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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 sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Acquisition/expulsion system for earth orbital propulsion system study. Volume 5: Earth storable design

A comprehensive analysis and parametric design effort was conducted under the earth-storable phase of the program. Passive Acquisition/expulsion system concepts were evaluated for a reusable Orbital Maneuvering System (OMS) application. The passive surface tension technique for providing gas free liquid on demand was superior to other propellant acquisition methods. Systems using fine mesh screens can provide the requisite stability and satisfy OMS mission requirements. Both fine mesh screen liner and trap systems were given detailed consideration in the parametric design, and trap systems were selected for this particular application. These systems are compatible with the 100- to 500-manned mission reuse requirements.

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NASA NTRS1973

Acquisition/expulsion system for earth orbital propulsion system study. Volume 3: Cryogenic test

A ground test program was conducted to verify several of the design methods and techniques that were used in designing cryogenic acquisition/expulsion systems. The testing of a 63.5-cm diameter DSL subscale model was particularly significant. Under these tests, the operational characteristics of the DSL concept were verified using LH2 and LN2. Demonstration of the gas free liquid expulsion characteristics was accomplished by expelling LH2 under -1 g using both GH2 and GHe pressurization. Loading of the acquisition/expulsion device was successfully accomplished using LH2 and LN2. The liquid free vapor venting performance of the model was limited because of the thermal stratification under the -1 g test conditions.

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NASA NTRS1979

The 18 and 30 GHz fixed service communication satellite system study: Executive summary

The use of the 18 and 30 GHz bands for fixed service satellite communications is examined. Primary objectives were to determine if satellite communication systems using this allocation (27.5 to 30.0 GHz uplink; 17.7 to 20.2 GHz downlink) can be cost competitive with alternate means of communication, and to determine what technological developments would be required to make these systems competitive. To meet these objectives, the cost and performance to be expected of 18 and 30 GHz hardware in the 1985 to 1990 era was assessed, selected trunking and direct to user concepts were optimized, and the cost of these systems was estimated. Finally, the technology developments required to make the most promising of the concepts competitive were identified.

Bronstein, L. M.↗
NASA NTRS1974

Space Tug systems study (storable). Volume 1: Overview presentation

Program plans are established for a storable propellant space tug used to perform high energy orbit transfers from the space transportation system (STS) orbiter. The mission model for the STS in the 1980's is analyzed. Performance and mission requirements are determined. Various flight operations modes are evaluated and selected. Subsystems are selected and synthesized into various tug configurations. Program options for these configurations are defined, analyzed, and selected. Selected program options are further defined and optimized, including program requirements, tug vehicle definition, mission accomplishment, ground and flight operations, programmatics and costs.

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NASA NTRS1972

Outer planet entry probe system study. Volume 1: Summary

General mission considerations and science prospectus, which are of a general nature that applies to several or all planetary applications, are presented. Five probe systems are defined: nominal Jupiter probe system, and Jupiter probe-dedicated alternative probe system, Jupiter spacecraft radiation-compatible alternative probe system, Saturn probe system, and Saturn probe applicability for Uranus. Parametric analysis is summarized for mission analysis of a general nature, and then for specific missions to Jupiter, Saturn, Uranus, and Neptune. The program is also discussed from the hardware availability viewpoint and the aspect of commonality.

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NASA NTRS2005

System Study: Technology Assessment and Prioritizing

The objective of this NASA funded project is to assess and prioritize advanced technologies required to achieve the goals for an "Intelligent Propulsion System" through collaboration among GEAE, NASA, and Georgia Tech. Key GEAE deliverables are parametric response surface equations (RSE's) relating technology features to system benefits (sfc, weight, fuel burn, design range, acoustics, emission, etc...) and listings of Technology Impact Matrix (TIM) with benefits, debits, and approximate readiness status. TIM has been completed for GEAE and NASA proposed technologies. The combined GEAE and NASA TIM input requirement is shown in Table.1. In the course of building the RSE's and TIM, significant parametric technology modeling and RSE accuracy improvements were accomplished. GEAE has also done preliminary ranking of the technologies using Georgia Tech/GEAE USA developed technology evaluation tools. System level impact was performed by combining beneficial technologies with minimum conflict among various system figures of merits to assess their overall benefits to the system. The shortfalls and issues with modeling the proposed technologies are identified, and recommendations for future work are also proposed.

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NASA NTRS1978

Control system studies for thermionic reactors

In core thermionic reactor concepts are of interest for space missions that require electrical power in the range of a few tens of kilowatts up to several megawatts. The physical principle involved--thermionic direct conversion of heat to electricity at net efficiencies up to 15 percent--offers potential advantages when compared to other nuclear powerplant concepts. However, the integration of the thermionic diode electrode structure with high-temperature nuclear fuel materials presents new design problems and new reactor physical constraints. Among the topics that must be investigated are those associated with the control system. The results of analytical and simulation studies of thermionic reactor control performed at the Jet Propulsion Laboratory are discussed.

Hermsen, R. J.↗
NASA NTRS1989

Multiple beam antenna/switch system study

In the study of the Multiple Beam Antenna/Switch for the space to ground link (SGL) uplink and downlink services, several issues related to system engineering, antenna, transmit/receive, and switch systems were addressed and the results are provided. Bandwidth allocation at Ku band is inadequate to serve the data rate requirements for the forward and return services. Rain and depolarization effects at EHF, especially at Ka band, pose a significant threat to the link availabilities at heavy rain areas. Hardware induced effects such as the nonlinear characteristics of the power amplifier may necessitate the use of linearizers and limiters. It is also important to identify the components that are susceptible to the space radiation effects and shield or redesign them with rad-hard technologies for meeting the requirements of the space environment.

