Author: Mark S. WilseyPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
A Parametric Analysis of Endoatmospheric Low-Earth-orbit Maintenance
Author: Mark S. WilseyMasters Theses in the Pure and Applied Sciences
Author: Wade H. ShaferPublisher: Springer Science & Business Media
ISBN: 1461519691
Category : Science
Languages : en
Pages : 426
Book Description
Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 38 (thesis year 1993) a total of 13,787 thesis titles from 22 Canadian and 164 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 38 reports theses submitted in 1993, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.
An Analysis of a Single-burn Algorithm for Low-earth Orbit Maintenance
Author: Paul A. GardnerPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
With the requirement for a spacecraft to maintain an orbital altitude band, a simple energy balance algorithm has been developed using a combination of radial distance and spacecraft specific energy for fixed-vector thruster control. While each trajectory produces a unique band, initial attempts at producing a pre-specified band have been unsuccessful. It is theorized that a certain radial bandwidth would correspond to a specific set of control parameters, and that by creating maps of the relationship between the two for various spacecraft configurations a method of maintaining the pre-specified band could be found. This thesis studies variations in spacecraft configurations and finds dependence of orbital bandwidth on thrust-to-drag ratio and ballistic coefficient. Also, within certain ranges of control parameters, multiple trajectories produce equivalent radial bands. Analysis shows that all single- burn trajectories are characterized by similar efficiencies, and are less efficient than a Forced Keplerian Trajectory (FKT).
A Numerical Study of Fuel-Optimal Low-Earth-Orbit Maintenance
Author: Lawrence E. HalbachPublisher:
ISBN: 9781423532118
Category :
Languages : en
Pages : 92
Book Description
This thesis studies the fuel optimal periodic reboost profile required to maintain a spacecraft experiencing drag in low-earth-orbit (LEO). Recent advances in computational optimal control theory are employed, along with a Legendre-Gauss-Lobatto Pseudospectral collocation code developed at the Naval Postgraduate School, to solve the problem. Solutions obtained by this method are compared against a previous study. Key issues were checking the optimality of the solutions by way of the necessary conditions and the behavior of the solution to changes in the thruster size. The results confirmed Jensen's findings of propellant savings of one to five percent when compared against a middle altitude Forced Keplerian Trajectory (FKT). Larger savings are predicted if compared against a finite-burn Hohmann transfer with drag. The costates estimates compared favorably against necessary conditions of Pontryagin's Minimum Principle. Analysis of the switching flinction yielded periods of thrust-modulated arcs. The optimal thrust profile appears to be a thrust- modulated burn to raise the orbit followed by an orbital decay and a terminating thrust-modulated arc. For a sufficiently low thrust-control authority, the switching structure includes a maximum thrust arc. Indirect optimization techniques to confirm these findings were unsuccessful.
Scientific and Technical Aerospace Reports
Author: Government Reports Announcements & Index
Author: Government Reports Annual Index
Author: Publisher:
ISBN:
Category : Research
Languages : en
Pages : 1190
Book Description
Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Space Weapons Earth Wars
Author: Robert PrestonPublisher: Rand Corporation
ISBN: 0833032526
Category : Technology & Engineering
Languages : en
Pages : 231
Book Description
This overview aims to inform the public discussion of space-based weapons by examining their characteristics, potential attributes, limitations, legality, and utility. The authors do not argue for or against space weapons, nor do they estimate the potential costs and performance of specific programs, but instead sort through the realities and myths surrounding space weapons in order to ensure that debates and discussions are based on fact.
International Aerospace Abstracts
Author: China's Strategic Modernization Implications for the United States
Author: Mark A. StokesPublisher: DIANE Publishing
ISBN: 1428911979
Category : Air defenses
Languages : en
Pages : 230
Book Description
Conventional wisdom portrays the People's Republic of China (PRC) People's Liberation Army (PLA) as a backward continental force that will not pose a military challenge to its neighbors or to the United States well into the 21st century. PLA writings that demonstrate interest in exploiting the revolution in military affairs (RMA) are dismissed by a large segment of the PLA- watching community as wistful fantasies. The author offers an alternative perspective by outlining emerging PLA operational concepts and a range of research and development projects that appear to have been heavily influenced by U.S. and Russian writings on the RMA. Fulfillment of the PLA's vision for the 21st century could have significant repercussions for U.S. interests in the Asia-Pacific region.