# A Satellite Task Planning Algorithm Based on a Symmetric Recurrent Neural Network
## 1 Introduction  
### Proposal of the Intelligent Satellite  
The various existing types of application satellites already have a strong performance. On the one hand, the communication ability, remote sensing, navigation, and other payloads of these satellites have been greatly improved, and they now basically meet the needs of military activities and civil fields. On the other hand, the life of satellites in orbit has been prolonged. However, once these satellites are launched into orbit, the performance parameters of their loads cannot be changed throughout the life of the device, which restricts the effective application of satellites to some extent. At the same time, compared with the open Internet ecological environment, the aerospace industry is relatively closed, and its research and development is basically based on hardware and software. A more common practice is to customize a satellite for a specific function or task. The process has a long development cycle and high research and development costs. Different satellite models are not compatible with each other in terms of hardware, and the components cannot be interchanged. Meanwhile, they are incompatible with each other in terms of software, and software developed for one model cannot be directly run on another satellite model. Developers cannot develop and deploy software for different satellite models. This hardware-based, software-assisted R&D process has become one of the important bottlenecks restricting the development of space technology [1; 2]. With the rapid advancement of satellite hardware and software technology, as well as the rapid promotion of software definition ideas, satellites are gradually developing toward miniaturization, a low cost, and a rapid design and deployment. Each country has made software-defined satellites and loads an important development direction. A lot of manpower and resources have been invested in this. A software defined radio (SDR) satellite is a space-based application extension of the SDR technology [3]. It can reconfigure some functions of a satellite through a software update. Since the concept of the software radio was proposed in the 1990s, the US Department of Defense and the National Aeronautics and Space Administration (NASA) have conducted long-term research, according to their respective needs, and formed corresponding standard specifications, mainly including the Software Communication Architecture (SCA) and Space Telecommunication Radio System (STRS) [4]. Both SCA and STRS standards use an open architecture that supports the decoupling of applications from the platform and supports the connection and communication of application components. STRS has become the first space-based software-defined radio technology standard for space applications that uses a lightweight software architecture design and has developed space-based applications, such as the NASA United General Dynamics Corporation and Harris Corporation's \"Space Communication and Navigation\" (SCaN) test platform project, and three STRS-based software defined radio loads have subsequently been developed [5]. The European Space Agency proposed the development of the world's first \"quantum\" satellite, with software-defined payloads, to achieve an in-orbit reconfiguration of coverage areas, frequency bands, bandwidth, and power [6]. In 2019, Loma announced that it will launch a micro-nano software-defined satellite, called \"SmartSat\" [7]. The satellite uses technologies and new architectures, such as virtual machines and multi-core processing, to significantly increase the speed of response, flexibility and in-orbit processing capabilities, as well as support satellites to change their presence in orbit tasks. [PERSON] also proposed the concept of the \"Software Satellite\", which means that the payload of such a satellite is a satellite system that uses the software radio, as a common platform, to define its functions through software [8].