Search NASA⌕ Search

SEARCH · Search NASA

Results for “Lessons Learned”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

Institutionalizing Lessons Learned

The NASA Integrated Action Team (NIAT) was formed by the NASA Administrator in March 2000. The purpose of this team was to identify the actions that NASA must take to address systemic findings reported in 4 different anomaly investigations. Team membership represented senior managers from all the field centers and NASA Headquarters. NIAT report addressed 165 findings and developed 17 action plans that are described in five themes: people and teams, technology, risk, formulation rigor, and communications. The NIAT actions present a systems solution for strengthening formulation and implementation of programs and improving the environment for their support. NIAT results included: enhancing success by avoiding failures that could have been prevented through good planning and sound practice; ensuring that prudent risks do not compromise safety; and ensuring that mission risks are objectively assessed, appropriately mitigated and consciously accepted by the program team and customers. Definitions of Faster, Better, Cheaper and Success Criteria were also developed and included as part of the NIAT report. As a result of the NIAT report, program and project management process changes were incorporated into NASA's quality system documentation, including NPG 7120.513, "NASA Program and Project Management Processes and Requirements. This paper describes the NIAT results and the resulting updates to NPG 7120.5 that keep this program and project management description a living process.

McBrayer, Robert O.↗
NASA NTRS2000

Tropical Rainfall Measuring Mission (TRMM) Satellite: Assessment and Lessons Learned After Three Flight Years

Tropical Rain Measuring Mission (TRMM) is an experiment in measuring rainfall and the associated latent heat release from space. A primary goal is to help in initializing the large-scale weather and climate models for crucial improvement in location and profile of atmospheric heat release. For this, precipitation and latent heating profiles are needed. This goal requires cloud-resolving models. The basic approach was to use passive microwave and rain radar in combination to issue a limited number of products, improving the retrieval algorithms by testing during flight, so the products are updated annually. Despite a tight budget, the TRMM observatory and data system worked excellently from launch for the past three years. A basic philosophy has been to do physical validation as much as possible, in preference to empirical adjustments for algorithm improvement. Additional information is contained in the original extended abstract.

Simpson, Joanne↗
NASA NTRS2000

An Open Source Web Map Server Implementation For California and the Digital Earth: Lessons Learned

This paper describes an Open Source implementation of the Open GIS Consortium's Web Map interface. It is based on the very popular Apache WWW Server, the Sun Microsystems Java ServIet Development Kit, and a C language shared library interface to a spatial datastore. This server was initially written as a proof of concept, to support a National Aeronautics and Space Administration (NASA) Digital Earth test bed demonstration. It will also find use in the California Land Science Information Partnership (CaLSIP), a joint program between NASA and the state of California. At least one WebMap enabled server will be installed in every one of the state's 58 counties. This server will form a basis for a simple, easily maintained installation for those entities that do not yet require one of the larger, more expensive, commercial offerings.

Sullivan, D. V.↗
NASA NTRS1995

Capsule Aerothermodynamics. CFD Prediction Methodology; Database for CFD Validation; Capsule Flight Programs: AFE and Apollo Lessons Learned

Features of chemically reacting separated hypersonic flows are identified and issues concerning their analysis and simulation are discussed. Emphasis is placed on flows of high temperature dissociating and ionizing air and current methods for studying and characterizing these flows, including separation, are reviewed. The aeroassist orbital transfer vehicle and its flight trajectory are used for illustration. Thermochemical nonequilibrium phenomena are emphasized and extension of continuum analysis to the high altitude slip-flow regime is considered.

Deiwert, George S.↗
NASA NTRS2001

Lessons Learned and Process Improvement for Payload Operations at the Launch Site

For every space mission, there are challenges with the launch site/field operations process that are addressed too late in the development cycle. This potentially causes schedule delays, cost overruns, and adds risk to the mission success. This paper will discuss how a single interface, representing the payload at the launch site in all phases of development, will mitigate risk, and minimize or even alleviate potential problems later on. Experience has shown that a single interface between the project and the launch site allows for issues to be worked in a timely manner and bridges the gap between two diverse cultures.

