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Yet corporations don't need a "Chief Electricity Officer" and a staff of highly trained professionals to manage and integrate electricity into their businesses. Does the historical adoption of electricity offer a useful analogy for today's innovations in cloud computing? While the utility model offers some insights, we must go beyond this simple analogy to understand cloud computing's real challenges and opportunities. Technical issues of innovation, scale, and geography will confront managers who attempt to take advantage of offsite resources. In addition, business model challenges related to complementarity, interoperability, and security will make it difficult for a stable cloud market to emerge. An overly simplistic reliance on the utility model risks blinding us to the real opportunities and challenges of cloud computing.cloud computing and the electricity model Definitions for cloud computing vary. From a practitioner standpoint: "Cloud computing is on-demand access to virtualized IT resources that are housed outside of your own data center, shared by others, simple to use, paid for via subscription, and accessed over the Web." From an academic perspective: "Cloud computing refers to both the applications delivered as services over the Internet and the hardware and systems software in the data centers that provide those services. … The data center hardware and software is what we will call a cloud. When a cloud is made available in a pay-as-you-go manner to the public, we call it a public cloud; the service being sold is utility computing." 1 Both definitions imply or explicitly use the "utility" model that embeds the logic of water supply, electrical grids, or sewage systems. This model is ubiquitous. While it has important strengths, it also has major weaknesses.Hardware providers introduced the language of "utility" computing into the market. But perhaps the most rigorous and vigorous assertion of the electricity model comes from Nicholas Carr, an independent blogger in his recent book, The Big Switch: "At a purely ecoan overly simplistic reliance on the utility model risks blinding us to the real opportunities and challenges of cloud computing. illustration by st ua rt bra dford nomic level, the similarities between electricity and information technology are even more striking. Both are what economists call general-purpose technologies. … General-purpose technologies, or GPTs, are best thought of not as discrete tools but as platforms on which many different tools, or applications, can be constructed. … Once it becomes possible to provide the technology centrally, large-scale utility suppliers arise to displace the private providers. It may take decades for companies to abandon their proprietary supply operations and all the investment they represent. But in the end the savings offered by utilities become too compelling to resist, even for the largest enterprises. The grid wins." 4 strengths of the utility model Carr correctly highlights the concept of a general-purpose technology. This class of techno...

Starting in late 2007 and continuing through the present, NFIRE (Near-Field Infrared Experiment), a Missile Defense Agency (MDA) experimental satellite and TerraSAR-X, a German commercial SAR satellite have been conducting mutual crosslink experiments utilizing a secondary laser communication payload built by Tesat-Spacecom. The narrow laser beam-widths and high relative inter-spacecraft velocities for the two low-earth-orbiting satellites imply strict pointing control and dynamics aboard both vehicles. The satellites have achieved rapid communication acquisition times and maintained communication for hundreds of seconds before losing line of sight to the counter satellite due to earth blockage. Through post-mission analysis and other related telemetry we will show results for pointing accuracy, disturbance environments and pre-engagement prediction requirements that support successful and reliable operations.

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