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Results for “cost and performance”

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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Rectenna system design

The function of the rectenna in the solar power satellite system is described and the basic design choices based on the desired microwave field concentration and ground clearance requirements are given. One important area of concern, from the EMI point of view, harmonic reradiation and scattering from the rectenna is also designed. An optimization of a rectenna system design to minimize costs was performed. The rectenna cost breakdown for a 56 w installation is given as an example.

Brown, W. C.↗
NASA NTRS1983

Cost Effectiveness of Hybrid Solar Powerplants

Report discusses cost effectiveness of high-temperature thermal storage system for representative parabolic dish solar powerplant. Economic viability of thermal storage system assesses; cost and performance projections made; cost of electricity generated by solar power plant also calculated.

Wen, L. C.↗
NASA NTRS1988

Accurate low-cost methods for performance evaluation of cache memory systems

Methods of simulation based on statistical techniques are proposed to decrease the need for large trace measurements and for predicting true program behavior. Sampling techniques are applied while the address trace is collected from a workload. This drastically reduces the space and time needed to collect the trace. Simulation techniques are developed to use the sampled data not only to predict the mean miss rate of the cache, but also to provide an empirical estimate of its actual distribution. Finally, a concept of primed cache is introduced to simulate large caches by the sampling-based method.

Laha, Subhasis↗
NASA NTRS1999

Low-Cost, High-Performance Cryocoolers for In-Situ Propellant Production

A key feature of many In-Situ Resource Utilization (ISRU) schemes is the production of rocket fuel and oxidizer from the Martian atmosphere. Many of the fuels under consideration will require cryogenic cooling for efficient long-term storage. Although significant research has been focused on the techniques for producing the fuels from Martian resources, little effort has been expended on the development of cryocoolers to efficiently liquefy these fuels. This paper describes the design of a pulse tube liquefier optimized for liquefying oxygen produced by an In-Situ Propellant Production (ISPP) plant on Mars.

Martin, J. L.↗
NASA NTRS1999

Low-Cost High-Performance Cryocoolers for In-Situ Propellant Production

A key feature of many In-Situ Resource Utilization (ISRU) schemes is the production of rocket fuel and oxidizer from the Martian atmosphere. Many of the fuels under consideration will require cryogenic cooling for efficient long-term storage. Although significant research has been focused on the techniques for producing the fuels from Martian resources, little effort has been expended on the development of cryocoolers to efficiently liquefy these fuels. This paper describes the design of a pulse tube liquefier optimized for liquefying oxygen produced by an In-Situ Propellant Production (ISPP) plant on Mars.

Martin, J. L.↗
NASA NTRS2015

Low-Cost, High-Performance Hall Thruster Support System

Colorado Power Electronics (CPE) has built an innovative modular PPU for Hall thrusters, including discharge, magnet, heater and keeper supplies, and an interface module. This high-performance PPU offers resonant circuit topologies, magnetics design, modularity, and a stable and sustained operation during severe Hall effect thruster current oscillations. Laboratory testing has demonstrated discharge module efficiency of 96 percent, which is considerably higher than current state of the art.

Hesterman, Bryce↗
NASA NTRS2015

Low-Cost, High-Performance Combustion Chamber

Ultramet designed and fabricated a lightweight, high-temperature combustion chamber for use with cryogenic LOX/CH4 propellants that can deliver a specific impulse of approx.355 seconds. This increase over the current 320-second baseline of nitrogen tetroxide/monomethylhydrazine (NTO/MMH) will result in a propellant mass decrease of 55 lb for a typical lunar mission. The material system was based on Ultramet's proven oxide-iridium/rhenium architecture, which has been hot-fire tested with stoichiometric oxygen/hydrogen for hours. Instead of rhenium, however, the structural material was a niobium or tantalum alloy that has excellent yield strength at both ambient and elevated temperatures. Phase I demonstrated alloys with yield strength-to-weight ratios more than three times that of rhenium, which will significantly reduce chamber weight. The starting materials were also two orders of magnitude less expensive than rhenium and were less expensive than the C103 niobium alloy commonly used in low-performance engines. Phase II focused on the design, fabrication, and hot-fire testing of a 12-lbf thrust class chamber with LOX/CH4, and a 100-lbf chamber for LOX/CH4. A 5-lbf chamber for NTO/MMH also was designed and fabricated.

Fortini, Arthur J.↗
NASA NTRS2016

Development of an Objective Space Suit Mobility Performance Metric Using Metabolic Cost and Functional Tasks

Existing methods for evaluating EVA suit performance and mobility have historically concentrated on isolated joint range of motion and torque. However, these techniques do little to evaluate how well a suited crewmember can actually perform during an EVA. An alternative method of characterizing suited mobility through measurement of metabolic cost to the wearer has been evaluated at Johnson Space Center over the past several years. The most recent study involved six test subjects completing multiple trials of various functional tasks in each of three different space suits; the results indicated it was often possible to discern between different suit designs on the basis of metabolic cost alone. However, other variables may have an effect on real-world suited performance; namely, completion time of the task, the gravity field in which the task is completed, etc. While previous results have analyzed completion time, metabolic cost, and metabolic cost normalized to system mass individually, it is desirable to develop a single metric comprising these (and potentially other) performance metrics. This paper outlines the background upon which this single-score metric is determined to be feasible, and initial efforts to develop such a metric. Forward work includes variable coefficient determination and verification of the metric through repeated testing.

