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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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This paper addresses the issues of the System Engineering processes and validation of performance specifications. It also describes the current status of the SIM Reference System Design.
This short presentation outlines an upcoming flight test to be performed as part of the Advanced Air Mobility (AAM) project. Referred to as the Integration of Automated Systems (IAS) flight test series, the objectives are to evaluate NASA research concepts and technologies for complex operations through integrated automation and candidate operational concepts and scenarios. The primary objective is to test mature AAM technologies in a relevant environment. The two primary systems under test are the Flight Path Management (FPM) and Hazard Perception and Avoidance (HPA) technology. This presentation focuses on the HPA technology developed by the FAA known as the Airborne Collision Avoidance System X for Rotorcraft (ACAS Xr) since the audience consists of committee members currently working on developing the minimum requirements for this system. The second half of the presentation explains the primary objectives and describes the scenarios expected to be tested in flight.
A disturbance isolation controller (DIC) is developed for a simplified model of the solar electric propulsion system (SEPS) flight experiment which consists of a rigid Sperry gimbal torquer (AGS) mounted to a rigid orbiter and the SEPS solar array (rigid) end mounted to the AGS. The main purpose of the DIC is to reduce the effects of orbiter disturbances which are transmitted to the flight experiment. The DIC uses an observer, which does not require the direct measurement of the plant inputs, to obtain estimates of the plant states and the rate of the plant states. The state and rate of state information is used to design a controller which isolates disturbances from specified segments of the plant, and for the flight experiment, the isolated segment is the SEPS solar array.
The Constellation program is an organization within NASA whose mission is to create the new generation of spacecraft that will replace the Space Shuttle after its planned retirement in 2010. In the event of a catastrophic failure on the launch pad or launch vehicle during ascent, the successful use of the launch abort system will allow crew members to escape harm. The Flight Test Office is the organization within the Constellation project that will flight-test the launch abort system on the Orion crew exploration vehicle. The Flight Test Office has proposed six tests that will demonstrate the use of the launch abort system. These flight tests will be performed at the White Sands Missile Range in New Mexico and are similar in nature to the Apollo Little Joe II tests performed in the 1960s. An overview of the launch abort system flight tests for the Orion crew exploration vehicle is given. Details on the configuration of the first pad abort flight test are discussed. Sample flight trajectories for two of the six flight tests are shown.
The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, distillation systems have been actively pursued as one of the technologies for water recovery. One such technology is the Cascade Distillation System (CDS) a multi-stage vacuum rotary distiller system designed to recover water in a microgravity environment. Its rotating cascading distiller operates similarly to the state of the art (SOA) vapor compressor distiller (VCD), but its control scheme and ancillary components are judged to be straightforward and simpler to implement into a successful design. Through the Advanced Exploration Systems (AES) Life Support Systems (LSS) Project, the NASA Johnson Space Center (JSC) in collaboration with Honeywell International is developing a second generation flight forward prototype (CDS 2.0). The key objectives for the CDS 2.0 design task is to provide a flight forward ground prototype that demonstrates improvements over the SOA system in the areas of increased reliability and robustness, and reduced mass, power and volume. It will also incorporate exploration-class automation. The products of this task are a preliminary flight system design and a high fidelity prototype of an exploration class CDS. These products will inform the design and development of the third generation CDS which is targeted for on-orbit DTO. This paper details the preliminary design of the CDS 2.0.
This paper addresses the application of identification techniques to flight data from the Space Shuttle Remote Manipulator System (RMS). A description of the remote manipulator, including structural and control system characteristics, sensors, and actuators is given. A brief overview of system identification procedures is presented, and the practical aspects of implementing system identification algorithms are discussed. In particular, the problems posed by desampling rate, numerical error, and system nonlinearities are considered. Simulation predictions of damping, frequency, and system order are compared with values identified from flight data to support an evaluation of RMS structural and control system models. Finally, conclusions are drawn regarding the application of identification techniques to flight data obtained from a flexible space structure.
