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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 343 records · Page 19

All sources NASA NTRS DOE OSTI

NASA NTRS1983

Shuttle derived vehicle analysis solid booster unmanned launch vehicle concept definition study, volume 2

The technical effort associated with the selection and definition of the recommended SRB-X concept is documented. Included are discussions concerning the trades leading to the selected concept, the analysis that established the concept's basic subsystem characteristics, selected configuration description and performance capabilities, launch site operations and facility needs, development schedule, cost characteristics, risk assessment, and a cursory comparison with other launch systems.

Source record↗

NASA NTRS2003

Mars sample return, updated to a groundbreaking approach

During 2001, NASA issued contracts to four industry teams to conduct broad trade studies of what they envisioned to be the best implementation of MSR and subsequently tasked with focusing on a specific concept, fleshing-out a specific design concept.

Mars sample return↗

NASA NTRSDate not supplied

NASA’s Moon to Mars (M2M) Transit Habitat Refinement Point of Departure Design

As NASA prepares for the next human footsteps on the lunar surface, the Agency is already looking ahead to systems that will enable a sustained human presence on the lunar surface and mission to Mars, including a lunar Surface Habitat (SH) and Mars Transit Habitat (TH). This paper describes the latest NASA government reference design for the TH and how it will support NASA's Moon to Mars human exploration architecture. First, it will serve as a test and demonstration platform in lunar orbit, demonstrating capabilities required for long-duration microgravity human spaceflight as part of the lunar-Mars analog missions. Then, the TH will serve as a major Mars exploration element to support crew habitation during their transit from the Earth’s orbit to Mars and returning safely before TH’s return to a lunar orbit. This paper will cover several considerations contributing to the latest habitat design refinement, including the TH's concept of operations, system functional definition, subsystem assumptions, notional interior layouts, a detailed mass and volume breakdown, and identify future trade studies and analyses required to close identified technology/ development/architecture gaps. In addition to a technical description of the TH, this paper describes how the current TH government reference design will achieve many of the current lunar and Mars mission goals. Additionally, there are many assumed technological advances needed to support the prescribed mission phases leading up to the crewed mission to Mars in the late 2030s. The paper will describe many of the TH systems requiring further technology development and identify architectural solutions to achieve these mass, reliability, autonomy, and crew health targets. As a whole, the data shows the government reference TH design meeting the 26.4 metric ton launch /trans-Mars injection burn control mass limit outlined within NASA’s Moon to Mars Campaign. This is achievable near the desired timeframe with moderate strategic investments including maintainable life support systems, innovative structures configuration and materials, and system/ logistics packaging. The resulting design detail and data contained in this paper are intended to help teams across NASA and potential commercial, academic, or international partners understand the current performance targets of the Transit Habitat and vehicle interface considerations imposed by the latest Moon to Mars mission scope.

Habitation Systems↗

NASA NTRS2026

Understanding and Controlling Hybrid Electric Gas Turbine Engine Transient Dynamics

The electrification of the gas turbine engine is known to increase the flexibility of aircraft architectures by enabling the generation of electrical power to distribute to other electrically based, thrust producing subsystems. It also has potential for direct performance benefits in the gas turbine engine itself, both at steady state and dynamically. Although the design focus of the gas turbine engine performance is primarily at steady state, it is often the instabilities occurring during transients that cause disequilibrium and constrain performance improvements. Instabilities arise due to the disequilibrium of the energy storage mechanisms within the traditional engine system and likewise for the electrified engine system. The primary energy storage mechanisms in the traditional system are the rotational inertia, gas path volumes, the thermal masses that make up the mechanical structure, and now, the electrical power system will provide additional contributions. Understanding the effect each of these energy storage mechanisms has on the others and controlling them appropriately allows for the suppression of state changes within the turbomachinery components to the degree that the components remain near steady state, thus reducing the disequilibrium within the system. The ability to tightly regulate the state changes of turbomachinery components, such as the compressor, minimizes the excursion of the compressor operating point from the operating line (operability), allowing for higher performing, more efficient compressor designs by decreasing the amount of stall margin needed for safe engine power level changes. Preliminary studies with the electrification of the turbine engine have shown that this is possible, and this concept can lead to design trades benefitting engine performance, weight, and volume. This paper explores in detail the energy storage mechanisms and control approaches for coordinating their state changes, and ultimately proposes that a higher performing, more efficient compressor design can result.

