In optics, jitter is used to refer to motion that has high temporal frequency relative to the integration/exposure time.
Jitter is typically differentiated from smear, which has a lower frequency relative to the integration time.
The equation for the optical Modulation transfer function associated with jitter is where k is the spatial frequency and
Meanwhile, spacecraft are compact and rigid, to withstand high launch loads.
Jitter, then, is transmitted easily and often a limiting factor for high-resolution optics.