Sps supplement Rough Draft-endi2011 Alpharetta 2011 / Boyce, Doshi, Hermansen, Ma, Pirani
Download 0.84 Mb.
|
- Navigate this page:
- AT: Weapons/Microwaves
AT: Aerostat CPAerostats are vulnerable- weather and enemies Christopher Bolkcom, Specialist in National Defense Foreign Affairs, Defense, and Trade Division, 2006 [“CRS Report for Congres”, September 1st, 2006, http://www.fas.org/sgp/crs/weapons/RS21886.pdf] The operational need for aerostats and their ability to satisfy this need appears the most mature of the three distinct lighter-than-air platforms. These systems are currently fielded and their capabilities and limitations appear well-documented. The role that they appear most suited for is persistent surveillance. Aerostats’ primary advantages over other platforms capable of providing elevated, persistent surveillance (manned aircraft and UAVs) appear to be low life cycle cost and long dwell time. 11 The primary operational concerns with employing aerostats appear to be vulnerability to weather and enemy ground fire. U.S. and foreign aerostats have been lost to severe weather, as have manned aircraft and UAVs. Aerostats tend not to fail in benign weather, however, while aircraft and UAVs, which are more complex and dynamic systems, suffer accidents caused by factors such as human error and mechanical failure. 12 The vulnerability of aerostats to enemy ground fire is debated. Opponents argue that aerostats are big targets within range of many enemy weapons. Proponents argue that despite their large size, aerostats are survivable because of a low radar cross section and their ability to endure numerous punctures before gradually losing altitude. Low flying aircraft and UAVs are also vulnerable to enemy ground fire. Spherical aerostat work- wind and oscillations C. Lambert et al, Dept. of Mechanical EngineeringMcGill University, 2003 [A. Saunders , C. Crawford and M. Nahon, “Design of a One-Third Scale Multi-Tethered Aerostat System for PrecisePositioning of a Radio Telescope Receiver”, 2003, http://www.scribd.com/doc/48815838/aerostat] The aerodynamic performance of the spherical aerostat is characterized by a single drag force on the hull which is proportional to its constant spherical cross section. To compare the drag coefficient of aspherical and streamlined aerostat, a reference Re of 10 6 was chosen which represents typical operating conditions of the scaled aerostat. The drag coefficient for a spherical body is about 0.15,while for a streamlined body of fineness ratio 2.4, it is in the approximately 0.05. 8 When the fins are added to the streamlined aerostat, its drag coefficient increases to 0.073. In addition to having a drag coefficient of about half that for a spherical shape, the streamlined aerostat also has a frontal area 1.7 times smaller for the same internal volume of Helium. Thus, the drag force acting on a streamlined aerostat is about 3.5 times smaller than on an equivalent spherical aerostat. The reduced drag of th estreamlined aerostat has important advantages for the tethered system. From a static perspective, the loading on the tether structure would be reduced and therefore the design can be lighter and mor eefficient, as was reported in the original analysis of the LAR concept. 3 As well, the disturbances to the tether tension structure due to wind gusts should be reduced which would result in smaller position errors of the receiver. Spherical bodies also tend to be subject to vortex shedding oscillations in steady flow 9 . These could substantially degrade the performance of the system with a spherical aerostat. This again suggests that a streamlined aerostat may be preferable for our application as asteadier leash tension is considered desirable
C. Lambert et al, Dept. of Mechanical EngineeringMcGill University, 2003 [A. Saunders , C. Crawford and M. Nahon, “Design of a One-Third Scale Multi-Tethered Aerostat System for PrecisePositioning of a Radio Telescope Receiver”, 2003, http://www.scribd.com/doc/48815838/aerostat] Ground handling and mooring are among the most difficult problems encountered in the operation of tethered aerostats 10 . The support system for handling the aerostat near or on the ground is often more complex and costly than the aerostat itself. The ground handling equipment for the streamlined aerostat must accommodate its tendency to rotate into the wind. If the aerostat is unableto rotate freely, the loading from even mild side winds is strong enough to generate very large forces.If the mooring station does not permit the aerostat to rotate freely, then it must completely shelter theaerostat from the wind. In this case, additional equipment is required to transport the aerostat from theshelter to the launch site. By contrast, the ground handling equipment for the spherical aerostat wouldbe substantially simpler since it does not need to weathervane. AT: Weapons/MicrowavesSPS cannot be used as a weapon and the microwave stuff is just fear. Osepchuk, PhD, Full Spectrum Consulting, 2 [John M. Osepchuk; “How Safe