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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 127 records · Page 7

Design, fabrication and test of graphite/polyimide composite joints and attachments for advanced aerospace vehicles

Principal program activities dealt with the literature survey, design of joint concepts, assessment of GR/PI material quality, fabrication of test panels and specimens, and small specimen testing. Bonded and bolted designs are presented for each of the four major attachment types. Quality control data are presented for prepreg Lots 2W4651 and 3W2020. Preliminary design allowables test results for tension tests and compression tests of laminates are also presented.

Source record↗

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Volume 2: Study results

Detailed computer models of the engine were developed to predict both the steady state and transient operation of the engine system. Mechanical design layout drawings were prepared for the following components: thrust chamber and nozzle; extendible nozzle actuating mechanism and seal; LOX turbopump and boost pump; hydrogen turbopump and boost pump; and the propellant control valves. The necessary heat transfer, stress, fluid flow, dynamic, and performance analyses were performed to support the mechanical design.

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Advanced launch vehicles

Vehicles capable of lifting very large and heavy payloads into low earth orbit (LEO) will be needed to support certain large-scale space missions being considered for the late 1990-2000 time period. These missions include the support of strategic national commitments, large space power systems, and interplanetary and lunar exploration. Nearer term missions will utilize the Space Shuttle and its direct derivatives, the Shuttle-Derived Vehicles (SDV), currently being defined under NASA and DOD sponsored studies. A conceptual design of a Heavy Lift Launch Vehicle (HLLV) that will lift a half million pounds to low earth orbit is presented. Design alternatives and key system design problems and issues are discussed. The new developments required, such as a new large liquid booster engine and Space Shuttle Main Engine (SSME) modifications, are identified. New candidate launch locations and launch facility requirements are also discussed. The commonality and utilization of the booster stage 'elements' as a liquid booster for a 'growth' Space Shuttle are conceptually defined.

Marshall, W. R.↗

Advanced launch vehicle upper stages using liquid propulsion and metallized propellants

Metallized propellants are liquid propellants with a metal additive suspended in a gelled fuel or oxidizer. Typically, aluminum particles are the metal additives. These propellants provide increase in the density and/or the specific impulse of the propulsion system. Using metallized propellants for volume- and mass-constrained upper stages can deliver modest increases in performance for Low Earth Orbit to Geosynchronous Earth Orbit and other Earth orbital transfer missions. Metallized propellants, however, can enable very fast planetary missions with a single-stage upper stage system. Trade studies comparing metallized propellant stage performance with non-metallized upper stages and the Inertial Upper Stage are presented. These upper stages are both one- and two-stage vehicles that provide the added energy to send payloads to altitudes and onto trajectories that are unattainable with only the launch vehicle. The stage designs are controlled by the volume and the mass constraints of the Space Transportation System and Space Transportation System-Cargo launch vehicles. The influences of the density and specific impulse increases enabled by metallized propellants are examined for a variety of different stage and propellant combinations.

Palaszewski, B. A.↗

Space transfer vehicle avionics advanced development needs

The assessment of preliminary transportation program options for the exploration initiative is underway. The exploration initiative for the Moon and Mars is outlined by mission phases. A typical lunar/Mars outpost technology/advanced development schedule is provided. An aggressive and focused technology development program is needed as early as possible to successfully support these new initiatives. The avionics advanced development needs, plans, laboratory facilities, and benefits from an early start are described.

Huffaker, C. F.↗

Attitude control/momentum management and payload pointing in advanced space vehicles

The design and evaluation of an attitude control/momentum management system for highly asymmetric spacecraft configurations are presented. The preliminary development and application of a nonlinear control system design methodology for tracking control of uncertain systems, such as spacecraft payload pointing systems are also presented. Control issues relevant to both linear and nonlinear rigid-body spacecraft dynamics are addressed, whereas any structural flexibilities are not taken into consideration. Results from the first task indicate that certain commonly used simplifications in the equations of motions result in unstable attitude control systems, when used for highly asymmetric spacecraft configurations. An approach is suggested circumventing this problem. Additionally, even though preliminary results from the second task are encouraging, the proposed nonlinear control system design method requires further investigation prior to its application and use as an effective payload pointing system design technique.

Parlos, Alexander G.↗

Advanced Launch Vehicle Upper Stages Using Liquid Propulsion and Metallized Propellants

Metallized propellants are liquid propellants with a metal additive suspended in a gelled fuel or oxidizer. Typically, aluminum (Al) particles are the metal additive. These propellants provide increase in the density and/or the specific impulse of the propulsion system. Using metallized propellant for volume-and mass-constrained upper stages can deliver modest increases in performance for low earth orbit to geosynchronous earth orbit (LEO-GEO) and other earth orbital transfer missions. Metallized propellants, however, can enable very fast planetary missions with a single-stage upper stage system. Trade studies comparing metallized propellant stage performance with non-metallized upper stages and the Inertial Upper Stage (IUS) are presented. These upper stages are both one- and two-stage vehicles that provide the added energy to send payloads to altitudes and onto trajectories that are unattainable with only the launch vehicle. The stage designs are controlled by the volume and the mass constraints of the Space Transportation System (STS) and Space Transportation System-Cargo (STS-C) launch vehicles. The influences of the density and specific impulse increases enabled by metallized propellants are examined for a variety of different stage and propellant combinations.

