Picture of classic books on shelf

Literary linguistics: Open Access research in English language

Strathprints makes available Open Access scholarly outputs by English Studies at Strathclyde. Particular research specialisms include literary linguistics, the study of literary texts using techniques drawn from linguistics and cognitive science.

The team also demonstrates research expertise in Renaissance studies, researching Renaissance literature, the history of ideas and language and cultural history. English hosts the Centre for Literature, Culture & Place which explores literature and its relationships with geography, space, landscape, travel, architecture, and the environment.

Explore all Strathclyde Open Access research...

Generation of optimal trajectories for Earth hybrid pole sitters

Ceriotti, Matteo and McInnes, Colin (2011) Generation of optimal trajectories for Earth hybrid pole sitters. Journal of Guidance, Control and Dynamics, 34 (3). pp. 847-859. ISSN 1533-3884

[img] PDF
Ceriotti_M_Pure_Generation_of_optimal_trajectories_for_Earth_hybrid_pole_sitters_9_Jan_2011.pdf
Accepted Author Manuscript

Download (623kB)

Abstract

A pole-sitter orbit is a closed path that is constantly above one of the Earth's poles, by means of continuous low thrust. This work proposes to hybridize solar sail propulsion and solar electric propulsion (SEP) on the same spacecraft, to enable such a pole-sitter orbit. Locally-optimal control laws are found with a semi-analytical inverse method, starting from a trajectory that satisfies the pole-sitter condition in the Sun-Earth circular restricted three-body problem. These solutions are subsequently used as first guess to find optimal orbits, using a direct method based on pseudospectral transcription. The orbital dynamics of both the pure SEP case and the hybrid case are investigated and compared. It is found that the hybrid spacecraft allows savings on propellant mass fraction. Finally, it is shown that for sufficiently long missions, a hybrid pole-sitter, based on mid-term technology, enables a consistent reduction in the launch mass for a given payload, with respect to a pure SEP spacecraft.