Catena, John↗
NASA NTRS2002

Fielding An Amphibious UAV: Development, Results, and Lessons Learned

This report summarizes the work completed on the design and flight-testing of a small, unmanned, amphibious demonstrator aircraft that flies autonomously. The aircraft named ACAT (Autonomous Cargo Amphibious Transport) is intended to be a large cargo carrying unmanned aircraft that operates from water to avoid airspace and airfield conflict issues between manned and unmanned aircraft. To demonstrate the feasibility of this concept, a demonstrator ACAT was designed, built, and flown that has a six-foot wingspan and can fly autonomously from land or water airfield. The demonstrator was designed for a 1-hour duration and 1-mile telemetry range. A sizing code was used to design the smallest demonstrator UAV to achieve these goals. The final design was a six-foot wingspan, twin hull configuration that distributes the cargo weight across the span, reducing the wing structural weight. The demonstrator airframe was constructed from balsa wood, fiberglass, and plywood. A 4-stroke model airplane engine powered by methanol fuel was mounted in a pylon above the wing and powers the ACAT UAV. Initial flight tests from land and water were conducted under manual radio control and confirmed the amphibious capability of the design. Flight avionics that were developed by MLB for production UAVs were installed in the ACAT demonstrator. The flight software was also enhanced to permit autonomous takeoff and landing from water. A complete autonomous flight from ahard runway was successfully completed on July 5, 2001 and consisted of a take-off, rectangular flight pattern, and landing under complete computer control. A completely autonomous flight that featured a water takeoff and landing was completed on October 4, 2001. This report describes these activities in detail and highlights the challenges encountered and solved during the development of the ACAT demonstrator. hard runway was successfully completed on July 5, 2001 and consisted of a take-off, rectangular flight pattern, and landing under complete computer control. A completely autonomous flight that featured a water takeoff and landing was completed on October 4, 2001. This report describes these activities in detail and highlights the challenges encountered and solved during the development of the ACAT demonstrator.

Pisanich, Greg↗
NASA NTRS2002

Lessons Learned from a Collaborative Sensor Web Prototype

This paper describes the Sensor Web Application Prototype (SWAP) system that was developed for the Earth Science Technology Office (ESTO). The SWAP is aimed at providing an initial engineering proof-of-concept prototype highlighting sensor collaboration, dynamic cause-effect relationship between sensors, dynamic reconfiguration, and remote monitoring of sensor webs.

Ames, Troy↗
NASA NTRS2002

NASA Technical Standards Program and Implications for Lessons Learned and Technical Standard Integration

The National Aeronautics and Space Agency consists of fourteen Facilities throughout the United States. They are organized to support the Agency's principal Enterprises: (1) Space Science, (2) Earth Science, (3) Aerospace Technology, (4) Human Exploration and Development of Space, and (5) Biological and Physical Research. Technical Standards are important to the activities of each Enterprise and have been an integral part in the development and operation of NASA Programs and Projects since the Agency was established in 1959. However, for years each Center was responsible for its own standards development and selection of non-NASA technical standards that met the needs of Programs and Projects for which they were responsible. There were few Agencywide applicable Technical Standards, mainly those in area of safety. Department of Defense Standards and Specifications were the foundation and main source for Technical Standards used by the Agency. This process existed until about 1997 when NASA embarked on a Program to convert NASA's Center-developed Technical Standards into Agencywide endorsed NASA Preferred Technical Standards. In addition, action was taken regarding the formal adoption of non-NASA Technical Standards (DOD, SAE, ASTM, ASME, IEEE, etc.) as NASA Preferred Technical Standards.

