at a frequency which is in accordance with the drive shaft rpm. Ordinarily, the vehicular velocity sensor is incorporated within a speedometer, and is adapted to sense the rotational speed of the transmission output shaft as the corresponding rotational speed of the speedometer cable, and to produce the vehicular velocity responsive signal, in the form of the constant-voltage pulses, at the same time that the speedometer indicates the velocity of the vehicle.
Failures which can develop in the foregoing system for sensing and transmitting the signal responsive to vehicular velocity include breakage of the speedometer cable, a malfunction in the gear train for transmitting the rotational speed, a malfunction in the vehicular velocity sensing reed switch per se, or severance of the wiring that carries the output signal fromcan be rotated independent of the entire station. The Station appears to rotate mostly because of the change of perspective while it's flying overhead, much like you see the front, the side and then the back of a car passing you.

XVV (X-axis parallel to the velocity vector) as you describe, is only one of the attitude programs available to the ISS, and granted, it is the one most flown. During assembly procedures, the ISS was in an inertial attitude. The station can also assume a "down and sideways" or YVV attitude, with the Cupola pointing at the Earth and the long axis of the station parallel to the direction of travel. This orientation is usually only used in situations where the angle between the sun and the plane