Search NASA⌕ Search

SEARCH · Search NASA

Results for “Launch Productivity”

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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Aerosol and Cloud Observations and Data Products by the GLAS Polar Orbiting Lidar Instrument

The Geoscience Laser Altimeter System (GLAS) launched in 2003 is the first polar orbiting satellite lidar. The instrument was designed for high performance observations of the distribution and optical scattering cross sections of clouds and aerosol. The backscatter lidar operates at two wavelengths, 532 and 1064 nm. Both receiver channels meet and exceed their design goals, and beginning with a two month period through October and November 2003, an excellent global lidar data set now exists. The data products for atmospheric observations include the calibrated, attenuated backscatter cross section for cloud and aerosol; height detection for multiple cloud layers; planetary boundary layer height; cirrus and aerosol optical depth and the height distribution of aerosol and cloud scattering cross section profiles. The data sets are now in open release through the NASA data distribution system. The initial results on global statistics for cloud and aerosol distribution has been produced and in some cases compared to other satellite observations. The sensitivity of the cloud measurements is such that the 70% global cloud coverage result should be the most accurate to date. Results on the global distribution of aerosol are the first that produce the true height distribution for model inter-comparison.

Spinhirne, J. D.↗
NASA NTRS2010

Testing Requirements for Refractory Materials

Launch Pads 39A and 39B currently use refractory material (Fondu Fyre) in the flame trenches. This material was initially approved for the Saturn program. This material had a lifetime of 10 years according to the manufacturer, and it has been used for over 40 years. As a consequence, the Fondu Fyre at Launch Complex 39 requires repair subsequent to almost every launch. A review of the literature indicates that the gunned Fondu Fyre refractory product (WA-1G) was never tested prior to use. With the recent severe damage to the flame trenches, a new refractory material is sought to replace Fondu Fyre. In order to replace Fondu Fyre, a methodology to test and evaluate refractory products was developed. This paper outlines this methodology and discusses current testing requirements, as well as the laboratory testing that might be required. Furthermore, this report points out the necessity for subscale testing, the locations where this testing can be performed, and the parameters that will be necessary to qualify a product. The goal is to identify a more durable refractory material that has physical, chemical, and thermal properties suitable to withstand the harsh environment of the launch pads at KSC.

Calle, Luz Marina↗
NASA NTRS2011

Testing Requirements for Refractory Materials

Launch Pads 39A and 39B currently use refractory material (Fondu Fyre) in the flame trenches. This material was initially approved for the Saturn program. This material had a lifetime of 10 years according to the manufacturer, and it has been used for over 40 years. As a consequence, the Fondu Fyre at Launch Complex 39 requires repair subsequent to almost every launch. A review of the literature indicates that the gunned Fondu Fyre refractory product (WA-1G) was never tested prior to use. With the recent severe damage to the flame trenches, a new refractory material is sought to replace Fondu Fyre. In order to replace Fondu Fyre, a methodology to test and evaluate refractory products was developed. This paper outlines this methodology and discusses current testing requirements, as well as the laboratory testing that might be required. Furthermore, this report points out the necessity for subscale testing, the locations where this testing can be performed, and the parameters that will be necessary to qualify a product. The goal is to identify a more durable refractory material that has physical, chemical, and thermal properties suitable to withstand the harsh environment of the launch pads at KSC.

Calle, Luz Marina↗
NASA NTRS2012

Testing Requirements for Refractory Materials

Launch Pads 39A and 39B currently use refractory material (Fondu Fyre) in the flame trenches. This material was initially approved for the Saturn program. This material had a lifetime of 10years according to the manufacturer, and it has been used for over 40 years. As a consequence, the Fondu Fyre at Launch Complex 39 requires repair subsequent to almost every launch. A review of the literature indicates that the gunned Fondu Fyre refractory product (WA-1 G) was never tested prior to use. With the recent severe damage to the flame trenches, a new refractory material is sought to replace Fondu Fyre. In order to replace Fondu Fyre, a methodology to test and evaluate refractory products was developed. This paper outlines this methodology and discusses current testing requirements, as well as the laboratory testing that might be required. Furthermore, this report points out the necessity for subscale testing, the locations where this testing can be performed, and the parameters that will be necessary to qualify a product. The goal is to identify a more durable refractory material that has physical, chemical, and thermal properties suitable to withstand the harsh environment of the launch pads at KSC.