The foundation for a safe and successful flight test of the National Aeronautics and Space Administration (NASA) X-57 Maxwell all-electric experimental airplane, or any X-Plane, is comprehensive system testing on the ground. This test campaign includes verification and validation (V&V) that the integrated system operates as designed and expected, as well as understanding how the system reacts and responds to failures that can occur during flight by performing failure modes and effects testing (FMET). The aircraft should be in the final flight configuration for these test activities because any modifications, even those that appear insignificant, could affect test outcomes. Although the plan was to perform V&V and FMET testing once the airplane was in the flight configuration, due to multiple component redesigns, concurrent software development, and other problems with on-aircraft testing, the X-57 Maxwell never made it into a full-flight configuration. As a result, a build-up approach was followed to test software and hardware as they became ready in order to continue making progress wherever possible. Using this approach revealed problems with the hardware and software faster than waiting for a full-flight configuration, allowing solutions to be found more quickly and in parallel with other project tasks. Other than unloaded motor testing in a lab setting, the only other test setup was on the airplane itself. On-aircraft testing was preferrable in order to test things as close to a flight configuration as possible but was time consuming due to the requirements for testing on the airplane. To overcome some of the on-aircraft barriers, off-aircraft test configurations, such as the Systems Integration Laboratory (SIL) and hardware-in-the-loop (HIL) setups, were used, but each of these setups had limitations to be considered. As a result, solutions found in the SIL or HIL configurations did not always work as expected on the airplane, resulting in an iterative process between on- and off-aircraft testing to find the final solution. Having a dedicated test platform such as an iron bird that closely represents the aircraft - without flight hardware - would have been the most effective off-aircraft test setup, which could have allowed the project to save time and money and potentially reach flight. This paper will highlight the V&V and FMET considerations and testing prerequisites, the build-up approaches to both software and system testing, the benefits and drawbacks to different test configurations, as well as battery testing and operations.
The foundation for a safe and successful flight test of the National Aeronautics and Space Administration (NASA) X-57 Maxwell all-electric experimental airplane, or any X-Plane, is comprehensive system testing on the ground. This test campaign includes verification and validation (V&V) that the integrated system operates as designed and expected, as well as understanding how the system reacts and responds to failures that can occur during flight by performing failure modes and effects testing (FMET). The aircraft should be in the final flight configuration for these test activities because any modifications, even those that appear insignificant, could affect test outcomes. Although the plan was to perform V&V and FMET testing once the airplane was in the flight configuration, due to multiple component redesigns, concurrent software development, and other problems with on-aircraft testing, the X-57 Maxwell never made it into a full-flight configuration. As a result, a build-up approach was followed to test software and hardware as they became ready in order to continue making progress wherever possible. Using this approach revealed problems with the hardware and software faster than waiting for a full-flight configuration, allowing solutions to be found more quickly and in parallel with other project tasks. Other than unloaded motor testing in a lab setting, the only other test setup was on the airplane itself. On-aircraft testing was preferrable in order to test things as close to a flight configuration as possible but was time consuming due to the requirements for testing on the airplane. To overcome some of the on-aircraft barriers, off-aircraft test configurations, such as the Systems Integration Laboratory (SIL) and hardware-in-the-loop (HIL) setups, were used, but each of these setups had limitations to be considered. As a result, solutions found in the SIL or HIL configurations did not always work as expected on the airplane, resulting in an iterative process between on- and off-aircraft testing to find the final solution. Having a dedicated test platform such as an iron bird that closely represents the aircraft - without flight hardware - would have been the most effective off-aircraft test setup, which could have allowed the project to save time and money and potentially reach flight. This paper will highlight the V&V and FMET considerations and testing prerequisites, the build-up approaches to both software and system testing, the benefits and drawbacks to different test configurations, as well as battery testing and operations.
An integrated flight propulsion control mode, the Adaptive Engine Control System (ADECS), has been developed and flight tested on an F-15 aircraft as part of the NASA Highly Integrated Digital Electronic Control program. The ADECS system realizes additional engine thrust by increasing the engine pressure ratio (EPR) at intermediate and afterburning power, with the amount of EPR uptrim modulated using a predictor scheme for angle-of-attack and sideslip angle. Substantial improvement in aircraft and engine performance was demonstrated, with a 16 percent rate of climb increase, a 14 percent reduction in time to climb, and a 15 percent reduction in time to accelerate. Significant EPR uptrim capability was found with angles-of-attack up to 20 degrees.
The article presents a summary of the propulsion system tests conducted on a number of aircraft at the NASA Dryden Flight Research Center. The tests included digital engine control systems, engine-inlet compatibility, inlet-airframe interactions, nozzle-boattail drag and advanced turboprop acoustics. Among the aircraft evaluated were the F-15, HiMAT, F-14, and the JetStar.
