public class NumericalPropagationWithManeuverSequence {
public static void main(String[] args) throws PatriusException {
// Patrius Dataset initialization (needed for example to get the UTC time)
PatriusDataset.addResourcesFromPatriusDataset() ;
// Recovery of the UTC time scale using a "factory" (not to duplicate such unique object)
final TimeScale TUC = TimeScalesFactory.getUTC();
// Date of the orbit given in UTC time scale)
final AbsoluteDate date = new AbsoluteDate("2010-01-01T12:00:00.000", TUC);
// Getting the frame with wich will defined the orbit parameters
// As for time scale, we will use also a "factory".
final Frame GCRF = FramesFactory.getGCRF();
// Initial orbit
final double sma = 7200.e+3;
final double exc = 0.01;
final double per = sma*(1.-exc);
final double apo = sma*(1.+exc);
final double inc = FastMath.toRadians(98.);
final double pa = FastMath.toRadians(0.);
final double raan = FastMath.toRadians(0.);
final double anm = FastMath.toRadians(0.);
final double MU = Constants.WGS84_EARTH_MU;
final ApsisRadiusParameters par = new ApsisRadiusParameters(per, apo, inc, pa, raan, anm, PositionAngle.MEAN, MU);
final Orbit iniOrbit = new ApsisOrbit(par, GCRF, date);
//SPECIFIC
// Creating a mass model (see also specific example)
final AssemblyBuilder builder = new AssemblyBuilder();
// Main part
final double iniMass = 900.;
builder.addMainPart("MAIN");
builder.addProperty(new MassProperty(iniMass), "MAIN");
// Tank part (ergols mass)
final double ergolsMass = 100.;
final TankProperty tank = new TankProperty("TANK", ergolsMass);
builder.addPart("TANK", "MAIN", Transform.IDENTITY);
builder.addProperty(tank, "TANK");
// Engine part
final double isp = 300.;
final double thrust = 400.;
final PropulsiveProperty prop = new PropulsiveProperty("PROP", thrust, isp);
builder.addPart("PROP", "MAIN", Transform.IDENTITY);
builder.addProperty(prop, "PROP");
final Assembly assembly = builder.returnAssembly();
final MassProvider mm = new MassModel(assembly);
// We create a spacecratftstate
final SpacecraftState iniState = new SpacecraftState(iniOrbit, mm);
//SPECIFIC
// Initialization of the Runge Kutta integrator with a 2 s step
final double pasRk = 2.;
final FirstOrderIntegrator integrator = new ClassicalRungeKuttaIntegrator(pasRk);
// Initialization of the propagator
final NumericalPropagator propagator = new NumericalPropagator(integrator);
propagator.resetInitialState(iniState);
// Forcing integration using cartesian equations
propagator.setOrbitType(OrbitType.CARTESIAN);
//SPECIFIC
// Event corresponding to the criteria to trigger the impulsive maneuver
final EventDetector event = new DateDetector(date);
// Creation of the impulsive maneuver
final Vector3D deltaV = new Vector3D(20., 0., 0.);
final ImpulseManeuver imp = new ImpulseManeuver(event, deltaV, prop, mm, tank, LOFType.TNW);
// Duration of the maneuver to reach the initial semi major axis
final double duration = 51.03781404091;
// Creation of the continuous thrust maneuver
final AbsoluteDate startDate = date.shiftedBy(0.5*(iniOrbit.getKeplerianPeriod()-duration));
final EventDetector eventStart = new DateDetector(startDate);
final EventDetector eventEnd = new DateDetector(startDate.shiftedBy(duration));
final Vector3D direction = new Vector3D(-1., 0., 0.);
final ContinuousThrustManeuver man = new ContinuousThrustManeuver(eventStart, eventEnd, prop, direction, mm, tank);
// Creation of the sequence of maneuver
ManeuversSequence seq = new ManeuversSequence(0., 0.);
seq.add(imp);
seq.add(man);
// Adding the maneuver sequence to the propagator
seq.applyTo(propagator);
// Adding additional state (change name add to set for V3.3)
propagator.setMassProviderEquation(mm);
// Adding an attitude law (or attitude sequence : mandatory)
final AttitudeLaw attitudeLaw = new LofOffset(LOFType.TNW, RotationOrder.ZYX, 0., 0., 0.);
propagator.setAttitudeProvider(attitudeLaw);
//SPECIFIC
// Propagating 100s
final double dt = iniOrbit.getKeplerianPeriod();
final AbsoluteDate finalDate = date.shiftedBy(dt);
final SpacecraftState finalState = propagator.propagate(finalDate);
final Orbit finalOrbit = finalState.getOrbit();
// Printing new date and semi major axis
System.out.println();
System.out.println("Initial semi major axis = "+iniOrbit.getA()/1000.+" km");
System.out.println("New date = "+finalOrbit.getDate().toString(TUC)+" deg");
System.out.println("Final semi major axis = "+finalOrbit.getA()/1000.+" km");
// Printing mass
System.out.println();
System.out.println("Dry Mass = "+finalState.getMass("MAIN")+" kg");
System.out.println("Ergols Mass = "+finalState.getMass("TANK")+" kg");
}
}