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At least 289 records · Page 16

Terrestrial Planet Finder Coronagraph Optical Modeling

The Terrestrial Planet Finder Coronagraph will rely heavily on modeling and analysis throughout its mission lifecycle. Optical modeling is especially important, since the tolerances on the optics as well as scattered light suppression are critical for the mission's success. The high contrast imaging necessary to observe a planet orbiting a distant star requires new and innovative technologies to be developed and tested, and detailed optical modeling provides predictions for evaluating design decisions. It also provides a means to develop and test algorithms designed to actively suppress scattered light via deformable mirrors and other techniques. The optical models are used in conjunction with structural and thermal models to create fully integrated optical/structural/thermal models that are used to evaluate dynamic effects of disturbances on the overall performance of the coronagraph. The optical models we have developed have been verified on the High Contrast Imaging Testbed. Results of the optical modeling verification and the methods used to perform full three-dimensional near-field diffraction analysis are presented.

space telescopes↗

James Webb Space Telescope - Applying Lessons Learned to I&T

The James Webb Space Telescope (JWST) is part of a new generation of spacecraft acquiring large data volumes from remote regions in space. To support a mission such as the JWST, it is imperative that lessons learned from the development of previous missions such as the Hubble Space Telescope and the Earth Observing System mission set be applied throughout the development and operational lifecycles. One example of a key lesson that should be applied is that core components, such as the command and telemetry system and the project database, should be developed early, used throughout development and testing, and evolved into the operational system. The purpose of applying lessons learned is to reap benefits in programmatic or technical parameters such as risk reduction, end product quality, cost efficiency, and schedule optimization. In the cited example, the early development and use of the operational command and telemetry system as well as the establishment of the intended operational database will allow these components to be used by the developers of various spacecraft components such that development, testing, and operations will all use the same core components. This will reduce risk through the elimination of transitions between development and operational components and improve end product quality by extending the verification of those components through continual use. This paper will discuss key lessons learned that have been or are being applied to the JWST Ground Segment integration and test program.

Johns, Alan↗

International Space Station Crew Restraint Design

With permanent human presence onboard the International Space Station (ISS), crews will be living and working in microgravity, dealing with the challenges of a weightless environment. In addition, the confined nature of the spacecraft environment results in ergonomic challenges such as limited visibility and access to the activity areas, as well as prolonged periods of unnatural postures. Without optimum restraints, crewmembers may be handicapped for performing some of the on-orbit tasks. Currently, many of the tasks on ISS are performed with the crew restrained merely by hooking their arms or toes around handrails to steady themselves. This is adequate for some tasks, but not all. There have been some reports of discomfort/calluses on the top of the toes. In addition, this type of restraint is simply insufficient for tasks that require a large degree of stability. Glovebox design is a good example of a confined workstation concept requiring stability for successful use. They are widely used in industry, university, and government laboratories, as well as in the space environment, and are known to cause postural limitations and visual restrictions. Although there are numerous guidelines pertaining to ventilation, seals, and glove attachment, most of the data have been gathered in a 1-g environment, or are from studies that were conducted prior to the early 1980 s. Little is known about how best to restrain a crewmember using a glovebox in microgravity. In 2004, The Usability Testing and Analysis Facility (UTAF) at the NASA Johnson Space Center completed development/evaluation of several design concepts for crew restraints to meet the various needs outlined above. Restraints were designed for general purpose use, for teleoperation (Robonaut) and for use with the Life Sciences Glovebox. All design efforts followed a human factors engineering design lifecycle, beginning with identification of requirements followed by an iterative prototype/test cycle. Anthropometric modeling was completed for the 5th percentile Asian female and the 95th percentile American male for all restraints. A series of three evaluations was performed onboard NASA's reduced gravity aircraft (KC-135). For all evaluations, participants performed representative tasks while being videotaped, and then completed a questionnaire following each flight day. The questionnaire included ratings scales and free format questions to assess topics such as comfort, stability provided, flexibility provided, etc. Results from the three flight evaluations are being used to develop the human factors design requirements for crew restraint concepts for 1) general purpose restraints, 2) teleoperation restraints and 3) glovebox restraints. The poster presentation will describe the detailed methodology used, results from each of the three evaluations, and the resulting human factors recommendations for the design of these restraints.

