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At least 901 records · Page 50

Operations and support for the next-generation space transportation system

The role of operations and support in the design of future space transportation systems (STSs) is studied. There is a need to reduce launch and operation costs for future space systems. Methods for reducing the cost of ground operations and supports for a STS are described. Technological advances such as expert systems, robotics, and sensors, and reduction in management of operations are discussed. Changes in the management of flight operations and control, from a manpower intensive monitoring to a strong vehicle autonomy, are examined. The development of equipment and procedures to improve space operations and reduce costs is analyzed. The use of a clean sheet approach for building a STS is proposed.

Sawaya, G. J.↗

Space Station Environmental Control and Life Support System Test Facility at Marshall Space Flight Center

Different aspects of Space Station Environmental Control and Life Support System (ECLSS) testing are currently taking place at Marshall Space Flight Center (MSFC). Unique to this testing is the variety of test areas and the fact that all are located in one building. The north high bay of building 4755, the Core Module Integration Facility (CMIF), contains the following test areas: the Subsystem Test Area, the Comparative Test Area, the Process Material Management System (PMMS), the Core Module Simulator (CMS), the End-use Equipment Facility (EEF), and the Pre-development Operational System Test (POST) Area. This paper addresses the facility that supports these test areas and briefly describes the testing in each area. Future plans for the building and Space Station module configurations will also be discussed.

Springer, Darlene↗

The 4-meter lunar engineering telescope

The 16-meter diffraction limited lunar telescope incorporates a primary mirror with 312 one-meter segments; 3 nanometer active optics surface control with laser metrology and hexapod positioners; a space frame structure with one-millimeter stability; and a hexapod mount for pointing. The design data needed to limit risk in this development can be obtained by building a smaller engineering telescope on the moon with all of the features of the 16-meter design. This paper presents a 4.33-meter engineering telescope concept developed by the Summer 1990 Student Program of the NASA/JHU Space Grant Consortium Lunar Telescope Project. The primary mirror, made up of 18 one-meter hexagonal segments, is sized to provide interesting science as well as engineering data. The optics are configured as a Ritchey-Chretien with a coude relay to the focal plane beneath the surface. The optical path is continuously monitored with 3-nanometer precision interferometrically. An active optics processor and piezoelectric actuators operate to maintain the end-to-end optical configuration established by wave front sensing using a guide star. The mirror segments, consisting of a one-centimeter thick faceplate on 30-cm deep ribs, maintain the surface figure to a few nanometers under lunar gravity and thermal environment.

Peacock, Keith↗

Modeling and managing risk early in software development

In order to improve the quality of the software development process, we need to be able to build empirical multivariate models based on data collectable early in the software process. These models need to be both useful for prediction and easy to interpret, so that remedial actions may be taken in order to control and optimize the development process. We present an automated modeling technique which can be used as an alternative to regression techniques. We show how it can be used to facilitate the identification and aid the interpretation of the significant trends which characterize 'high risk' components in several Ada systems. Finally, we evaluate the effectiveness of our technique based on a comparison with logistic regression based models.

Briand, Lionel C.↗

Performance and reliability of the NASA biomass production chamber

The Biomass Production Chamber (BPC) at the Kennedy Space Center is part of the Controlled Ecological Life Support System (CELSS) Breadboard Project. Plants are grown in a closed environment in an effort to quantify their contributions to the requirements for life support. Performance of this system is described. Also, in building this system, data from component and subsystem failures are being recorded. These data are used to identify problem areas in the design and implementation. The techniques used to measure the reliability will be useful in the design and construction of future CELSS. Possible methods for determining the reliability of a green plant, the primary component of CELSS, are discussed.

Fortson, R. E.↗

Performance and reliability of the NASA Biomass Production Chamber

The Biomass Production Chamber (BPC) at the Kennedy Space Center is part of the Controlled Ecological Life Support System (CELSS) Breadboard Project. Plants are grown in a closed environment in an effort to quantify their contributions to the requirements for life support. Performance of this system is described. Also, in building this system, data from component and subsystem failures are being recorded. These data are used to identify problem areas in the design and implementation. The techniques used to measure the reliability will be useful in the design and construction of future CELSS. Possible methods for determining the reliability of a green plant, the primary component of a CELSS, are discussed.