Gill, Paul S.↗
NASA NTRS2002

Structural Acoustic Response of a Shape Memory Alloy Hybrid Composite Panel (Lessons Learned)

This study presents results from an effort to fabricate a shape memory alloy hybrid composite (SMAHC) panel specimen and test the structure for dynamic response and noise transmission characteristics under the action of thermal and random acoustic loads. A method for fabricating a SMAHC laminate with bi-directional SMA reinforcement is described. Glass-epoxy unidirectional prepreg tape and Nitinol ribbon comprise the material system. Thermal activation of the Nitinol actuators was achieved through resistive heating. The experimental hardware required for mechanical support of the panel/actuators and for establishing convenient electrical connectivity to the actuators is presented. Other experimental apparatus necessary for controlling the panel temperature and acquiring structural acoustic data are also described. Deficiency in the thermal control system was discovered in the process of performing the elevated temperature tests. Discussion of the experimental results focuses on determining the causes for the deficiency and establishing means for rectifying the problem.

Turner, Travis L.↗
NASA NTRS2003

Advanced Durability and Damage Tolerance Design and Analysis Methods for Composite Structures: Lessons Learned from NASA Technology Development Programs

Aerospace vehicles are designed to be durable and damage tolerant. Durability is largely an economic life-cycle design consideration whereas damage tolerance directly addresses the structural airworthiness (safety) of the vehicle. However, both durability and damage tolerance design methodologies must address the deleterious effects of changes in material properties and the initiation and growth of microstructural damage that may occur during the service lifetime of the vehicle. Durability and damage tolerance design and certification requirements are addressed for commercial transport aircraft and NASA manned spacecraft systems. The state-of-the-art in advanced design and analysis methods is illustrated by discussing the results of several recently completed NASA technology development programs. These programs include the NASA Advanced Subsonic Technology Program demonstrating technologies for large transport aircraft and the X-33 hypersonic test vehicle demonstrating technologies for a single-stage-to-orbit space launch vehicle.

Harris, Charles E.↗
NASA NTRS2003

Atmospheric Ionizing Radiation (AIR): Analysis, Results, and Lessons Learned From the June 1997 ER-2 Campaign

The United States initiated a program to assess the technology required for an environmentally safe and operationally efficient High Speed Civil Transport (HSCT) for entrance on the world market after the turn of the century. Due to the changing regulations on radiation exposures and the growing concerns over uncertainty in our knowledge of atmospheric radiations, the NASA High Speed Research Project Office (HSRPO) commissioned a review of "Radiation Exposure and High-Altitude Flight" by the National Council on Radiation Protection and Measurements (NCRP). On the basis of the NCRP recommendations, the HSRPO funded a flight experiment to resolve the environmental uncertainty in the atmospheric ionizing radiation levels as a step in developing an approach to minimize the radiation impact on HSCT operations. To minimize costs in this project, an international investigator approach was taken to assure coverage with instrument sensitivity across the range of particle types and energies to allow unique characterization of the diverse radiation components. The present workshop is a result of the flight measurements made at the maximum intensity of the solar cycle modulated background radiation levels during the month of June 1997.

Wilson, J. W.↗
NASA NTRS2003

Lessons Learned from NASA UAV Science Demonstration Program Missions

During the summer of 2002, two airborne missions were flown as part of a NASA Earth Science Enterprise program to demonstrate the use of uninhabited aerial vehicles (UAVs) to perform earth science. One mission, the Altus Cumulus Electrification Study (ACES), successfully measured lightning storms in the vicinity of Key West, Florida, during storm season using a high-altitude Altus(TM) UAV. In the other, a solar-powered UAV, the Pathfinder Plus, flew a high-resolution imaging mission over coffee fields in Kauai, Hawaii, to help guide the harvest.

Wegener, Steven S.↗
NASA NTRS2003

Acquisition of Earth Science Remote Sensing Observations from Commercial Sources: Lessons Learned from the Space Imaging IKONOS Example

In an effort to more full explore the potential of commercial remotely sensed land data sources, the NASA Earth Science Enterprise (ESE) implemented an experimental Scientific Data Purchase (SDP) that solicited bids from the private sector to meet ESE-user data needs. The images from the Space Imaging IKONOS system provided a particularly good match to the current ESE missions such as Terra and Landsat 7 and therefore serve as a focal point in this analysis.