Whitmore, M.↗

NASA's Ares I and Ares V Launch Vehicles--Effective Space Operations Through Efficient Ground Operations

The United States (U.S.) is charting a renewed course for lunar exploration, with the fielding of a new human-rated space transportation system to replace the venerable Space Shuttle, which will be retired after it completes its missions of building the International Space Station (ISS) and servicing the Hubble Space Telescope. Powering the future of space-based scientific exploration will be the Ares I Crew Launch Vehicle, which will transport the Orion Crew Exploration Vehicle to orbit where it will rendezvous with the Altair Lunar Lander, which will be delivered by the Ares V Cargo Launch Vehicle (fig. 1). This configuration will empower rekindled investigation of Earth's natural satellite in the not too distant future. This new exploration infrastructure, developed by the National Aeronautics and Space Administration (NASA), will allow astronauts to leave low-Earth orbit (LEO) for extended lunar missions and preparation for the first long-distance journeys to Mars. All space-based operations - to LEO and beyond - are controlled from Earth. NASA's philosophy is to deliver safe, reliable, and cost-effective architecture solutions to sustain this multi-billion-dollar program across several decades. Leveraging SO years of lessons learned, NASA is partnering with private industry and academia, while building on proven hardware experience. This paper outlines a few ways that the Engineering Directorate at NASA's Marshall Space Flight Center is working with the Constellation Program and its project offices to streamline ground operations concepts by designing for operability, which reduces lifecycle costs and promotes sustainable space exploration.

Singer, Christopher E.↗

Constellation Program Life-cycle Cost Analysis Model (LCAM)

The Constellation Program (CxP) is NASA's effort to replace the Space Shuttle, return humans to the moon, and prepare for a human mission to Mars. The major elements of the Constellation Lunar sortie design reference mission architecture are shown. Unlike the Apollo Program of the 1960's, affordability is a major concern of United States policy makers and NASA management. To measure Constellation affordability, a total ownership cost life-cycle parametric cost estimating capability is required. This capability is being developed by the Constellation Systems Engineering and Integration (SE&I) Directorate, and is called the Lifecycle Cost Analysis Model (LCAM). The requirements for LCAM are based on the need to have a parametric estimating capability in order to do top-level program analysis, evaluate design alternatives, and explore options for future systems. By estimating the total cost of ownership within the context of the planned Constellation budget, LCAM can provide Program and NASA management with the cost data necessary to identify the most affordable alternatives. LCAM is also a key component of the Integrated Program Model (IPM), an SE&I developed capability that combines parametric sizing tools with cost, schedule, and risk models to perform program analysis. LCAM is used in the generation of cost estimates for system level trades and analyses. It draws upon the legacy of previous architecture level cost models, such as the Exploration Systems Mission Directorate (ESMD) Architecture Cost Model (ARCOM) developed for Simulation Based Acquisition (SBA), and ATLAS. LCAM is used to support requirements and design trade studies by calculating changes in cost relative to a baseline option cost. Estimated costs are generally low fidelity to accommodate available input data and available cost estimating relationships (CERs). LCAM is capable of interfacing with the Integrated Program Model to provide the cost estimating capability for that suite of tools.

Prince, Andy↗

Strategic Analysis Overview

NASA s Constellation Program employs a strategic analysis methodology in providing an integrated analysis capability of Lunar exploration scenarios and to support strategic decision-making regarding those scenarios. The strategic analysis methodology integrates the assessment of the major contributors to strategic objective satisfaction performance, affordability, and risk and captures the linkages and feedbacks between all three components. Strategic analysis supports strategic decision making by senior management through comparable analysis of alternative strategies, provision of a consistent set of high level value metrics, and the enabling of cost-benefit analysis. The tools developed to implement the strategic analysis methodology are not element design and sizing tools. Rather, these models evaluate strategic performance using predefined elements, imported into a library from expert-driven design/sizing tools or expert analysis. Specific components of the strategic analysis tool set include scenario definition, requirements generation, mission manifesting, scenario lifecycle costing, crew time analysis, objective satisfaction benefit, risk analysis, and probabilistic evaluation. Results from all components of strategic analysis are evaluated a set of pre-defined figures of merit (FOMs). These FOMs capture the high-level strategic characteristics of all scenarios and facilitate direct comparison of options. The strategic analysis methodology that is described in this paper has previously been applied to the Space Shuttle and International Space Station Programs and is now being used to support the development of the baseline Constellation Program lunar architecture. This paper will present an overview of the strategic analysis methodology and will present sample results from the application of the strategic analysis methodology to the Constellation Program lunar architecture.