transient dynamics↗

NASA NTRS1991

Space transfer vehicle concepts and requirements, volume 2, book 1

The objective of the systems engineering task was to develop and implement an approach that would generate the required study products as defined by program directives. This product list included a set of system and subsystem requirements, a complete set of optimized trade studies and analyses resulting in a recommended system configuration, and the definition of an integrated system/technology and advanced development growth path. A primary ingredient in the approach was the TQM philosophy stressing job quality from the inception. Included throughout the Systems Engineering, Programmatics, Concepts, Flight Design, and Technology sections are data supporting the original objectives as well as supplemental information resulting from program activities. The primary result of the analyses and studies was the recommendation of a single propulsion stage Lunar Transportation System (LTS) configuration that supports several different operations scenarios with minor element changes. This concept has the potential to support two additional scenarios with complex element changes. The space based LTS concept consists of three primary configurations--Piloted, Reusable Cargo, and Expendable Cargo.

Source record↗

NASA NTRS1991

Cost studies for commercial fuselage crown designs

Studies were conducted to evaluate the cost and weight potential of advanced composite design concepts in the crown region of a commercial transport. Two designs from each of three design families were developed using an integrated design-build team. A range of design concepts and manufacturing processes were included to allow isolation and comparison of cost centers. Detailed manufacturing/assembly plans were developed as the basis for cost estimates. Each of the six designs was found to have advantages over the 1995 aluminum benchmark in cost and weight trade studies. Large quadrant panels and cobonded frames were found to save significant assembly labor costs. Comparisons of high- and intermediate-performance fiber systems were made for skin and stringer applications. Advanced tow placement was found to be an efficient process for skin lay up. Further analysis revealed attractive processes for stringers and frames. Optimized designs were informally developed for each design family, combining the most attractive concepts and processes within that family. A single optimized design was selected as the most promising, and the potential for further optimization was estimated. Technical issues and barriers were identified.

Walker, T. H.↗

NASA NTRSDate not supplied

Trade Study Analysis of a Cryogenic Oxygen Architecture for Lunar Outpost Life Support

A trade study was performed to compare the use of cryogenic liquid oxygen (LOX) with high pressure gaseous oxygen (GOX) and electrolysis approaches for Lunar outpost life support, which consists of a surface habitat and pressurized rover. This study presents the mission details pertaining to a Lunar outpost architecture, discusses the viable concept of operations for each architecture, and compares the equivalent system mass (ESM) of the cryogenic LOX, high pressure GOX, and electrolysis approaches across different parameter trades, e.g. mission duration or extravehicular activity frequency, for the single and 10-year mission architectures. For a single nominal mission, high pressure GOX is favored for short missions (< 50 days); cryogenic LOX is favored for a wide-range of mission durations (50 – 270 days); and the electrolysis approach is favored for long missions (> 270 days). However, when considering a 10-year mission architecture, each additional resupply negatively impacts cryogenic LOX due to the additional replacement tankage. Thus, over a 10-year mission, an electrolysis approach, which can provide all life support O2 utilizing solely recovered H2O, appears to be favored over cryogenic LOX. However, a real electrolysis system may need resupplied H2O due to incomplete closure of the air revitalization loop. Thus, the cryogenic LOX approach was compared with the electrolysis approaches utilizing 100% resupplied or 100% recovered H2O to approximate the resupplied to recovered H2O ratio, i.e. the degree of loop closure, where one approach trades over the other. Additionally, gaps were identified, which are expected to affect the viability and trade of cryogenic LOX. These include the development of cryogenic pumps and vaporizers to generate high pressure GOX from LOX as well as understanding payload limitations which can affect O2 resupply.

