1,721,468 research outputs found
Space Trajectory Optimisation in a Concurrent Design Environment: Results and Related Issues
No full textRobustness Optimisation of Aerocapture Trajectories Design Using a Hybrid Co-Evolutionary Approach
No full textPreface : Advances in asteroid and space debris science and technology-Part 1
Full text linkThe first part of this special issue collects four papers on recent advances on the dynamics of artificial satellites in different orbit regimes around the Earth, followed by four papers on measurements, observations and orbit determination dedicated to space debris. The paper on the criticality of spacecraft index then proposes an index to quantify the criticality of space objects and rank them according to their environmental impact. Three papers follow presenting strategies for the removal of spacecraft from libration points and high elliptical orbits, the active removal of space debris with harpoons and the detumbling of satellites exploiting eddy currents. The last four papers are dedicated to topics relevant to the mitigation of the threat from near-Earth objects and the manipulation of small bodies
Comparison Between Cyclers and Stop-Over Cyclers for a Regular Earth-Mars Transportation System
No full textNetwork resilience optimisation of complex systems
Full text linkThis paper presents a method for the design for resilience of complex systems under uncertainty. In this approach, the complexity of the system is captured by a network formulation. Each node i is completely determined by two indicators: a performance fi and a functionality ci. Both these measures depend on time, decision and uncertain variables. In particular, we suggest the functional measure of resilience. The node resilience depends on the evolution over time of its state xi which is solution of a differential equation. Bifurcation theory is used to continuously model transitions between fully functioning and degraded states, disruptions and shocks that could affect the node. This work shows how to exploit the network properties and to optimise the global connected resilience emerging from the coupled dynamics of the single nodes
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