Search NASA⌕ Search

SEARCH · Search NASA

Results for “Transfer Vehicle”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15

Optimal guidance of aero-assisted transfer vehicles based on matched asymptotic expansions

This paper addresses a number of issues related to the matched asymptotic expansions analysis of skip trajectories, or any class of problems that give rise to inner layers that are not associated directly with satisfying boundary conditions. The procedure for matching inner and outer solutions, and using the composite solution to satisfy boundary conditions is rigorously followed in developing a complete algebraic solution to the problem of inclination change with minimum energy loss. Repeated solution of these algebraic equations along the trajectory, treating each current state as an initial state, constitute a feedback guidance algorithm.

Calise, A. J.↗

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle (STV)

An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

Upadhyay, Triveni N.↗

A space transfer vehicle for lunar missions

Two 'low profile' strategies for supporting the lunar outpost concept developed by NASA-JSC Planetary Surface Systems are examined. The first strategy involves the design of missions that require only a single launch of a derivative 'National Launch System' (NLS) vehicle. The launch capacity of the derivatives range from 80 to 140 percent of the Apollo/Saturn capacity and use only conventional cryogenic or stable chemical propulsion. The second strategy involves the design of missions that only require the currently planned NASA NLS vehicle to be built. This strategy uses either one or two launches with an earth and/or lunar orbit rendezvous for stage assembly. Advance propulsion concepts, in addition to cryogenics, for the translunar injection stage are addressed.

Andrews, Dana↗

Space transfer vehicles for an affordable lunar exploration program

The paper describes a lunar transportation system (LTS) based on a minimum cost approach to the lunar exploration scenario. A three-part exercise was conducted to minimize the cost and risk of lunar exploration, and the results of these optimization studies are presented. Particular consideration is given to the proposed concepts for the translunar injection stages, the common crew module of the LTS, the lander configuration, the LTS performance, and a concept of a long-range rover ('Rover First ') for discovering and mapping lunar resources for future utilization.

Andrews, Dana G.↗

In-space operations for lunar and Mars space transfer vehicles

The in-space operations required to process the lunar and Mars mission vehicles foreseen in early studies for the SEI are discussed. Those studies that have examined the degree to which on-orbit operations alter as a function of the earth-to-orbit launch vehicle size, identified a common set of on-orbit vehicle processing tasks, and generated functional requirements for in-space processing nodes, are summarized. Attention is focused on the amount of time these processing operations might necessitate and how this time duration changes as a result of how the operation is executed and how the hardware is designed.

Raper, James L., Sr.↗

Cargo transfer vehicle - An element of the National Launch System

The paper describes the cargo transport vehicle (CTV), a rendezvous- and capture-capable on-orbit maneuvering stage of the NASA/DOD National Launch System (NLS) developed for off-loading the Space Shuttle for cargo delivery to the Space Station Freedom. Special attention is given to the background of the NLS CTV technology, a typical Space Station delivery mission profile, the design features of the payload accommodation system, and the forward propulsion module. The feasibility of the CTV functioning as an upper stage, in addition to acting as an on-orbit maneuvering system, is being presently considered.

Buchanan, Harry↗

Space transfer vehicle concepts and requirements, volume 2, book 1

The objective of the systems engineering task was to develop and implement an approach that would generate the required study products as defined by program directives. This product list included a set of system and subsystem requirements, a complete set of optimized trade studies and analyses resulting in a recommended system configuration, and the definition of an integrated system/technology and advanced development growth path. A primary ingredient in the approach was the TQM philosophy stressing job quality from the inception. Included throughout the Systems Engineering, Programmatics, Concepts, Flight Design, and Technology sections are data supporting the original objectives as well as supplemental information resulting from program activities. The primary result of the analyses and studies was the recommendation of a single propulsion stage Lunar Transportation System (LTS) configuration that supports several different operations scenarios with minor element changes. This concept has the potential to support two additional scenarios with complex element changes. The space based LTS concept consists of three primary configurations--Piloted, Reusable Cargo, and Expendable Cargo.

Source record↗

National launch system overview with focus on cargo transfer vehicle

As a result of the Augustine Committee's recommendation to the National Space Council, NASA, and the DOD have embarked on a joint program to provide the nation with a new capability for transporting payloads into space. The National Launch System (NLS) consists of a family of modular launch vehicles, combining elements of current launchers (Titan and Shuttle) with newly developed components. This family consists of (1) NLS-1 (a vehicle capable of delivering 80 k to SSF), (2) NLS-2 (a vehicle capable of delivering 50k to LEO), and (3) NLS-3 (a vehicle capable of delivering 20 k to LEO). Management of the program is shared between the two agencies with a Joint Program Office carrying out the level 2 management and integration function while both the NASA and Air Force field organizations are charged with the various development and operational responsibilities.

Buchanan, Harry↗

Fully autonomous navigation for the NASA cargo transfer vehicle

A great deal of attention has been paid to navigation during the close approach (less than or equal to 1 km) phase of spacecraft rendezvous. However, most spacecraft also require a navigation system which provides the necessary accuracy for placing both satellites within the range of the docking sensors. The Microcosm Autonomous Navigation System (MANS) is an on-board system which uses Earth-referenced attitude sensing hardware to provide precision orbit and attitude determination. The system is capable of functioning from LEO to GEO and beyond. Performance depends on the number of available sensors as well as mission geometry; however, extensive simulations have shown that MANS will provide 100 m to 400 m (3(sigma)) position accuracy and 0.03 to 0.07 deg (3(sigma)) attitude accuracy in low Earth orbit. The system is independent of any external source, including GPS. MANS is expected to have a significant impact on ground operations costs, mission definition and design, survivability, and the potential development of very low-cost, fully autonomous spacecraft.