Norcross, J. R.↗
NASA NTRS2016

Development of an Objective Space Suit Mobility Performance Metric Using Metabolic Cost and Functional Tasks

Existing methods for evaluating EVA suit performance and mobility have historically concentrated on isolated joint range of motion and torque. However, these techniques do little to evaluate how well a suited crewmember can actually perform during an EVA. An alternative method of characterizing suited mobility through measurement of metabolic cost to the wearer has been evaluated at Johnson Space Center over the past several years. The most recent study involved six test subjects completing multiple trials of various functional tasks in each of three different space suits; the results indicated it was often possible to discern between different suit designs on the basis of metabolic cost alone. However, other variables may have an effect on real-world suited performance; namely, completion time of the task, the gravity field in which the task is completed, etc. While previous results have analyzed completion time, metabolic cost, and metabolic cost normalized to system mass individually, it is desirable to develop a single metric comprising these (and potentially other) performance metrics. This paper outlines the background upon which this single-score metric is determined to be feasible, and initial efforts to develop such a metric. Forward work includes variable coefficient determination and verification of the metric through repeated testing.

McFarland, Shane M.↗
NASA NTRS1994

Low cost booster and high performance orbit injection propulsion extended abstract

Space transportation is currently a major element of cost for communications satellite systems. For every dollar spent in manufacturing the satellite, somewhere between 1 and 3 dollars must be spent to launch the satellite into its initial operational orbit. This also makes the weight of the satellite a very critical cost factor because it is important to maximize the useful payload that is placed into orbit to maximize the return on the original investment. It seems apparent then, that tremendous economic advantage for satellite communications systems can be gained from improvements in two key highly leveraged propulsion areas. The first and most important economic improvement can be achieved by significantly lowering the cost of today's launch vehicles. The second gain that would greatly benefit the communications satellite business position is to increase both the useful (payload) weight placed into the orbit and the revenue generating lifetime of the satellite on-orbit. The point of this paper is to first explain that these two goals can best be achieved by cost reduction and performance increasing advancements in rocket propulsion for both the launch vehicle and for the satellite on-board apogee insertion and on-orbit velocity control systems.

Sackheim, R. L.↗
NASA NTRS1993

A low cost alternative to high performance PCM bit synchronizers

The Code Converter/Clock Regenerator (CCCR) provides a low-cost alternative to high-performance Pulse Code Modulation (PCM) bit synchronizers in environments with a large Signal-to-Noise Ratio (SNR). In many applications, the CCCR can be used in place of PCM bit synchronizers at about one fifth the cost. The CCCR operates at rates from 10 bps to 2.5 Mbps and performs PCM code conversion and clock regeneration. The CCCR has been integrated into a stand-alone system configurable from one to six channels and has also been designed for use in VMEbus compatible systems.

Deshong, Bruce↗
DOE OSTI2022

Affordable Solid Panel "Perfect Wall" System

The SPS is an innovative interpretation of the “perfect wall” concept, in which environmental control layers are located on the exterior side of the structural components, as opposed to traditional cavity insulated, stud-framed walls. The primary objective of this study is to validate the SPS technology in terms of its constructability, cost, and performance. Specifically for this project, we partnered with two affordable housing nonprofits in Minnesota—Twin Cities Habitat for Humanity and Urban Homeworks—to build five new houses using SPS walls, as well as two high-performance stud-framed comparison homes. We also reviewed cost and performance data from 13 SPS homes built prior to this project by MonoPath and Spero Environmental Builders. Reviewing the outcomes of these 20 homes total, we find promising results in terms of constructability, cost, and performance, although more structural performance data are needed before this new technology can see widespread adoption.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1974

Multispectral scanner data applications evaluation. Volume 2: Sensor system study

The optimization of a thematic mapper for earth resources application is discussed in terms of cost versus performance. Performance tradeoffs and the cost impact are analyzed. The instrument design and radiometric performance are also described. The feasibility of a radiative cooler design for a scanning spectral radiometer is evaluated along with the charge coupled multiplex operation. Criteria for balancing the cost and complexity of data acquisition instruments against the requirements of the user, and a pushbroom scanner version of the thematic mapper are presented.

Source record↗
DOE OSTI2023

Adopting occupancy-based HVAC controls in commercial building energy codes: Analysis of cost-effectiveness and decarbonization potential

Recent research has shown the energy-saving potential of occupancy-based HVAC controls (OBCs) in commercial buildings. However, building energy codes have not fully adopted this technology. This study aims to evaluate the cost-effectiveness and decarbonization benefits of OBCs and provide guidance for integrating occupancy sensors into building energy code development. To this end, a parametric simulation using EnergyPlus and a nationwide cost-effectiveness analysis are carried out considering three building types and 40 representative cities in the U.S. Here, the findings reveal that the current cost-effectiveness performance of OBCs is limited due to the high cost of occupancy sensors. However, incorporating the societal cost of carbon factor in future energy and environmental policy could greatly enhance the actual cost-effectiveness performance. Besides, a reduction in the cost of occupancy sensors to approximately 60% of the current price level could also greatly shorten the discounted payback period of OBCs. Additionally, OBCs demonstrate significant potential in building decarbonization, with potential CO 2 emissions savings of more than 5.56 million metric tons across the three building types and 40 selected cities. Finally, policy implications are provided to guide the incorporation of occupancy-based HVAC controls in future energy codes.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1991

The hydrogen technology assessment, phase 1

The purpose of this phase 1 report is to begin to form the information base of the economics and energy uses of hydrogen-related technologies on which the members of the National Hydrogen Association (NHA) can build a hydrogen vision of the future. The secondary goal of this report is the development of NHA positions on national research, development, and demonstration opportunities. The third goal, with the aid of the established hydrogen vision and NHA positions, is to evaluate ongoing federal research goals and activities. The evaluations will be performed in a manner that compares the costs associated with using systems that achieve those goals against the cost of performing those tasks today with fossil fuels. From this ongoing activity should emerge an NHA information base, one or more hydrogen visions of the future, and cost and performance targets for hydrogen applications to complete in the market place.

Bain, Addison↗