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NASA NTRS1992

Operationally efficient propulsion system study (OEPSS) data book: Launch Operations Index (LOI) Design Features and Options - Volume 7

A design tool of figure of merit was developed that allows the operability of a propulsion system design to be measured. This Launch Operations Index (LOI) relates Operations Efficiency to System Complexity. The figure of Merit can be used by conceptual designers to compare different propulsion system designs based on their impact on launch operations. The LOI will improve the design process by making sure direct launch operations experience is a necessary feedback to the design process.

Ziese, James M.↗
NASA NTRS1989

Liquid Rocket Booster (LRB) for the Space Transportation System (STS) systems study. Appendix F: Performance and trajectory for ALS/LRB launch vehicles

By simply combining two baseline pump-fed LOX/RP-1 Liquid Rocket Boosters (LRBs) with the Denver core, a launch vehicle (Option 1 Advanced Launch System (ALS)) is obtained that can perform both the 28.5 deg (ALS) mission and the polar orbit ALS mission. The Option 2 LRB was obtained by finding the optimum LOX/LH2 engine for the STS/LRB reference mission (70.5 K lb payload). Then this engine and booster were used to estimate ALS payload for the 28.5 deg inclination ALS mission. Previous studies indicated that the optimum number of STS/LRB engines is four. When the engine/booster sizing was performed, each engine had 478 K lb sea level thrust and the booster carried 625,000 lb of useable propellant. Two of these LRBs combined with the Denver core provided a launch vehicle that meets the payload requirements for both the ALS and STS reference missions. The Option 3 LRB uses common engines for the cores and boosters. The booster engines do not have the nozzle extension. These engines were sized as common ALS engines. An ALS launch vehicle that has six core engines and five engines per booster provides 109,100 lb payload for the 28.5 deg mission. Each of these LOX/LH2 LRBs carries 714,100 lb of useable propellant. It is estimated that the STS/LRB reference mission payload would be 75,900 lb.

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NASA NTRS1977

Automatic vehicle monitoring systems study. Report of phase O. Volume 1: Executive summary

A set of planning guidelines is presented to help law enforcement agencies and vehicle fleet operators decide which automatic vehicle monitoring (AVM) system could best meet their performance requirements. Improvements in emergency response times and resultant cost benefits obtainable with various operational and planned AVM systems may be synthesized and simulated by means of special computer programs for model city parameters applicable to small, medium, and large urban areas. Design characteristics of various AVM systems and the implementation requirements are illustrated and cost estimated for the vehicles, the fixed sites, and the base equipments. Vehicle location accuracies for different RF links and polling intervals are analyzed.

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NASA NTRS1985

Space Transportation System (STS) propellant scavenging system study. Volume 1: Technical report

The objectives are to define the most efficient and cost effective methods for scavenging cryogenic and storable propellants and then define the requirements for these scavenging systems. For cryogenic propellants, scavenging is the transfer of propellants from the Shuttle orbiter external tank (ET) and/or main propulsion subsystems (MPS) propellant lines into storage tanks located in the orbiter payload bay for delivery to the user station by a space based transfer stage or the Space Transportation System (STS) by direct insertion. For storable propellants, scavenging is the direct transfer from the orbital maneuvering subsystem (OMS) and/or tankage in the payload bay to users in LEO as well as users in the vicinity of the Space Station.

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NASA NTRS1985

Satellite voice broadcast system study, volume 2

This study investigates the feasibility of providing Voice of America (VOA) broadcasts by satellite relay, rather than via terrestrial relay stations. Satellite voice broadcast systems are described for three different frequency bands: HF (26 MHz), VHF (68 MHz), and L-band (1.5 GHz). The geographical areas of interest at HF and L-band include all major land masses worldwide with the exception of the U.S., Canada, and Australia. Geostationary satellite configurations are considered for both frequency bands. In addition, a system of subsynchronous, circular satellites with an orbit period of 8 hours is developed for the HF band. VHF broadcasts, which are confined to the Soviet Union, are provied by a system of Molniya satellites. Satellites intended for HF or VHF broadcastinbg are extremely large and heavy. Satellite designs presented here are limited in size and weight to the capability of the STS/Centaur launch vehicle combination. Even so, at HF it would take 47 geostationary satellites or 20 satellites in 8-hour orbits to fully satisfy the voice-channel requirements of the broadcast schedule provided by VOA. On the other hand, three Molniya satellites suffice for the geographically restricted schedule at VHF. At L-band, only four geostationary satellites are needed to meet the requirements of the complete broadcast schedule. Moreover, these satellites are comparable in size and weight to current satellites designed for direct broadcast of video program material.

Horstein, M.↗
NASA NTRS1985

Advanced orbit transfer vehicle propulsion system study

A reuseable orbit transfer vehicle concept was defined and subsequent recommendations for the design criteria of an advanced LO2/LH2 engine were presented. The major characteristics of the vehicle preliminary design include a low lift to drag aerocapture capability, main propulsion system failure criteria of fail operational/fail safe, and either two main engines with an attitude control system for backup or three main engines to meet the failure criteria. A maintenance and servicing approach was also established for the advanced vehicle and engine concepts. Design tradeoff study conclusions were based on the consideration of reliability, performance, life cycle costs, and mission flexibility.

Cathcart, J. A.↗
NASA NTRS1989

Liquid Rocket Booster (LRB) for the Space Transportation System (STS) systems study. Appendix A: Stress analysis report for the pump-fed and pressure-fed liquid rocket booster

Pressure effects on the pump-fed Liquid Rocket Booster (LRB) of the Space Transportation System are examined. Results from the buckling tests; bending moments tests; barrel, propellant tanks, frame XB1513, nose cone, and intertank tests; and finite element examination of forward and aft skirts are presented.

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