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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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NASA NTRS1987

Tropical rainfall measuring mission (TRMM)

By measuring rainfall in the tropics, the Tropical Rainfall Measuring Mission (TRMM) will make possible the understanding of the heat engine that drives the global weather. The TRMM mission parameters are given, and the spacecraft is described. The instruments are examined, including the precipitation radar, TRMM microwave radiometer, and Advanced Very High Frequency Radiometer. The mission life is addressed, including atmospheric data, fuel consumption, and life extension methods. The spacecraft interfaces, payload configuration, and deployment sequence are considered. The subsystems are described, including propulsion, power, command, data handling, and tracking. A Japanese Experimental Data Relay Tracking Satellite experimental package working with TRMM is briefly addressed.

Keating, Thomas↗

NASA NTRS1989

Looking at the architecture

Architectural and systems-engineering considerations and tradeoffs are primary design-drivers in Martian and lunar missions, entailing studies of such fundamental choices as the use of rapid trajectories in the course of which crews live in zero-g or slower trajectories in which crews are subjected to artificial gravity. The best use of transportation way-points, the integration of launch vehicles with spacecraft of various configurations, and the incorporation of such advanced concepts as solar sail propulsion, are additional considerations to be studied. The planning of lunar and Martian missions must always take into account the extent to which local resources can diminish earth-supplied logistics requirements.

Bekey, Ivan↗

NASA NTRS1989

Near-term nuclear space missions

This paper summarizes the current status of proposed NASA Human Exploration Missions (MEMs) presenting detail with respect to schedule and system features. Using the Lunar exploration and Mars exploration missions as design drivers, new vehicle elements have been configured and optimized to meet proposed mission requirements. Both conventional chemical propulsion and alternative vehicle designs incorporating advanced nuclear propulsion systems are included, and the total mass required in Low Earth Orbit (LEO) is compared for each propulsion system.

Andrews, Dana G.↗

NASA NTRS1990

Pulsed plasmoid electric propulsion

A method of electric propulsion is explored where plasmoids such as spheromaks and field reversed configurations (FRC) are formed and then allowed to expand down a diverging conducting shell. The plasmoids contain a toroidal electric current that provides both heating and a confining magnetic field. They are free to translate because there are no externally supplied magnetic fields that would restrict motion. Image currents in the diverging conducting shell keep the plasmoids from contacting the wall. Because these currents translate relative to the wall, losses due to magnetic flux diffusion into the wall are minimized. During the expansion of the plasma in the diverging cone, both the inductive and thermal plasma energy are converted to directed kinetic energy producing thrust. Specific impulses can be in the 4000 to 20000 sec range with thrusts from 0.1 to 1000 Newtons, depending on available power.

Bourque, Robert F.↗

NASA NTRS1991

Optimization of vehicle weight for Mars excursion missions

The excursion class mission to Mars is defined as a mission with one year durations coupled with a stay time of up to 30 days. The fuel budget for such a mission is investigated. The overall figure of merit in such an assessment is the vehicle weight ratio, the ratio between the wet vehicle weight to the dry vehicle weight. It is necessary to minimize the overall fuel budget for the mission in order to maximize the benefits that could be obtained by sending humans to Mars. Assumptions used in the analysis are: each mission will depart and terminate in low-earth-orbit (LEO) (500 km circular) and the maximum stay time at Mars is 30 days. The maximum mission duration is one year (355-375 days). The mass returned to LEO is 135,000 kg, the dropoff mass left at Mars is 168,000 kg. Three propulsive techniques for atmospheric interface are investigated: aerobraking, all-chemical propulsion, and nuclear thermal propulsion. By defining the fuel requirements, the space transfer vehicle's configuration is defined.

Ferebee, Melvin J., Jr.↗

NASA NTRS1992

Dynamics and control of hypersonic aeropropulsive/aeroelastic vehicles

The guidance and control of hypersonic vehicles is examined by studying the airframe/engine/structural-dynamic interactions of a generic vehicle with scramjet propulsion. The pitch-attitude dynamics are described for the vehicle configuration that can sustain hypersonic flight at near-orbital altitudes. These aerospacecraft have strong airframe/engine/elastic coupling in attitude dynamics and engine responses with static instability with respect to pitch. An integrated airframe-engine control system is presented for the control of the system's strong aeropropulsive/aeroelastic coupling. The control methodology utilizes feedback of measured/synthesized values of angle of attack, blended pitch rate, thrust, and combustor-inlet pressure. The multiinput/multioutput engine controller requires high-bandwidth actuation of the fuel-flow control and the effective diffuser ratio. The proposed control laws do not provide optimized performance in terms of pitch response suggesting that additional control crossfeeds and filtering is needed.

