Closest Approach#

class ClosestApproach#

A close approach between an orbit and a target orbit. Obtained by calling Orbit.next_closest_approach() or Orbit.closest_approaches().

Note

The object names the approach rather than describing it once: each member estimates the time of closest approach from where the two orbits are now, and describes the state at that time. The estimate moves as the game runs, so members read at different moments can differ a little; members read in one physics tick all describe the same estimate. Relative quantities are the target relative to the orbiting object (target minus self).

The search runs forward over one orbital period from the current time. Once an approach has passed and the two orbits are moving apart, the closest point in that period is the current one, so the object reports the approach as now, at the present separation, until the orbits bring another one within range.

ut#

The universal time of the closest approach, in seconds.

Attribute:: Read-only, cannot be set
Return type:: float

time_to#

The time until the closest approach, in seconds.

Attribute:: Read-only, cannot be set
Return type:: float

distance#

The distance between the objects at the closest approach, in meters.

Attribute:: Read-only, cannot be set
Return type:: float

relative_speed#

The relative speed of the objects at the closest approach, in meters per second. This is the magnitude of ClosestApproach.relative_velocity(), and does not depend on the choice of reference frame.

Attribute:: Read-only, cannot be set
Return type:: float

vessel#

The vessel doing the approaching, or None if it is not a vessel.

Attribute:: Read-only, cannot be set
Return type:: Vessel or None

body#

The celestial body doing the approaching, or None if it is not a celestial body.

Attribute:: Read-only, cannot be set
Return type:: CelestialBody or None

target_vessel#

The vessel being approached, or None if the target is not a vessel.

Attribute:: Read-only, cannot be set
Return type:: Vessel or None

target_body#

The celestial body being approached, or None if the target is not a celestial body.

Attribute:: Read-only, cannot be set
Return type:: CelestialBody or None

position([reference_frame=None])#

The position of the orbiting object at the closest approach.

Parameters:: reference_frame (ReferenceFrame or None) – The reference frame that the returned position vector is in. Defaults to the orbital reference frame of the object the orbit belongs to.
Returns:: The position as a vector.
Return type:: tuple(float, float, float)

target_position([reference_frame=None])#

The position of the target object at the closest approach.

Parameters:: reference_frame (ReferenceFrame or None) – The reference frame that the returned position vector is in. Defaults to the orbital reference frame of the object the orbit belongs to.
Returns:: The position as a vector.
Return type:: tuple(float, float, float)

velocity([reference_frame=None])#

The velocity of the orbiting object at the closest approach.

Parameters:: reference_frame (ReferenceFrame or None) – The reference frame that the returned velocity vector is in. Defaults to the orbital reference frame of the object the orbit belongs to.
Returns:: The velocity as a vector.
Return type:: tuple(float, float, float)

target_velocity([reference_frame=None])#

The velocity of the target object at the closest approach.

Parameters:: reference_frame (ReferenceFrame or None) – The reference frame that the returned velocity vector is in. Defaults to the orbital reference frame of the object the orbit belongs to.
Returns:: The velocity as a vector.
Return type:: tuple(float, float, float)

relative_position([reference_frame=None])#

The position of the target relative to the orbiting object at the closest approach.

Parameters:: reference_frame (ReferenceFrame or None) – The reference frame whose axes the returned vector is expressed in. Defaults to the orbital reference frame of the object the orbit belongs to.
Returns:: The relative position as a vector.
Return type:: tuple(float, float, float)

relative_velocity([reference_frame=None])#

The velocity of the target relative to the orbiting object at the closest approach.

Parameters:: reference_frame (ReferenceFrame or None) – The reference frame whose axes the returned vector is expressed in. Defaults to the orbital reference frame of the object the orbit belongs to.
Returns:: The relative velocity as a vector.
Return type:: tuple(float, float, float)