Low-thrust, optimal strategies are investigated for making a smooth landing on a uniformly rotating, homogeneous rectangular parallelepiped while avoiding the sharp corners during the approach. The individual effects of principal spherical harmonic coefficients on the stability against impact are determined numerically. An iterative predictor-corrector algorithm is utilized to find a direct and retrograde family of equatorial orbits. Stability analysis of equatorial orbits confirms the fact that retrograde orbits are less prone to disturbances than direct orbits. For an optimal landing, each approach trajectory begins from a stable equatorial orbit, and terminates at a prescribed landing point. The optimality conditions are given by Euler-Lagrange equations, and the associated two-point boundary value problem is solved by a collocation method with additional path constraints, and its results are compared with those of a direct nonlinear programming search technique. It is observed that a smaller energy expenditure is required for a landing made further away from the initial location such that sufficient time is allowed for the spacecraft to remain in an unforced orbital trajectory for a majority of the trajectory. A sample inclined orbit is also studied for a possible non-planar optimal approach in the body-fixed frame, and further investigated for various landing locations.
Optimal Landing Strategy on a Uniformly Rotating Homogeneous Rectangular Parallelepiped
J Astronaut Sci
The Journal of the Astronautical Sciences ; 68 , 1 ; 120-149
2021-03-01
30 pages
Article (Journal)
Electronic Resource
English
Astrodynamics , Guidance , Control and dynamics , Spacecraft guidance and control , Trajectory optimization , Orbital stability Engineering , Aerospace Technology and Astronautics , Mathematical Applications in the Physical Sciences , Space Sciences (including Extraterrestrial Physics, Space Exploration and Astronautics)
Experimental Investigation of Parachute Canopies with Rectangular Parallelepiped Geometries
Online Contents | 2013
|British Library Conference Proceedings | 2001
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