Why does a satellite requires two bridges?

Two bridges are being used in the satellite to avoid the delay in the communication of packets/Frames between the sites.

Explanation:

To avoid the delay in the communication of packets/Frames between the sites two bridges are being used. Two Ethernet connections can be connected using the bridge. NIC's are not there in the repeaters whereas the bridge has two of them which make the bridge different than the repeater. On one of the side in the bridge process of addressing to the node is being done and other ends take care of communicating the packets.