  We discuss various methods for acquiring optical links in space using a
dedicated acquisition sensor. Statistical models are developed and simple
analytical equations derived that compare the performance between a single and
dual spiral scan approach as well as between sequential and parallel
acquisition of link chains. Simple derived analytical equations allow relating
essential search parameters such as track width, variance of the uncertainty
distribution, capture radius and scan speed to the probabilities of acquiring
the links within a specific time. We also assess the probability of failing to
acquire a link due to beam jitter and derive a simple analytical model that
allows determining the maximum tolerable jitter for a given beam overlap and
required probability of success. All results are validated by Monte Carlo
simulations and applied to the concrete example of the GRACE FO mission.