ECLSS↗

NASA NTRS1979

A turbojet-boosted two-stage-to-orbit space transportation system design study

The concept to use twin turbo-powered boosters for acceleration to supersonic staging speed followed by an all rocket powered orbiter stage was proposed. A follow-on design study was then made of the concept with the performance objective of placing a 29,483 Kg payload into a .2.6 X 195.3 km orbit. The study was performed in terms of analysis and trade studies, conceptual design, utility and economic analysis, and technology assessment. Design features of the final configuration included: strakes and area rule for improved take off and low transonic drag, variable area inlets, exits and turbine, and low profile fixed landing gear for turbojet booster stage. The payload required an estimated GLOW of 1,270,000 kg for injection in orbit. Each twin booster required afterburning turbojet engines each with a static sea level thrust rating of 444,800 N. Life cycle costs for this concept were comparable to a SSTO/SLED concept except for increased development cost due to the turbojet engine propulsion system.

Hepler, A. K.↗

NASA NTRSDate not supplied

Subsonic Single Aft Engine (SUSAN) Transport Aircraft Concept and Trade Space Exploration

A trade space exploration of a new NASA regional transport aircraft concept called the SUbsonic Single Aft eNgine (SUSAN) Electrofan is presented. The SUSAN concept uses a 20MW Electrified Aircraft Propulsion (EAP) system to enable advance Propulsion Airframe Integration (PAI) in transport category aircraft. Alternative fuels will be used to reduce the amount of emissions per energy used. By combining these features there is the potential to reduce aircraft emissions by 50% per passenger/mile while retaining the size, speed, and range of large regional jets. SUSAN is has a 750 mile economic mission, a 2500 mile design range and a maximum capacity of 180 passengers. The SUSAN configuration utilizes a single aft mounted engine and distributed electric wing-mounted thrusters on a tube and wing arrangement with a T-tail empennage. The SUSAN Electrofan employs a hybrid powertrain to enable: single turbofan operation on a large transport category aircraft; increased aerodynamic and propulsive efficiency through placement of electric engines; optimized turbofan sizing and efficiency through control and electric boosting, reduced control surface sizing through thrust augmentation. A single use battery is employed as the power source in case of turbofan failure. The design study also considers the constraints of operating within the current airport, airspace and economic constraints. This paper presents the status of the trade space exploration; however the concept definition is not finished. Forward work includes optimizing the overall aircraft configuration and including certain hard to model features like boundary layer ingestion or natural laminar flow across all appliable subsystems. Additional work forward work is a more extensive analysis of the configuration using alternative fuels.

Ralph H. Jansen↗

NASA NTRS1983

Thermal-protection requirements for near-earth aero-assisted orbital-transfer vehicle missions

The thermal protection required for decelerating and maneuvering spacecraft by aerodynamic forces is determined for return missions from geosynchronous to low-earth orbits. The effect of vehicle configuration on surface heating rates and selection of heat-shield materials is analyzed. Effects of the current widespread estimates in the structure of atmospheric density are also evaluated. It is shown that nonequilibrium radiation can be a major source of surface heating during atmospheric entry and a significant factor to heat-shielding requirements. It is also demonstrated that drag-brake concepts have application to a broad range of orbital-transfer missions, because of the favorable trade-offs with aeromaneuvering vehicles in volumetric efficiency, retrothrust plane-change capability, and heat-protection requirements. In addition, the results of this study indicate that the aero-assist technique produces small penalties in vehicle payload capacity for drag-brake concepts, because of the system's heat protection requirements, and is highly attractive relative to all-propulsive orbital-change maneuvers.

