Satellite Security and Performance in an Era of Dual Use

Since the mid-1990s the U.S. Government and military forces have placed more and more reliance on commercial satellite systems for military communications of a non-tactical nature. Requirements such as the U.S. Armed Forces Radio and Television require a great deal of bandwidth but do not require any special security protection. Further there are many other forms of communications involving national security or defense systems where a varying degree of security is required. Many of these applications do not require a very high level of top secret protection since these communications do involve tactical, strategic or highly classified messages. For instance, communications services that allow overseas forces to talk to their family and friends can be provided with only a minimum of digital encryption protection

Advanced Satellite Research Project: SCAR Research Database. Bibliographic analysis

The literature search was provided to locate and analyze the most recent literature that was relevant to the research. This was done by cross-relating books, articles, monographs, and journals that relate to the following topics: (1) Experimental Systems - Advanced Communications Technology Satellite (ACTS), and (2) Integrated System Digital Network (ISDN) and Advance Communication Techniques (ISDN and satellites, ISDN standards, broadband ISDN, flame relay and switching, computer networks and satellites, satellite orbits and technology, satellite transmission quality, and network configuration). Bibliographic essay on literature citations and articles reviewed during the literature search task is provided

Satellite communications systems and technology. Executive Summary

NASA and the National Science Foundation (NSF) commissioned a panel of US experts to study the international status of satellite communications systems and technology. The study covers emerging systems concepts, applications, services, and the attendant technologies. The panel members travelled to Europe, Japan, and Russia to gather information first-hand. They visited 17 sites in Europe, 20 sites in Japan, and four in Russia. These included major manufacturers, government organizations, service providers, and associated R&D facilities. The panel's report was reviewed by the sites visited, by the panel, and by representatives of US industry. The report details the information collected and compares it to US activities

Information and communication technology

NASA and the National Science Foundation (NSF) commissioned a panel of U.S. experts to study the international status of satellite communications systems and technology. The study covers emerging systems concepts, applications, services, and the attendant technologies. The panel members traveled to Europe, Japan, and Russia to gather information firsthand. They visited 17 sites in Europe, 20 in Japan, and 4 in Russia. These included major manufacturers, government organizations, service providers, and associated research and development facilities. The panel's report was reviewed by the sites visited, by the panel, and by representatives of U.S. industry. The report details the information collected and compares it to U.S. activities

Controversy surrounding the increased expression of TGFβ1 in asthma

Asthma is a waxing and waning disease that leads to structural changes in the airways, such as subepithelial fibrosis, increased mass of airway smooth muscle and epithelial metaplasia. Such a remodeling of the airways futher amplifies asthma symptoms, but its etiology is unknown. Transforming growth factor β1 is a pleiotropic cytokine involved in many fibrotic, oncologic and immunologic diseases and is believed to play an essential role in airway remodeling that occurs in asthmatic patients. Since it is secreted in an inactive form, the overall activity of this cytokine is not exclusively determined by its level of expression, but also by extensive and complex post-translational mechanisms, which are all importanin modulating the magnitude of the TGFβ1 response. Even if TGFβ1 upregulation in asthma is considered as a dogma by certain investigators in the field, the overall picture of the published litterature is not that clear and the cellular origin of this cytokine in the airways of asthmatics is still a contemporaneous debate. On the other hand, it is becoming clear that TGFβ1 signaling is increased in the lungs of asthmatics, which testifies the increased activity of this cytokine in asthma pathogenesis. The current work is an impartial and exhaustive compilation of the reported papers regarding the expression of TGFβ1 in human asthmatics. For the sake of comparison, several studies performed in animal models of the disease are also included. Inconsistencies observed in human studies are discussed and conclusions as well as trends from the current state of the litterature on the matter are proposed. Finally, the different points of regulation that can affect the amplitude of the TGFβ1 response are briefly revised and the possibility that TGFβ1 is disregulated at another level in asthma, rather than simply in its expression, is highlighted

Video Course 1: Basics of Satellite Communications: Lecture 1: Services, History, and Orbits

This is an introductory course in satellite communications for the non-engineer. It covers the basic systems technology for all types of satellite systems for telecommunications including Fixed Satellite Systems (FSS), Mobile Satellite Systems, and Broadcast Satellite Systems (BSS) as well as provides a quick introduction to all ITU defined communications and scientific services. This course gives an overview of spacecraft structures, power systems, advances in solar cells, thermal management, radiation and high energy bombardment, stabilization and deployment techniques, TTC&M, and orbital orientation. It also provides the basic concepts and a working understanding with regard to modulation, multiplexing, and coding systems for modern communications satellite transmission systems and ground systems

Video Course 1: Basics of Satellite Communications: Lecture 4: Modulation, Multiplexing and Link Budgets

This is an introductory course in satellite communications for the non-engineer. It covers the basic systems technology for all types of satellite systems for telecommunications including Fixed Satellite Systems (FSS), Mobile Satellite Systems, and Broadcast Satellite Systems (BSS) as well as provides a quick introduction to all ITU defined communications and scientific services. This course gives an overview of spacecraft structures, power systems, advances in solar cells, thermal management, radiation and high energy bombardment, stabilization and deployment techniques, TTC&M, and orbital orientation. It also provides the basic concepts and a working understanding with regard to modulation, multiplexing, and coding systems for modern communications satellite transmission systems and ground systems

Video Course 1: Basics of Satellite Communications: Lecture 2: Frequency Allocations, Spectrum and Key Terms

This is an introductory course in satellite communications for the non-engineer. It covers the basic systems technology for all types of satellite systems for telecommunications including Fixed Satellite Systems (FSS), Mobile Satellite Systems, and Broadcast Satellite Systems (BSS) as well as provides a quick introduction to all ITU defined communications and scientific services. This course gives an overview of spacecraft structures, power systems, advances in solar cells, thermal management, radiation and high energy bombardment, stabilization and deployment techniques, TTC&M, and orbital orientation. It also provides the basic concepts and a working understanding with regard to modulation, multiplexing, and coding systems for modern communications satellite transmission systems and ground systems

Video Course 1: Basics of Satellite Communications: Lecture 5: Ground Segment and Practical Aspects of Satcom

This is an introductory course in satellite communications for the non-engineer. It covers the basic systems technology for all types of satellite systems for telecommunications including Fixed Satellite Systems (FSS), Mobile Satellite Systems, and Broadcast Satellite Systems (BSS) as well as provides a quick introduction to all ITU defined communications and scientific services. This course gives an overview of spacecraft structures, power systems, advances in solar cells, thermal management, radiation and high energy bombardment, stabilization and deployment techniques, TTC&M, and orbital orientation. It also provides the basic concepts and a working understanding with regard to modulation, multiplexing, and coding systems for modern communications satellite transmission systems and ground systems