Sager, J. C.↗

Native Peoples-Native Homelands Climate Change Workshop: Lessons Learned

The Native Peoples-Native Homelands Climate Change Workshop was held on October 28 through November 01,1998, as part of a series of workshops being held around the U.S. to improve the understanding of the potential consequences of climate variability and change for the Nation. This workshop was specifically designed by Native Peoples to examine the impacts of climate change and extreme weather variability on Native Peoples and Native Homelands from an indigenous cultural and spiritual perspective and to develop recommendations as well as identify potential response actions. The workshop brought together interested Native Peoples, representatives of Tribal governments, traditional elders, Tribal leaders, natural resource managers, Tribal College faculty and students, and climate scientists fiom government agencies and universities. It is clear that Tribal colleges and universities play a unique and critical role in the success of these emerging partnerships for decision-making in addition to the important education function for both Native and non-Native communities such as serving as a culturally-appropriate vehicle for access, analysis, control, and protection of indigenous cultural and intellectual property. During the discussions between scientists and policy-makers from both Native and non-Native communities, a number of important lessons emerged which are key to building more effective partnerships between Native and non-Native communities for collaboration and decision-making for a more sustainable future. This talk summarizes the key issues, recommendations, and lessons learned during this workshop.

Maynard, Nancy G.↗

Forecasting Weather with a Wave of the Hand

Building upon its successful collaboration with NASA, Cybernet introduced GestureStorm(TradeMark), a weather map management system that utilizes both body tracking and gesture recognition technology for televised weather reports. The GestureStorm software interface enables meteorologists to control the computerized visual effects on weather maps using hand gestures and body movements. Prior to this, meteorologists prepared scripted on-air reports to coincide with the timing of graphics on the computerized maps. They knew when and where weather and Doppler radar maps would appear on the monitor, but could not react in real time. Cybernet s new product frees forecasters from a script, enabling them to directly interact with the weather picture in real time, significantly reducing the preparation time for the broadcast. With this technology, meteorologists control the pace of the visuals and can incorporate spontaneous close-ups with simple hand movements. In cases of severe weather, meteorologists strive to report new information as quickly as possible. GestureStorm gives forecasters an edge as they track late-breaking storms. The reduced preparation and real-time interaction shave critical minutes from the time required to broadcast severe weather warnings.

Source record↗

Design and Analysis of the International X-Ray Observatory Mirror Modules

The Soft X-Ray Telescope (SXT) modules are the fundamental focusing assemblies on NASA's next major X-ray telescope mission, the International X-Ray Observatory (IXO). The preliminary design and analysis of these assemblies has been completed, addressing the major engineering challenges and leading to an understanding of the factors effecting module performance. Each of the 60 modules in the Flight Mirror Assembly (FMA) supports 200-300 densely packed 0.4 mm thick glass mirror segments in order to meet the unprecedented effective area required to achieve the scientific objectives of the mission. Detailed Finite Element Analysis (FEA), materials testing, and environmental testing have been completed to ensure the modules can be successfully launched. Resulting stress margins are positive based on detailed FEA, a large factor of safety, and a design strength determined by robust characterization of the glass properties. FEA correlates well with the results of the successful modal, vibration, and acoustic environmental tests. Deformation of the module due to on-orbit thermal conditions is also a major design driver. A preliminary thermal control system has been designed and the sensitivity of module optical performance to various thermal loads has been determined using optomechanical analysis methods developed for this unique assembly. This design and analysis furthers the goal of building a module that demonstrates the ability to meet IXO requirements, which is the current focus of the IXO FMA technology development team.

McClelland, Ryan S.↗

Envisioning Cognitive Robots for Future Space Exploration

Cognitive robots in the context of space exploration are envisioned with advanced capabilities of model building, continuous planning/re-planning, self-diagnosis, as well as the ability to exhibit a level of 'understanding' of new situations. An overview of some JPL components (e.g. CASPER, CAMPOUT) and a description of the architecture CARACaS (Control Architecture for Robotic Agent Command and Sensing) that combines these in the context of a cognitive robotic system operating in a various scenarios are presented. Finally, two examples of typical scenarios of a multi-robot construction mission and a human-robot mission, involving direct collaboration with humans is given.

robot consciousness↗

Space Shuttle Upgrade Liquid Oxygen Tank Thermal Stratification

In 1997, NASA initiated a study of a liquid oxygen and ethanol orbital maneuvering and reaction control system for space shuttle upgrades as well as other reusable launch vehicle applications. The pressure-fed system uses sub-cooled liquid oxygen at 2413.2 KPa (350 psia) stored passively using insulation. Thermal stratification builds up while the space shuttle is docked at the international space station. The venting from the space shuttle's liquid oxygen tank is not desired during this 96-hr time period. Once the shuttle undocks from the space station there could be a pressure collapse in the liquid oxygen tank caused by fluid mixing due to the thruster fU"ings . The thermal stratification and resulting pressure rise in the tank were examined by a computational fluid dynamic model. Since the heat transfer from the pressurant gas to the liquid will result in a decrease in tank pressure the final pressure after the 96 hours will be significantly less when the tank is pressurized with ambient temperature helium. Therefore, using helium at ambient temperature to pressurize the tank is preferred to pressurizing the tank with helium at the liquid oxygen temperature. The higher helium temperature will also result in less mass of helium to pressurize the tank.

