Engineering topics

Vajk, J. P.

Publications and source records attributed to Vajk, J. P..

3 records

NASA NTRS1983

Moving finite elements in 2-D

The mathematical background regarding the moving finite element (MFE) method of Miller and Miller (1981) is discussed, taking into account a general system of partial differential equations (PDE) and the amenability of the MFE method in two dimensions to code modularization and to semiautomatic user-construction of numerous PDE systems for both Dirichlet and zero-Neumann boundary conditions. A description of test problem results is presented, giving attention to aspects of single square wave propagation, and a solution of the heat equation.

Gelinas, R. J.↗

NASA NTRS1979

Habitat and logistic support requirements for the initiation of a space manufacturing enterprise

A detailed scenario for the initiation of a space manufacturing enterprise using lunar materials to construct solar power satellites (SPS) was developed, with particular attention to habitat design and logistic support requirements. If SPS's can be constructed exclusively from lunar materials, the entire enterprise can be initiated in a 7 year period of launch activity (beginning as early as 1985) using the Space Shuttle and a low-cost, Shuttle-derived heavy lift vehicle. If additional chemical feedstocks must be imported from earth in significant quantities, it may be necessary to bring the next-generation launch vehicle (single-stage-to-orbit) into operation by 1991. The scenario presented features use of the mass-driver reaction engine for orbit-to-orbit transfer of cargos and makes extensive use of the expendable Shuttle external propellant tanks.

Vajk, J. P.↗

NASA NTRS1978

Satellite Power System (SPS) financial/management scenarios

The possible benefits of a Satellite Power System (SPS) program, both domestically and internationally, justify detailed and imaginative investigation of the issues involved in financing and managing such a large-scale program. In this study, ten possible methods of financing a SPS program are identified ranging from pure government agency to private corporations. The following were analyzed and evaluated: (1) capital requirements for SPS; (2) ownership and control; (3) management principles; (4) organizational forms for SPS; (5) criteria for evaluation; (6) detailed description and preliminary evaluation of alternatives; (7) phased approaches; and (8) comparative evaluation. Key issues and observations and recommendations for further study are also presented.

Vajk, J. P.↗