not-yet-known not-yet-known not-yet-known unknown This article digs into the current significance of Low Earth Orbit (LEO) Satellite Networks in both academia and industry, starting with an examination of the various uses envisioned for Low Earth Orbit Satellites (LEOS) and its clear advantages over 5G technology, LEOS offer global internet access, low latency, and scalability, surpassing 5G’s coverage. The applications of LEO satellites include global connectivity, remote sensing, and aerospace advancements, revolutionizing communication and space exploration. Notably, These networks, which include SpaceX, OneWeb, LeoSat, Telesat, and Amazon Kuiper, have been in development since 2018. The satellites operate as routing nodes connected via ISLs, and terminals connect dynamically to one or more satellites in these networks, which also have onboard processing capabilities. The dynamic changes in the network architecture present particular challenges for service planning and traffic routing. To determine an optimal path for transmitting data from a single source terminal to a single destination terminal within the dynamic and complex network architecture of LEO satellites is known as unicast routing. We are interested in unicast routing because it addresses the specific needs of individual communication, optimizing network efficiency, minimizing latency, and enhancing security, all of which are critical factors in the success of these networks. There are changes in routing information that might be frequent and have a latency of 100 ms due to the continual movement of satellites and the Earth. Routing traffic from a source terminal to a destination terminal connected to several satellites is a challenge. In this paper, we will present different approaches from literature to model the satellite constellation and solve the routing problem (with or without inter-satellite links and w/wo dynamic routing). This paper also introduces the simulators to model satellite constellation such as Starlink constellation.