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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.

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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

System Study: Auxiliary Feedwater 1998-2020

This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear reactors. Demand, run hour, and failure data from calendar year 1998–2020 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Industry Reporting and Information System (IRIS), formerly the INPO Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period while yearly estimates for system unreliability are provided for the entire active period. Statistically significant decreasing trends were identified in the industry-wide estimates of AFW system start-only unreliability and AFW system 8-hour mission unreliability.

99 GENERAL AND MISCELLANEOUS↗
NASA NTRSDate not supplied

The NASA JSC Hypervelocity Impact Technology (HVIT) Office

The Hypervelocity Impact Technology (HVIT) office at the Johnson Space Center (JSC) is dedicated to support NASA flight programs in meeting their meteoroid and orbital debris (MMOD) protection requirements both efficiently and effectively, with a minimum of shielding mass, volume, and cost. This paper provides an overview of HVIT capabilities in providing hypervelocity tests, analyses, MMOD risk assessments and shielding expertise. HVIT personnel work closely with NASA Program personnel to develop program-specific MMOD protection requirements which are achievable based on initial risk assessments. Then HVIT proceeds with hypervelocity impact testing and hydrocode assessments to update and verify ballistic limit equations used in the MMOD risk assessment. The final MMOD risk assessment prior to flight will show compliance with MMOD requirements. This final assessment will also incorporate changes in the MMOD environment from meteoroid showers and orbital debris breakups. After the mission is flown, post-flight inspections are performed by HVIT to document and trend MMOD damage to returned spacecraft surfaces and hardware. A majority of the hypervelocity impact tests are performed at the NASA WSTF Remote Hypervelocity Test Laboratory (RHTL), although other hypervelocity facilities that provide complementary test capabilities are called on when necessary to fill data gaps. HVIT accomplishments in NASA mission support are described. In addition, current HVIT activities to aid on-going NASA crewed missions and science missions are presented.

Hypervelocity↗
DOE OSTI2025

System Study: Emergency Power System 1998-2024

This report presents an unreliability evaluation of the emergency power system (EPS) at 93 U.S. commercial operating nuclear reactors. New Standardized Plant Analysis Risk (SPAR) models with the most recent SPAR parameter update results were used in this report. Demand, run hour, and failure data from 1998 to 2024 for selected components were obtained from the Institute of Nuclear Power Operations Industry Reporting and Information System. The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the industry-wide estimates of EPS system start-only unreliability, but a statistically significant decreasing trend was identified in the industry-wide estimates of EPS system 24-hour mission unreliability.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2026

System Study: Auxiliary Feedwater 1998-2024

This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 62 U.S. commercial operating nuclear reactors. New Standardized Plant Analysis Risk (SPAR) models with the most recent SPAR parameter update results were used in this report. Demand, run hour, and failure data from calendar years 1998 to 2024 for selected components were obtained from the Institute of Nuclear Power Operations Industry Reporting and Information System. The unreliability results are trended for the most recent 10 year period and yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the industry-wide estimates of AFW system start-only unreliability, but a statistically significant decreasing trend was identified in the industry-wide estimates of AFW system 24-hour mission unreliability.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS2010

Mission Performance of the GLAS Thermal Control System - 7 Years In Orbit

ICESat (Ice, Cloud and land Elevation Satellite) was launched in 2003 carrying a single science instrument - the Geoscience Laser Altimeter System (GLAS). Its primary mission was to measure polar ice thickness. The GLAS thermal control architecture utilized propylene Loop Heat Pipe (LHP) technology to provide selectable and stable temperature control for the lasers and other electronics over a widely varying mission thermal environment. To minimize expected degradation of the radiators, Optical Solar Reflectors (OSRs) were used for both LHP radiators to minimize degradation caused by UV exposure in the various spacecraft attitudes necessary throughout the mission. Developed as a Class C mission, with selective redundancy, the thermal architecture was single st ring, except for temperature sensors used for heater control during normal operations. Although originally planned for continuous laser operations over the nominal three year science mission, laser anomalies limited operations to discrete measurement campaigns repeated throughout the year. For trending of the science data, these periods were selected to occur at approximately the same time each year, which resulted in operations during similar attitudes and beta angles. Despite the laser life issues, the LHPs have operated nearly continuously over this time, being non-operational for only brief periods. Using mission telemetry, this paper looks at the performance of the thermal subsystem during these periods and provides an assessment of radiator degradation over the mission lifetime.

Grob, Eric W.↗
NASA NTRS1985

Large Antenna Control Methods: Current Status and Future Trends

Current methods for control of large antennas, as well as future trends required for improved performance are addressed. Some of the target missions in which these methods would be used are: the Land Mobile Satellite System (LMSS) for communications; the Satellite Surveillance (SSS) for aircraft traffic control; the orbiting Very Long Baseline Interferometer (VLBI), or QUASAT, for radio astronomy; and the Large Deployable Reflector (LDR) for IR and submillimeter astronomy.

