50kg micro-satellite achieves 348Mb/s download speed
Recently, 50kg-class micro satellites have been able to observe the Earth’s surface with high resolution, enabling the detection of ground-level objects with a size of several metres. These small satellites, however, cannot currently send large quantities of image data to the ground station, due to power and mass constraints.
Professor Hirobumi Saito, of the Institute of Space and Astronautical Sciences (ISAS), JAXA and the Graduate School of Engineering, Department of Electrical Engineering and Information Systems, University of Tokyo, alongside a research group, has developed technologies that enable the use of high speed on-board transmitters that consume less power and the associated ground-based technologies for reception of the transmitted data.
Together with the group of Professor Shinichi Nakasuka, Graduate School of Engineering, UoT, they developed the flight model of the X-band high speed transmitter for the small satellite Hodoyoshi-4. In December 2014, the 3.8m antenna station at ISAS received data at 348Mb/s with 16 QAM and successfully demodulated/decoded the data without error. This communication speed is roughly half that of Daichi 2, a Japanese earth observation satellite with a mass of two tons, and as of February 2015 is the world’s fastest as a 50kg class micro satellite.
As a result of this research, indicates that the data transmission capabilities of small satellites is approaching that of large satellites. The remaining issues are the improvement of optical and radar sensor capabilities compatible to micro satellites.