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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 289 records · Page 16

Electrifying Transit: A Guidebook for Implementing Battery Electric Buses

This guidebook is organized to give transit decision-makers and relevant stakeholders an overview of BEB facts, data, and considerations important for planning their implementation in a variety of jurisdictions. First, the benefits and barriers for BEB are identified. Second, BEB basics in terms of the major components, including a) the bus, b) the battery, and c) the numerous charging options. BEB introduces new, high demand loads as the buses are charging and thus have a number of interactions with the electricity grid and the utility, which are explored third. Operation and maintenance of BEBs are considered fourth as BEBs should not be operated and maintained in the same approach as diesel buses. Fifth, the costs of BEB prices are summarized – and the choices of bus and battery are explored in how they impact BEB prices. Funding and financing options that support BEBs and their charging stations are also explored. Safety is a key consideration for BEBs and the guidebook touches upon codes and standards, hazards, and emergencies. The final section examines project execution, bringing together information from all the other sections so that long-term planning, route analysis, and fleet and infrastructure planning can be considered in the preparation of BEB deployment, and then deployment can be evaluated on a regular basis. A final conclusion revisits the information covered in the guidebook.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

FY22 Year End Report of Delivery Environments Predictive Capabilities Use in Analysis of SRP Programs

As was established in a previous milestone report for FY20, W-13 continues to be tasked with analyses that require knowledge of in-flight environments and require an in-house capability to generate such environments. To this end, FY21 work included obtaining and benchmarking the use of such tools for an in-house capability. With these tools available for analysis tasks, FY22 work has been to continue the development of analysis for Responsive Development Experiment (ReDX) flights in the Stockpile Responsiveness Program (SRP). While no flights were executed in FY22 that leveraged internal flight analysis., this report shows that both CBAERO and TAOS were used in W-13 under the Delivery Environments Program for the FY22 milestone in order to predict the flight environments of ReDX flight 3 and determine preliminary environments of the Calypso flight vehicle which includes a deployable heat shield.

42 ENGINEERING↗

Operations analysis (study 2.1). Program SEPSIM (solar electric propulsion stage simulation)

Program SEPSIM is a FORTRAN program which performs deployment, servicing, and retrieval missions to synchronous equatorial orbit using a space tug with a continuous low thrust upper stage known as a solar electric propulsion stage (SEPS). The SEPS ferries payloads back and forth between an intermediate orbit and synchronous orbit, and performs the necessary servicing maneuvers in synchronous orbit. The tug carries payloads between the orbiter and the intermediate orbit, deploys fully fueled SEPS vehicles, and retrieves exhausted SEPS vehicles when, and if, required. The program is presently contained in subroutine form in the Logistical On-orbit VEhicle Servicing (LOVES) Program, but can also be run independently with the addition of a simple driver program.

Lang, T. J.↗

Saving Skylab

Initial difficulties encountered with the launch and operational deployment of the Skylab vehicle are described in terms of early indications of hardware failures, ground-based efforts at diagnosing the nature and significance of damage, and organization of improvized means and procedures for repair operations. Attention is given to heating and power-supply problems stemming from the loss of a micrometeoroid shield and a solar cell array. Systems engineering problems arising from the necessity of achieving a compromise among thermal, electrical, and stabilization requirements are explained, and repair solutions and operations in space and on the ground are described in detail.-

Schneider, W. C.↗

Carbon composites in space vehicle structures

Recent developments in the technology of carbon or graphite filaments now provide the designer with greatly improved materials offering high specific strength and modulus. Besides these advantages are properties which are distinctly useful for space applications and which provide feasibility for missions not obtainable by other means. Current applications include major and secondary structures of communications satellites. A number of R & D projects are exploring carbon-fiber application to rocket engine motor cases, advanced antenna systems, and space shuttle components. Future system studies are being made, based on the successful application of carbon fibers for orbiting space telescope assemblies, orbital transfer vehicles, and very large deployable energy generation systems. Continued technology development is needed in analysis, material standards, and advanced structural concepts to exploit the full potential of carbon filaments in composite materials.