Calle, Luz Marina↗
NASA NTRS2023

Commercial Smallsat Data Acquisition Program On-ramp #2 Airbus U.S. Synthetic Aperture Radar (SAR) Evaluation Report

In 2017, NASA’s Earth Science Division (ESD) launched the Private-Sector Small Constellation Satellite Data Product Pilot, now referred to as the Commercial Smallsat Data Acquisition (CSDA) program. The objective of CSDA is to identify, evaluate, and acquire commercial remote sensing data that support NASA’s Earth science research and application activities. The Pilot successfully concluded in early 2020, when CSDA transitioned into a sustained program with on-ramping opportunities for new vendors as the industry emerges with new candidates and capabilities. In October 2019, a Request for Information (RFI) seeking capability statements from parties interested in providing data from spaceborne platforms was released for the CSDA on-ramp #2 evaluations. To be responsive to the RFI, the commercial satellite constellations had to consist of three or more operating spacecraft actively collecting data in a non-geostationary orbit with full latitudinal coverage and be U.S. companies. Two vendors responded to the RFI and were evaluated by a committee composed of NASA ESD leadership, program managers, and scientists. Both vendors satisfied the RFI requirements and were asked to respond to a Request for Proposal (RFP). After review of the proposals, NASA entered into a Blanket Purchase Agreement (BPA) with Airbus Defense and Space GEO, Inc. (Airbus) U.S. in September 2021 and with BlackSky Geospatial Solutions, Inc. (BlackSky) in November 2021. In this report, CSDA provides an evaluation of the usefulness of data provided by the Airbus U.S. Synthetic Aperture Radar (SAR) satellite constellation, consisting of TerraSAR-X (launched in 2007), TanDEM-X (launched in 2010), and PAZ (launched in 2018), for advancing NASA’s Earth system science research and applications. The evaluation of the BlackSky commercial data will be provided in a separate report. To conduct the Airbus evaluation, NASA’s ESD augmented 13 existing research projects that could potentially benefit from, and had the expertise to evaluate, the commercial data being considered for longer-term purchase. Investigators from NASA’s Research and Analysis Program science focus areas and from NASA’s Applied Sciences Program elements participated in the evaluation. A summary of the research areas evaluated by the Principal Investigator (PI) teams is presented in Figure 3. CSDA also funded a dedicated activity to evaluate the satellite data quality (calibration and geolocation) independently by assessing the accuracy of data from Airbus. Evaluation activities were carried out by the selected PIs from December 7, 2022, to December 7, 2023. Delivery of datasets requested by the researchers began in January 2023. The vendors were evaluated on the accessibility of data, accuracy and completeness of metadata, and promptness and quality of user support services. Datasets purchased during the evaluation have been archived by NASA and will be made available to current and future government-funded researchers in accordance with the End User License Agreement (EULA). This synthesis report distills and integrates the findings of research reports commissioned by NASA for the Airbus evaluation. This report also includes recommendations that inform the way ahead for the program. The scientific results from the evaluations demonstrated that the commercial data from Airbus were able to advance NASA research and applications. However, the PIs encountered limitations that diminished the usefulness of the data due to the amount of effort that was required to access, preprocess, and analyze these data. One significant issue encountered was the limited spatial and temporal coverage of the data in the Airbus archive that could be used to conduct time series analyses or assessments over large spatial scales. Overall, however, the utility and the quality of the evaluated data outweighed the difficulties encountered, and NASA has concluded that the Airbus SAR data would complement NASA’s existing Earth observation capabilities and Airbus U.S. would qualify to participate in the sustained phase of the program.