Schmidt, David K.↗

NASA NTRS2003

Aircraft Drag Reduction-A Review

The paper summarizes the state of the art in aeronautical drag reduction across the speed range for the conventional drag components of viscous drag, drag due to lift and wave drag. It also describes several emerging drag-reduction approaches that are either active or reactive/interactive and the drag reduction potentially available from synergistic combinations of advanced configuration aerodynamics, viscous drag-reduction approaches, revolutionary structural concepts and propulsion integration.

Bushnell, D. M.↗

NASA NTRS2007

Design and Data Management System

The Design and Data Management System (DDMS) was developed to automate the NASA Engineering Order (EO) and Engineering Change Request (ECR) processes at the Propulsion Test Facilities at Stennis Space Center for efficient and effective Configuration Management (CM). Prior to the development of DDMS, the CM system was a manual, paper-based system that required an EO or ECR submitter to walk the changes through the acceptance process to obtain necessary approval signatures. This approval process could take up to two weeks, and was subject to a variety of human errors. The process also requires that the CM office make copies and distribute them to the Configuration Control Board members for review prior to meetings. At any point, there was a potential for an error or loss of the change records, meaning the configuration of record was not accurate. The new Web-based DDMS eliminates unnecessary copies, reduces the time needed to distribute the paperwork, reduces time to gain the necessary signatures, and prevents the variety of errors inherent in the previous manual system. After implementation of the DDMS, all EOs and ECRs can be automatically checked prior to submittal to ensure that the documentation is complete and accurate. Much of the configuration information can be documented in the DDMS through pull-down forms to ensure consistent entries by the engineers and technicians in the field. The software also can electronically route the documents through the signature process to obtain the necessary approvals needed for work authorization. The workflow of the system allows for backups and timestamps that determine the correct routing and completion of all required authorizations in a more timely manner, as well as assuring the quality and accuracy of the configuration documents.

Messer, Elizabeth↗

NASA NTRS2011

Blended Wing Body Concept Development with Open Rotor Engine Intergration

The purpose of this study is to perform a systems analysis of a Blended Wing Body (BWB) open rotor concept at the conceptual design level. This concept will be utilized to estimate overall noise and fuel burn performance, leveraging recent test data. This study will also investigate the challenge of propulsion airframe installation of an open rotor engine on a BWB configuration. Open rotor engines have unique problems relative to turbofans. The rotors are open, exposed to flow conditions outside of the engine. The flow field that the rotors are immersed in may be higher than the free stream flow and it may not be uniform, both of these characteristics could increase noise and decrease performance. The rotors sometimes cause changes in the flow conditions imposed on aircraft surfaces. At high power conditions such as takeoff and climb out, the stream tube of air that goes through the rotors contracts rapidly causing the boundary layer on the body upper surface to go through an adverse pressure gradient which could result with separated airflow. The BWB / Open Rotor configuration must be designed to mitigate these problems.

Pitera, David M.↗

NASA NTRS2012

Radioisotope Stirling Engine Powered Airship for Low Altitude Operation on Venus

The feasibility of a Stirling engine powered airship for the near surface exploration of Venus was evaluated. The heat source for the Stirling engine was limited to 10 general purpose heat source (GPHS) blocks. The baseline airship utilized hydrogen as the lifting gas and the electronics and payload were enclosed in a cooled insulated pressure vessel to maintain the internal temperature at 320 K and 1 Bar pressure. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the Venus surface based on the available thermal power. The atmospheric conditions on Venus were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Venus surface. From this baseline design additional trades were made to see how other factors affected the design such as the internal temperature of the payload chamber and the flight altitude. In addition other lifting methods were evaluated such as an evacuated chamber, heated atmospheric gas and augmented heated lifting gas. However none of these methods proved viable.