Cirillo, William M.↗

Modifying the Heliophysics Data Policy to Better Enable Heliophysics Research

The Heliophysics (HP) Science Data Management Policy, adopted by HP in June 2007, has helped to provide a structure for the HP data lifecycle. It provides guidelines for Project Data Management Plans and related documents, initiates Resident Archives to maintain data services after a mission ends, and outlines a route to the unification of data finding, access, and distribution through Virtual observatories. Recently we have filled in missing pieces that assure more coherence and a home for the VxOs (through the 'Heliophsyics Data and Model Consortium'), and provide greater clarity with respect to long term archiving. In particular, the new policy which has been vetted with many community members, details the 'Final Archives' that are to provide long-term data access. These are distinguished from RAs in that they provide little additional service beyond servicing data, but critical to their success is that the final archival materials include calibrated data in useful formats such as one finds in CDAWeb and various ASCII or FITS archives. Having a clear goal for legacy products, to be detailed as part of the Mission Archives Plans presented at Senior Reviews, will help to avoid the situation so common in the past of having archival products that preserve bits well but not readily usable information. We hope to avoid the need for the large numbers of 'data upgrade' projects that have been necessary in recent years.

Hayes, Jeffrey↗

SPICE Module for the Satellite Orbit Analysis Program (SOAP)

A SPICE module for the Satellite Orbit Analysis Program (SOAP) precisely represents complex motion and maneuvers in an interactive, 3D animated environment with support for user-defined quantitative outputs. (SPICE stands for Spacecraft, Planet, Instrument, Camera-matrix, and Events). This module enables the SOAP software to exploit NASA mission ephemeris represented in the JPL Ancillary Information Facility (NAIF) SPICE formats. Ephemeris types supported include position, velocity, and orientation for spacecraft and planetary bodies including the Sun, planets, natural satellites, comets, and asteroids. Entire missions can now be imported into SOAP for 3D visualization, playback, and analysis. The SOAP analysis and display features can now leverage detailed mission files to offer the analyst both a numerically correct and aesthetically pleasing combination of results that can be varied to study many hypothetical scenarios. The software provides a modeling and simulation environment that can encompass a broad variety of problems using orbital prediction. For example, ground coverage analysis, communications analysis, power and thermal analysis, and 3D visualization that provide the user with insight into complex geometric relations are included. The SOAP SPICE module allows distributed science and engineering teams to share common mission models of known pedigree, which greatly reduces duplication of effort and the potential for error. The use of the software spans all phases of the space system lifecycle, from the study of future concepts to operations and anomaly analysis. It allows SOAP software to correctly position and orient all of the principal bodies of the Solar System within a single simulation session along with multiple spacecraft trajectories and the orientation of mission payloads. In addition to the 3D visualization, the user can define numeric variables and x-y plots to quantitatively assess metrics of interest.

Coggi, John↗

Final Report on Portable Laser Coating Removal Systems Field Demonstrations and Testing

