Packet loss patterns over unidirectional satellite link provide useful information for improving the performance of applications like bulk data transfer to many recipients. In this paper, we present our observations and analysis of packet loss patterns on one-to-many multicast sessions taken over an extended period of time. We collected the packet loss data on four multicast receivers in four different geographic locations. The measurements taken demonstrate possible reasons of packet loss in both sender and receiver sides including the burstiness behavior of the channel. It is found in our result that setting priority for multicast traffic in the sender side router is one of the key factors for packet loss. We found a significant amount of bursty or consecutive packet losses contributing to the overall loss percentage while the number of occurrences of bursty loss is relatively small.