Tunc, Gokturk↗

Multi-point Adjoint-Based Design of Tilt-Rotors in a Noninertial Reference Frame

Optimization of tilt-rotor systems requires the consideration of performance at multiple design points. In the current study, an adjoint-based optimization of a tilt-rotor blade is considered. The optimization seeks to simultaneously maximize the rotorcraft figure of merit in hover and the propulsive efficiency in airplane-mode for a tilt-rotor system. The design is subject to minimum thrust constraints imposed at each design point. The rotor flowfields at each design point are cast as steady-state problems in a noninertial reference frame. Geometric design variables used in the study to control blade shape include: thickness, camber, twist, and taper represented by as many as 123 separate design variables. Performance weighting of each operational mode is considered in the formulation of the composite objective function, and a build up of increasing geometric degrees of freedom is used to isolate the impact of selected design variables. In all cases considered, the resulting designs successfully increase both the hover figure of merit and the airplane-mode propulsive efficiency for a rotor designed with classical techniques.

Jones, William T.↗

Building a QC Database of Meteorological Data From NASA KSC and the United States Air Force's Eastern Range

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) Natural Environments Branch (EV44) has provided atmospheric databases and analysis in support of space vehicle design and day-of-launch operations for NASA and commercial launch vehicle programs launching from the NASA Kennedy Space Center (KSC), co-located on the United States Air Force's Eastern Range (ER) at the Cape Canaveral Air Force Station. The ER is one of the most heavily instrumented sites in the United States measuring various atmospheric parameters on a continuous basis. An inherent challenge with the large databases that EV44 receives from the ER consists of ensuring erroneous data are removed from the databases, and thus excluded from launch vehicle design analyses. EV44 has put forth great effort in developing quality control (QC) procedures for individual meteorological instruments; however, no standard QC procedures for all databases currently exist resulting in QC databases that have inconsistencies in variables, methodologies, and periods of record. The goal of this activity is to use the previous efforts by EV44 to develop a standardized set of QC procedures from which to build flags within the meteorological databases from KSC and the ER, while maintaining open communication with end users from the launch community to develop ways to improve, adapt and grow the QC database. Details of the QC checks are described. The flagged data points will be plotted in a graphical user interface (GUI) as part of a manual confirmation that the flagged data do indeed need to be removed from the archive. As the rate of launches increases with additional launch vehicle programs, more emphasis is being placed to continually update and check weather databases for data quality before use in launch vehicle design and certification analyses.

Brenton, James C.↗

Lessons Learned From the Construction of a Portable Cleanroom for NASA OSIRIS-REx Mission Deintegration

NASA Johnson Space Center (JSC) Infrastructure and Astromaterials Acquisition & Curation Office completed construction and commissioning of the OSIRIS-REx (OREx) Deintegration portable cleanroom at the Utah Test and Training Range (UTTR). The new portable cleanroom was designed to receive the OREx sample return capsule from the landing point on the range to an ISO7 environment. Scientists used the portable clean-room to deintegrate the sample canister from the sample return capsule. Once separated, the sample canister was put in a container under nitrogen purge for transportation to B31 at the Johnson Space Center for astromaterial sample extraction, preliminary analysis, and long-term curation. The portable cleanroom was built by a subcontractor at their facility and then deconstructed to be transported to the remote location at UTTR. Since construction was completed in a remote location all tools and materials had to be transported from contractor site in Dallas, TX. The cleanroom was constructed within an existing facility, which provided conditioned air, electric power, and protection from the elements. Careful coordination was required between the host facility, cleanroom contractor, mission scientists, and JSC facilities and curation personnel. An existing anteroom at JSC was transported to UTTR and added to the portable cleanroom after there was concern about contamination without one for personnel entry/exit. The scientific study of organics is critical for the mission, so a stringent contamination control plan was implemented for low organics. Given these mission requirements the cleanroom construction materials were carefully selected to not hinder the scientific search for amino acids and the study of organics in the samples. The same cleanroom contractor that built the long-term astromaterial curation cleanroom back at JSC Houston, TX was selected to build the portable cleanroom and instructed to use the same materials. The cleanroom had double doors to open and allow the sample return capsule to fit into the cleanroom on its stand and be transferred to a clean stand already in the cleanroom. The portable cleanroom successfully completed its mission and the sample canister was safely deintegrated and transported to JSC under nitrogen purge.

