Abstract
The descent of a lander from an initial circular orbit to the surface of a planet using gravity turn was studied. By choosing a controller depending upon the flight-path angle, an analytical expression was obtained for the required control as a function of the initial radius and the radius of the planet. With this controller, the system was also shown to possess an interesting geometry. The initial circular orbits and, through a proper scaling, the final states at the surface of the planet were shown to be equilibria of the system. The solutions to the problem were then geometrically interpreted as heteroclinic connections between these equilibria. The constant thrust-to-mass controller was treated numerically, and through a proper scaling the required control for a given initial and final radius through one single planar plot was determined. However, for the constant thrust-to-weight controller it was numerically concluded that the ratio between the radius of the initial circular orbit to the radius of the planet could not exceed ≊1.162.
Original language | English |
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Journal | Journal of Guidance, Control, and Dynamics |
Volume | 34 |
Issue number | 3 |
Pages (from-to) | 911-915 |
ISSN | 0731-5090 |
DOIs | |
Publication status | Published - 2011 |
Externally published | Yes |