Menees, G. P.↗

NASA NTRS1993

HL-20 subsystem design

The NASA Langley Research Center has been developing a lifting-body configuration called the HL-20 for potential application as a personnel launch system orbiter that will provide the crew changeout at the Space Station Freedom. The objectives have been to provide an alternate manned access to space with a more cost-effective, efficient, reliable, and safer system for the routine transportation of people to LEO. The detailed study of this concept includes the subsystem design, flight software sizing, and mass properties that are discussed in this paper. The goals were to develop a subsystem complement to maximize operational efficiency with minimum development costs while using current technology. Subsystem selection and trade studies showed that current technology components will provide the required performance and operational effectiveness. Many of the selected components have Shuttle flight histories or considerable development heritage from other programs that will help minimize development costs.

Stone, H. W.↗

NASA NTRS1977

Large space erectable structures - building block structures study

A modular planar truss structure and a long slender boom concept identified as building block approaches to construction of large spacecraft configurations are described. The concepts are compatible in weight and volume goals with the Space Transportation System, use standard structural units, and represent high on-orbit productivity in terms of structural area or beam length. Results of structural trade studies involving static and dynamic analyses of a single module and rigid body deployment analyses to assess kinetics and kinematics of automatic deployment of the building block modules are presented.

Armstrong, W. H.↗

NASA NTRSDate not supplied

A New Concurrent Engineering Tool for the New Mission Design Center at NASA Ames Research Center

The NASA Ames Mission Design Center (MDC) has undergone a significant transformation process in recent years, culminating in becoming a true Concurrent Engineering Center. The underlying goal of this transformation is to better serve the Ames PI community in a cost-effective and rapidly-responsive way, providing quality products pivotal to the decision-making proposal strategy of our center. The four pillars of the change focus on four areas: personnel, physical places, tools, and training. Personnel: the MDC switched from using a dedicated pool of engineers—mostly entry-level career—for a matrixed approach with more experienced Subject Matter Experts, usually involved in spaceflight projects. These SMEs get detailed to the MDC for the duration of the study on a part-time or full-time basis. Physical places: The physical aspect pertains mostly to the layout of the new Engineering building and the dedicated concurrent engineering layout to foster collaboration. The current plan includes a dedicated space for concurrent engineering sessions as well as dedicated project rooms for concept studies. Tool: the MDC team is developing a new in-house concurrent engineering tool to facilitate concurrent engineering sessions. The team leveraged the many lessons learned and insight gained from using the current concurrent engineering tool, in use since 2007. SMEs have been involved throughout its design and development, ensuring accuracy and providing validity to the implementation approach. This new tool is database-driven and allows a team to work concurrently on the same model of a mission concept. “Workspaces” are provided for each of the traditional spacecraft mission design disciplines, including cost accounting and systems engineering. There are multiple tiers of fidelity available within each workspace, which can be completed parametrically or independently from the other disciplines as needed or synchronously with the other disciplines. A “commit” step synchronizes a workspace with the mission database and identifies any potential conflicts, along with the user who entered the conflicting data. A Mission Summary workspace enables a Study Lead to run an effective CE session, displaying key graphics, workspace status information, and technical and monetary budget information. This new CE tool will be undergoing Beta Testing with its primary user base and a limited Parts database in the summer of 2020. The team plans to release the first fully operational version in December 2020. Training: working in early concept development and maturation for a space mission requires a unique mindset and being comfortable with uncertainties in an environment where requirements are not yet fully developed, and where changes and trade-offs happen at a high tempo. The MDC started a weekly training program to ensure a common knowledge base on how do develop and mature early concept studies, as well as how to operate in a concurrent engineering environment. In conclusion, the MDC transformation will provide the overall PI community focused on cost-effective small satellite scientific missions with a powerful tool to address and mature early concepts more effectively and efficiently.