Batuhan Osmanoglu↗
NASA NTRS2011

From Paper to Production to Test: An Update on NASA's J-2X Engine for Exploration

The NASA/industry team responsible for developing the J-2X upper stage engine for the Space Launch System (SLS) Program has made significant progress toward moving beyond the design phase and into production, assembly, and test of development hardware. The J-2X engine exemplifies the SLS Program goal of using proven technology and experience from more than 50 years of United States spaceflight experience combined with modern manufacturing processes and approaches. It will power the second stage of the fully evolved SLS Program launch vehicle that will enable a return to human exploration of space beyond low earth orbit. Pratt & Whitney Rocketdyne (PWR) is under contract to develop and produce the engine, leveraging its flight-proven LH2/LOX, gas generator cycle J-2 and RS-68 engine capabilities, recent experience with the X-33 aerospike XRS-2200 engine, and development knowledge of the J-2S tap-off cycle engine. The J- 2X employs a gas generator operating cycle designed to produce 294,000 pounds of vacuum thrust in primary operating mode with its full nozzle extension. With a truncated nozzle extension suitable to support engine clustering on the stage, the nominal vacuum thrust level in primary mode is 285,000 pounds. It also has a secondary mode, during which it operates at 80 percent thrust by altering its mixture ratio. The J-2X development philosophy is based on proven hardware, an aggressive development schedule, and early risk reduction. NASA Marshall Space Flight Center (MSFC) and PWR began development of the J-2X in June 2006. The government/industry team of more than 600 people within NASA and PWR successfully completed the Critical Design Review (CDR) in November 2008, following extensive risk mitigation testing. Assembly of the first development engine was completed in May 2011 and the first engine test was conducted at the NASA Stennis Space Center (SSC), test stand A2, on 14 July 2011. Testing of the first development engine will continue through the autumn of 2011, be paused for test stand modifications to the passive diffuser, and then restart in the spring of 2012. This testing will be followed by specialized powerpack testing intended to examine the design and operating margins of the engine turbomachinery. The development plan beyond this point leads through more system-level, engine testing of several samples, analytical model validation activities, functional and performance verification, and then ultimate certification to support human spaceflight. This paper will discuss the J-2X development background, provide top-level information on design and development planning, and will explore some of the development challenges and mitigation activities pursued to date.

Kynard, Michael↗
NASA NTRS2014

GPM Data Products, Their Availability, and Production Status

On February 28, 2014, Japan Standard Time, the Global Precipitation Measurement (GPM) mission was launched in a picture-perfect launch activity. On March 4, 2014, the GPM Microwave Imager (GMI) was put into science observation mode. The Dual-Frequency Radar (DPR) was put in science observation mode on March 8, 2014. The Precipitation Processing System (PPS) produced products immediately upon receiving the data. Both regular science products and Near-realtime (NRT) products were produced. These were made immediately available to a group of early adopters. In mid-June 2014, GMI level-1 brightness temperature products were made publicly available. In mid-July 2014, GMI and partner-radiometer precipitation retrievals were made public. GMI public availability was several months ahead of the planned release. The DPR products became publicly available on the planned release date of September 2, 2014. Data continues to be available to any user desiring it.

