/// <summary>
/// Callback to compute the launch transfer times and display them in the scene.
/// </summary>
public void Compute()
{
int itemNo = destDropdown.value;
NBody toNbody = destinations[itemNo].GetComponent <NBody>();
OrbitData fromOrbit = new OrbitData();
fromOrbit.SetOrbit(fromNbody, centerNbody);
OrbitData toOrbit = new OrbitData();
toOrbit.SetOrbit(toNbody, centerNbody);
HohmannXfer hohmannXfer = new HohmannXfer(fromOrbit, toOrbit, true);
// Find launch windows
double[] times = hohmannXfer.LaunchTimes(numWindows);
List <Dropdown.OptionData> items = new List <Dropdown.OptionData>();
foreach (double t in times)
{
Dropdown.OptionData item = new Dropdown.OptionData();
item.text = GravityScaler.GetWorldTimeFormatted(t, GravityScaler.Units.SOLAR);
items.Add(item);
}
launchTimes.ClearOptions();
launchTimes.AddOptions(items);
}
public string ApproachPrediction(string moonName)
{
// @TODO: Too much C&P!
// Step 1: Determine the patched conic xfer
OrbitData shipOrbit = new OrbitData();
NBody shipNbody = spaceshipCtrl.GetNBody();
shipOrbit.SetOrbit(shipNbody, centralMass);
OrbitData moonOrbit = new OrbitData();
NBody moonNbody = GetTargetByName(moonName);
moonOrbit.SetOrbit(moonNbody, centralMass);
//Make a copy of the universe state and evolve forward to find min distance to
// moon.
GravityEngine ge = GravityEngine.Instance();
GravityState gs = ge.GetGravityStateCopy();
// run a simulation and find the closest approach (Expensive!)
LunarCourseCorrection lcc = new LunarCourseCorrection(shipNbody, moonNbody);
// want to be within 10% of Earth-Moon distance, before start checking
courseCorrectionData = new LunarCourseCorrection.CorrectionData();
courseCorrectionData.gravityState = gs;
courseCorrectionData.approachDistance = 0.1f * moonOrbit.a;;
courseCorrectionData.correction = 0;
courseCorrectionData.maxPhysTime = time_to_moon_phys;
lcc.ClosestApproachAsync(courseCorrectionData, MoonPreviewCompleted);
return("Calculation started...\n");
}
public List <OrbitTransfer> FindTransfers()
{
// find orbit parameters for each body.
OrbitData shipOrbit = new OrbitData();
shipOrbit.SetOrbit(ship, centralMass);
OrbitData targetOrbit = new OrbitData();
targetOrbit.SetOrbit(target, centralMass);
//Debug.Log("ship:" + shipOrbit.LogString());
//Debug.Log("target:" + targetOrbit.LogString());
List <OrbitTransfer> transfers = new List <OrbitTransfer>();
if ((shipOrbit.ecc < 1f) && (targetOrbit.ecc < 1f))
{
// both ellipses
if (shipOrbit.ecc >= DELTA_ECC)
{
// add option to circularize our orbit (independent of target)
// TODO: need more general ellipse tuning
transfers.Add(new CircularizeXfer(shipOrbit));
}
if ((shipOrbit.ecc < DELTA_ECC) && (targetOrbit.ecc < DELTA_ECC))
{
// both circular - can use Hohmann
if (Mathf.Abs(shipOrbit.inclination - targetOrbit.inclination) > DELTA_INCL)
{
// change in inclination
// DEBUG hack
// transfers.Add(new CircularPlaneChange(shipOrbit, targetOrbit));
}
else
{
transfers.Add(new HohmannXfer(shipOrbit, targetOrbit));
if (BiellipticXfer.HasLowerDv(shipOrbit, targetOrbit))
{
// need to pick (or let user select) the xfer radius - could show a curve?
// Test code - just pick 1.5x dest as xfer radius
// TODO: Make transfer radius selectable
transfers.Add(new BiellipticXfer(shipOrbit, targetOrbit, targetOrbit.a * 1.5f));
}
}
}
else
{
Debug.Log("TODO: Transfer between co-planar ellipses.");
}
}
else
{
Debug.Log("Not transfer between ellipses.");
}
return(transfers);
}
/// <summary>
/// Initiate a transfer of the spaceship to the moon. The name of the targets[] entry that is the moon
/// is provided as a string argument.
///
/// Typically called by the GEConsole.