Palaszewski, Bryan A.↗

An approach to optimal guidance of an advanced launch vehicle concept

An approximate solution for the maximum payload trajectory of a two-stage launch vehicle using a regular perturbation technique is presented. A zero-order solution for a two-stage vehicle based on a flat-earth approximation and negligible atmospheric effects is obtained in closed form. High-order correction terms are obtained from the solution of nonhomogeneous, first-order linear differential equations by quadrature. This promises the capability for an onboard optimal guidance law implementation.

Leung, Martin S.↗

Fire safety design considerations for advanced space vehicles

The desire to understand and explore space has driven man to overcome the confines of the Earth's atmosphere and accept the challenge of spaceflight. With our increasing ability to travel, work, and explore in space comes a need for a better understanding of the hazards in this relatively new endeavor. One of the most important and immediate needs is to be able to predict the ignition, spread, and growth of fire on board spacecraft. Fire safety aboard spacecraft has always been a concern; however, with the increasing number and duration of proposed missions, it is imperative that the spacecraft be designed with a solid understanding of fire hazards, insuring that all risks have been minimized and extinguishment systems are available.

Source record↗

Importance of the Natural Terrestrial Environment with Regard to Advanced Launch Vehicle Design and Development

The terrestrial environment is an important forcing function in the design and development of the launch vehicle. The scope of the terrestrial environment includes the following phenomena: Winds; Atmospheric Thermodynamic Models and Properties; Thermal Radiation; U.S. and World Surface Environment Extremes; Humidity; Precipitation, Fog, and Icing; Cloud Characteristics and Cloud Cover Models; Atmospheric Electricity; Atmospheric Constituents; Vehicle Engine Exhaust and Toxic Chemical Release; Occurrences of Tornadoes and Hurricanes; Geological Hazards, and Sea States. One must remember that the flight profile of any launch vehicle is in the terrestrial environment. Terrestrial environment definitions are usually limited to information below 90 km. Thus, a launch vehicle's operations will always be influenced to some degree by the terrestrial environment with which it interacts. As a result, the definition of the terrestrial environment and its interpretation is one of the key launch vehicle design and development inputs. This definition is a significant role, for example, in the areas of structures, control systems, trajectory shaping (performance), aerodynamic heating and take off/landing capabilities. The launch vehicle's capabilities which result from the design, in turn, determines the constraints and flight opportunities for tests and operations.

Pearson, S. D.↗

Stage-by-Stage and Parallel Flow Path Compressor Modeling for a Variable Cycle Engine, NASA Advanced Air Vehicles Program - Commercial Supersonic Technology Project - AeroServoElasticity

This paper covers the development of stage-by-stage and parallel flow path compressor modeling approaches for a Variable Cycle Engine. The stage-by-stage compressor modeling approach is an extension of a technique for lumped volume dynamics and performance characteristic modeling. It was developed to improve the accuracy of axial compressor dynamics over lumped volume dynamics modeling. The stage-by-stage compressor model presented here is formulated into a parallel flow path model that includes both axial and rotational dynamics. This is done to enable the study of compressor and propulsion system dynamic performance under flow distortion conditions. The approaches utilized here are generic and should be applicable for the modeling of any axial flow compressor design accurate time domain simulations. The objective of this work is as follows. Given the parameters describing the conditions of atmospheric disturbances, and utilizing the derived formulations, directly compute the transfer function poles and zeros describing these disturbances for acoustic velocity, temperature, pressure, and density. Time domain simulations of representative atmospheric turbulence can then be developed by utilizing these computed transfer functions together with the disturbance frequencies of interest.

Compressor Modeling Modeling↗

Energy Augmentation for Vehicle Electric Systems (EAVES)

This preliminary study evaluated eight concepts for augmenting the energy state of electric Vertical Take-Off and Landing vehicles. Advanced Air Mobility electric vehicles could need additional charge due to depleted batteries (e.g., strong winds along the way) while approaching their destination. There are five direct charging and three indirect charging concepts presented in this paper. The concepts are in the preliminary research stage and are being refined. Considering the concepts are for the year 2045 timeframe, there is sufficient time to evolve them, along with the designs of these electric air vehicles. This Technical Memorandum describes more detail and provides a discussion on the desirability, viability, feasibility, and wickedness of these energy augmentation concepts. A discussion of barriers and initial investigation approach for the concepts is presented as well. One intent for the presentation of this Technical Memorandum is to capture the work done from March through September 2022 within NASA’s Convergent Aeronautics Solutions (CAS) Project, in the Transformative Aeronautics Concepts Program. At the end of the effort, it was decided that only one concept would be further investigated. The rest of the concepts for energy augmentation would be described in this document and could be picked up later if NASA chose to further investigate them. This document is a collection of input from the authors regarding the concepts they worked on. It is not intended to be a conference or journal publication, but a record of research conducted on the concepts considered by the Energy Augmentation for Vehicle Electric Systems (EAVES) team consisting of the authors. Mr. Todd Stinchfield was the Principal Investigator.

Kapil Sheth↗