Colozza, Anthony J.↗

NASA NTRS2014

Radioisotope Stirling Engine Powered Airship for Atmospheric and Surface Exploration of Titan

The feasibility of an advanced Stirling radioisotope generator (ASRG) powered airship for the near surface exploration of Titan was evaluated. The analysis did not consider the complete mission only the operation of the airship within the atmosphere of Titan. The baseline airship utilized two ASRG systems with a total of four general-purpose heat source (GPHS) blocks. Hydrogen gas was used to provide lift. The ASRG systems, airship electronics and controls and the science payload were contained in a payload enclosure. This enclosure was separated into two sections, one for the ASRG systems and the other for the electronics and payload. Each section operated at atmospheric pressure but at different temperatures. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the surface of Titan based on the available power from the ASRGs. The atmospheric conditions on Titan were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Titan surface. From this baseline design additional trades were made to see how other factors affected the design such as the flight altitude and payload mass and volume.

Titan↗

NASA NTRS2016

NASA ERA Integrated CFD for Wind Tunnel Testing of Hybrid Wing-Body Configuration

NASAs Environmentally Responsible Aviation (ERA) Project explores enabling technologies to reduce aviations impact on the environment. One research challenge area for the project has been to study advanced airframe and engine integration concepts to reduce community noise and fuel burn. In order to achieve this, complex wind tunnel experiments at both the NASA Langley Research Centers (LaRC) 14x22 and the Ames Research Centers 40x80 low-speed wind tunnel facilities were conducted on a Boeing Hybrid Wing Body (HWB) configuration. These wind tunnel tests entailed various entries to evaluate the propulsion airframe interference effects including aerodynamic performance and aeroacoustics. In order to assist these tests in producing high quality data with minimal hardware interference, extensive Computational Fluid Dynamic (CFD) simulations were performed for everything from sting design and placement for both the wing body and powered ejector nacelle systems to the placement of aeroacoustic arrays to minimize its impact on the vehicles aerodynamics. This paper will provide a high level summary of the CFD simulations that NASA performed in support of the model integration hardware design as well as some simulation guideline development based on post-test aerodynamic data. In addition, the paper includes details on how multiple CFD codes (OVERFLOW, STAR-CCM+, USM3D, and FUN3D) were efficiently used to provide timely insight into the wind tunnel experimental setup and execution.

Computational Fluid Dynamics↗

NASA NTRSDate not supplied

X-57 Systems Engineering Lessons Learned

The X-57 Maxwell is an electric aircraft based on a 4-passenger, twin engine Tecnam P2006T General Aviation aircraft. The X-57 project originally envisioned a straightforward integration of commercial-off-the-shelf hardware components and software into a novel configuration to demonstrate the aerodynamic and performance benefits of Distributed Electric Propulsion (DEP). The project was initially started with a high-risk venture capitalist approach under NASA’s Convergent Aeronautics Solutions (CAS) project, which led to an initial philosophy of Project Management “light” (which was then interpreted as Systems Engineering (SE) “light”). As the project matured, it was forced to transition to one with increasing SE-rigor as the project scope changed, hardware and software deficiencies were found, and the team realized the magnitude of the technical and integration challenges. In hindsight, these technical challenges came in part from an overly optimistic technology readiness assessment (TRA) at the beginning of the project, which resulted in the project assuming that little to no subsystem development would be required. The project’s approach to systems engineering evolved throughout three separate informal phases of the project as it underwent two key transitions as a result of the team wrestling with the technical challenges and resultant changing project scope. This paper discusses the assumptions, approaches, and challenges encountered from a Systems Engineering standpoint in each of the three informal phases of the X-57 project. This paper also provides recommendations on how future projects can apply Systems Engineering best practices upfront along with a realistic TRA to aid projects that find themselves with similar challenges.