Processes currently used throughout the National Aeronautics and Space Administration (NASA) to remove corrosion and coatings from structures, ground service equipment and small components results in waste streams consisting of toxic chemicals, spent media blast materials, and waste water. When chemicals are used in these processes they are typically high in volatile organic compounds (VOC) and are considered hazardous air pollutants (HAP). When blast media is used, the volume of hazardous waste generated is increased significantly. Many of the coatings historically used within NASA contain toxic metals such as hexavalent chromium, and lead. These materials are highly regulated and restrictions on worker exposure continue to increase. Most recently the EPA reduced the permissible exposure limit (PEL) for hexavalent chromium. The new standard lowers OSHA's PEL for hexavalent chromium from 52 to 5 micrograms of Cr(V1) per cubic meter of air as an 8-hour time-weighted average. Hexavalent chromium is found in the pretreatment and primer coatings used within the Shuttle Program. In response to the need to continue to protect assets within the agency and the growing concern over these new regulations, NASA is researching different ways to continue the required maintenance of both facility and flight equipment in a safe, efficient and environmentally preferable manner. The use of laser energy to remove prepare surfaces for a variety of processes, such as corrosion and coating removal, weld preparation and non destructive evaluation is a relatively new technology that has shown itself to be environmentally preferable and in many cases less labor intensive than currently used removal methods. The development of a Portable Laser Coating Removal System (PLCRS) started as the goal of a Joint Group on Pollution Prevention (JG-PP) project, led by the Air Force, where several types of lasers in several configurations were thoroughly evaluated. Following this project, NASA decided to evaluate the best performers on processes and coatings specific to the agency. Laser systems used during this project were all of a similar design, most of which had integrated vacuum systems in order to collect materials removed from substrate surfaces during operation. Due to the fact that the technology lends itself to a bide variety of processes, several site demonstrations were organized in order to allow for greater evaluation of the laser systems across NASA. The project consisted of an introductory demonstration and a more in-depth evaluation at Wright-Patterson Air Force Base. Additionally, field demonstrations occurred at Glenn Research Center and Kennedy Space Center. During these demonstrations several NASA specific applications were evaluated, including the removal of coatings within Orbiter tile cavities and Teflon from Space Shuttle Main Engine gaskets, removal of heavy grease from Solid Rocket Booster components and the removal of coatings on weld lines for Shuttle and general ground service equipment for non destructive evaluation (NDE). In addition, several general industry applications such as corrosion removal, structural coating removal, weld-line preparation and surface cleaning were evaluated. This included removal of coatings and corrosion from surfaces containing lead-based coatings and applications similar to launch-structure maintenance and Crawler maintenance. During the project lifecycle, an attempt was made to answer process specific concerns and questions as they arose. Some of these initially unexpected questions concerned the effects lasers might have on substrates used on flight equipment including strength, surface re-melting, substrate temperature and corrosion resistance effects. Additionally a concern was PPE required for operating such a system including eye, breathing and hearing protection. Most of these questions although not initially planned, were fully explored as a part of this project. Generally the results from tesng were very positive. Corrosion was effectively removed from steel, but less successfully from aluminum alloys. Coatings were able to be removed, with varying results, generally dark, matte and thin coatings were easier to remove. Steel and aluminum panels were able to be cleaned for welding, with no known deleterious effects and weld-lines were able to have coatings removed in critical areas for NDE while saving time as compared to other methods.

Rothgeb, Matthew J.↗

Tool for Human-Systems Integration Assessment: HSI Scorecard

This paper describes the development and rationale for a human-systems integration (HSI) scorecard that can be used in reviews of vehicle specification and design. This tool can be used to assess whether specific HSI related criteria have been met as part of a project milestone or critical event, such as technical reviews, crew station reviews, mockup evaluations, or even review of major plans or processes. Examples of HSI related criteria include Human Performance Capabilities, Health Management, Human System Interfaces, Anthropometry and Biomechanics, and Natural and Induced Environments. The tool is not intended to evaluate requirements compliance and verification, but to review how well the human related systems have been considered for the specific event and to identify gaps and vulnerabilities from an HSI perspective. The scorecard offers common basis, and criteria for discussions among system managers, evaluators, and design engineers. Furthermore, the scorecard items highlight the main areas of system development that need to be followed during system lifecycle. The ratings provide a repeatable quantitative measure to what has been often seen as only subjective commentary. Thus, the scorecard is anticipated to be a useful HSI tool to communicate review results to the institutional and the project office management.