Rodriguez, G.↗
NASA NTRS1988

Requirements for significant problem reporting and trend analysis

This handbook supplements policies, requirements, and procedures of NMI 8070.3 to ensure that NASA management at each organizational level is: fully aware of trends affecting both the level of safety and the potential for mission success established for both NASA manned space programs and its supporting institutions; fully and independently informed of problems that represent significant risk to the safety of all personnel (including the general populace) and to the success of a mission or operation through a program mechanism herein defined as Significant Problem Reporting; and in full agreement with the level of elimination of these problems through the closed-loop accounting of corrective actions. The requirements of this handbook are supportive of the agency's safety, reliability, maintainability, and quality assurance (SRM&QA) program objectives and are applicable to all organizational elements of NASA connected with or supporting developmental or operational manned space program/projects (including associated payloads) and the related institutional facilities.

George A Rodney↗
NASA NTRS1995

Effect of spaceflight on oxidative and antioxidant enzyme activity in rat diaphragm and intercostal muscles

There are limited data regarding changes in oxidative and antioxidant enzymes induced by simulated or actual weightlessness, and any additional information would provide insight into potential mechanisms involving other changes observed in muscles from animals previously flown in space. Thus, the NASA Biospecimen Sharing Program was an opportunity to collect valuable information. Oxidative and antioxidant enzyme levels, as well as lipid peroxidation, were measured in respiratory muscles from rates flown on board Space Shuttle mission STS-54. The results indicated that there was an increasing trend in citrate synthase activity in the flight diaphragm when compared to ground based controls, and there were no significant changes observed in the intercostal muscles for any of the parameters. However, the lipid peroxidation was significantly (p less than 0.05) decreased in the flight diaphragm. These results indicate that 6 day exposure to microgravity may have a different effect on oxidative and antioxidant activity in rat respiratory muscles when compared to data from previous 14 day hindlimb suspension studies.

Lee, Mona D.↗
NASA NTRS2005

Performance Cycle Analysis of a Two-Spool, Separate-Exhaust Turbofan With Interstage Turbine Burner

This paper presents the performance cycle analysis of a dual-spool, separate-exhaust turbofan engine, with an Interstage Turbine Burner serving as a secondary combustor. The ITB, which is located at the transition duct between the high- and the low-pressure turbines, is a relatively new concept for increasing specific thrust and lowering pollutant emissions in modern jet engine propulsion. A detailed performance analysis of this engine has been conducted for steady-state engine performance prediction. A code is written and is capable of predicting engine performances (i.e., thrust and thrust specific fuel consumption) at varying flight conditions and throttle settings. Two design-point engines were studied to reveal trends in performance at both full and partial throttle operations. A mission analysis is also presented to assure the advantage of saving fuel by adding ITB.

Liew, K. H.↗
NASA NTRS2000

Development of a Spaceborne Embedded Cluster

Over the last decade and continuing into the foreseeable future, a trend has developed in the spacecraft industry of both number of missions and the amount of data taken by each mission increasing faster than bandwidth capabilities to send these data to Earth.

parallel processing message passing fault toleranc↗
NASA NTRS2005

An Interdisciplinary Approach at Studying the Earth-Sun System with GPS/GNSS and GPS-like Signals

The value of Global Positioning Satellites (GPS) measurements to atmospheric science, space physics, and ocean science, is now emerging or showing a potential to play a major role in the evolving programs of NASA, NSF and NOAA. The objective of this communication is to identify and articulate the key scientific questions that are optimally, or perhaps uniquely, addressed by GPS or GPS-like observations, and discuss their relevance to existing or planned national Earth-science research programs. The GPS-based ocean reflection experiments performed to date have demonstrated the precision and spatial resolution suitable to altimetric applications that require higher spatial resolution and more frequent repeat than the current radar altimeter satellites. GPS radio occultation is promising as a climate monitoring tool because of its benchmark properties: its raw observable is based on extremely accurate timing measurements. GPS-derived temperature profiles can provide meaningful climate trend information over decadal time scales without the need for overlapping missions or mission-to-mission calibrations. By acquiring data as GPS satellites occult behind the Earth's limb, GPS also provides high vertical resolution information on the vertical structure of electron density with global coverage. New experimental techniques will create more comprehensive TEC maps by using signals reflected from the oceans and received in orbit. This communication will discuss a potential future GNSS Earth Observing System project which would deploy a constellation of satellites using GPS and GPS-like measurements, to obtain a) topography measurements based on GPS reflections with an accuracy and horizontal resolution suitable for eddy monitoring, and h) climate-records quality atmospheric temperature profiles. The constellation would also provide for measurements of ionospheric elec tron density. This is a good example of an interdisciplinary mission concept, with broad science objectives of high societal relevance, al l resting on common cost-effective technology.