astromaterials curation↗

Portable Cleanroom for NASA OSIRIS-REx Mission Deintegration

NASA Johnson Space Center (JSC) Infrastructure and Astromaterials Acquisition & Curation Office completed construction and commissioning of the OSIRIS-REx (OREx) Deintegration portable cleanroom at the Utah Test and Training Range (UTTR). The new portable cleanroom was designed to receive the OREx sample return capsule from the landing point on the range to an ISO7 environment. Scientists used the portable clean-room to deintegrate the sample canister from the sample return capsule. Once separated, the sample canister was put in a container under nitrogen purge for transportation to B31 at the Johnson Space Center for astromaterial sample extraction, preliminary analysis, and long-term curation. The portable cleanroom was built by a subcontractor at their facility and then deconstructed to be transported to the remote location at UTTR. Since construction was completed in a remote location all tools and materials had to be transported from contractor site in Dallas, TX. The cleanroom was constructed within an existing facility, which provided conditioned air, electric power, and protection from the elements. Careful coordination was required between the host facility, cleanroom contractor, mission scientists, and JSC facilities and curation personnel. An existing anteroom at JSC was transported to UTTR and added to the portable cleanroom after there was concern about contamination without one for personnel entry/exit. The scientific study of organics is critical for the mission, so a stringent contamination control plan was implemented for low organics. Given these mission requirements the cleanroom construction materials were carefully selected to not hinder the scientific search for amino acids and the study of organics in the samples. The same cleanroom contractor that built the long-term astromaterial curation cleanroom back at JSC Houston, TX was selected to build the portable cleanroom and instructed to use the same materials. The cleanroom had double doors to open and allow the sample return capsule to fit into the cleanroom on its stand and be transferred to a clean stand already in the cleanroom. The portable cleanroom successfully completed its mission and the sample canister was safely deintegrated and transported to JSC under nitrogen purge.

astromaterials curation↗

A Stigmergic Cooperative Multi-Robot Control Architecture

In nature, there are numerous examples of complex architectures constructed by relatively simple insects, such as termites and wasps, which cooperatively assemble their nests. A prototype cooperative multi-robot control architecture which may be suitable for the eventual construction of large space structures has been developed which emulates this biological model. Actions of each of the autonomous robotic construction agents are only indirectly coordinated, thus mimicking the distributed construction processes of various social insects. The robotic construction agents perform their primary duties stigmergically, i.e., without direct inter-agent communication and without a preprogrammed global blueprint of the final design. Communication and coordination between individual agents occurs indirectly through the sensed modifications that each agent makes to the structure. The global stigmergic building algorithm prototyped during the initial research assumes that the robotic builders only perceive the current state of the structure under construction. Simulation studies have established that an idealized form of the proposed architecture was indeed capable of producing representative large space structures with autonomous robots. This paper will explore the construction simulations in order to illustrate the multi-robot control architecture.

Howsman, Thomas G.↗

On the automatic generation of FEM models for complex gears - A work-in-progress report

A description is presented of the development and use of a preprocessor to create a NASTRAN finite element model of a complex spur, helical, or spiral bevel gear quickly, inexpensively, and accurately. The preprocessor creates a ready to run NASTRAN input deck including the executive, case control, and bulk data sections. It generates nodes and solid elements to model spur, helical, or spiral bevel gear teeth with integral shafting. Either a complete gear shafting model or a symmetric model is created. The fundamental building block of the gear model is the base layer. The base layer is the mesh configuration of one layer of one tooth segment which is in turn duplicated, translated, and rotated to create the completed model of the gear. Once the base layer is created, the construction of the finite element model is straightforward.

Drago, R. J.↗

Characteristics of a prototype experiment

A new proposed software system was prototyped. Since the system, the Flight Dynamics Analysis System (FDAS), was to be a source code control system, and not the more typical flight dynamics software which NASA personnel were more familiar with, the decision was made to prototype an initial implementation in order to gain insights into the actual features needed to build a full FDAS and to evaluate the idea of prototype in NASA environment. The status of that project at the end of 1983 is described.

Sukri, J.↗