Orbit

class Orbit

Describes an orbit. For example, the orbit of a vessel, obtained by calling Vessel.Orbit, or a celestial body, obtained by calling CelestialBody.Orbit.

CelestialBody Body { get; }

The celestial body (e.g. planet or moon) around which the object is orbiting.

Game Scenes:

All

Double Apoapsis { get; }

Gets the apoapsis of the orbit, in meters, from the center of mass of the body being orbited.

Game Scenes:

All

Note

For the apoapsis altitude reported on the in-game map view, use Orbit.ApoapsisAltitude.

Double Periapsis { get; }

The periapsis of the orbit, in meters, from the center of mass of the body being orbited.

Game Scenes:

All

Note

For the periapsis altitude reported on the in-game map view, use Orbit.PeriapsisAltitude.

Double ApoapsisAltitude { get; }

The apoapsis of the orbit, in meters, above the sea level of the body being orbited.

Game Scenes:

All

Note

This is equal to Orbit.Apoapsis minus the equatorial radius of the body.

Double PeriapsisAltitude { get; }

The periapsis of the orbit, in meters, above the sea level of the body being orbited.

Game Scenes:

All

Note

This is equal to Orbit.Periapsis minus the equatorial radius of the body.

Double SemiMajorAxis { get; }

The semi-major axis of the orbit, in meters.

Game Scenes:

All

Double SemiMinorAxis { get; }

The semi-minor axis of the orbit, in meters.

Game Scenes:

All

Double Radius { get; }

The current radius of the orbit, in meters. This is the distance between the center of mass of the object in orbit, and the center of mass of the body around which it is orbiting.

Game Scenes:

All

Note

This value will change over time if the orbit is elliptical.

Double RadiusAt (Double ut)

The orbital radius at the given time, in meters.

Parameters:

• ut – The universal time to measure the radius at.

Game Scenes:

All

Tuple<Double, Double, Double> PositionAt (Double ut, ReferenceFrame referenceFrame)

The position at a given time, in the specified reference frame.

Parameters:

• ut – The universal time to measure the position at.

• referenceFrame – The reference frame that the returned position vector is in.

Returns:

The position as a vector.

Game Scenes:

All

Double Speed { get; }

The current orbital speed of the object in meters per second.

Game Scenes:

All

Note

This value will change over time if the orbit is elliptical.

Double Period { get; }

The orbital period, in seconds.

Game Scenes:

All

Double TimeToApoapsis { get; }

The time until the object reaches apoapsis, in seconds.

Game Scenes:

All

Double TimeToPeriapsis { get; }

The time until the object reaches periapsis, in seconds.

Game Scenes:

All

Double Eccentricity { get; }

The eccentricity of the orbit.

Game Scenes:

All

Double Inclination { get; }

The inclination of the orbit, in radians.

Game Scenes:

All

Double LongitudeOfAscendingNode { get; }

The longitude of the ascending node, in radians.

Game Scenes:

All

Double ArgumentOfPeriapsis { get; }

The argument of periapsis, in radians.

Game Scenes:

All

Double MeanAnomalyAtEpoch { get; }

The mean anomaly at epoch.

Game Scenes:

All

Double Epoch { get; }

The time since the epoch (the point at which the mean anomaly at epoch was measured, in seconds.

Game Scenes:

All

Double MeanAnomaly { get; }

The mean anomaly.

Game Scenes:

All

Double MeanAnomalyAtUT (Double ut)

The mean anomaly at the given time.

Parameters:

• ut – The universal time in seconds.

Game Scenes:

All

Double EccentricAnomaly { get; }

The eccentric anomaly.

Game Scenes:

All

Double EccentricAnomalyAtUT (Double ut)

The eccentric anomaly at the given universal time.

Parameters:

• ut – The universal time, in seconds.

Game Scenes:

All

Double TrueAnomaly { get; }

The true anomaly.

Game Scenes:

All

Double TrueAnomalyAtUT (Double ut)

The true anomaly at the given time.

Parameters:

• ut – The universal time in seconds.

Game Scenes:

All

Double TrueAnomalyAtRadius (Double radius)

The true anomaly at the given orbital radius.

Parameters:

• radius – The orbital radius in meters.

Game Scenes:

All

Double UTAtTrueAnomaly (Double trueAnomaly)

The universal time, in seconds, corresponding to the given true anomaly.

Parameters:

• trueAnomaly – True anomaly.

Game Scenes:

All

Double RadiusAtTrueAnomaly (Double trueAnomaly)

The orbital radius at the point in the orbit given by the true anomaly.

Parameters:

• trueAnomaly – The true anomaly.

Game Scenes:

All

Double TrueAnomalyAtAN (Orbit target)

The true anomaly of the ascending node with the given target orbit.

Parameters:

• target – Target orbit.

Game Scenes:

All

Double TrueAnomalyAtDN (Orbit target)

The true anomaly of the descending node with the given target orbit.

Parameters:

• target – Target orbit.

Game Scenes:

All

Double OrbitalSpeed { get; }

The current orbital speed in meters per second.

Game Scenes:

All

Double OrbitalSpeedAt (Double time)

The orbital speed at the given time, in meters per second.

Parameters:

• time – Time from now, in seconds.

Game Scenes:

All

static Tuple<Double, Double, Double> ReferencePlaneNormal (IConnection connection, ReferenceFrame referenceFrame)

The direction that is normal to the orbits reference plane, in the given reference frame. The reference plane is the plane from which the orbits inclination is measured.

Parameters:

• referenceFrame – The reference frame that the returned direction is in.

Returns:

The direction as a unit vector.

Game Scenes:

All

static Tuple<Double, Double, Double> ReferencePlaneDirection (IConnection connection, ReferenceFrame referenceFrame)

The direction from which the orbits longitude of ascending node is measured, in the given reference frame.

Parameters:

• referenceFrame – The reference frame that the returned direction is in.

Returns:

The direction as a unit vector.

Game Scenes:

All

Double RelativeInclination (Orbit target)

Relative inclination of this orbit and the target orbit, in radians.

Parameters:

• target – Target orbit.

Game Scenes:

All

Double TimeToSOIChange { get; }

The time until the object changes sphere of influence, in seconds. Returns NaN if the object is not going to change sphere of influence.

Game Scenes:

All

Orbit NextOrbit { get; }

If the object is going to change sphere of influence in the future, returns the new orbit after the change. Otherwise returns null.

Game Scenes:

All

Double TimeOfClosestApproach (Orbit target)

Estimates and returns the time at closest approach to a target orbit.

Parameters:

• target – Target orbit.

Returns:

The universal time at closest approach, in seconds.

Game Scenes:

All

Double DistanceAtClosestApproach (Orbit target)

Estimates and returns the distance at closest approach to a target orbit, in meters.

Parameters:

• target – Target orbit.

Game Scenes:

All

IList<IList<Double>> ListClosestApproaches (Orbit target, Int32 orbits)

Returns the times at closest approach and corresponding distances, to a target orbit.

Parameters:

• target – Target orbit.

• orbits – The number of future orbits to search.

Returns:

A list of two lists. The first is a list of times at closest approach, as universal times in seconds. The second is a list of corresponding distances at closest approach, in meters.

Game Scenes:

All