//  Copyright (c) CNES  2008
//
//  This software is part of CelestLab, a CNES toolbox for Scilab
//
//  This software is governed by the CeCILL  license under French law and
//  abiding by the rules of distribution of free software.  You can  use,
//  modify and/ or redistribute the software under the terms of the CeCILL
//  license as circulated by CEA, CNRS and INRIA at the following URL
//  'http://www.cecill.info'.

function Xdot = CL__3b_RHS(t,X,MU)
// Motion model in the 2-body system
// Inputs: 
// t: time
// X: vector (6x1) (position+velocity)
// MU: mass ratio (> 0 and <= 1)
//
// Outputs: 
// Xdot: derivative (6x1) (position+velocity)
//
// Author:
// B. MEYSSIGNAC (CNES DCT/SB/MO)

// Declarations:


// Code:

r0 = sqrt((X(1)+MU)^2+X(2)^2+X(3)^2);
r1 = sqrt((X(1)-1+MU)^2+X(2)^2+X(3)^2);

Xdot = [X(4);
    X(5);
    X(6);
    2*X(5)+X(1)-(1-MU)*(X(1)+MU)/(r0^3)-MU*(X(1)-1+MU)/(r1^3);
    -2*X(4)+X(2)-(1-MU)*X(2)/(r0^3)-MU*X(2)/(r1^3);
    -(1-MU)*X(3)/(r0^3)-MU*X(3)/(r1^3)];

endfunction