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Results for “TRADE OFF ANALYSIS”

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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Manned Orbital Transfer Vehicle (MOTV). Volume 2: Mission handbook

The use of the manned orbit transfer vehicle (MOTV) for support of future space missions is defined. Some 20 generic missions are defined each representative of the types of missions expected to be flown in the future. These include the service and update of communications satellites, emergency repair of surveillance satellites, and passenger transport of a six man crew rotation/resupply service to a deep space command post. The propulsive and functional capabilities required of the MOTV to support a particular mission are described and data to enable the user to determine the number of STS flights needed to support the mission, mission peculiar equipment requirements, parametrics on mission phasing and requirements, ground and flight support requirements, recovery considerations, and IVA/EVA trade analysis are presented.

Boyland, R. E.↗
NASA NTRS1983

Space station needs, attributes and architectural options. Volume 1, attachment 1: Executive summary NASA

User alignment plan, physical and life sciences and applications, commercial requirements national security, space operations, user needs, foreign contacts, mission scenario analysis and architectural concepts, alternative systems concepts, mission operations architectural development, architectural analysis trades, evolution, configuration, and technology development are discussed.

Source record↗
NASA NTRS1985

Integrated digital/electric aircraft concepts study

The integrated digital/electrical aircraft (IDEA) is an aircraft concept which employs all electric secondary power systems and advanced digital flight control systems. After trade analysis, preferred systems were applied to the baseline configuration. An additional configuration, the alternate IDEA, was also considered. For this concept the design ground rules were relaxed in order to quantify additional synergistic benefits. It was proposed that an IDEA configuration and technical risks associated with the IDEA systems concepts be defined and the research and development required activities to reduce these risks be identified. The selected subsystems include: power generation, power distribution, actuators, environmental control system and flight controls systems. When the aircraft was resized, block fuel was predicted to decrease by 11.3 percent, with 7.9 percent decrease in direct operating cost. The alternate IDEA shows a further 3.4 percent reduction in block fuel and 3.1 percent reduction in direct operating cost.

Cronin, M. J.↗
NASA NTRS2000

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystem Concepts: Executive Summary - Volume 1

The Alternate Propulsion Subsystem Concepts contract had seven tasks defined that are reported under this contract deliverable. The tasks were: FAA Restart Study, J-2S Restart Study, Propulsion Database Development. SSME Upper Stage Use. CERs for Liquid Propellant Rocket Engines. Advanced Low Cost Engines, and Tripropellant Comparison Study. The two restart studies, F-1A and J-2S, generated program plans for restarting production of each engine. Special emphasis was placed on determining changes to individual parts due to obsolete materials, changes in OSHA and environmental concerns, new processes available, and any configuration changes to the engines. The Propulsion Database Development task developed a database structure and format which is easy to use and modify while also being comprehensive in the level of detail available. The database structure included extensive engine information and allows for parametric data generation for conceptual engine concepts. The SSME Upper Stage Use task examined the changes needed or desirable to use the SSME as an upper stage engine both in a second stage and in a translunar injection stage. The CERs for Liquid Engines task developed qualitative parametric cost estimating relationships at the engine and major subassembly level for estimating development and production costs of chemical propulsion liquid rocket engines. The Advanced Low Cost Engines task examined propulsion systems for SSTO applications including engine concept definition, mission analysis. trade studies. operating point selection, turbomachinery alternatives, life cycle cost, weight definition. and point design conceptual drawings and component design. The task concentrated on bipropellant engines, but also examined tripropellant engines. The Tripropellant Comparison Study task provided an unambiguous comparison among various tripropellant implementation approaches and cycle choices, and then compared them to similarly designed bipropellant engines in the SSTO mission This volume overviews each of the tasks giving its objectives, main results. and conclusions. More detailed Final Task Reports are available on each individual task.

Levack, Daniel J. H.↗
NASA NTRS2004

Development of an Aircraft Approach and Departure Atmospheric Profile Generation Algorithm

In support of NASA Virtual Airspace Modeling and Simulation (VAMS) project, an effort was initiated to develop and test techniques for extracting meteorological data from landing and departing aircraft, and for building altitude based profiles for key meteorological parameters from these data. The generated atmospheric profiles will be used as inputs to NASA s Aircraft Vortex Spacing System (AVOLSS) Prediction Algorithm (APA) for benefits and trade analysis. A Wake Vortex Advisory System (WakeVAS) is being developed to apply weather and wake prediction and sensing technologies with procedures to reduce current wake separation criteria when safe and appropriate to increase airport operational efficiency. The purpose of this report is to document the initial theory and design of the Aircraft Approach Departure Atmospheric Profile Generation Algorithm.

Buck, Bill K.↗
NASA NTRS2004

Multi-Mission Strategic Technology Prioritization Study

This viewgraph presentation provides an overview of a pilot study intended to demonstrate in an auditable fashion how advanced space technology development can best impact future NASA missions. The study was a joint project by staff members of NASA's Jet Propulsion Laboratory (JPL), and Goddard Space Flight Center (GSFC). The other goals of the study were to show an approach to deal effectively with inter-program analysis trades, and to explore the limits of these approaches and tools in terms of what can be realistically achieved.

