After a satellite leaves the factory, it has to go through multiple links such as transportation, launch, orbit insertion, and orbital operation. Each link is subject to various environmental influences and effects. Moreover, once a satellite is launched into space, it is extremely difficult to remedy any problems that arise in the future. This requires the satellite to be able to fully withstand various expected launch environments and space orbital environments, and to minimize potential defects on the ground by taking various measures before launch. To achieve this goal, in addition to careful design and manufacturing, conducting a large number of environmental tests during the development process is also a very important means. Therefore, environmental testing must be carried out throughout the entire development process of the satellite, from materials, components, parts, components, sub-systems to the entire satellite, step by step. Only after passing a prescribed test can the development work continue.
When actually carrying out environmental testing, the first thing to do is to understand the environment that the product will withstand, because if the environmental test conditions are set too strictly, it will cause over-testing, and if the conditions are set too wide, it will cause under-testing, which is detrimental to the product. Excessive testing will cause the product to suffer undue damage during the test, which will increase development costs and time and delay the progress. Lack of testing will prevent the product from receiving due assessment and verification, increasing the risk of satellite launches. Therefore, in order to ensure the effectiveness of environmental testing, at the beginning of satellite development, a comprehensive environmental testing plan that fully considers the characteristics of the model must be formulated. When formulating a plan, first, try to expose and eliminate problems in the early stages of the development phase. Only when the test purpose of one phase is achieved can the next phase of development work be transferred. The second is to expose and eliminate problems at the lowest possible assembly level, starting from electronic components and materials, and inspect them step by step, so as not to leave problems at low assembly levels to high assembly levels. The third is to determine the environmental test conditions, including test magnitude, duration, number of cycles, test margin, etc., on the basis of sufficient environmental prediction work, and make them as reasonable as possible. Fourth, the order of environmental tests should generally follow the order of environmental loads experienced by the satellite during flight. Dynamic tests such as sound and vibration should be placed before thermal tests. Fifth, before environmental testing, comprehensive functional tests and inspections should be conducted on the products being tested, to discover and eliminate product defects in advance, confirm that the products are qualified, and provide baseline data for performance comparison during the test process and after the test.
According to the characteristics of satellite development, satellite environmental testing is mainly divided into three stages. The first stage is the development and testing of the preliminary prototype. The main purpose is to verify the correctness of the product design and manufacturing process plan, expose possible problems and product defects before moving to the design and manufacturing of the prototype product, and take corrective measures to try not to leave hidden dangers until the prototype stage. There is no fixed method for the initial prototyping stage. The projects to be done and the specific requirements mainly depend on the maturity and inheritance of the subsystems and components used in the satellite. The second is the qualification test at the prototype stage. The main purpose is to verify that the product design meets the requirements and has sufficient margin. After the product passes the qualification test, it can be considered that its design has been fully assessed and can withstand the worst expected environment and work normally. The third is the acceptance test, whose main purpose is to expose potential defects in product manufacturing (including defects in process, assembly, components and materials used) and try to eliminate early failures. The conditions of the acceptance test must be stringent enough to expose these defects without impairing the effective life of the product being tested.
When carrying out specific environmental test projects, the test projects are generally considered based on the environment that the satellite has experienced at each stage of its life cycle. During the ground storage and transportation stage, the main test items that need to be considered include temperature test, humidity test, transportation test, vibration test, etc.; during the launch into orbit stage, the main test items that need to be considered include acceleration test, vibration test, noise test, impact test, Vacuum discharge (corona, arc discharge, micro-discharge), pressure profile test, etc.; during the on-orbit operation stage, the main test items that need to be considered include thermal balance test, thermal vacuum test, thermal cycle test, atomic oxygen test, charge and discharge test, magnetic test, weight loss simulation test, etc.
