perturbations module

Perturbations module for attitude determination and control system.

This module models perturbing torques acting on a spacecraft given the relevant spacecraft parameters and its current state.

perturbations.gravity_gradient_torque(r, J)

Computes the gravity gradient torque acting on a spacecraft

Parameters:

• r (numpy ndarray) – the inertial position of the spacecraft (m)
• J (numpy ndarray) – the spacecraft’s inertia tensor (3x3) (kg * m^2)

Returns:

the gravity gradient torque acting on the spacecraft

coordinatized in the body frame

Return type:

numpy ndarray

perturbations.magnetic_field_torque(r, dipole, DCM)

Computes the magnetic field torque acting on a spacecraft

Parameters:

• r (numpy ndarray) – the inertial position of the spacecraft (m)
• dipole (numpy ndarray) – the spacecraft’s residual magnetic dipole vector (A * m^2)
• DCM (numpy ndarray) – the DCM from inertial to body frame

Returns:

the magnetic field torque acting on the spacecraft

coordinatized in the body frame

Return type:

numpy ndarray