Laser-based Ground-to-Satellite optical communications have been already researched by NICT or JAXA, but the technologies have not become widespread in laser-based Ground-to-Satellite optical communications. We are planning to mount laser-based optical communication systems on our microsatellite at work now. The purpose of this study is to develop the package of optical transmit-receive system on the ground and the small optical transmit-receive module on the microsatellite. We conducted basic Laser link experiments at close range, and got success in the establishment of the link. This paper reviews the mathematic model of laser-based Ground-to-Satellite optical communications and provides the results and discussions of the experiments. On the next stage, we will conduct further experiments at long range, 10 or 20 km. As a supplement, please accept the discordance between the title of this paper and the contents.
In those days, the development and use of nano-satellite are becoming popular globally, and to increase communication capacity is required. As a solution of this problem, there is free space optical (FSO) communication technology. This technology is researched and developed by ESA, DLR, JAXA, NICT, NASA and so on. NICT developed Small Optical TrAnsponder (SOTA), made experiments of micro-satellite-ground laser communication. We are developing a nano-satellite for hyperspectral remote-sensing, and planning to downlink the image data by optical communication. The purpose of this study is to develop the useful package of optical transmit-receive system on the ground and to develop the space use transmit-receive module. We have been developing proto-type communication module and making experiments at the range of 170m, 1km. This paper shows the evaluation about the range feasible for communication of our proto-type module. On the next stage, we will conduct further experiments at long range, 10 or 20 km.
Hokkaido Satellite Project was started since 2003 for the purpose of creating an agricultural remote sensing business. The agricultural remote sensing is one of strong tools for precision farming. For industrialization of space technologies the space utilization becomes very important with respect to management. We have constructed the business model of agricultural remote sensing. A hyper-spectral sensor was selected for space agricultural business because of the narrow spectral band signal detection capability, that is, the narrow band spectrums can predict the growth of crops precisely in comparison with that by conventional multi-spectral sensors. We have developed the hyperspectral camera step by step since then. We have developed the proto-model (PM) space-borne hype-spectral camera “HSC” in 2011. The HSC has the spectral band range from 450 to 900 nm, the spectral width of 8 nm (average), 46 bands, and GSD of 15m. A laser communication unit for satellites and the laser tracking module are investigated for the purpose of the downlink of spectral data sets.
Non-destructive damage evaluation of rocket engine combustion chamber was investigated by using replica method through rapid setting silicon rubber molding agent. Scratch marks, grinding marks and an oxide film on the combustion side surface of the repeated burning test were successfully transferred to this replica sheet without complicated surface treatment. Observation results of the sampled replica showed the traces of the oxide film formation, disappearance of the grinding marks and crack formations on the oxide films due to redox reaction during repeated uses. The surface roughness of light and dark lines parallel to the cooling grooves with cracked oxide film was evaluated by laser scanning microscope. The surface roughness parameter could be useful to evaluate the damage of the reusable sounding rocket engine.