The fundamental basis for assessing whether a satellite link will work is the calculation of the link budget. This determines how much signal transmitted from the uplink will arrive at the downlink, and hopefully with enough in hand to give some degree of margin for physical factors that can vary or cannot be calculated in a theoretical link budget.
What are we trying to measure with the calculation of a link budget?
Fundamentally, whether enough signal transmitted from the uplink can be received at the downlink to convey the information carried accurately. This encompasses the uplink and the downlink equipment, the uplink and the downlink paths, as well as the effects of the reception and transmission through the satellite.