Module frames 

The launch frame, the body frame and launch attitude angles.

docs/physics/frames.md is the specification; this module implements it.

• Launch frame L: East-North-Up at the launch site. Origin at the pad on the ground; x_L east, y_L north, z_L up along the ellipsoid normal. See LaunchFrame.
• Body frame B: z_B along the rocket’s axis of symmetry, positive toward the nose; x_B along the design’s reference radial direction; y_B = z_B × x_B.
• Attitude: the unit quaternion q with v_L = q ⊗ v_B ⊗ q* (crate::attitude).
• Launch angles: azimuth A (clockwise from true north), elevation E (above the horizon) and roll φ (about z_B), with q = R_z(−A) R_x(E − π/2) R_z(φ). See LaunchAngles.

Structs

LaunchAngles

The attitude of the body axis relative to the launch frame, as launch-rail style angles.

LaunchFrame

An East-North-Up frame tied to a point on an ellipsoid: the launch frame L.