The Design And Implementation Of Microsatellite Ground Testing System

1.IntroductionThe spaceflight technique of our country advanced rapidly develop through the development of satellite over more than 30 years. The satellite has already been close contacted with our life, it not only been used for science research, also extensive application in the telecom, weather, navigate, the resources survey,survey and map and the ecosystem and so on. Along with the continuously Extend of the satellite function, the electricity equipments of the satellite is gradually complicated, its cost also raises gradually. But so far, people can't maintain the satelite on the orbit.Because of these factor, we have to carry on a great deal of test work in the manufacture process of the satellite,to examine the accuracy, credibility of its design. Meantime, test is also for the sake of improvement design project, control the quality of product. So it is an important means in the design and production line, through out the whole research and manufacture process.According to the statistic, a quite part of time to used for a test and adjust in the product period, and the manpower, material resources and the price of the equipments for the test cost is also a nice bit of. We can see that the progress of the spaceflight technical can not get away from the test work. In every part of the research and manufacture process, the test of the satellite is to insure satellite to work normally, guarantee circulate safety.This topic come from the photoelectricity academe of CAS have take part in the develop of microsatellite ground testing system. The ground testing system of satellite is the main tool of whole ship test and the test in the launch field, belong to the system class test of the satellite. This system is exclusively designed for its satellite. It is a complicated system gather computer communication,real time control, real time data processing, analysis after and so on. It can test the function and electric performance of the satellite, exam connects whether match or not, verify the compatibility and dependability of the soft hardware of system.2.The total system constituteThe system composed of ground test controller, RF front-end, CORTEX, software of ground esting system and platform. It is show in figure 1. The test system have two modes in the test process, namely wire test and wireless test. Wire test is using the separation plug of satellite and wire test equipment to test the function and performance of the satellite. Wireless test is using the Data transmitter, Transponder and wireless test equipment to test the function and performance of the satellite. The most function of the system is through wire test and wireless test to send telecommand, programmed instructions and data into information; receive datas from satellite, deal with kinds of datas.3.The procedure of the system applicationThe software receive datas from ground test controller or CORTEX, through CORTEX sed telecommand, and through ground test controller send ground test instructions; sustain whole ship test and the test in the launch field. Aim at multitask and multiple data streams of the test system, the design of system used distributed for receiving and processing methods. Based dividing of the data stream, the software of the system composed of five independent part, namely receive and process engineering software, information management software, test control software, engineering data processing and display software, image data processing software. The function of the five parts relatively independence. They can complete data communication, data processing, data archiving functions.System software use the development tools of Visual C + + 6.0. Software systems and satellite used TCP agreement to communication, the data transmitted between software systems used UDP to communication, the agreement in the software is to be achieved through Windows Sockets Programming. Aimd at the specific data communications format of satellite, the software grouped the data frame or packages, then converted into binary stream to sent; dispelled the received data packages, then processing in the corresponding need. All the datas been saved in the database in the end. The operate of the software been wrote to log for query.4.Result and evaluate of the experimentAfter unit test, system-level test and pressure test, the whole system and satellite processed docking test. Through the test ,it examed the function and electric performance of the satellite. Through the ground test controller or CORTEX exchange data with satellite.The fulfillment proves that system function is good, the system is steady and credible, the data is accurate, coming to the request of design and use completely, obtained good test result and estimate. so can say, so can say, that test not only satisfy actual produce need, and do contribution to the test technic of ground test of satellite for our country.