Design And Implementation Of High Reliability Storage For Space Application

Along with the rapid development of space technology,the evaluate standard of the country’s space technology has changed from the ability of entering space to the ability of using space.In terms of using space,the earth observing technology is the most closely related to us,which is not only the need for national defense construction and national security,but also plays a significant role in human life and survival,natural disasters,resources,meteorology and biological diversity,so every country pays more attention to earth observing.All the equipment on the satellite cannot be repaired once the satellite is on track,so the correctness and high-reliability of data as well as the long life of the memory are very critical for the satellite to complete its task.Therefore,the fault-tolerant design and high-reliability design for space-based applications is meaningful for the long life of our satellites.In addition,there exists a tricky problem for the development of memory in China’scommonly used FLASH memory chip at present.For this issue,memory oriented to the fault tolerance and high reliability design of space application is not only a hardware and software collaborative design problem,but also is a significance topic for the long life of China’s satellites.The main work of this thesis is as follows:In thisthesis,application characteristics of China’s satellites and the current development status of international memory chips is analyzed deeply.Also,functional requirements,application requirements and fault-tolerant requirements of the satellite memory are proposed.Aiming at actual application requirements of satellite storage,the hardware and software with fault-tolerant strategies of storage equipment for space applications are designed.The design of hardware and software aims to fully cover the requirements of users,as well as the reliability and fault – tolerance design is conducted to improve the reliability of the memory.The key components of the high-reliability’ storage,function of each module and the implementation of software are given,and the corresponding system software is developed.For the designing of fault-tolerant,design ideas and feasible methods of multi-level and multi-variety are described in detail,including three-modules redundancy,data error correction,m – n redundancy,etc.Particularly,the on-orbit space storage reconstruction is achieved with software to effectively solve the lack of reliability in China’s existing equipment with FLASH as the memory.The system is tested in three levels.First,for the test of reconstructionaccuracy,many test cases are designed manually to verify the accuracy of the reconstruction algorithm.Second,for the test of reconstruction effectiveness,we make a comparison between the results obtained with and without a reconstruction technique to evaluate the effectiveness of the reconstruction algorithm.Last,based on the environment of the storagein space application,different on-orbit applications are simulated to test the storage modules respectively,and the functional and performance indexes of each experiment are gotten.The test results show that the storage modules meet the requirements of the space application.This work has been finished in 2016 and the storage device of thework has been equipped in XX-1 satellite for three months,which has been running without any issues.