Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multi-Revolution Low-Thrust Trajectory Optimization Using Symplectic
  Methods   Optimization of low-thrust trajectories that involve a larger number of orbit
revolutions is considered a challenging problem. This paper describes a
high-precision symplectic method and optimization techniques to solve the
minimum-energy low-thrust multi-revolution orbit transfer problem. First, the
optimal orbit transfer problem is posed as a constrained nonlinear optimal
control problem. Then, the constrained nonlinear optimal control problem is
converted into an equivalent linear quadratic form near a reference solution.
The reference solution is updated iteratively by solving a sequence of
linear-quadratic optimal control sub-problems, until convergence. Each
sub-problem is solved via a symplectic method in discrete form. To facilitate
the convergence of the algorithm, the spacecraft dynamics are expressed via
modified equinoctial elements. Interpolating the non-singular equinoctial
orbital elements and the spacecraft mass between the initial point and end
point is proven beneficial to accelerate the convergence process. Numerical
examples reveal that the proposed method displays high accuracy and efficiency.

10
The categories of this paper are: q-bio
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: econ
33
The categories of this paper are: plasm-ph