Mayer, N. J.↗

The construction of a highly transportable laser ranging station

The technology of the transportable Laser Ranging Station (TLRS) used in crustal dynamics studies was examined. The TLRS used a single photoelectron beam of limited energy density returned from the Laser Geodynamic Satellite (LAGEOS). Calibration was accomplished by the diversion of a small portion of the outgoing beam attenuated to the same level as the satellite return. Timing for the system was based on a self calibrating Ortec TD811, 100 picosec time interval device. The system was contained in a modified, single chassis recreational vehicle that allowed rapid deployment. The TLRS system was only airmobile on the largest transport aircraft. A 30 cm simple plano/concave transfer lens telescope aided in beam direction. The TLRS system fulfills the need for an accurate method of obtaining range measurements to the LAGEOS satellite incorporated in a mobile, air transportable, and economical configuration.

Source record↗

Propulsion evaluation for orbit-on-demand vehicles

Future earth-to-orbit vehicles may be required to reach orbit within hours or even minutes of a decision. A study has been conducted to consider vehicles with such a capability. In Phase I of the study, 11 vehicles were designed to deploy 5000 lb to a polar orbit. Changes in the designs were examined parametrically for increased on-orbit maneuvers, increased payload, and other mission variations. Based on the results, two concepts were selected for Phase II design work: a vertical-takeoff, two-stage system and a horizontal-takeoff, two-stage system with an airbreathing subsonic first stage. The results of several propulsion evaluations are presented, including liftoff thrust-to-weight effects, dual-fuel propulsion for a horizontal-takeoff concept, and the effect of using fluorine.

Martin, J. A.↗

Weights assessment for orbit-on-demand vehicles

Future manned, reusable earth-to-orbit vehicles may be required to reach orbit within hours or even minutes of a mission decision. A study has been conducted to consider vehicles with such a capability. In the initial phase of the study, 11 vehicles were sized for deployment of 5000 lbs to a polar orbit. From this matrix, two of the most promising concepts were resized for a modified mission and payload. A key feature of the study was the use of consistent mass estimating techniques for a broad range of concepts, allowing direct comparisons of sizes and weights.

Macconochie, I. O.↗

Stabilizing Wheels For Rover Vehicle

Proposed articulated, normally-four-wheeled vehicle holds extra pair of wheels in reserve. Deployed to lengthen wheelbase on slopes, thereby making vehicle more stable, and to aid vehicle in negotiating ledge or to right vehicle if turned upside down. Extra wheels are drive wheels mounted on arms so they pivot on axis of forward drive wheels. Both extra wheels and arms driven by chains, hydraulic motors, or electric motors. Concept promises to make remotely controlled vehicles more stable and maneuverable in such applications as firefighting, handling hazardous materials, and carrying out operations in dangerous locations.

Collins, Earl R., Jr.↗

Simple autonomous Mars walker

Under a contract with NASA's Jet Propulsion Laboratory, Martin Marietta has developed several alternative rover concepts for unmanned exploration of the planet Mars. One of those concepts, the 'Walking Beam', is the subject of this paper. This concept was developed with the goal of achieving many of the capabilities of more sophisticated articulated-leg walkers with a much simpler, more robust, less computationally demanding and more power efficient design. It consists of two large-base tripods nested one within the other which alternately translate with respect to each other along a 5-meter beam to propel the vehicle. The semiautonomous navigation system relies on terrain geometry sensors and tacticle feedback from each foot to autonomously select a path which avoids hazards along a route designated from earth. Both mobility and navigation features of this concept are discussed including a top-level description of the vehicle's physical characteristics, deployment strategy, mobility elements, sensor suite, theory of operation, navigation and control processes, and estimated performance.

