The satellite development team of Nihon University’s students has already developed and launched the cube-sat in 2006 and 2008. And the “SEEDS-II”, which launched in 2008, is still operated by students. Because of engine trouble, our first satellite “SEEDS” cannot go to the space. Also we make use of it for education of space engineering for the students, enlightenment of the space engineering for the ham radio operators and under the high school students, and technology exchange between overseas researchers. In addition, we designed the “PRIMROSE” which win a grand prize of “14th Satellite design contest” in 2006. The PRIMROSE's purpose is transformation of the orbit by increasing the air resistance by deployment of inflatable tubes with the membrane.
    These days, the inflatable structures are next-generation’s space structure’s research field. For example, they can be used as antenna (use for radar, the space communication, and so on), large solar panel (use for electric power generation), and much more. Also, the material production technology is advanced, so hurdles for practical use of it is lower. It is possible to realize the beam structure as well as extension boom that is used in a number of the satellite to date, but the inflatable tube can also realize complicated beam structures because of freedom to tube shape. It is different point between the inflatable tube and the extension boom.
    And furthermore, because the nano-satellite has strict space and weight’s rule, so, we think that inflatable structure can be able to make the most of its characteristics by the attribute, such as lightweight, high storability, and so on. But the inflatable structures using in the space still has few results and storage, and deployment is also still in research phase. In proceeding research, the nano-satellite has two merits. One is that nano-satellite can be quickly development from a concept to development and execution. Second is that we can launch it low cost by using piggyback.
    Therefore, we make the satellite, the SPROUT, the harbinger of the basic technological demonstration about the inflatable tube at the nano-satellite.