## 1 Introduction
This study shows that geometrical imperfections at different ratios of \(t/R\) may have decreasing, neutral, or increasing effects on buckling resistance and can result in a softening or stiffening behavior of the shells. These studies are mainly used at ground level for relatively large storage tanks. Aerospace storage tanks, especially satellite propulsion storage tanks, require much more stringent requirements for their performance. A propulsion system has a direct impact on the life, reliability, orbit, and altitude control of a pico-satellite. Hence, it is an important component of pico-satellites [23]. With the continuous development of pico-satellites, the design of each system encountered by the satellite has many new challenges. The installation space constraints are the most obvious. Experts and scholars studying propulsion systems are concerned about the problems of improving the structure strength, the ability of the system to carry propellant, and the propulsion efficiency in a limited space. A micro-satellite propulsion system is limited by the performance, installation space, and weight. Chemical propulsion, electric propulsion, and laser propulsion systems have further limitations, such as a complex structure, a large volume, and a large weight [24; 25; 26]. Hence, they cannot be applied to micro-satellites. A pico-satellite or nano-satellite has a smaller volume and weight. Therefore, the installation and volume utilization rate of the propulsion system becomes more of a prominent problem. Currently, a pico-satellite mainly uses a storage tank propulsion system that is a high-pressure, thin-walled storage tank [27; 28]. Owing to the requirements of the processing method, pressure, and weight, conventional propulsion storage tanks are oval or spherical in shape. When the storage tank occupies the same installation envelope, the volume utilization rate is low. To fully utilize the installation space for a pico-satellite, the conventional storage tank must be changed to a complex or special-shaped storage tank. A rational design can effectively improve the strength and volume utilization rate, and can reduce the weight [29; 30]. With the rapid development of 3D metal printing technology, its scope of applications has gradually broadened while its performance has continuously improved. This technique is widely used in the aerospace, automotive, and medical fields [31; 32; 33]. This kind of manufacturing method without conventional tools or holds can realize complex structures that are difficult to process using conventional processes. It can simplify the production process, shorten the manufacturing cycle, and reduce cost. With the use of high-strength materials, such as titanium alloy, aluminum alloy,and nickel alloy, in printing [34; 35], the mechanical properties and appearance are comparable to those obtained from conventional machining methods. A conventional storage tank only withstands pressure through the internal wall, but when using 3D metal printing, it can be designed as a mesh structure, which can withstand higher pressure, improve the volume, and reduce the weight. Even the pipelines and other storage tank accessories can be printed directly. This new process method facilitates the development of an improved storage structure for propulsion systems [36; 37; 38]. This paper presents an improved mesh storage tank structure obtained using selective laser melting (SLM) 3D metal printing. The storage tank is optimized using a multi-objective uniform design method. The parameters of the mesh structure, such as the length, three direction intervals, wall thickness, and the connecting distance to the side wall, are considered the optimization factors. The compressive stress, volume utilization ratio, and weight parameters are considered the optimization objectives.