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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 577 records · Page 32
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Enabling Architecture Trades and Design Exploration for Nuclear Electric Propulsion

Recent renewed interest in Nuclear Electric Propulsion (NEP) at NASA has driven the need for design space exploration and analysis of alternative architectures to evaluate performance and feasibility of NEP concepts. It has been over a decade since NASA last invested in Nuclear Electric Propulsion development efforts, and the landscape has shifted in both mission objectives and technology readiness levels. This also means that many of the engineering analyses and design frameworks tailored to NEP date back to the Jupiter Icy Moons Orbiter (JIMO) days of the early 2000s. Thus, a need was identified for updating and modernizing the modeling and simulation toolsets for NEP. This paper will detail the development efforts in the Marshall Space Flight Center’s Advanced Concepts Office, with a particular focus on the development of the NEP stage of the NEP-Chem vehicle. The paper will cover the various models used, and their current development status, as well as provide an overview of the integrated vehicle model and plans for further development.

Nuclear↗
NASA NTRSDate not supplied

Pressurized Rover Lunar Surface Windows Thermal Trade Study

The pressurized rover (PR) is a habitable lunar vehicle that supports up to two crew members and EVAs. The PR is expected to operate with a crew at the lunar south pole for up to 30 consecutive days. Lunar surface missions represent a significant thermal challenge due in part to the extreme changes in temperature environment. Minimizing heat leaks is essential to be able to survive cold phases of lunar surface missions. Windows in particular can be a significant source of heat leak when designed without thermal performance in mind. In addition, correctly modeling windows, and transparent materials in general, represents a significant thermal challenge. It can also be challenging to obtain accurate radiative properties for modern window materials. This study focuses on the modeling approach, results, and possible window heat leak mitigation techniques for pressurized rover. Mitigation techniques explored in this study include low emissivity coatings and removable internal or external covers. Window layup, geometry, and size are also assessed in this study for their impact to heat leak.

Sydney June Taylor↗
NASA NTRSDate not supplied

Characterization of in-Space Propulsion Trade Space to Support Initial Human Mars Segment

The National Aeronautics and Space Administration’s Exploration Systems Development Mission Directorate has been developing architecture concepts for human missions to Mars in alignment with the agency’s Moon to Mars blueprint objectives. The focus of the Architecture Development Office has been to decompose the blueprint objectives into the characteristics and needs for both lunar and Mars missions and develop functional needs to enable an integrated end-to-end mission architecture. One of the key components of a human Mars mission is the in-space transportation system that delivers crew and cargo to Mars vicinity and return crew safely back to Earth. The Mars Architecture Team has been evaluating four in-space transportation options to satisfy this functional need: 1) Hybrid Nuclear Electric/ Chemical Propulsion, 2) Nuclear Thermal Propulsion, 3) Hybrid Solar Electric/ Chemical Propulsion, and 4) All-Chemical propulsion. To answer the question “which transportation option is best?” decision makers will need to understand the performance characteristics—and limitations—for each architecture in the context of their preferred metric. Each option could be considered “better” than the others, depending on whether the primary selection criteria is fast, cheap, maximum cross-government applicability, maximizes commercial capabilities, and/or any other desired metrics. The Mars Architecture Team has completed considerable analysis on the Hybrid Nuclear Electric/Chemical Propulsion concept over the past three years. The Space Nuclear Propulsion program has also conducted significant work on the Nuclear Thermal Propulsion concept. The Hybrid Solar Electric/Chemical Propulsion concept, derived from technology planned for the Gateway program, was originally configurated for minimum vehicle stack mass (and, hence, minimum Earth-launched mass/cost), leveraging a highly efficient propulsion system on a minimum energy Conjunction Class trajectory. Historically, All-Chemical concepts were considered impractical due to the enormous propellant mass required, even for minimum energy Conjunction Class/long stay mission opportunities. However, considering the emerging commercial heavy-lift capabilities, the concept must be reevaluated across a range of concepts that leverage reusable launch vehicle capabilities to reduce the cost of launching large quantities of transportation elements needed for missions of various duration. This paper aims to provide an overview of the in-space transportation assessment work that is on-going within NASA.

Mars↗
NASA NTRSDate not supplied

Characterization of in-Space Propulsion Trade Space to Support Initial Human Mars Segment

The National Aeronautics and Space Administration’s Exploration Systems Development Mission Directorate has been developing architecture concepts for human missions to Mars in alignment with the agency’s Moon to Mars blueprint objectives. The focus of the Architecture Development Office has been to decompose the blueprint objectives into the characteristics and needs for both lunar and Mars missions and develop functional needs to enable an integrated end-to-end mission architecture. One of the key components of a human Mars mission is the in-space transportation system that delivers crew and cargo to Mars vicinity and return crew safely back to Earth. The Mars Architecture Team has been evaluating four in-space transportation options to satisfy this functional need: 1) Hybrid Nuclear Electric/ Chemical Propulsion, 2) Nuclear Thermal Propulsion, 3) Hybrid Solar Electric/ Chemical Propulsion, and 4) All-Chemical propulsion. To answer the question “which transportation option is best?” decision makers will need to understand the performance characteristics—and limitations—for each architecture in the context of their preferred metric. Each option could be considered “better” than the others, depending on whether the primary selection criteria is fast, cheap, maximum cross-government applicability, maximizes commercial capabilities, and/or any other desired metrics. The Mars Architecture Team has completed considerable analysis on the Hybrid Nuclear Electric/Chemical Propulsion concept over the past three years. The Space Nuclear Propulsion program has also conducted significant work on the Nuclear Thermal Propulsion concept. The Hybrid Solar Electric/Chemical Propulsion concept, derived from technology planned for the Gateway program, was originally configurated for minimum vehicle stack mass (and, hence, minimum Earth-launched mass/cost), leveraging a highly efficient propulsion system on a minimum energy Conjunction Class trajectory. Historically, All-Chemical concepts were considered impractical due to the enormous propellant mass required, even for minimum energy Conjunction Class/long stay mission opportunities. However, considering the emerging commercial heavy-lift capabilities, the concept must be reevaluated across a range of concepts that leverage reusable launch vehicle capabilities to reduce the cost of launching large quantities of transportation elements needed for missions of various duration. This paper aims to provide an overview of the in-space transportation assessment work that is on-going within NASA.