Data Products↗
NASA NTRS1995

Atmospheric environmental implications of propulsion systems

Three independent studies have been conducted for assessing the impact of rocket launches on the earth's environment. These studies have addressed issues of acid rain in the troposphere, ozone depletion in the stratosphere, toxicity of chemical rocket exhaust products, and the potential impact on global warming from carbon dioxide emissions from rocket launches. Local, regional, and global impact assessments were examined and compared with both natural sources and anthropogenic sources of known atmospheric pollutants with the following conclusions: (1) Neither solid nor liquid rocket launches have a significant impact on the earth's global environment, and there is no real significant difference between the two. (2) Regional and local atmospheric impacts are more significant than global impacts, but quickly return to normal background conditions within a few hours after launch. And (3) vastly increased space launch activities equivalent to 50 U.S. Space Shuttles or 50 Russian Energia launches per year would not significantly impact these conclusions. However, these assessments, for the most part, are based upon homogeneous gas phase chemistry analysis; heterogeneous chemistry from exhaust particulates, such as aluminum oxide, ice contrails, soot, etc., and the influence of plume temperature and afterburning of fuel-rich exhaust products, need to be further addressed. It was the consensus of these studies that computer modeling of interactive plume chemistry with the atmosphere needs to be improved and computer models need to be verified with experimental data. Rocket exhaust plume chemistry can be modified with propellant reformulation and changes in operating conditions, but, based upon the current state of knowledge, it does not appear that significant environmental improvements from propellant formulation changes can be made or are warranted. Flight safety, reliability, and cost improvements are paramount for any new rocket system, and these important aspects cannot be compromised. A detailed environmental cost-benefit-risk analysis must be conducted before any new chemistry or changes in rocket operating conditions should be seriously considered for any future space or defense applications. This paper presents a summary of the results of environmental assessments contained in these independent studies.

Mcdonald, Allan J.↗
NASA NTRS1988

In-situ propellant advantages for fast transfer to Mars

The advantages of in situ propellant for a fast transfer to Mars were studied as compared to all earth-based propellants and other options for reduction of total masss in low earth orbit. For a 10-year, 10-mission model and a baseline vehicle taken from the literature, the total reduction in number of earth launches was calculated. The scenario in which the return propellants are transferred to Mars on a slow cargo vehicle provides a 29-percent reduction in ALS launches over the baseline scenario in which all propellants are brought directly from earth. The scenarios in which in situ propellants are used for a successively greater portion of the total mission continue to reduce the number of launches required. With Mars propellant used for the Mars ascent vehicle and the return leg of the mission, a 59-percent reduction in launches is obtained. Finally, if the oxygen, or oxygen and fuel, for the outbound leg of the mission is also obtained by in situ production, from the moon for example, then the total reduction in number of earth launches is more than 80 percent.

Galecki, Diane L.↗
NASA NTRS2019

Liftoff and Transition Database Generation for Launch Vehicles Using Data-Fusion-Based Modeling

A data fusion technique for merging multiple data sources with differing fidelity and resolution was developed to support the production of aerodynamic line load databases for the Liftoff and Transition (LOT) flight phase of the Space Launch System (SLS). The technique uses a reduced order model based on a high-fidelity line load data set from Computational Fluid Dynamics (CFD) to predict solutions for a much larger solution space. Even higher-fidelity force and moment information (from wind-tunnel tests) is then used to adjust the model. The adjustment uses constrained optimization through the method of Lagrange multipliers in order to minimize the deviation of the line load distribution from the spatially-dense CFD solution, while ensuring that the integrated force and moment values match those observed in physical wind tunnel measurements. Though the wind-tunnel data are operationally-dense (available at many flow conditions), they are spatially coarse (as only the overall forces and moments are available). Conversely, CFD for such complex configurations is expensive, and thus operationally sparse. Data fusion techniques are necessary to make the most efficient use of available information, delivering accurate results within time and resource constraints.

Wignall, T. J.↗
NASA NTRS1993

SIMSAT: An object oriented architecture for real-time satellite simulation

Real-time satellite simulators are vital tools in the support of satellite missions. They are used in the testing of ground control systems, the training of operators, the validation of operational procedures, and the development of contingency plans. The simulators must provide high-fidelity modeling of the satellite, which requires detailed system information, much of which is not available until relatively near launch. The short time-scales and resulting high productivity required of such simulator developments culminates in the need for a reusable infrastructure which can be used as a basis for each simulator. This paper describes a major new simulation infrastructure package, the Software Infrastructure for Modelling Satellites (SIMSAT). It outlines the object oriented design methodology used, describes the resulting design, and discusses the advantages and disadvantages experienced in applying the methodology.