Larimer, Stanley J.↗

Free-decay time-domain modal identification for large space structures

Concept definition studies for the Modal Identification Experiment (MIE), a proposed space flight experiment for the Space Station Freedom (SSF), have demonstrated advantages and compatibility of free-decay time-domain modal identification techniques with the on-orbit operational constraints of large space structures. Since practical experience with modal identification using actual free-decay responses of large space structures is very limited, several numerical and test data reduction studies were conducted. Major issues and solutions were addressed, including closely-spaced modes, wide frequency range of interest, data acquisition errors, sampling delay, excitation limitations, nonlinearities, and unknown disturbances during free-decay data acquisition. The data processing strategies developed in these studies were applied to numerical simulations of the MIE, test data from a deployable truss, and launch vehicle flight data. Results of these studies indicate free-decay time-domain modal identification methods can provide accurate modal parameters necessary to characterize the structural dynamics of large space structures.

Kim, Hyoung M.↗

Special Investigation Report: Commercial Space Launch Incident, Launch Procedure Anomaly Orbital Sciences Corporation PEGASUS/SCD-1, 80 Nautical Miles East of Cape Canaveral, Florida, February 9, 1993

This report explains the procedural anomaly that occurred during the launch sequence of an Orbital Sciences Corporation Pegasus expendable launch vehicle, which was subsequently deployed successfully from an NB-52B airplane, on 9 Feb. 1993. The safety issues discussed in the report include command, control and communications responsibility, launch crew fatigue, launch interphone procedures, efficiency of launch constraints, and the lack of common launch documents. Safety recommendations concerning these issues were made to the Department of Transportation, the National Aeronautics and Space Administration, and the Orbital Sciences Corporation.

Source record↗

SEE Design Guide and Requirements for Electrical Deadfacing

The purpose of this design guide is to present information for understanding and mitigating the potential hazards associated with de-mating and mating powered electrical connectors on space flight vehicles. The process of staging is a necessary function in the launching of space vehicles and in the deployment of satellites, and now in manned assembly of systems in space. During this electrical interconnection process, various environments may be encountered that warrant the restriction of the voltage and current present across the pins of an electrical connector prior to separation, mating, or in a static open non-mated configuration. This process is called deadfacing. These potentially hazardous environments encompass the obvious explosive fuel vapors and human shock hazard, to multiple Electro-Magnetic Interference (EMI) phenomena related to the rapid rate of change in current as well as exposure to Radio Frequency (RF) fields.

Berki, Joe M.↗

Description of New Inflatable/Rigidizable Hexapod Structure Testbed for Shape and Vibration Control

Larger and more powerful space based instruments are needed to meet increasingly sophisticated scientific demand. To support this need, concepts for telescopes with apertures of 100 meters are being investigated, but the required technologies are not in hand today. Due to the capacity limits of launch vehicles, the idea of deploying, erecting, or inflating large structures in space is being considered. Recently, rigidization concepts of large inflatable structures have demonstrated the capability of weight reductions of up to 50% from current concepts with packaging efficiencies near 80%. One of the important aspects of inflatable structures is vibration mitigation and line-of-sight control. Such control tasks are possible only after actuators/sensors are properly integrated into a rigidizable concept. To study these issues, we have developed an inflatable/rigidizable hexapod structure testbed. The testbed integrates state of the art piezo-electric self-sensing actuators into an inflatable/rigidizable structure and a flat membrane reflector. Using this testbed, we plan to experimentally demonstrate achievable vibration and line-of-sight control. This paper contains a description of the testbed and an outline of the test plan.

