## 1 Introduction
The objective is to minimize the total transmit power of both satellites and base stations, while guaranteeing user rate requirements. An alternating optimization scheme is proposed to optimize beamforming weight vectors and phase shifters at the RIS iteratively, using singular value decomposition, uplink-downlink duality, Taylor expansion, and penalty function methods. Simulation results demonstrate the superiority of the proposed scheme over benchmark schemes [11]. [PERSON] et al. 's paper focuses on the physical layer security of a satellite network sharing its downlink spectral resource with a terrestrial cellular network. The proposed solution employs a multi-antenna base station as a source of green interference to enhance secure transmission in the satellite network. The mutual interference between the two networks is considered, and a constrained optimization problem is formulated to maximize the instantaneous rate of the terrestrial user while satisfying the interference probability constraint of the satellite user. Two beamforming schemes, hybrid zero-forcing and partial zero-forcing, are presented to solve the optimization problem and obtain the beamforming weight vectors. The secrecy performance of the primary satellite network is analyzed considering two practical scenarios, with analytical expressions derived for secrecy outage probability and average secrecy rate. Numerical results demonstrate the superiority of the proposed beamforming schemes and validate the performance analysis [12]. For each mission, it is important to design and select an orbit that meets the requirements of the mission [13; 14; 15]. Since there are various subtypes of LEO orbits, there are several parameters that need to be taken into account while designing a satellite orbit. Sun-synchronous orbit (SSO) is the most common orbit that CubeSats with various missions are launched into. Satellites in the SSO have an inclination angle of 98\({}^{\circ}\) and cross the polar regions of the Earth, and because their orbital plane is synchronized with the sun, they will continuously view a specific region on Earth at the same time of the day [16]. This phenomenon is useful for earth observation and remote sensing. However, for an IoT communication mission, the time is not a constraint, but it is more about the number of passes that the satellite makes over the ground station to downlink the data. Therefore, a lower inclination orbit seems to be more effective for LoRa-IoT communication satellites. In related works, there are several missions with different selections of orbits. Some missions utilized a propulsion system that continuously maneuver the satellite between the targets to ensure that the entire regions are covered and get a higher resolution measurement [17]. However, this technique has restrictions since a propulsion system is needed. Other remote sensing missions, such as the Indian remote sensing satellite use, SSO so that the satellite's orbit is phased to pass repeatedly over a targeted location every specific period [18]. Moreover, for earth observation missions, it is useful to use a repeat ground track orbit since one of the mission's requirements is ground track repeatability [19; 20]. In addition, the satellite pass's position in relation to the ground stations remains constant. Though, a maneuver correction is necessary to keep the repeatability of the ground track [21]. The overall system configuration and operational costs are influenced by the number of orbits, the number of satellites in each orbit, the types of orbits, and the altitude of the orbits [22]. According to [PERSON] and Assadian [20], revisit time and repeat cycle are the most important parameters that need to be considered while designing the orbit. To build and develop a nanosatellite, it is essential to follow a certain standard. The Lean Satellite Standard [23], also known as the Cho Standard, is a set of guidelines for designing and building small satellites, such as CubeSats.