Williams, Adam P.↗
NASA NTRS2011

Pros, Cons, and Alternatives to Weight Based Cost Estimating

Many cost estimating tools use weight as a major parameter in projecting the cost. This is often combined with modifying factors such as complexity, technical maturity of design, environment of operation, etc. to increase the fidelity of the estimate. For a set of conceptual designs, all meeting the same requirements, increased weight can be a major driver in increased cost. However, once a design is fixed, increased weight generally decreases cost, while decreased weight generally increases cost - and the relationship is not linear. Alternative approaches to estimating cost without using weight (except perhaps for materials costs) have been attempted to try to produce a tool usable throughout the design process - from concept studies through development. This paper will address the pros and cons of using weight based models for cost estimating, using liquid rocket engines as the example. It will then examine approaches that minimize the imp~ct of weight based cost estimating. The Rocket Engine- Cost Model (RECM) is an attribute based model developed internally by Pratt & Whitney Rocketdyne for NASA. RECM will be presented primarily to show a successful method to use design and programmatic parameters instead of weight to estimate both design and development costs and production costs. An operations model developed by KSC, the Launch and Landing Effects Ground Operations model (LLEGO), will also be discussed.

Joyner, Claude R.↗
NASA NTRS2011

Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant is iodine; however, with the end of the Space Shuttle program, there is a need to develop redundant biocide systems which are less dependent on hardware that would need to be launched on a regular basis. Three systems for electrochemical production of potable water disinfectants are being assessed for use on the International Space Station (ISS). Since there is a wide variability in the literature with regards to efficacy in both concentration and exposure time of these disinfectants, there is a need to establish baseline efficacy values. This paper describes a series of tests performed in order to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria and to determine whether these electrochemical disinfection devices are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on ISS.

Vega, Leticia↗
NASA NTRS2016

Dynamic Gas Flow Effects on the ESD of Aerospace Vehicle Surfaces

The purpose of this work is to develop a dynamic version of Paschen's Law that takes into account the flow of ambient gas past aerospace vehicle surfaces. However, the classic Paschen's Law does not take into account the flow of gas of an aerospace vehicle, whose surfaces may be triboelectrically charged by dust or ice crystal impingement, traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance by the electric field between the electrodes is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised Paschen equation must be a function of the mean velocity, v(sub xm), of the ambient gas and reduces to the classical version of Paschen's law when the gas mean velocity, v(sub xm) = 0. New formulations of Paschen's Law, taking into account Mach number and dynamic pressure, derived by the authors, will be discussed. These equations will be evaluated by wind tunnel experimentation later this year. Based on the results of this work, it is hoped that the safety of aerospace vehicles will be enhanced with a redefinition of electrostatic launch commit criteria. It is also possible that new products, such as new anti-static coatings, may be formulated from this data.

Paschens Law↗
NASA NTRS2016

Dynamic Gas Flow Effects on the ESD of Aerospace Vehicle Surfaces

The purpose of this work is to develop a dynamic version of Paschen's Law that takes into account the flow of ambient gas past aerospace vehicle surfaces. However, the classic Paschen's Law does not take into account the flow of gas of an aerospace vehicle, whose surfaces may be triboelectrically charged by dust or ice crystal impingement, traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance by the electric field between the electrodes is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised Paschen equation must be a function of the mean velocity, v(sub xm), of the ambient gas and reduces to the classical version of Paschen's law when the gas mean velocity, v(sub xm) = 0. New formulations of Paschen's Law, taking into account Mach number and dynamic pressure, derived by the authors, will be discussed. These equations will be evaluated by wind tunnel experimentation later this year. Based on the results of this work, it is hoped that the safety of aerospace vehicles will be enhanced with a redefinition of electrostatic launch commit criteria. It is also possible that new products, such as new anti-static coatings, may be formulated from this data.

