area heading. The reports themselves follow in the order of the project area headings.

Morgan, R. G.↗

Technology requirements for advanced NASA missions

Two recent reports, one by the National Commission on Space and the second by the Ride committee, have urged NASA to look at a variety of future missions. Among these are manned missions to Mars and permanent bases on the moon and Mars. Addressed here is a wide variety of technologies needed for such missions as well as areas where power is required. An estimate of power ranges and photovoltaic opportunities is also presented.

Curtis, Henry B.↗

The NASA Langley Research Center 0.3-meter transonic cryogenic tunnel T-P/Re-M controller manual

A new microcomputer based controller for the 0.3-m Transonic Cryogenic Tunnel (TCT) has been commissioned in 1988 and has reliably operated for more than a year. The tunnel stagnation pressure, gas stagnation temperature, tunnel wall structural temperature and flow Mach number are precisely controlled by the new controller in a stable manner. The tunnel control hardware, software, and the flow chart to assist in calibration of the sensors, actuators, and the controller real time functions are described. The software installation details are also presented. The report serves as the maintenance and trouble shooting manual for the 0.3-m TCT controller.

Balakrishna, S.↗

Ergonomic Models of Anthropometry, Human Biomechanics and Operator-Equipment Interfaces

The Committee on Human Factors was established in October 1980 by the Commission on Behavioral and Social Sciences and Education of the National Research Council. The committee is sponsored by the Office of Naval Research, the Air Force Office of Scientific Research, the Army Research Institute for the Behavioral and Social Sciences, the National Aeronautics and Space Administration, and the National Science Foundation. The workshop discussed the following: anthropometric models; biomechanical models; human-machine interface models; and research recommendations. A 17-page bibliography is included.

Kroemer, Karl H. E.↗

Fiji South Pacific Severe Storm Detection and Warning System Project (SPSSD/WS)

In August 1986, a South Pacific Severe Storm Detection and Warning System (SPSSD/WS) was installed by NASA at the Fiji Meteorological Service (FMS) in Nadi, Fiji. The system consists of a 6.1 meter parabolic dish antenna, a satellite ground station, and computer and image processing facilities. The system allows tracking of all South Pacific tropical cyclones with real-time, high resolution reception of visible and infrared cloud images from both the Japanese Geostationary Meteorological Satellite (GMS) and the U.S. Geostationary Operational Environmental Satellite (GOES-WEST). Training was also provided in system usage and operations. In December 1986, the U.S. AID Office of U.S. Foreign Disaster Assistance (OFDA) commissioned an evaluation of the SPSSD/WS. The system was recognized as one of the most advanced of its kind in the Pacific Basin. It has functioned successfully since installation with only minor interruptions, and it has become the prime tool in supporting the FMS' role as the regional tropical cyclone warning center for the Southwest Pacific. However, it was noted that there are needed enhancements to the system.

Vermillion, C.↗

Exploration case studies

NASA's Office of Exploration has undertaken four case studies for prospective expansion of manned space activities beyond earth orbit. The subjects of these studies are (1) an expedition to the Martian moon Phobos; (2) a three-mission expedition to Mars; (3) the construction of a man-tended lunar observatory; and (4) the construction of a lunar outpost to serve as the basis for construction of a Martian outpost. The fourth alternative would follow the recommendation of the National Commission on Space for the creation of a 'bridge between worlds' in which explorers would develop ways in which to 'live off the land' in a space environment.

Underwood, Jimmy M.↗

The GEM-T2 gravitational model

The GEM-T2 is the latest in a series of Goddard Earth Models of the terrestrial field. It was designed to bring modeling capabilities one step closer towards ultimately determining the TOPEX/Poseidon satellite's radial position to an accuracy of 10-cm RMS (root mean square). It also improves models of the long wavelength geoid to support many oceanographic and geophysical applications. The GEM-T2 extends the spherical harmonic field to include more than 600 coefficients above degree 36 (which was the limit for its predecessor, GEM-T1). Like GEM-T1, it was produced entirely from satellite tracking data, but it now uses nearly twice as many satellites (31 vs. 17), contains four times the number of observations (2.4 million), has twice the number of data arcs (1132), and utilizes precise laser tracking from 11 satellites. The estimation technique for the solution has been augmented to include an optimum data weighting procedure with automatic error calibration for the gravitational parameters. Results for the GEM-T2 error calibration indicate significant improvement over previous satellite-only models. The error of commission in determining the geoid has been reduced from 155 cm in GEM-T1 to 105 cm for GEM-T2 for the 36 x 36 portion of the field, and 141 cm for the entire model. The orbital accuracies achieved using GEM-T2 are likewise improved. Also, the projected radial error on the TOPEX satellite orbit indicates 9.4 cm RMS for GEM-T2, compared to 24.1 cm for GEM-T1.