Mars↗
NASA NTRSDate not supplied

Medical Resource Set Bulky Item Trade Space Analysis for Spaceflight Medical Risk

The NASA engineering community utilizes event-driven and fault-tree probabilistic techniques to classify risks in the space environment by taking advantage of the inherent knowledge of complex spaceflight system design and testing to quantify failure risk. In harmonizing the risk of human space flight, answering the question of ‘How do we balance health, performance and resource risks with other engineering risks on long duration space missions?’ remains a deeply challenging and largely qualitative practice. The Medical Extensible Dynamic Probabilistic Risk Assessment Tool (MEDPRAT) is one aspect of the efforts by NASA’s Human Research Program (HRP) to quantitatively assess the impact of health and performance risk. One of MEDPRAT’s key features is its high degree of computational efficiency. Coupled with the HRP High Performance Compute cluster located at NASA’s Glenn Research Center, MEDPRAT runs millions of simulated missions in a matter of minutes. This degree of computational efficiency provides the novel opportunity to explore the relationship between medical set mass, volume, and medical resource size. Of particular interest for future human spaceflight missions are ‘bulky’ items, medical resources like devices, which occupy a large portion of the small, allocated mass and volume for the medical set leaving less room for other resources. This talk will present results showing the quantitative impact of forced inclusion of several bulky items across a variety of medical kit constraints, and the effect that a potential research investment into reducing the bulky item mass and volume may have on risk.

Lauren Mcintyre↗
NASA NTRS2024

Wheel Module Motor Trade Study for Lunar Terrain Vehicle Thermal Control System

Conducting a lunar mission, whether it is a robotic mission or one with astronauts, has many challenges; one of which is the thermal control of the motors of the wheel module that are used to propel and steer the vehicle. This paper describes the thermal analysis approach, design assumptions, and results of passive thermally controlled wheel module motors, meaning there are not cold plates, fluid loops, or other active thermal control methods to controlling the temperatures. It will also highlight challenges faced in the design of wheel modules for a rover on the lunar south pole. There are three main design change approaches that are considered, the first one keeps the nominal design with the motors mounted at the wheel hub on each wheel, but the motors have lower temperature limits. The second approach requires no thermal control of the motors, allowing them to get below the manufacturers lowest thermal limit and warming them back up prior to actuation during the lunar day. The last approach moves the motors inside of the main body of the vehicle.

Thermal Control System↗
NASA NTRSDate not supplied

Quantification of Design Trade-Offs When Comparing Transonic Truss-Braced Wing to Advanced Tube and Wing Aircraft

Interest in novel aircraft configurations has continued to grow in response to increasing demand for improved fuel efficiency. One such configuration of interest is the Transonic Truss-Braced Wing (TTBW). Because the improvement of the TTBW comes from increased efficiency during cruise, it offers increasing returns as the mission distance increases. As a result, there is often a crossover point which represents the minimum mission range where the TTBW will offer a fuel burn reduction relative to a similar Tube and Wing aircraft with similar component technology levels. Aircraft rarely fly missions at their maximum range, so it is important to investigate not only the maximum benefit, but also the most likely benefit. Design decisions and analysis assumptions that significantly impact this crossover point include whether to put fuel in body tanks, how weight build-up estimation is calibrated, engine technology selection, and flight Mach number. This study, conducted under NASA’s Sustainable Flight Demonstration project and inspired by differing assumptions made by different research teams, details the impacts of changing these design decisions and assumptions.

Carl J Recine↗
NASA NTRSDate not supplied

Quantification of Design Trade-Offs When Comparing Transonic Truss-Braced Wing to Advanced Tube and Wing Aircraft

Interest in novel aircraft configurations has continued to grow in response to increasing demand for improved fuel efficiency. One such configuration of interest is the Transonic Truss-Braced Wing (TTBW). Because the improvement of the TTBW comes from increased efficiency during cruise, it offers increasing returns as the mission distance increases. As a result, there is often a crossover point which represents the minimum mission range where the TTBW will offer a fuel burn reduction relative to a similar Tube and Wing aircraft with similar component technology levels. Aircraft rarely fly missions at their maximum range, so it is important to investigate not only the maximum benefit, but also the most likely benefit. Design decisions and analysis assumptions that significantly impact this crossover point include whether to put fuel in body tanks, how weight build-up estimation is calibrated, engine technology selection, and flight Mach number. This study, conducted under NASA’s Sustainable Flight Demonstration project and inspired by differing assumptions made by different research teams, details the impacts of changing these design decisions and assumptions.

Carl J Recine↗