LandingCost2D:

% Cost for the landing for a 2D flat planet problem.
 The cost is the total time for the maneuver.
 This is computed from the decision variable.
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   Form:
   cost = LandingCost2D( x, ~ )
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   Inputs
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   x       (:,1)   [beta;dT]
   d        (.)    Data structure describing spacecraft model

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   Outputs
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   cost    (1,1)   Total time

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