/// </summary>
public string MoonTransfer(string moonName, float angle)
{
// Find xfer choices and present to user
OrbitData shipOrbit = new OrbitData();
shipOrbit.SetOrbit(spaceshipCtrl.GetNBody(), centralMass);
OrbitData targetOrbit = new OrbitData();
targetOrbit.SetOrbit(GetTargetByName(moonName), centralMass);
OrbitTransfer xfer = new PatchedConicXfer(shipOrbit, targetOrbit, angle);
spaceshipCtrl.SetTransfer(xfer);
SetState(State.MANEUVER);
// display the maneuver in the console (will only be one for patched conic)
return(xfer.GetManeuvers()[0].LogString() + "\n");
}
/// <summary>
/// Determine the correction required to establish the desired distance to the moon (i.e. that which
/// was predicted by the preview)
/// </summary>
/// <param name="moonName"></param>
/// <returns></returns>
public string LunarCourseCorrection(string moonName)
{
NBody moon = GetTargetByName(moonName);
OrbitData moonOrbit = new OrbitData();
NBody moonNbody = GetTargetByName(moonName);
moonOrbit.SetOrbit(moonNbody, centralMass);
GravityEngine.Instance().SetEvolve(false);
lcc = new LunarCourseCorrection(spaceshipCtrl.GetNBody(), moon);
float approachDistance = 0.1f * moonOrbit.a;
double targetDistance = predictedDistance;
double targetAccuracy = 0; // Does not matter for closest
string result = lcc.CorrectionCalcAsync(targetDistance, targetAccuracy, approachDistance,
time_to_moon_phys, CorrectionCalcCompleted);
// GravityEngine.Instance().SetEvolve(true);
return(result);
}
private void SetMarkers()
{
if (shipOrbitData == null)
{
// Cannot rely on controller start after GE start, so instead of forcing
// start order, do a lazy init here
shipOrbitData = new OrbitData();
shipOrbitData.SetOrbit(spaceshipNBody, shipOrbit.centerNbody);
}
// skip scaling since we are in dimensionless units
Vector3 pos = shipOrbitData.GetPhysicsPositionforEllipse(fromPhase);
fromMarker.transform.position = pos;
pos = shipOrbitData.GetPhysicsPositionforEllipse(toPhase);
toMarker.transform.position = pos;
}
public string MoonPreview(string moonName, float lambda1, bool async)
{
// Step 1: Determine the patched conic xfer
OrbitData shipOrbit = new OrbitData();
NBody shipNbody = spaceshipCtrl.GetNBody();
shipOrbit.SetOrbit(shipNbody, centralMass);
OrbitData moonOrbit = new OrbitData();
NBody moonNbody = GetTargetByName(moonName);
moonOrbit.SetOrbit(moonNbody, centralMass);
OrbitTransfer xfer = new PatchedConicXfer(shipOrbit, moonOrbit, lambda1);
// Step 2: Make a copy of the universe state and evolve forward to find min distance to
// moon.
GravityEngine ge = GravityEngine.Instance();
GravityState gs = ge.GetGravityStateCopy();
// there is only one maneuver to add
gs.maneuverMgr.Add(xfer.GetManeuvers()[0]);
// run a simulation and find the closest approach (Expensive!)
LunarCourseCorrection lcc = new LunarCourseCorrection(shipNbody, moonNbody);
// want to be within 10% of Earth-Moon distance, before start checking
courseCorrectionData = new LunarCourseCorrection.CorrectionData();
courseCorrectionData.gravityState = gs;
courseCorrectionData.approachDistance = 0.1f * moonOrbit.a;;
courseCorrectionData.correction = 0;
courseCorrectionData.maxPhysTime = time_to_moon_phys;
// Direct (unthreaded) calculation
if (async)
{
lcc.ClosestApproachAsync(courseCorrectionData, MoonPreviewCompleted);
return("Calculation started...\n");
}
else
{
predictedDistance = lcc.ClosestApproach(courseCorrectionData);
return(string.Format("Patched Conic with lambda={0} => approach={1}\n", lambda1, predictedDistance));
}
}
public List <OrbitTransfer> FindTransfers(bool rendezvous)
{
// find orbit parameters for each body.
OrbitData shipOrbit = new OrbitData();
shipOrbit.SetOrbit(ship, centralMass);
//shipOrbit.SetOrbitForVelocity(ship, centralMass);
OrbitData targetOrbit = new OrbitData();
targetOrbit.SetOrbit(target, centralMass);
//targetOrbit.SetOrbitForVelocity(target, centralMass);
//Debug.Log("ship:" + shipOrbit.LogString());
//Debug.Log("target:" + targetOrbit.LogString());
List <OrbitTransfer> transfers = new List <OrbitTransfer>();
if ((shipOrbit.ecc < 1f) && (targetOrbit.ecc < 1f))
{
// both ellipses
if (shipOrbit.ecc >= DELTA_ECC)
{
// add option to circularize our orbit (independent of target)
// TODO: need more general ellipse tuning
transfers.Add(new CircularizeXfer(shipOrbit));
}
if ((shipOrbit.ecc < DELTA_ECC) && (targetOrbit.ecc < DELTA_ECC))
{
// both circular - can use Hohmann
if (Mathf.Abs(shipOrbit.inclination - targetOrbit.inclination) > DELTA_INCL)
{
// Change in inclination
// If same radius can use CircularInclinationAndAN()
if (Mathf.Abs(shipOrbit.a - targetOrbit.a) < DELTA_RADIUS)
{
transfers.Add(new CircularInclinationAndAN(shipOrbit, targetOrbit));
}
else
{
Debug.Log("TODO: transfer between non-coplaner circles");
}
}
else
{
// Same inclination
transfers.Add(new HohmannXfer(shipOrbit, targetOrbit, true));
// If the target is a moon (mass > 0) then consider a patched conic transfer
if (target.mass > 0)
{
// Need to let user pick the angle of arrival
transfers.Add(new PatchedConicXfer(shipOrbit, targetOrbit, PatchedConicXfer.LAMBDA1_DEFAULT));
}
if (BiellipticXfer.HasLowerDv(shipOrbit, targetOrbit))
{
// Pick 50% excess for orbit (UI can re-adjust as needed)
transfers.Add(new BiellipticXfer(shipOrbit, targetOrbit, 50f));
}
}
}
else
{
Debug.Log("TODO: Transfer between co-planar ellipses.");
}
}
else
{
Debug.Log("Not transfer between ellipses.");
}
return(transfers);
}
