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World's fastest communication from 50kg-class satellite

Micro satellite Hodoyoshi-4 succeeds in down link communication of 348 Mbps


Graduate School of Engineering / Faculty of Engineering

© 2015 Hirobumi Saito

© 2015 Hirobumi Saito

Recently, 50kg-class micro satellites have been able to observe the Earth’s surface with high resolution, able to detect objects on the ground with a size of several meters. These small satellites, however, cannot send large quantities of image data the ground station due to power and mass constraints.

The research group of Professor Hirobumi Saito, Institute of Space and Astronautical Sciences (ISAS), JAXA and the University of Tokyo Graduate School of Engineering Department of Electrical Engineering and Information Systems, has developed novel 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 in the University of Tokyo Graduate School of Engineering, 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 348 Megabits per second (Mbps) with 16 quadrature amplitude modulation (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.

Press release


Tomoya Fukami, Hiromi Watanabe, Atsushi Tomiki, Takahide Mizuno, Hirobumi Saito, Naohiko Iwakiri, Takahiro Shinke, Kaname Kojima, Koichi Kawamoto, Osamu Shigeta, Hitoshi Nunomura, Yasuaki Kanda, "On-Orbit Demonstration of the X-band 348 Mbps Communication System for the Nano Satellite: Hodoyoshi-4", Space, Aeronautical and Navigational Electronics (SANE), IEICE Technical Report vol. 114, no. 448, SANE2014-132, pp. 25-30, Institute of Electronics, Information and Communication Engineers, Okinawa: 2015/02/19 (Japan time)
Article link (Publication)


Graduate School of Engineering

Department of Electrical Engineering and Information Systems (EEIS), Graduate School of Engineering

Hirobumi Saito Laboratory, Division of Space craft Engineering, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency

Japan Aerospace Exploration Agency

Institute of Space and Astronautical Science

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