Adetona, O.↗

Mars Tumbleweed: FY2003 Conceptual Design Assessment

NASA LaRC is studying concepts for a new type of Mars exploration vehicle that would be propelled by the wind. Known as the Mars Tumbleweed, it would derive mobility through use of the Martian surface winds. Tumbleweeds could conceivably travel greater distances, cover larger areas of the surface, and provide access to areas inaccessible by conventional vehicles. They would be lightweight and relatively inexpensive, allowing a multiple vehicle network to be deployed on a single mission. Tumbleweeds would be equipped with sensors for conducting science and serve as scouts searching broad areas to identify specific locations for follow-on investigation by other explorers. An extensive assessment of LaRC Tumbleweed concepts was conducted in FY03, including refinement of science mission scenarios, definition of supporting subsystems (structures, power, communications), testing in wind tunnels, and development of a dynamic simulation capability.

Antol, Jeffrey↗

Cabin Air Quality On Board Mir and the International Space Station: A Comparison

The maintenance of the cabin atmosphere aboard spacecraft is critical not only to its habitability but also to its function. Ideally, air quality can be maintained by striking a proper balance between the generation and removal of contaminants. Both very dynamic processes, the balance between generation and removal can be difficult to maintain and control because the state of the cabin atmosphere is in constant evolution responding to different perturbations. Typically, maintaining a clean cabin environment on board crewed spacecraft and space habitats is the central function of the environmental control and life support (ECLS) system. While active air quality control equipment is deployed on board every vehicle to remove carbon dioxide, water vapor, and trace chemical components from the cabin atmosphere, perturbations associated with logistics, vehicle construction and maintenance, and ECLS system configuration influence the resulting cabin atmospheric quality. The air-quality data obtained from the International Space Station (ISS) and NASA-Mir programs provides a wealth of information regarding the maintenance of the cabin atmosphere aboard long-lived space habitats. A comparison of the composition of the trace chemical contaminant load is presented. Correlations between ground-based and in-flight operations that influence cabin atmospheric quality are identified and discussed, and observations on cabin atmospheric quality during the NASA-Mir expeditions and the International Space Station are explored.

Macatangay, Ariel↗

Tele-Supervised Adaptive Ocean Sensor Fleet

The Tele-supervised Adaptive Ocean Sensor Fleet (TAOSF) is a multi-robot science exploration architecture and system that uses a group of robotic boats (the Ocean-Atmosphere Sensor Integration System, or OASIS) to enable in-situ study of ocean surface and subsurface characteristics and the dynamics of such ocean phenomena as coastal pollutants, oil spills, hurricanes, or harmful algal blooms (HABs). The OASIS boats are extended- deployment, autonomous ocean surface vehicles. The TAOSF architecture provides an integrated approach to multi-vehicle coordination and sliding human-vehicle autonomy. One feature of TAOSF is the adaptive re-planning of the activities of the OASIS vessels based on sensor input ( smart sensing) and sensorial coordination among multiple assets. The architecture also incorporates Web-based communications that permit control of the assets over long distances and the sharing of data with remote experts. Autonomous hazard and assistance detection allows the automatic identification of hazards that require human intervention to ensure the safety and integrity of the robotic vehicles, or of science data that require human interpretation and response. Also, the architecture is designed for science analysis of acquired data in order to perform an initial onboard assessment of the presence of specific science signatures of immediate interest. TAOSF integrates and extends five subsystems developed by the participating institutions: Emergent Space Tech - nol ogies, Wallops Flight Facility, NASA s Goddard Space Flight Center (GSFC), Carnegie Mellon University, and Jet Propulsion Laboratory (JPL). The OASIS Autonomous Surface Vehicle (ASV) system, which includes the vessels as well as the land-based control and communications infrastructure developed for them, controls the hardware of each platform (sensors, actuators, etc.), and also provides a low-level waypoint navigation capability. The Multi-Platform Simulation Environment from GSFC is a surrogate for the OASIS ASV system and allows for independent development and testing of higher-level software components. The Platform Communicator acts as a proxy for both actual and simulated platforms. It translates platform-independent messages from the higher control systems to the device-dependent communication protocols. This enables the higher-level control systems to interact identically with heterogeneous actual or simulated platforms.

Lefes, Alberto↗