Goward, Samuel N.↗
NASA NTRS2003

Lessons Learned from using a Livingstone Model to Diagnose a Main Propulsion System

NASA researchers have demonstrated that qualitative, model-based reasoning can be used for fault detection in a Main Propulsion System (MPS), a complex, continuous system. At the heart of this diagnostic system is Livingstone, a discrete, propositional logic-based inference engine. Livingstone comprises a language for specifying a discrete model of the system and a set of algorithms that use the model to track the system's state. Livingstone uses the model to test assumptions about the state of a component - observations from the system are compared with values predicted by the model. The intent of this paper is to summarize some advantages of Livingstone seen through our modeling experience: for instance, flexibility in modeling, speed and maturity. We also describe some shortcomings we perceived in the implementation of Livingstone, such as modeling continuous dynamics and handling of transients. We list some upcoming enhancements to the next version of Livingstone that may resolve some of the current limitations.

Sweet, Adam↗
NASA NTRS2004

Building Hybrid Rover Models for NASA: Lessons Learned

Particle filters have recently become popular for diagnosis and monitoring of hybrid systems. In this paper we describe our experiences using particle filters on a real diagnosis problem, the NASA Ames Research Center's K-9 rover. As well as the challenge of modelling the dynamics of the system, there are two major issues in applying a particle filter to such a model. The first is the asynchronous nature of the system-observations from different subsystems arrive at different rates, and occasionally out of order, leading to large amounts of uncertainty in the state of the system. The second issue is data interpretation. The particle filter produces a probability distribution over the state of the system, from which summary statistics that can be used for control or higher-level diagnosis must be extracted. We describe our approaches to both these problems, as well as other modelling issues that arose in this domain.

Willeke, Thomas↗
NASA NTRS2000

Crew/Automation Interaction in Space Transportation Systems: Lessons Learned from the Glass Cockpit

The progressive integration of automation technologies in commercial transport aircraft flight decks - the 'glass cockpit' - has had a major, and generally positive, impact on flight crew operations. Flight deck automation has provided significant benefits, such as economic efficiency, increased precision and safety, and enhanced functionality within the crew interface. These enhancements, however, may have been accrued at a price, such as complexity added to crew/automation interaction that has been implicated in a number of aircraft incidents and accidents. This report briefly describes 'glass cockpit' evolution. Some relevant aircraft accidents and incidents are described, followed by a more detailed description of human/automation issues and problems (e.g., crew error, monitoring, modes, command authority, crew coordination, workload, and training). This paper concludes with example principles and guidelines for considering 'glass cockpit' human/automation integration within space transportation systems.

Rudisill, Marianne↗
NASA NTRS2002

Lessons learned from Shuttle/Mir: psychosocial countermeasures

BACKGROUND: During future long-duration space missions, countermeasures need to be developed to deal with psychosocial issues that might impact negatively on crewmember performance and well-being. METHODS: In our recently completed NASA-funded study of 5 U.S. astronauts, 8 Russian cosmonauts, and 42 U.S. and 16 Russian mission control personnel who participated in the Shuttle/Mir program, we evaluated a number of important psychosocial issues such as group tension, cohesion, leadership role, and the displacement of negative emotions from crewmembers to people in mission control and from mission control personnel to management. RESULTS: Based on our findings, which are reviewed, a number of psychosocial countermeasures are suggested to help ameliorate the negative impact of potential psychosocial problems during future manned space missions. CONCLUSIONS: Crewmembers should be selected not only to rule out psychopathology but also to select-in for group compatibility and facility in a common language. Training should include briefings and team building related to a number of psychosocial issues and should involve both crewmembers and mission control personnel. During the mission, both experts on the ground and the crewmembers themselves should be alert to potential interpersonal problems, including the displacement of negative emotions from the crew to the ground. Supportive activities should consist of both individual and interpersonal strategies, including an awareness of changing leisure time needs. Finally, attention should be given to postmission readjustment and to supporting the families on Earth.

Non-NASA Center↗