Are Microwaves and Solar Power from Space?”; 2002 published in IEE Microwave Magazine, December; http://electricalandelectronics.org/wp-content/uploads/2008/10/01145676.pdf; Boyce] In the popular press, the potential danger of an SPS turned into a weapon has often been raised, but at lower microwave frequencies, this is ruled out by physical limits on focusing. Beneficial weather modification, such as preventing damaging freezes in orange groves, does seem feasible. More dramatic applications, like the proposal to suppress tornadoes [13], would require more highly focused beams and, hence, higher frequency than that suitable for SPS. Well before the SPS or the more futuristic applications of microwave beams from space become reality, public perception of “microwaves” will have to be changed from that of mysterious, unseen “radiation” to a recognized extension and amplification of the solar spectrum that already exists—per the oversimplified and should not be encouraged. Instead, the best antidote to such philosophy and the fears they precipitate is the strengthening of broad-consensus safety standards developed under due process, such as by the International Committee on Electromagnetic Safety (ICES) [15], sponsored by the IEEE. The IEEE is the world’s largest technical professional society, with over 350,000 members (over 33% are outside of the United States). At present, ICES members outside of the United States comprise about 20% of ICES. Trends both in the IEEE and ICES indicate about 50% non-U.S. participation by 2010. ICES operates in a transparent manner, with full documentation, consensus balloting, and input invited from all stakeholders, including that of industry. ICES cooperates with other national and international groups like the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and the International Electrotechnical Commission (IEC), which are more restricted in membership, process, and stakeholder input. It is increasingly clear that the development of SPS systems with MPT, along with the resolution of environmental issues, will be a global endeavor. It is also clear that the increasingly global economy means that sources of key components for advanced technology, with low-cost manufacturing, are outside the United States [16] and, indeed, often in the underdeveloped parts of the world. For example, almost all the mass manufacture of cooker magnetrons is now carried out in Korea, Thailand, and China. On the other hand, electrophobia has spread from the United States around the world, and today the most intense fears of EM energy are found outside the United States, particularly in Europe, China, and part of the bloc of former communist countries in Eastern Europe. Thus, the activities of ICES and the IEEE become very relevant in achieving the goal of rational, international safe exposure standards, as well as international consensus on regulation of RFI, such as through the Comité International Spéciale der Perturbations Radioélectriques (CISPR/IEC). The realization of the SPS concept holds great promise for solving energy crises and improving the lot of mankind. Serious discussions and education are required before most of mankind accepts this type of technology with global dimensions. Fears are based mostly on ingrained perceptions built up over the years as irrational attacks have been made on each successive wave of EM technology—from the microwave oven and radar to today’s wireless phone. In the history of man, great strides in human welfare have occurred after the acceptance of air-conditioning, the automobile, modern appliances, and airplanes. Man has progressed not by demanding absolute proof of safety before developing technology but by learning as work pro gresses [17], along with reasonable precautions based on science. Furthermore, fears of changing the environment should be dispelled if we realize, as Huber teaches [18], that efficient use of land and resources is possible only by applying the best hard technology (big, not small). Finally, we look forward to universal acceptance of the premise that EM energy is a key tool to improve the quality of life for mankind. It is not a “pollutant” but, more aptly, a man-made extension of the naturally generated electromagnetic spectrum that provides heat and light for our sustenance. From this viewpoint, the SPS is merely a down frequency converter from the visible spectrum to microwaves. Directory: files files -> Answer True False 2 points Question 2 files -> Integer programming and game theory files -> 4 Integer Programming files -> Bpa vehicle Window Repair Scenario #1 task: Procure vehicle window relacement. Objective files -> Pop Warner History files -> North Carolina Inclusion Initiative Mapping Where Children with ieps are Being Served Purpose files -> Fall 2013 Spring 2014 Program Data: Standard 1 Exhibit 4d files -> Hanban – asia society confucius classrooms network 2010 request for proposal files -> Northern England’s set-jetting locations Download 0.84 Mb. Share with your friends:
|