Research dealt with the general area of optimal flight control synthesis for manned flight vehicles. The work was generic; no specific vehicle was the focus of study. However, the class of vehicles generally considered were those for which high authority, multivariable control systems might be considered, for the purpose of stabilization and the achievement of optimal handling characteristics. Within this scope, the topics of study included several optimal control synthesis techniques, control-theoretic modeling of the human operator in flight control tasks, and the development of possible handling qualities metrics and/or measures of merit. Basic contributions were made in all these topics, including human operator (pilot) models for multi-loop tasks, optimal output feedback flight control synthesis techniques; experimental validations of the methods developed, and fundamental modeling studies of the air-to-air tracking and flared landing tasks.
The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission. NICER is a NASA Explorer Mission of Opportunity that will be hosted on the International Space Station (ISS). SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper gives an overview of the SEXTANT system architecture and describes progress prior to environmental testing of the NICER flight instrument. It provides descriptions and development status of the SEXTANT flight software and ground system, as well as detailed description and results from the flight software functional and performance testing within the highfidelity Goddard Space Flight Center (GSFC) X-ray Navigation Laboratory Testbed (GXLT) software and hardware simulation environment. Hardware-in-the-loop simulation results are presented, using the engineering model of the NICER timing electronics and the GXLT pulsar simulator-the GXLT precisely controls NASA GSFC's unique Modulated X-ray Source to produce X-rays that make the NICER detector electronics appear as if they were aboard the ISS viewing a sequence of millisecond pulsars.
The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission. NICER is a NASA Explorer Mission of Opportunity that will be hosted on the International Space Station (ISS). SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper gives an overview of the SEXTANT system architecture and describes progress prior to environmental testing of the NICER flight instrument. It provides descriptions and development status of the SEXTANT flight software and ground system, as well as detailed description and results from the flight software functional and performance testing within the high-fidelity Goddard Space Flight Center (GSFC) X-ray Navigation Laboratory Testbed (GXLT) software and hardware simulation environment. Hardware-in-the-loop simulation results are presented, using the engineering model of the NICER timing electronics and the GXLT pulsar simulator-the GXLT precisely controls NASA GSFC's unique Modulated X-ray Source to produce X-rays that make the NICER detector electronics appear as if they were aboard the ISS viewing a sequence of millisecond pulsars
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The design and development of large antenna systems are discussed. The validation objectives and techniques of the structural behavior of the system are outlined along with studies of the dynamics, deployment, and unpacking. The validation of flexible control and system performance are also considered.
The unexpected duration for the flight of the Long Duration Exposure Facility (LDEF) conducted CNES to create a special investigation group in order to analyze all the materials and systems which compose the French Cooperative Payload (FRECOPA) except the experiments especially prepared for the flight. The FRECOPA tray was on the trailing face (V-) of the LDEF and protected from the atomic oxygen flux during all the flight. However, the solar irradiation was very important with solar flux quite perpendicular to the experiment once an orbit. There was also a good vacuum environment. The objectives are to test the effects of the combined space environment on materials and components like: structure, thermal control coatings and blankets, electronic unit, motors, and mechanical fixtures. When the LDEF returned to Kennedy Space Center, a visual inspection showed the very good behavior of the materials used and it was noted that the three mechanisms to open and close the experiment canisters worked completely. Many impacts of micrometeoroids or space debris on the structure and on the thermal protections were observed. After FRECOPA was brought back to Toulouse, many tests were performed and include: working order tests, mechanical tests (tension), optical and electronic microscopy (SEM), surface analysis (ESCA, SIMS, RBS, AUGER, etc.), thermal analysis, pressure measurements, and gas analysis (outgassing tests). The results of these experiments are discussed.
A world leader in space technology, JPL has over 30 years experience in developing spacecraft systems and managing deep space missions for NASA. Future scientific missions will require the rapid development of small, lightweight, high-technology, low-cost spacecraft. JPL is developing a method of meeting these requirements: a test facility specifically for supporting a rapid prototyping development environment that creates a virtual (simulated) spacecraft in which system-level evaluations of components can be carried out very early in the development cycle, long before an actual spacecraft is built.