The economic and social benefits of space communication : A global overview of past, present and future applications

This study takes two different approaches to trying to estimate the ‘worth’ of satellite applications, one based upon tariff services and their pyramidal value and the other of estimating derived benefits on a sector-by-sector basis to total the economic value of business and application satellite services. These procedures result in an order-of-magnitude estimate for direct and indirect benefits of satellites of $390 billion per year or about 2% of the global economy. Estimations of social benefits are more difficult to quantify. The business, cultural, social and educational benefits of satellite communications are shown to be tremendous, and wherever possible clear economic terms are used.     

The morphology of fair weather cumulus cloud fields as remotely-sensed from satellites and some applications

The morphology of fair weather Cumulus cloud field over several ocean areas distributed globally has been studied using LANDSAT data. Distribution functions of cloud size, spacing, perimeter and other relevant parameters have been derived, as well as their correlations and moments.Examples of distribution functions of cloud size, cloud spacing and fractal dimension of the cloud fields over oceanic areas are given and applied to several problem in Cu convection.     

The Swift Ultra-Violet/Optical Telescope

The Ultra-Violet/Optical Telescope (UVOT) is one of three instruments flying aboard the Swift Gamma-ray Observatory. It is designed to capture the early (∼1 min) UV and optical photons from the afterglow of gamma-ray bursts in the 170–600 nm band as well as long term observations of these afterglows. This is accomplished through the use of UV and optical broadband filters and grisms. The UVOT has a modified Ritchey–Chrétien design with micro-channel plate intensified charged-coupled device detectors that record the arrival time of individual photons and provide sub-arcsecond positioning of sources. We discuss some of the science to be pursued by the UVOT and the overall design of the instrument.     

The Long-Term Evolution of the Atmosphere of Venus: Processes and Feedback Mechanisms

Space Science Reviews - The BepiColombo Environment Radiation Monitor (BERM) on board the European Space Agency’s Mercury Planetary Orbiter (MPO), is designed to measure the radiation...     

The Space Shuttle—Evaluating an American icon

The Space Transportation System (STS), for better or worse, has dominated the US space program for some 30 years and is now an American icon. The Space Shuttle orbiters have flown over 120 missions and certainly accomplished some amazing feats, including the deployment of the International Space Station (ISS), the launch and double repair of the Hubble Telescope, a number of classified missions for the US defense establishment and the cementing of international cooperation in space. As the remaining Space Shuttle orbiters head toward various museums, it is timely to look at the STS program in terms of key US space policy decisions that have paralleled the Space Shuttle’s often troubled history. This article seeks, from both a historical and a policy perspective, to assess what might have been. While noting the major accomplishments of the STS, it also identifies what can best be characterized as major lost opportunities and flawed policy decisions that have had multi-billion dollar consequences. In this regard, the US Congress, the White House, and NASA leadership have all played a role. If there have been failings, they have not been by NASA alone, but the entire US space policy leadership.     

CNS effects of heavy particle irradiation in space: behavioral implications.

Research from several sources indicates that young (3 mo) rats exposed to heavy particle irradiation (56Fe irradiation) produces changes in motor behavior as well as alterations in neuronal transmission similar to those seen in aged (22-24 mo) rats. These changes are specific to neuronal systems that are affected by aging. Since 56Fe particles make up approximately 1-2% of cosmic rays, these findings suggest that the neuronal effects of heavy particle irradiation on long-term space flights may be significant, and may even supercede subsequent mutagenic effects in their mission capabilities. It is suggested that among other methods, it may be possible to utilize nutritional modification procedures to offset the putative deleterious effects of these particles in space.     

A new space vision for NASA—And for space entrepreneurs too?

Despite its scientific successes, NASA has over the past two decades lost its way, spending billions of dollars on transportation systems that have at bottom been failures. President Obama's cancellation of the costly and unwieldy Constellation program provides an opportunity for genuine reform of the agency and the US space program, through harnessing the innovatory and cost-effective power of commercial entrepreneurs. Examples of the kinds of project they might undertake – including solar power satellites, ‘space taxis’ and a space elevator – are discussed.     

Effects of exposure to different types of radiation on behaviors mediated by peripheral or central systems.

The effects of exposure to ionizing radiation on behavior may result from effects on peripheral or on central systems. For behavioral endpoints that are mediated by peripheral systems (e.g., radiation-induced conditioned taste aversion or vomiting), the behavioral effects of exposure to heavy particles (56Fe, 600 MeV/n) are qualitatively similar to the effects of exposure to gamma radiation (60Co) and to fission spectrum neutrons. For these endpoints, the only differences between the different types of radiation are in terms of relative behavioral effectiveness. For behavioral endpoints that are mediated by central systems (e.g., amphetamine-induced taste aversion learning), the effects of exposure to 56Fe particles are not seen following exposure to lower LET gamma rays or fission spectrum neutrons. These results indicate that the effects of exposure to heavy particles on behavioral endpoints cannot necessarily be extrapolated from studies using gamma rays, but require the use of heavy particles.     

High-Energy Atmospheric Physics: Terrestrial Gamma-Ray Flashes and Related Phenomena

It is now well established that both thunderclouds and lightning routinely emit x-rays and gamma-rays. These emissions appear over wide timescales, ranging from sub-microsecond bursts of x-rays associated with lightning leaders, to sub-millisecond bursts of gamma-rays seen in space called terrestrial gamma-ray flashes, to minute long glows from thunderclouds seen on the ground and in or near the cloud by aircraft and balloons. In particular, terrestrial gamma-ray flashes (TGFs), which are thought to be emitted by thunderclouds, are so bright that they sometimes saturate detectors on spacecraft hundreds of kilometers away. These TGFs also generate energetic secondary electrons and positrons that are detected by spacecraft in the inner magnetosphere. It is generally believed that these x-ray and gamma-ray emissions are generated, via bremsstrahlung, by energetic runaway electrons that are accelerated by electric fields in the atmosphere. In this paper, we review this newly emerging field of High-Energy Atmospheric Physics, including the production of runaway electrons, the production and propagation of energetic radiation, and the effects of both on atmospheric electrodynamics.