Electrostatic Discharge↗
NASA NTRS2017

Revision of Paschen's Law Relating to the ESD of Aerospace Vehicle Surfaces

The purpose of this work is to develop a version of Paschen's law that takes into account the flow of ambient gas past electrode surfaces. Paschen's law does not consider the flow of gas past an aerospace vehicle whose surfaces may be triboelectrically charged by dust or ice crystal impingement while traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance between electrode surfaces is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised theoretical model must be a function of the mean velocity vxm of the ambient gas and reduce to Paschen's law when the mean velocity is zero. A new theoretical formulation of Paschen's law, taking into account the Mach number and compressible dynamic pressure, derived by the authors, will be discussed. This equation has been evaluated by wind tunnel experimentation. Initial data of the baseline wind tunnel experiments show results consistent with the hypothesis. This work may enhance the safety of aerospace vehicles through a redefinition of electrostatic launch commit criteria. It is also possible for new products, such as antistatic coatings, to be formulated based on this data.

electrostatic↗
NASA NTRS2017

Revision of Paschen's Law Relating to the ESD of Aerospace Vehicle Surfaces

The purpose of this work is to develop a version of Paschens law that takes into account the flow of ambient gas past electrode surfaces. Paschens law does not consider the flow of gas past an aerospace vehicle whose surfaces may be triboelectrically charged by dust or ice crystal impingement while traversing the atmosphere. The basic hypothesis of this work is that the number of electron-ion pairs created per unit distance between electrode surfaces is mitigated by the electron-ion pairs removed per unit distance by the flow of gas. The revised theoretical model must be a function of the mean velocity vxm of the ambient gas and reduce to Paschens law when the mean velocity is zero. A new theoretical formulation of Paschens law, taking into account the Mach number and compressible dynamic pressure, derived by the authors, will be discussed. This equation has been evaluated by wind tunnel experimentation. Initial data of the baseline wind tunnel experiments show results consistent with the hypothesis. This work may enhance the safety of aerospace vehicles through a redefinition of electrostatic launch commit criteria. It is also possible for new products, such as antistatic coatings, to be formulated based on this data.

discharge↗
NASA NTRS2020

Enabling Assurance in the MBSE Environment

A number of specific benefits that fit within the hallmarks of effective development are realized with implementation of model-based approaches to systems and assurance. Model Based Systems Engineering (MBSE) enabled by standardized modeling languages (e.g., SysML®) is at the core. These benefits in the context of spaceflight system challenges can include [1]: • Improved management of complex development • Reduced risk in the development process • Improved cost management • Improved design decisions With appropriate modeling techniques the assurance community also can improve early oversight and insight into project development. NASA has shown the basic constructs of SysML in an MBSE environment offer several key advantages, within a Model Based Mission Assurance (MBMA) initiative [2, 3]. These include the following: • Model viewpoints that promote rapid and systematic assessment of requirements coverage, hazard tagging and risk management • Embedded safety assessments for launch vehicles • Deployment of model assisted development of reliability products - Failure Modes and Effects Analyses (FMEAs) and Fault Trees • Test Planning • Validation and Verification of complex functions • Support of Assurance Case development for complex systems In addition, while there are benefits to be harvested, there is a realization that these do not come without effort and cost. Enabling model-based approaches requires structure, not only in an organizational context, but in a modeling context as well. There can be a steep learning curve and costs associated to train skilled modelers. But, on the other hand, not all of the assurance community need to be modelers. Models themselves must conform to ontologies that enable assurance. This places constraints upon the models and modelers. Optimums have yet to be developed where resources and constraints on modeling must be traded off in the organization and modeling efforts for projects. A number of barriers need to be overcome, as well, which pose challenges to the developers of the software that supports MBSE/MBMA. Information and data must be made to flow seamlessly through the life cycle. Because there is a wide variety of tools used in the community, to avoid the problems of the past of silos, delays, and diverging interests, information should flow among these tools to support the “single source of truth” paradigm of MBSE. This will greatly facilitate MBMA and advancement of assurance functions.

Evans, John W.↗