Global Navigation Satellite System (GNSS)↗
NASA NTRS2016

NASA Near Earth Network (NEN) and Space Network (SN) Support of CubeSat Communications

There has been a historical trend to increase capability and drive down the Size, Weight and Power (SWAP) of satellites and that trend continues today. NASA scientists and engineers across many of NASAs Mission Directorates and Centers are developing exciting CubeSat concepts and welcome potential partnerships for CubeSat endeavors. From a Telemetry, Tracking and Command (TTC) Systems and Flight Operations for Small Satellites point of view, small satellites including CubeSats are a challenge to coordinate because of existing small spacecraft constraints, such as limited SWAP and attitude control, and the potential for high numbers of operational spacecraft. The NASA Space Communications and Navigation (SCaN) Programs Near Earth Network (NEN) and Space Network (SN) are customer driven organizations that provide comprehensive communications services for space assets including data transport between a missions orbiting satellite and its Mission Operations Center (MOC). This paper presents how well the SCaN networks, SN and NEN, are currently positioned to support the emerging small small satellite and CubeSat market as well as planned enhancements for future support.

Satellite↗
NASA NTRS2021

A Survey of CubeSat Deployable Structures: The First Decade

In the past decade CubeSats have made their way into the spotlight. They have evolved from small, university educational opportunities, to industry and governments using them make new discoveries and monetize space. However, with the small, constrained CubeSat form factor; there is often a need to expand the CubeSat through deployable mechanisms once the satellite is in space. This paper is a survey of deployable structures and their actuating mechanisms for CubeSats. The goal of this paper is to provide the applications within which deployable structures have been used in the past for CubeSats, the mechanisms with regards to how they deploy, the lessons learned, and limitations of the various types of deployables. The inputs to this paper come from a relational database in development to track launched CubeSat missions with deployable structures. From this database we can find insightful trends. This paper specifically focuses on the first decade of CubeSat deployables, from 2000 to 2010.

Arya, Manan↗
NASA NTRS2016

Demonstrating the Error Budget for the Climate Absolute Radiance and Refractivity Observatory Through Solar Irradiance Measurements

The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission addresses the need to observe highaccuracy, long-term climate change trends and to use decadal change observations as a method to determine the accuracy of climate change. A CLARREO objective is to improve the accuracy of SI-traceable, absolute calibration at infrared and reflected solar wavelengths to reach on-orbit accuracies required to allow climate change observations to survive data gaps and observe climate change at the limit of natural variability. Such an effort will also demonstrate National Institute of Standards and Technology (NIST) approaches for use in future spaceborne instruments. The current work describes the results of laboratory and field measurements with the Solar, Lunar for Absolute Reflectance Imaging Spectroradiometer (SOLARIS) which is the calibration demonstration system (CDS) for the reflected solar portion of CLARREO. SOLARIS allows testing and evaluation of calibration approaches, alternate design and/or implementation approaches and components for the CLARREO mission. SOLARIS also provides a test-bed for detector technologies, non-linearity determination and uncertainties, and application of future technology developments and suggested spacecraft instrument design modifications. Results of laboratory calibration measurements are provided to demonstrate key assumptions about instrument behavior that are needed to achieve CLARREO's climate measurement requirements. Absolute radiometric response is determined using laser-based calibration sources and applied to direct solar views for comparison with accepted solar irradiance models to demonstrate accuracy values giving confidence in the error budget for the CLARREO reflectance retrieval.

CLARREO↗
NASA NTRS1980

Changes in erythropoietin levels during space flight or space flight simulation

Two hundred and seventy samples from 24 subjects involved in 3 bedrest studies and from 3 subjects involved in Spacelab Mission Development Test 3 were assayed for erythropoietin (Ep), in an in vitro fetal mouse liver cell assay, and for ferritin using a commercially available immunoradiometric assay kit. No trends or significant changes in serum Ep were observed. Serum ferritin concentrations tended to increases slightly during the 'missions', reflecting a redirection of iron from the suppressed erythron into iron stores.

Dunn, C. D. R.↗
NASA NTRS2016

Topic Modeling of NASA Space System Problem Reports: Research in Practice

Problem reports at NASA are similar to bug reports: they capture defects found during test, post-launch operational anomalies, and document the investigation and corrective action of the issue. These artifacts are a rich source of lessons learned for NASA, but are expensive to analyze since problem reports are comprised primarily of natural language text. We apply topic modeling to a corpus of NASA problem reports to extract trends in testing and operational failures. We collected 16,669 problem reports from six NASA space flight missions and applied Latent Dirichlet Allocation topic modeling to the document corpus. We analyze the most popular topics within and across missions, and how popular topics changed over the lifetime of a mission. We find that hardware material and flight software issues are common during the integration and testing phase, while ground station software and equipment issues are more common during the operations phase. We identify a number of challenges in topic modeling for trend analysis: 1) that the process of selecting the topic modeling parameters lacks definitive guidance, 2) defining semantically-meaningful topic labels requires nontrivial effort and domain expertise, 3) topic models derived from the combined corpus of the six missions were biased toward the larger missions, and 4) topics must be semantically distinct as well as cohesive to be useful. Nonetheless,topic modeling can identify problem themes within missions and across mission lifetimes, providing useful feedback to engineers and project managers.

