Development and operations of nano-satellite FITSAT-1 (NIWAKA) Takushi Tanaka a,n , Yoshiyuki Kawamura b , Takakazu Tanaka c a Department of Computer Science and Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi-ku, Fukuoka 811-0295, Japan b Department of Intelligent Mechanical Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi-ku, Fukuoka 811-0295, Japan c Logical Product Corp., 2-25-5 Nakahara-bldg., Matoba, Minami-ku, Fukuoka 811-1314, Japan article info Article history: Received 13 April 2014 Received in revised form 10 October 2014 Accepted 17 October 2014 Available online 12 November 2014 Keywords: CubeSat High speed transmission Flashing LEDs FITSAT NIWAKA Optical communication abstract FITSAT-1 (NIWAKA) is a 10 cm 3 satellite that was deployed from the International Space Station (ISS) on October 5, 2012. It continued to operate until its orbit decayed on July 4, 2013. The main FITSAT-1 mission was to demonstrate a high speed transmitter module developed by our group (115.2 kbps, 5.84 GHz, FSK, 2 W RF output). Each of the JPEG VGA image (640 Â 480 pixels) taken at the time of deployment was received in 2–6 s. The second mission was to make the satellite twinkle as an “artificial star” using high-output LEDs and investigate the possibility of visible light communication between the satellite and the ground. This light from the satellite was photographed in many places. Our FITSAT team succeeded in acquiring the light signal using a photomultiplier attached to a telescope. Moreover, we discovered that the FITSAT-1 rotation speed gradually increased. & 2014 IAA. Published by Elsevier Ltd. All rights reserved. 1. Introduction [1,2] FITSAT-1 (NIWAKA) is a 10 cm 3 satellite that was deployed from International Space Station (ISS) on October 5, 2012. It continued to operate until its orbit decayed on July 4, 2013. The main FITSAT-1 mission was to demon- strate a high speed transmitter module developed by our group (115.2 kbps, 5.84 GHz, FSK, 2 W RF output). Each JPEG VGA image (640 Â 480 pixels) taken at the time of deployment was received in 2–6 s. The 5.84 GHz signal was received not only by our ground station, but also at Niigata, Japan, Ageo, Japan, Vermont, USA, and Bochum, Germany. The AMSAT-DL team succeeded in decoding 14 of the 20 images transmitted with the 5.84 GHz signal using a 20 m parabolic antenna at Bochum Observatory. The second mission was to make the satellite twinkle as an “artificial star” using high-output LEDs. These experiments were controlled by remote commands from the ground station using the 437 MHz and 1.26 GHz ham radio bands. The light from the satellite was pictured in Kurashiki Japan, Seoul Korea, Ebina Japan, Toyama Japan (movie), Kimizu Japan, Ehime Japan, and Kumamoto Japan. Our FITSAT-team succeeded in extraction of the light signal using a photo-multiplier attached to a telescope. More- over, we discovered that FITSAT-1 is increasing its rotation speed from stored data in the satellite. 2. Structure 2.1. Overview The top of FITSAT-1 has a 5.84 GHz patch antenna, 50 green LEDs, and a hole for the front camera lens (Fig. 1). Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/actaastro Acta Astronautica http://dx.doi.org/10.1016/j.actaastro.2014.10.023 0094-5765/& 2014 IAA. Published by Elsevier Ltd. All rights reserved. n Corresponding author. Acta Astronautica 107 (2015) 112–129