Whitmore, Nihriban↗

Proven Innovations and New Initiatives in Ground System Development

The state-of-the-practice for engineering and development of Ground Systems has evolved significantly over the past half decade. Missions that challenge ground system developers with significantly reduced budgets in spite of requirements for greater and previously unimagined functionality are now the norm. Making the right trades early in the mission lifecycle is one of the key factors to minimizing ground system costs. The Mission Operations Strategic Leadership Team at the Jet Propulsion Laboratory has spent the last year collecting and working through successes and failures in ground systems for application to future missions.

Mission Operations System (MOS)↗

Building on 50 Years of Mission Operations Experience for a New Era of Space Exploration

The U.S. National Space Policy, I the 14-nation Global Exploration Strategy,2 and the National Aeronautics and Space Administration's (NASA) 2006 Strategic Plan3 provide foundational direction for far-ranging missions, from safely flying the Space Shuttle and completing construction of the International Space Station by 2010, to fielding a next generation space transportation system consisting of the Ares I Crew Launch Vehicle!Orion Crew Exploration Vehicle and the Ares V Cargo Launch Vehicle!Altair Lunar Lander (fig. 1). Transportation beyond low-Earth orbit will open the frontier for a lunar outpost, where astronauts will harness in-situ resources while exploring this 4 billion-year-old archaeological site, which may hold answers to how the Earth and its satellite were formed. Ultimately, this experience will pave the way for the first human footprint on Mars. In October 2007, NASA" announced assignments for this lunar exploration work.4 The Marshall Space Flight Center is responsible for designing, developing, testing, and evaluating the Ares I and Ares V, which are Space Shuttle derived launch vehicles, along with a number of lunar tasks. The Marshall Center's Engineering Directorate provides the skilled workforce and unique manufacturing, testing, and operational infrastructure needed to deliver space transportation solutions that meet the requirements stated in the Constellation Architecture Requirements Document (CARD). While defining design reference missions to the Station and the Moon, the CARD includes goals that include reducing recurring and nonrecurring costs, while increasing safety and reliability. For this reason, future systems are being designed with operability considerations and lifecycle expenses as independent variables in engineering trade studies.

Onken, Jay F.↗

Survey of Product-line Verification and Validation Techniques

This report presents the results from the first task of the SARP Center Initiative, 'Product Line Verification of Safety-Critical Software.' Task 1 is a literature survey of available techniques for product line verification and validation. Section 1 of the report provides an introduction to product lines and motivates the survey of verification techniques. It describes what is reused in product-line engineering and explains the goal of verifiable conformance of the developed system to its product-line specifications. Section 2 of the report describes six lifecycle steps in product-line verification and validation. This description is based on, and refers to, the best practices extracted from the readings. It ends with a list of verification challenges for NASA product lines (2.7) and verification enablers for NASA product lines (2.8) derived from the survey. Section 3 provides resource lists of related conferences, workshops, industrial and defense industry experiences and case studies of product lines, and academic/industrial consortiums. Section 4 is a bibliography of papers and tutorials with annotated entries for relevant papers not previously discussed in sections 2 or 3.

testing↗

PLM Innovation in Far Away Places

This viewgraph presentation reviews Jet Propulsion Laboratory's Product Lifecycle Management (PLM) mission to upgrade to product data management systems.

PLM↗

Human-Centered Design Capability

For NASA, human-centered design (HCD) seeks opportunities to mitigate the challenges of living and working in space in order to enhance human productivity and well-being. Direct design participation during the development stage is difficult, however, during project formulation, a HCD approach can lead to better more cost-effective products. HCD can also help a program enter the development stage with a clear vision for product acquisition. HCD tools for clarifying design intent are listed. To infuse HCD into the spaceflight lifecycle the Space and Life Sciences Directorate developed the Habitability Design Center. The Center has collaborated successfully with program and project design teams and with JSC's Engineering Directorate. This presentation discusses HCD capabilities and depicts the Center's design examples and capabilities.

Fitts, David J.↗

Technology Infusion of CodeSonar into the Space Network Ground Segment (RII07)

The NASA Software Assurance Research Program (in part) performs studies as to the feasibility of technologies for improving the safety, quality, reliability, cost, and performance of NASA software. This study considers the application of commercial automated source code analysis tools to mission critical ground software that is in the operations and sustainment portion of the product lifecycle.

Benson, Markland↗