  The frequency at which a large space telescope's (e.g. NGST's) detector chips
are read, or the sample rate, is tightly coupled to many hardware and
operational aspects of the telescope's instrument and data handling elements.
In this paper we discuss many of the drivers and important implications fo the
sample rate: the data rate to the ground; onboard computer storage, bandwidth,
and speed; the number of A->D chips, and therefore the overall size and power
requirements of the analog electronics; cryocabling requirements; and detector
noise and power. We discuss and parametrize these and other elements related to
sample rate. Finally, we discuss the implications of sample rate in the context
of achieving the most important science goals under the constraint of fixed
cost.