Marsh, J. G.↗

Trace element abundance determinations by Synchrotron X Ray Fluorescence (SXRF) on returned comet nucleus mineral grains

Trace element analyses were performed on bulk cosmic dust particles by Proton Induced X Ray Emission (PIXE) and Synchrotron X Ray Fluorescence (SXRF). When present at or near chondritic abundances the trace elements K, Ti, Cr, Mn, Cu, Zn, Ga, Ge, Se, and Br are presently detectable by SXRF in particles of 20 micron diameter. Improvements to the SXRF analysis facility at the National Synchrotron Light Source presently underway should increase the range of detectable elements and permit the analysis of smaller samples. In addition the Advanced Photon Source will be commissioned at Argonne National Laboratory in 1995. This 7 to 8 GeV positron storage ring, specifically designed for high-energy undulator and wiggler insertion devices, will be an ideal source for an x ray microprobe with one micron spatial resolution and better than 100 ppb elemental sensitivity for most elements. Thus trace element analysis of individual micron-sized grains should be possible by the time of the comet nucleus sample return mission.

Flynn, G. J.↗

Software verification plan for GCS

This verification plan is written as part of an experiment designed to study the fundamental characteristics of the software failure process. The experiment will be conducted using several implementations of software that were produced according to industry-standard guidelines, namely the Radio Technical Commission for Aeronautics RTCA/DO-178A guidelines, Software Consideration in Airborne Systems and Equipment Certification, for the development of flight software. This plan fulfills the DO-178A requirements for providing instructions on the testing of each implementation of software. The plan details the verification activities to be performed at each phase in the development process, contains a step by step description of the testing procedures, and discusses all of the tools used throughout the verification process.

Dent, Leslie A.↗

GCS plan for software aspects of certification

As part of the Guidance and Control Software (GCS) research project being sponsored by NASA to evaluate the failure processes of software, standard industry software development procedures are being employed. To ensure that these procedures are authentic, the guidelines outlined in the Radio Technical Commission for Aeronautics (RTCA/DO-178A document entitled, software considerations in airborne systems and equipment certification, were adopted. A major aspect of these guidelines is proper documentation. As such, this report, the plan for software aspects of certification, was produced in accordance with DO-178A. An overview is given of the GCS research project, including the goals of the project, project organization, and project schedules. It also specifies the plans for all aspects of the project which relate to the certification of the GCS implementations developed under a NASA contract. These plans include decisions made regarding the software specification, accuracy requirements, configuration management, implementation development and verification, and the development of the GCS simulator.

Shagnea, Anita M.↗

The determination of maximum deep space station slew rates for a high Earth orbiter

As developing national and international space ventures, which seek to employ NASA's Deep Space Network (DSN) for tracking and data acquisition, evolve, it is essential for navigation and tracking system analysts to evaluate the operational capability of Deep Space Station antennas. To commission the DSN for use in tracking a highly eccentric Earth orbiter could quite possibly yield the greatest challenges in terms of slewing capability; certainly more so than with a deep-space probe. The focus here is on the determination of the maximum slew rates needed to track a specific high Earth orbiter, namely the Japanese MUSES-B spacecraft of the Very Long Baseline Interferometry Space Observatory Program. The results suggest that DSN 34-m antennas are capable of meeting the slew rate requirements for the nominal MUSES-B orbital geometries currently being considered.

Estefan, J. A.↗

GCS support/development system configuration document

The software programming environment used in the development of Guidance and Control Software (GCS) implementations used in a software error studies experiment conducted by the Research Triangle Institute (RTI) and the NASA-Langley is described. The Radio Technical Commission for Aeronautics RTCA/DO-178A guidelines are fulfilled, and requirements for document number 9 in which the hardware, software, and processes used to develop and maintain the software for the GCS project are described. The software programming environment for GCS largely consists of tools that are included in Digital Equipment Corporations software layered product library or are a part of the VAX/VMS baseline system.

Lowman, Douglas S.↗

OSI in the NASA science internet: An analysis

The Open Systems Interconnection (OSI) protocol suite is a result of a world-wide effort to develop international standards for networking. OSI is formalized through the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). The goal of OSI is to provide interoperability between network products without relying on one particular vendor, and to do so on a multinational basis. The National Institute for Standards and Technology (NIST) has developed a Government OSI Profile (GOSIP) that specified a subset of the OSI protocols as a Federal Information Processing Standard (FIPS 146). GOSIP compatibility has been adopted as the direction for all U.S. government networks. OSI is extremely diverse, and therefore adherence to a profile will facilitate interoperability within OSI networks. All major computer vendors have indicated current or future support of GOSIP-compliant OSI protocols in their products. The NASA Science Internet (NSI) is an operational network, serving user requirements under NASA's Office of Space Science and Applications. NSI consists of the Space Physics Analysis Network (SPAN) that uses the DECnet protocols and the NASA Science Network (NSN) that uses TCP/IP protocols. The NSI Project Office is currently working on an OSI integration analysis and strategy. A long-term goal is to integrate SPAN and NSN into one unified network service, using a full OSI protocol suite, which will support the OSSA user community.

Nitzan, Rebecca↗