Wertz, James R.↗

Orbital transfer vehicle oxygen turbopump technology. Volume 3: Hot oxygen testing

This report covers the work done in preparation for a liquid oxygen rocket engine turbopump test utilizing high pressure hot oxygen gas for the turbine drive. The turbopump (TPA) is designed to operate with 400 F oxygen turbine drive gas. The goal of this test program was to demonstrate the successful operation of the TPA under simulated engine conditions including the hot oxygen turbine drive. This testing follows a highly successful series of tests pumping liquid oxygen with gaseous nitrogen as the turbine drive gas. That testing included starting of the TPA with no assist to the hydrostatic bearing. The bearing start entailed a rubbing start until the pump generated enough pressure to support the bearing. The articulating, self-centering hydrostatic bearing exhibited no bearing load or stability problems. The TPA was refurbished for the hot gas drive tests and facility work was begun, but unfortunately funding cuts prohibited the actual testing.

Urke, Robert L.↗

Designing the Space Transfer Vehicle (STV)

An evolutionary approach to develop STV system features that provide modularity, design margines, and simple interfaces is presented. A modular design minimizes modifications and requalification for block changes. Since several subsystems do not have to be modified in response to a change in another subsystem, design margins provide options for growth. It is concluded that the approach will lower program schedule and cost risk, while enhancing safety and reliability.

Austin, Robert E.↗

An evaluation of ablative materials for a lunar transfer vehicle aerobrake

An evaluation of the utility of an ablative thermal protection system (TPS) for use on a lunar mission return aerobrake has been completed. Requirements are established and criteria developed specifically for the ablator application. A quantitative and qualitative multi-attribute utility analysis is employed to establish a relative ranking among candidates and a performance threshold. A review of the applicable existing ablator material database is made and appropriate thermochemical/melting ablation analysis is employed to evaluate thermal performance. Ablatives are shown to be potentially both performance capable and cost effective in single-use roles. Reusable surface insulation is also shown to be competitive as an ablator with certain modifications.

Lane, J. G.↗

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle

An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

Upadhyay, Triveni N.↗

Space transfer vehicle concepts and requirements. Volume 4: Summary of special studies

Our final report for Phase 1 addressed the future space transportation needs and requirements based on the current assets, at the time, and their evolution through technology/advanced development using a path and schedule that supported the world leadership role of the United States in a responsible and realistic financial forecast. Always, and foremost, the recommendations placed high values on the safety and success of missions both manned and unmanned through a total quality management philosophy at Martin Marietta. The second phase of the STV contract involved the use of Technical Directives (TD) to provide short-term support for specialized tasks as required by the COTR. Three of these tasks were performed in parallel with Phase 1. These tasks were the Liquid Acquisition Experiment (LACE), Liquid Reorientation Experiment (LIRE), and Expert System for Design, Operation, and Technology Studies (ESDOTS). The results of these TD's were reported in conjunction with the Phase 1 Final Report. Cost analysis of existing launch systems has demonstrated a need for a new upper stage that will increase America's competitiveness in the global launch services market. To provide a growth path of future exploration class STV's, near-term low-cost upper stages featuring modularity, portability, scalability, and evolvability must be developed. These recommendations define a program that: leverages ongoing activities to establish a new development environment, develop technologies that benefit the entire life cycle of a system, and result in a scalable hardware platform that provides a growth path to future upper stages.

Source record↗

Design and Performance Analysis of a Conical Aerobrake Orbital Transfer Vehicle Concept

A Shuttle-compatible systems design based on the core concept of attachable modules for the major vehicle components is proposed. The principal features include a disposable cargo/extra-propellant tank module; a porous, radiative, back-scattering drag-brake surface material of thin silica cloth; and a lightweight carbon-composite support structure. The mission payload capability for delivery, retrieval, and combined operations is determined for a broad range of missions including NASA/DOD requirements and extending through cislunar space. The effects of finite-rate surface catalysis, negative lift, and multiple atmospheric passes in reducing the aerothermodynamic heating rates are also investigated. In addition, the structural and thermal protection problems of the drag-brake support apparatus are analyzed, and recommendations are proposed for future design refinements.

Menees, Gene P.↗

Exergy Efficiency of Interplanetary Transfer Vehicles

In order to optimize systems, systems engineers require some sort of measure with which to compare vastly different system components. One such measure is system exergy, or the usable system work. Exergy balance analysis models provide a comparison of different system configurations, allowing systems engineers to compare different systems configuration options. This paper presents the exergy efficiency of several Mars transportation system configurations, using data on the interplanetary trajectory, engine performance, and vehicle mass. The importance of the starting and final parking orbits is addressed in the analysis, as well as intermediate hyperbolic escape and entry orbits within Earth and Mars' spheres of influence (SOIs). Propulsion systems analyzed include low-enriched uranium (LEU) nuclear thermal propulsion (NTP), high-enriched uranium (HEU) NTP, LEU methane (CH4) NTP, and liquid oxygen (LOX)/liquid hydrogen (LH2) chemical propulsion.

Owen, Sean T.↗