Systems Engineering↗

NASA NTRS2015

Second Annual Transformative Vertical Flight Concepts Workshop: Enabling New Flight Concepts Through Novel Propulsion and Energy Architectures

On August 3rd and 4th, 2015, a workshop was held at the NASA Ames Research Center, located at the Moffett Federal Airfield in California to explore the aviation communities interest in Transformative Vertical Flight (TVF) Concepts. The Workshop was sponsored by the AHS International (AHS), the American Institute of Aeronautics and Astronautics (AIAA), the National Aeronautics and Space Administration (NASA), and hosted by the NASA Aeronautics Research Institute (NARI). This second annual workshop built on the success and enthusiasm generated by the first TVF Workshop held in Washington, DC in August of 2014. The previous Workshop identified the existence of a multi-disciplinary community interested in this topic and established a consensus among the participants that opportunities to establish further collaborations in this area are warranted. The desire to conduct a series of annual workshops augmented by online virtual technical seminars to strengthen the TVF community and continue planning for advocacy and collaboration was a direct outcome of the first Workshop. The second Workshop organizers focused on four desired action-oriented outcomes. The first was to establish and document common stakeholder needs and areas of potential collaborations. This includes advocacy strategies to encourage the future success of unconventional vertiport capable flight concept solutions that are enabled by emerging technologies. The second was to assemble a community that can collaborate on new conceptual design and analysis tools to permit novel configuration paths with far greater multi-disciplinary coupling (i.e., aero-propulsive-control) to be investigated. The third was to establish a community to develop and deploy regulatory guidelines. This community would have the potential to initiate formation of an American Society for Testing and Materials (ASTM) F44 Committee Subgroup for the development of consensus-based certification standards for General Aviation scale vertiport capable flight systems. These standards need to accommodate novel fixed wing concepts that do not fit within the existing Federal Aviation Administration (FAA) rotorcraft certification framework (Code of Federal Regulations, Title 14, Chapter I, Subchapter C, Part 27). The fourth desired outcome was to launch an information campaign to ensure key U.S. Government agencies understand the potential benefits and industry interest in establishing new vertiport capable flight markets. This record of the Workshop proceedings documents Workshop activities and products including summaries of the video recorded technical presentations, overviews of three breakout sessions (Missions Operational Concepts, Prioritized Technical Challenges, Regulatory Roadmap), and a preliminary draft roadmap framework for TVF.

V/STOL↗

NASA NTRS1992

Briefing notes on propulsion stability codes ADMIT, NYQUIST, and SSFREQ

The piping in a liquid rocket can assume complex configurations due to multiple tanks, multiple engines, and structures that piping must go around. The capability to handle some of these complex configurations have been incorporated into the Low Frequency Code (ADMIT), the Nyquist Code (NYQUIST), and the Intermediate Frequency code (SSFREQ). The capability to modify the input on line has been implemented. The configurations allowed include multiple tanks, multiple engines, and the splitting of a pipe into unequal segments going to different (or the same) engines. Straight pipes, bends, inline accumulators, tuned stubs, Helmholtz resonators, parallel resonators, and pumps are the types of piping that may be used. The three codes require the computation of admittance looking toward the tank. Therefore, they all have a number of similar routines for reading in the tank, piping, and engine descriptions. They also have similar routines for computing the admittance looking toward the tank. ADMIT uses only one type of feedline, either a LOX or FUEL line. NYQUIST can use no feedlines, one feedline (either LOX or FUEL), or two feedlines (both LOX and FUEL). SSFREQ requires both feedlines to be present (LOX and FUEL). The common features of the three codes are discussed first, with two sample runs described. Then each of the three codes are discussed along with the sample runs. Several on-line variations are suggested for the second sample run. Input descriptions and the input for the sample runs are given in the appendices.

