A new routing algorithm for Low-earth orbit (LEO) satellite networks is designed in this study. For this reason genetic algorithms are used. A new objective function is obtained to find the suitable path according to the criteria of the delay and an aging factor. Also Call Blocking Probabilities (CBPs) are considered due to the dynamic nature of the satellite systems. This dynamic routing type of new method is compared with the static routing which was introduced before. For practical application, several LEO systems having different numbers of satellites are discussed.