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

A close approach is a snapshot: the time of closest approach is estimated once when the object is created, and every member describes the state at that time. Relative quantities are the target relative to the orbiting object (target minus self).

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

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

target_vessel#

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

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

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

position([reference_frame=None])#

The position of the orbiting object at the closest approach.

Parameters:: reference_frame (ReferenceFrame) – 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) – 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) – 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) – 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) – 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) – 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)