David Mauro↗

NASA NTRS2009

Control-Relevant Modeling, Analysis, and Design for Scramjet-Powered Hypersonic Vehicles

Within this paper, control-relevant vehicle design concepts are examined using a widely used 3 DOF (plus flexibility) nonlinear model for the longitudinal dynamics of a generic carrot-shaped scramjet powered hypersonic vehicle. Trade studies associated with vehicle/engine parameters are examined. The impact of parameters on control-relevant static properties (e.g. level-flight trimmable region, trim controls, AOA, thrust margin) and dynamic properties (e.g. instability and right half plane zero associated with flight path angle) are examined. Specific parameters considered include: inlet height, diffuser area ratio, lower forebody compression ramp inclination angle, engine location, center of gravity, and mass. Vehicle optimizations is also examined. Both static and dynamic considerations are addressed. The gap-metric optimized vehicle is obtained to illustrate how this control-centric concept can be used to "reduce" scheduling requirements for the final control system. A classic inner-outer loop control architecture and methodology is used to shed light on how specific vehicle/engine design parameter selections impact control system design. In short, the work represents an important first step toward revealing fundamental tradeoffs and systematically treating control-relevant vehicle design.

Rodriguez, Armando A.↗

NASA NTRS1981

Definition of optical systems payloads

The various phases in the formulation of a major NASA project include the inception of the project, planning of the concept, and the project definition. A baseline configuration is established during the planning stage, which serves as a basis for engineering trade studies. Basic technological problems should be recognized early, and a technological verification plan prepared before development of a project begins. A progressive series of iterations is required during the definition phase, illustrating the complex interdependence of existing subsystems. A systems error budget should be established to assess the overall systems performance, identify key performance drivers, and guide performance trades and iterations around these drivers, thus decreasing final systems requirements. Unnecessary interfaces should be avoided, and reasonable design and cost margins maintained. Certain aspects of the definition of the Advanced X-ray Astrophysics Facility are used as an example.

Downey, J. A., III↗

NASA NTRS2016

Electrostatic Discharge Testing of Carbon Composite Solar Array Panels for NASA's Planned Europa Mission to Jupiter

The next planned NASA mission to visit Jupiter is known as the Europa Mission. The objective of this mission concept is to enter orbit around Jupiter in order to conduct multiple close flybys of the icy moon Europa. After careful trade studies, the mission designers have selected solar arrays as the baseline power system for the proposed mission rather than more traditional radioisotope thermoelectric generators. In order to examine the risk of using solar arrays, a series of tests were devised to determine the response of a typical solar array coupon to energetic electrons. Test coupons were fabricated and exposed to electrons ranging from 10 keV to 100 keV, at 1 nA/cm2, while being held at both room and cryogenic temperatures and exposed to end of mission radiation levels. While under electron bombardment, electrical discharges were observed and recorded with the majority of discharges occurring with electron energies of 25 keV. The largest effects on discharge size and rate were the decrease in temperature and the reduction of dielectric material on the sample surface. These tests indicate that solar array panels could be used by the planned Europa Mission in the Jovian environment, but that electrostatic discharges could be expected on the carbon composite solar arrays.

carbon composite↗

NASA NTRSDate not supplied

Mission Planning and Trajectory Design of Roundtrip Mars Transfers

NASA’s Exploration Systems Development Mission Directorate has been evaluating architecture concepts that can deliver crew and cargo to Mars vicinity and return the crew safely back to Earth. A series of trade studies and sensitivity analyses are performed to explore the trade space in an effort to inform the decision of the transportation architecture for future human missions to Mars. This paper documents the tools and methods used to perform mission scans for systems that use high-thrust propulsion and provides discussion on some interesting challenges for the roundtrip transportation architecture. Results for the reference trajectories from the current analysis cycle are presented.

Mars↗

NASA NTRSDate not supplied

Mission Planning and Trajectory Design of Roundtrip Mars Transfers

Mars↗