P Cygni: An Extraordinary Luminous Blue Variable

P Cygni is a prototype for understanding mass loss from massive stars. This textbook star is known first of all because of two great eruptions in the 17th century. In the first half of this century it has given its name to a class of stars which are characterized by spectral lines consisting of nearly undisplaced emissions accompanied by a blue-displaced absorption component. This characteristic P Cygni-type profile betrays the presence of a stellar wind, but P Cygni's wind is quite unlike that of other hot supergiants. P Cygni was the first star that showed the effects of stellar evoluton from a study of its photometric history. It shares some common properties with the so-called Luminous Blue Variables. However, P Cygni is a unique object. This review deals with P Cygni's photometric properties, its circumstellar environment - including infrared and radio observations - and its optical and ultraviolet spectrum. Smaller sections deal with P Cygni's wind structure and evolution. This revised version was published online in August 2006 with corrections to the Cover Date.     

Viral attack to Internet banking applications

The PC Bank may be the most timesaving banking innovation since the ATM (Automatic Teller Machine). However, it also brings new possibilities for thieves. This is mainly because we have not completely solved the growing problem of computer viruses and Trojans that can act on our computers against our will. Several methods are used against them, although none can be considered 100% effective. Even more, most personal computers have little or no virus protection, so they are very easy to attack. This can become a problem as nearly all PC banking systems rely on authentication with identification passwords. This system is vulnerable and we will show that it does not provide enough protection for the users that want to make transfer operations from their accounts     

Damage assessment of large space structures through the variational approach

The present investigation is focused on the solution of a dynamic inverse problem which is concerned with the assessment of damage in large space structures by means of measured vibration data. This inverse problem has been presented as an optimization problem and has been solved through the use of the conjugate gradient method with the adjoint equation, also called the variational approach. When a high number of damaged elements has to be found and these elements are also severely damaged, it is shown that the use of an additional method is necessary in order to provide a better initial guess for the conjugate gradient method. A stochastic method, represented by the genetic algorithm method, has been chosen because it provides robust search in complex spaces and also reduces the chance of converging to local optima. The application of this hybrid approach showed that better results can be achieved, although the computational time for the application analyzed here could increase. The damage estimation has been evaluated using noiseless and noisy synthetic experimental data, and the reported results are concerned with a space truss structure.     

Watersheds in the modern world: the space viewpoint

A new world order has begun to appear since the early 1990s. The simplicity of interaction between individual states, based on the rivalry between the two superpowers, is gradually being replaced by new attitudes formed in a complex, uncertain and risky context. States still have a role, discussing, negotiating, legislating, creating infrastructures and issuing directives. However, political power, with its laws, its order and its reasoning, is being supplemented and often dominated by other forms of power: economic, financial or influence. Space policies follow or sometimes precede political trends. They were the spearhead of the ‘glory years’ and still bear the imprint of the simple rules which applied twenty years ago. However, amid the current uncertainty, it is possible to perceive the outline of the space policies of the future, which may contribute to the definition of new watersheds in the modern world.     

Task planning for robotic manipulation in space applications

Space-based robotic systems will require novel technologies of planning and manipulation to accomplish complex tasks such as diagnosis, repair, and assembly task representation, discrete task planning, and control synthesis which provide a design environment for assembly systems, and which extend to planning of manipulation operations in unstructured environments. In this approach, assembly planning is carried out using the AND/OR graph representation which encompasses all possible partial orders of operations and may be used to plan assembly sequences. A novel algorithm for planning disassembly and repair using the AND/OR graph is introduced, and examples of repair sequences generated for a satellite electrical module are described. For discrete task planning, the configuration map facilitates search over discrete parameters in the space of bounded configuration sets     

Microgravity effects on Drosophila melanogaster development and aging: comparative analysis of the results of the Fly experiment in the Biokosmos 9 biosatellite flight.

The results are presented of the exposure of Drosophila melanogaster to microgravity conditions during a 15-day biosatellite flight, Biokosmos 9, in a joint ESA-URSS project. The experimental containers were loaded before launch with a set of Drosophila melanogaster Oregon R larvae so that imagoes were due to emerge half-way through the flight. A large number of normally developed larvae were recovered from the space-flown containers. These larvae were able to develop into normal adults confirming earlier results that Drosophila melanogaster of a wild-type constitution can develop normally in the absence of gravity. However, microgravity exposure clearly enhances the number of growing embryos laid by the flies and possibly slows down the developmental pace of the microgravity-exposed animals. Due to some problems in the experimental set-up, this slowing down needs to be verified in future experiments. No live adult that had been exposed to microgravity was recovered from the experiment, so that no life span studies could be carried out, but adult males emerged from the recovered embyros showed a slight shortening in life span and a lower performance in other experimental tests of aging. This agrees with the results of previous experiments performed by our groups.     

Inter-orbital low-thrust transfers in an arbitrary field of forces

Low-thrust transfers between preset orbits are considered in the presence of perturbations of different origin. A simple method of finding the transfer trajectory is suggested, based on linearization of motion near reference orbits. The required accuracy of calculations is achieved by way of increasing the number of reference orbits. The method can also be used in the case of a large number of revolutions around the attracting center: no averaging of motion is required in this case. The suggested method is applicable as well, when the final orbit is specified partially and when there are constraints on the thrust direction. The optimal solution to the linearized problem is not optimal for the original problem; closeness of solutions to these two problems is estimated using a numerical example. Capabilities of the method are also illustrated by examples.     

The merger of two global commons: The need for new governance

The RUSI ‘Space and UK National Security’ conference was held in London on 2 October 2012 and, with the ‘Cyber Alliances: Strategy Partnerships in Cyber Space’ conference’ of 14–15 November 2012, brought together space and cyberspace specialists from more than 15 countries, across four continents. Alixe Buckerfield de la Roche reports on key points discussed across both conferences: (1) space as a shared domain, and building resilience; (2) governance; (3) national responses to space security; (4) partnerships and alliances, space situational awareness, space debris, and new initiatives; (5) the space–cyberspace merger; and (6) commercial and military sectors. Consensus on critical areas for further action emerged, and for that reason the conjunction of the two conferences was significant.