Weisbin, C. R.↗
NASA NTRS1993

(abstract) Generic Modeling of a Life Support System for Process Technology Comparisons

This paper describes a simulation model called the Life Support Systems Analysis Simulation Tool (LiSSA-ST), the spreadsheet program called the Life Support Systems Analysis Trade Tool (LiSSA-TT), and the Generic Modular Flow Schematic (GMFS) modeling technique. Results of using the LiSSA-ST and the LiSSA-TT will be presented for comparing life support systems and process technology options for a Lunar Base and a Mars Exploration Mission.

life support system long-duration missions simulat↗
NASA NTRS1993

Generic Modeling of a Life Support System for Process Technology Comparison

This paper describes a simulation model called the Life Support Systems Analysis Simulation Tool (LiSSA-ST), the spreadsheet program called the Life Support Systems Analysis Trade Tool (LiSSA-TT), and the Generic Modular Flow Schematic (GMFS) modeling technique. Results of using the LiSSA-ST and the LiSSA-TT will be presented for comparing life support system and process technology options for a Lunar Base with a crew size of 4 and mission lengths of 90 and 600 days. System configurations to minimize the life support system weight and power are explored.

lunar base life support systems processes simulati↗
NASA NTRS2009

High-Pressure Oxygen Generation for Outpost EVA Study

The amount of oxygen consumption for crew extravehicular activity (EVA) in future lunar exploration missions will be significant. Eight technologies to provide high pressure EVA O2 were investigated. They are: high pressure O2 storage, liquid oxygen (LOX) storage followed by vaporization, scavenging LOX from Lander followed by vaporization, LOX delivery followed by sorption compression, water electrolysis followed by compression, stand-alone high pressure water electrolyzer, Environmental Control and Life Support System (ECLSS) and Power Elements sharing a high pressure water electrolyzer, and ECLSS and In-Situ Resource Utilization (ISRU) Elements sharing a high pressure electrolyzer. A trade analysis was conducted comparing launch mass and equivalent system mass (ESM) of the eight technologies in open and closed ECLSS architectures. Technologies considered appropriate for the two architectures were selected and suggested for development.

Jeng, Frank F.↗
NASA NTRS2010

A Densified Liquid Methane Delivery System for the Altair Ascent Stage

The Altair Lunar Lander is currently carrying options for both cryogenic and hypergolic ascent stage propulsion modules. The cryogenic option uses liquid methane and liquid oxygen to propel Altair from the lunar surface back to rendezvous with the Orion command module. Recent studies have determined that the liquid methane should be densified by subcooling it to 93 K in order to prevent over-pressurization of the propellant tanks during the 210 day stay on the lunar surface. A trade study has been conducted to determine the preferred method of producing; loading, and maintaining the subcooled, densified liquid methane onboard Altair from a ground operations perspective. The trade study took into account the limitations in mass for the launch vehicle and the mobile launch platform as well as the historical reliability of various components and their thermal efficiencies. Several unique problems were encountered, namely delivering a small amount of a cryogenic propellant to a flight tank that is positioned over 350 ft above the launch pad as well as generating the desired delivery temperature of the methane at 93 K which is only 2.3 K above the methane triple point of 90.7 K. Over 20 methods of subcooled liquid methane production and delivery along with the associated system architectures were investigated to determine the best solutions to the problem. The top four cryogenic processing solutions were selected for further evaluation and detailed thermal modeling. This paper describes the results of the preliminary trade analysis of the 20 plus methane densification methods considered. The results of the detailed analysis will be briefed to the Altair Project Office and their propulsion team as well as the Ground Operations Project Office before the down-select is made between cryogenic and hypergolic ascent stages in August 2010.

Tomsik, Thomas M.↗
NASA NTRS2013

Flight Performance Feasibility Studies for the Max Launch Abort System

In 2007, the NASA Engineering and Safety Center (NESC) initiated the Max Launch Abort System Project to explore crew escape system concepts designed to be fully encapsulated within an aerodynamic fairing and smoothly integrated onto a launch vehicle. One objective of this design was to develop a more compact launch escape vehicle that eliminated the need for an escape tower, as was used in the Mercury and Apollo escape systems and what is planned for the Orion Multi-Purpose Crew Vehicle (MPCV). The benefits for the launch vehicle of eliminating a tower from the escape vehicle design include lower structural weights, reduced bending moments during atmospheric flight, and a decrease in induced aero-acoustic loads. This paper discusses the development of encapsulated, towerless launch escape vehicle concepts, especially as it pertains to the flight performance and systems analysis trade studies conducted to establish mission feasibility and assess system-level performance. Two different towerless escape vehicle designs are discussed in depth: one with allpropulsive control using liquid attitude control thrusters, and a second employing deployable aft swept grid fins to provide passive stability during coast. Simulation results are presented for a range of nominal and off-nominal escape conditions.