Armstrong, W. C.↗

NASA NTRS2017

NASA's Space Launch System: Enabling Exploration and Discovery

As NASA's new Space Launch System (SLS) launch vehicle continues to mature toward its first flight and beyond, so too do the agency's plans for utilization of the rocket. Substantial progress has been made toward the production of the vehicle for the first flight of SLS - an initial "Block 1" configuration capable of delivering more than 70 metric tons (t) to Low Earth Orbit (LEO). That vehicle will be used for an uncrewed integrated test flight, propelling NASA's Orion spacecraft into lunar orbit before it returns safely to Earth. Flight hardware for that launch is being manufactured at facilities around the United States, and, in the case of Orion's service module, beyond. At the same time, production has already begun on the vehicle for the second SLS flight, a more powerful Block 1B configuration capable of delivering more than 105 t to LEO. This configuration will be used for crewed launches of Orion, sending astronauts farther into space than anyone has previously ventured. The 1B configuration will introduce an Exploration Upper Stage, capable of both ascent and in-space propulsion, as well as a Universal Stage Adapter - a payload bay allowing the flight of exploration hardware with Orion - and unprecedentedly large payload fairings that will enable currently impossible spacecraft and mission profiles on uncrewed launches. The Block 1B vehicle will also expand on the initial configuration's ability to deploy CubeSat secondary payloads, creating new opportunities for low-cost access to deep space. Development work is also underway on future upgrades to SLS, which will culminate in about a decade in the Block 2 configuration, capable of delivering 130 t to LEO via the addition of advanced boosters. As the first SLS draws closer to launch, NASA continues to refine plans for the human deep-space exploration it will enable. Planning currently focuses on use of the vehicle to assemble a Deep Space Gateway, which would comprise a habitat in the lunar vicinity allowing astronauts to gain experience living and working in deep space, a testbed for new systems and capabilities needed for exploration beyond, and a departure point for NASA and partners to send missions to other destinations. Assembly of the Gateway would be followed by a Deep Space Transport, which would be a vehicle capable of carrying astronauts farther into our solar system and eventually to Mars. This paper will give an overview of SLS' current status and its capabilities, and discuss current utilization planning.

Schorr, Andrew↗

NASA NTRS2017

NASA's Space Launch System: Enabling Exploration and Discovery

As NASA's new Space Launch System (SLS) launch vehicle continues to mature toward its first flight and beyond, so too do the agency's plans for utilization of the rocket. Substantial progress has been made toward the production of the vehicle for the first flight of SLS - an initial "Block 1" configuration capable of delivering more than 70 metric tons (t) to Low Earth Orbit (LEO). That vehicle will be used for an uncrewed integrated test flight, propelling NASA's Orion spacecraft into lunar orbit before it returns safely to Earth. Flight hardware for that launch is being manufactured at facilities around the United States, and, in the case of Orion's service module, beyond. At the same time, production has already begun on the vehicle for the second SLS flight, a more powerful Block 1B configuration capable of delivering more than 105 metric tons to LEO. This configuration will be used for crewed launches of Orion, sending astronauts farther into space than anyone has previously ventured. The 1B configuration will introduce an Exploration Upper Stage, capable of both ascent and in-space propulsion, as well as a Universal Stage Adapter - a payload bay allowing the flight of exploration hardware with Orion - and unprecedentedly large payload fairings that will enable currently impossible spacecraft and mission profiles on uncrewed launches. The Block 1B vehicle will also expand on the initial configuration's ability to deploy CubeSat secondary payloads, creating new opportunities for low-cost access to deep space. Development work is also underway on future upgrades to SLS, which will culminate in about a decade in the Block 2 configuration, capable of delivering 130 metric tons to LEO via the addition of advanced boosters. As the first SLS draws closer to launch, NASA continues to refine plans for the human deep-space exploration it will enable. Planning currently focuses on use of the vehicle to assemble a Deep Space Gateway, which would comprise a habitat in the lunar vicinity allowing astronauts to gain experience living and working in deep space, a testbed for new systems and capabilities needed for exploration beyond, and a departure point for NASA and partners to send missions to other destinations. Assembly of the Gateway would be followed by a Deep Space Transport, which would be a vehicle capable of carrying astronauts farther into our solar system and eventually to Mars. This paper will give an overview of SLS' current status and its capabilities, and discuss current utilization planning.

Robinson, Kimberly F.↗

NASA NTRS1999

Propulsion Induced Effects (PIE) Test Program

The Propulsion Induced Effects (PIE) test program is being lead by NASA Ames for Configuration Aerodynamics (CA). Representatives from CA, Technology Integration (TI), Inlet, and the Nozzle ITD's are working with Ames in defining and executing this test program. The objective of the CA 4-14 milestone is to assess the propulsion/airframe integration characteristics of the Technology Concept Airplane (TCA) and design variations using computational and experimental methods. The experimental aspect includes static calibrations, transonic and supersonic wind tunnel testing. The test program will generate a comprehensive database that will include all appropriate wind tunnel corrections, with emphasis placed on establishing the propulsion induced effects on the flight performance of the TCA.

Cappuccio, Gelsomina↗