Data Mining↗
NASA NTRS2017

Data Production on Past and Future NASA Missions

Data return is a metric that is commonly publicized for all space science missions. In the early days of the Space Program, this figure was small, and could be described in bits or maybe even megabits. But now, missions are capable of returning data volumes two or three orders of magnitude larger. For example, Voyager 1 and 2 combined produced a little over 5 Terabits of data in 39 years of operation. In contrast, the Cassini mission, launched two decades after Voyager, produced about one and a half times those data volumes in half the time. NISAR, an Earth Science Mission currently in implementation, plans to produce over 28 Petabits of raw data in just 3 years. This means that NISAR will produce about as many data in 30 days as the combined data production of nearly all planetary missions to date. These increases in capability are a result of technology enhancements in two main areas: telecommunications architecture (both space and ground segments) and data storage technology. This paper describes the progression of these two technologies over the course of more than three decades of space missions and provides additional insight into the design of the end-to-end NISAR Data System Architecture. Trends in the data are briefly explored and compared to Moore’s Law which provides only a qualitative model for memory growth but not for data production. In summary, early missions are found to be driven by unrefined processes while later missions, having utilized earlier lessons learned, focus more on improvements to flight and ground capabilities. Data return seems to fall into three categories. First, deep space missions are driven by the large distances that limit data return to the Earth. Next, the orbiter infrastructure around Mars helps these missions generate more data than other deep space spacecraft. Finally, near-Earth missions have the greatest capabilities for the studied metrics due to their close proximity to Earth and the ground network availability.

Xaypraseuth, Peter↗
NASA NTRS2024

Looking to the Future: A Call to Action for Advanced GNC Algorithm Verification and Validation

Future space systems will rely on autonomous Guidance, Navigation, and Control (GNC) functions to efficiently manage safe and precise self-directed operations in uncertain complex environments. Fundamentally, the GNC system plays a key role in mission performance and safety because it computes the ideal trajectory (Guidance), determines the actual trajectory (Navigation), and executes the ideal trajectory (Control) of a vehicle’s position and attitude. Our current GNC systems are highly automated and already have a high degree of complexity. As missions become more ambitious, GNC systems for launch vehicles and space platforms (e.g., spacecraft, probes, and landers) will require higher levels of performance and autonomous operation than previously encountered, for example, this includes GNC for optimizing aerodynamic and/or propulsion performance during planetary entry. This GNC Verification and Validation (V&V) paper highlights concerns with what undoubtedly will be a trend towards increased complexity as fully autonomous GNC systems are developed for future space missions. Clearly, complex GNC systems pose challenges in the prelaunch V&V phase, which is a relatively expensive part of a mission’s life cycle. Essentially the V&V phase is focused on checking that the system effectively meets all the design and operational requirements for the mission. The authors of this paper (i.e., the Inter-Agency Working Group of GNC subject matter experts) focused on this fundamental question over the past few years: Will the GNC engineering community of practice be sufficiently prepared to perform the necessary V&V on evolving GNC architectures that are driven by very demanding requirements for autonomy, resiliency, reconfigurability, adaptability, and mission cost-benefit balance? It is the viewpoint of our Inter-Agency team that the GNC V&V approaches and processes needed to address the next generation of complex GNC systems, which likely will employ various forms of modern GNC technology, are not currently established to the level the community will need in the future. While researchers and practitioners have made some progress in developing new GNC V&V methods for modern GNC systems, a good deal of work remains to be done to codify such methods in a comprehensive and systematic manner. Thus, the Inter-Agency team’s partner organizations [the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), the National Centre for Space Studies (CNES), the German Aerospace Center (DLR), the French Aerospace Lab (ONERA), and ISAE-SUPAERO] have conducted preliminary investigations into advancing GNC V&V techniques, which resulted in the identification of the need for education, new V&V tools, and benchmark problems for the GNC community. The necessary proactive steps to be taken to meet the challenges and fill the gaps in GNC V&V are summarized in this paper. The first steps include identifying advanced analysis tools, developing a GNC V&V roadmap, and expanding education and training programs for GNC practitioners. This paper is a call to action and proposes a comprehensive set of recommended actions for all our stakeholders: space agencies, researchers, and industry.

Samir Bennani↗