Tarabini, Paul V.↗
NASA NTRS2020

Deep Space Human-Systems Research Recommendations for Future Human-Automation/Robotic Integration

Appropriate integration between automation and robotics systems and their human operators is essential for future space exploration. The Human Factors and Behavioral Performance Element of NASA’s Human Research Program requires a systematic understanding of the critical human-automation/robotic (HAR) integration, or HARI, design challenges for future space exploration. This document reports the results of a systematic assessment of the spaceflight-relevant HARI technologies and research topics addressing critical gaps in spaceflight-relevant HARI knowledge, and prioritizes research required for successful human performance and HAR integration. We reviewed relevant literature across the past ten years and interviewed ten subject matter experts to investigate the current state of HARI technology, challenges facing development, the state of HARI research across a wide range of fields, and opportunities for advancing the state of the art through directed research. This information was used to identify relevant HARI technologies and research topics, as well as factors to assess relative priority of HARI technologies. We worked with NASA stakeholders to weight the factors relevant to assessing HARI specific technologies. A multi-dimensional trade analysis was performed to objectively score HARI research topics and specific technologies to recommended investment priorities for NASA.

human-automation interaction↗
NASA NTRS2024

Determining Simulation Fidelity Necessary for Evaluating Onboard Vehicle Capabilities and Crew Roles on Long Duration Exploration Missions Beyond Low-Earth Orbit

Identification of onboard vehicle capabilities and crew roles and responsibilities necessary for achieving effective human-systems collaboration will require iterative cycles of concept development and empirical evaluation of human performance in complex operations. This report presents the results of an effort to lay the groundwork for determining the level of fidelity of simulated environments most suitable for validating concepts and evaluating implementations of a new Human Systems Integration Architecture (HSIA) that will support the flight crew on long duration exploration missions beyond low-Earth orbit. To do that, we conducted a literature review on simulation fidelity and surveyed simulation capabilities inside and outside of NASA used in NASA-sponsored research. We also analyzed two International Space Station (ISS) vehicle anomalies to identify the types of scenario events and crew activities that may need to be simulated. Our survey findings reveal that most NASA simulation facilities are designed to achieve high physical fidelity while HSIA risk mitigation requires simulation emphasizing task and functional fidelity aspects. A trade analysis shows that, for standard and requirement development, evaluation conducted using synthetic task environments with inexperienced participants will support testing a wide variety of conditions and yield findings robust enough to be generalized to a wide variety of designs on which developed standards and requirements might be levied while allowing human performance standard measures to be collected using consistent methods across tasks and conditions. For technology/tool development, because findings will only need to be generalized to the actual target environment in which the technology/tool will be used, it is more suitable to evaluate the prototypes in a scaled world that preserves functional relationships present in the actual target environment with intended user populations. To wrap up, we give an overview of a well-known synthetical task environment in the space domain and discuss what it takes to construct a synthetic task environment.

simulation fidelity↗
NASA NTRS1976

Final definition and preliminary design study for the initial atmospheric cloud physics laboratory, a Spacelab mission payload

The following areas related to the final definition and preliminary design study of the initial atmospheric cloud physics laboratory (ACPL) were covered: (1) proposal organization, personnel, schedule, and project management, (2) proposed configurations, (3) study objectives, (4) ACPL experiment program listing and description, (5) mission/flight flexibility and modularity/commonality, (6) study plan, and (7) description of following tasks: requirement analysis and definition task flow, systems analysis and trade studies, subsystem analysis and trade studies, specifications and interface control documents, preliminary design task flow, work breakdown structure, programmatic analysis and planning, and project costs. Finally, an overview of the scientific requirements was presented.

Source record↗
NASA NTRS2011

Thermal Management Tools for Propulsion System Trade Studies and Analysis

Energy-related subsystems in modern aircraft are more tightly coupled with less design margin. These subsystems include thermal management subsystems, vehicle electric power generation and distribution, aircraft engines, and flight control. Tighter coupling, lower design margins, and higher system complexity all make preliminary trade studies difficult. A suite of thermal management analysis tools has been developed to facilitate trade studies during preliminary design of air-vehicle propulsion systems. Simulink blocksets (from MathWorks) for developing quasi-steady-state and transient system models of aircraft thermal management systems and related energy systems have been developed. These blocksets extend the Simulink modeling environment in the thermal sciences and aircraft systems disciplines. The blocksets include blocks for modeling aircraft system heat loads, heat exchangers, pumps, reservoirs, fuel tanks, and other components at varying levels of model fidelity. The blocksets have been applied in a first-principles, physics-based modeling and simulation architecture for rapid prototyping of aircraft thermal management and related systems. They have been applied in representative modern aircraft thermal management system studies. The modeling and simulation architecture has also been used to conduct trade studies in a vehicle level model that incorporates coupling effects among the aircraft mission, engine cycle, fuel, and multi-phase heat-transfer materials.

McCarthy, Kevin↗
NASA NTRS1975

Analysis and trade-off studies of large lightweight mirror structures

A candidate mirror, hexagonally lightweighted, is analyzed under various loadings using as complete a procedure as possible. Successive simplifications are introduced and compared to an original analysis. A model which is a reasonable compromise between accuracy and cost is found and is used for making trade-off studies of the various structural parameters of the lightweighted mirror.

Soosaar, K.↗