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SPROUT



    【Publication】
    In this page, we explain and publish about envilomental testing which we have to check in developping satellite. We also publish about analysing data on orbit.


    1 Flow of developping satellite


    Before we explain about testing, we show the process about developing satellite. If we write the process and detail in brief, it is as follows.

    @Conceptual design・・・We discuss what we make things to achive that and the significance and social positioning. By these discussing, we solidify functions what the thing will achieve.
    AMDR(Mission Design Review)・・・We validate validity about conceptual design.
    BSystem design・・・We decide how the things achive functions that are decided in Conceptual design phase specifically.
    CSDR(System Design Review)・・・We validate validity about system design.
    DMaking BBM(Bread Board Model)・・・We start to make along the way which decided in system design. Also we check moving these. After the operation checkig at each systems, we combine each systems and check moving as one thing.
    EPDR(Preliminary Design Review)・・・We validate validity about including systems and verification so far.
    FEM(Engineering Model)・・・We remake the things which we checked moving in BBM phase go in real body structure size and atrengthen the design of structure. And that, we do enviromental testing by using EM.
    GCDR(Critical Design Review)・・・We validate validity about all design before now.
    HFM(Flight Model)・・・We make real launch vehicle. After checking move, we do testing which request by rocket. If we pass the test, we can launch.

    Generally, satellites go through these process. In early stage, we do "thinking", "researching" and "analysing to show the grounds" rather than making things using hands. After that, we manufucture the thing which we designed and check by testing whether it meets the purpose and requirements.
    In this page, we focuse on the latter. We want many people to get images like "If we make satellites, we do those testing and checking" by photos and movies.

    Photo. the flow of development

    2 Envilomental test by EM


    2.1 Vibration test
    There is two kind of testing of vibration test. One is sinusoidal vibration test and other is rundom vibration test. Sinusoidal vibration test uses to search the resonance point by pulsuting the subject while changing the number of vibration and so on. And other one, it is the rundom vibration test, is a acting rundum vibration which is superimposed sinusoidal waves each of which is changing amplitude and phase. It can reappear real enviroment and check responses when the thing is acted many type of vibration.
    When rocket is launched, it moves highspeed in air, because it vibrates violently because of burning of engine and rubbing air. So, satellites in fairling of the rocket also receive the vibration. We must check that "Even if a satellite get vibration, it never causes destruction, breakdowns both of which doesn't give a damage to oter satellites, and malfunction.". So the purpose of these two vibration tests is to checking there is no regional destroying, lacking of components, presence or absence of resonance, and operation after vibration test.
    2.2 Vacuum environmental test
    Because space is very high vacuum of atmospheric conditions, we must check that satellite systems will be operated normal. So, we put satellite into vacuum chamber and check that satellite's systems work normally and each component doesn't burst and corrupt under the vacuum situation.
    2.3 Thermostat chmber test
    Because satellite's on orbit templature is different intence between part of satellite where the sunlite is shining to other part where the sunlight isn't shining, equipments internal of satellite will expose under severe enviroment of a large templature dofference. All electronic components and equipments have tenplature range that works normally. So, we have to check that satellite operates normally under the severe templature environment.
    2.4 Impact test
    When satellites separate from rocket, satellites get impact other than vibration from rocket. By this test, we check that satellites will resist impact.

    3 Testing by FM and Checj by EM


    At testing by FM, we did same test plus something. And we check "deployment membrane structure" phase by EM. In this term, we publish pictures and movies of these test.

    4 On orbit


    In this itemize, we publish pictures which are taken on early orbit and sensing data. This itemize is frequently updated. Just for information, pictures transmitted by SSTV are published this page.


    5 Source books


    Upon writing those sentences, we use these books as reference.  
    1.Yasuyuki Miyazaki,”Making satellite”,Ohm-sha,2011
    2.Masamichi Shigehara,”Satellite design introduction”,Baifu-kan,2002