Cute-1.7 + APD II - Overview -

Top Overview

Overview

"Cute-1.7 + APD II" is a follow-on satellite to the "Cute-1.7 + APD," and much improvements will be conducted in many components of "Cute-1.7 + APD II", in particular, for amateur communications system, camera system, APD sensor and so on, based on the experiences acquired in the development and operation of "Cute-1.7 + APD." The followings are to be improved.

Design with radiation tolerance. Each microcomputer which has possibility of SEL related trouble is installed with a current limitation circuit.
Structural design that can decrease time required to assemble in order to achieve a lot of integration tests. The equipment arrangement to be able to facilitate the assembly is achieved.
The power generation of the solar cell is improved. The operations had been delayed because of the electric power shortage. To improve this, the size of the satellite is to be 20cm*15cm*10cm for the power generation of solar cells to be increased.

The launch of "Cute-1.7 + APD II" is planned to summer in 2007.

About Cute-1.7 + APD

Cute-1.7 + APD project is a satellite development project mainly by students at Laboratory for Space Systems, Tokyo Institute of Technology. The Avalanche Photo Diode sensor module, or APD, embarked on this nano-satellite was also developped by the Tokyo Institute of Technology Kawaii Laboratory.
To launch our satellite in 2006, the project has started in January, 2004. Our satellite, named Cute-1.7 + APD, is 200mm x 100mm x 100mm in size. It became the second satellite made in Tokyo Institute of Technology after the first one, CUTE-I, which was launched in June, 2003.
This project is based on the international CubeSat project.

"Cute-1.7+APD"-#1 was launched into orbit as a subpayload of the JAXA M-V-#8 Rocket in february 2006. The separation mechanism for release in orbit was also developped at the Tokyo Institute of Technology Matunaga Laboratory for Space System. It is based on the TSD(Tokyo-Tech Separation System Demonstration) experiment regarding CUTE-I.
The orbit of "Cute-1.7 + APD " is 250-280km in perigee height and 750km in apogee height, so lifetime of "Cute-1.7 + APD " is estimated much less than two year for the shortest due to atmospheric reentry. The exact lifetime is dependent on the actual rocket flight condition and atmospheric density.

The web site will be updated as progress is made on the development of this project.

The Goals of This Project

To facilitate future microsatellite development by demonstrating a new design methodology.

PDA and its peripheral devices, which are small and have various functionality, must facilitate microsatellite development. Of course, sufficient preparation is essential to use in space, where radiation effects are primary concern for electronics. We will propose and demonstrate a new method to protect complicated devices like PDAs from radiation effects with those devices treated as blackbox. We want to make it so good that future projects adopt it.
SatelliteCore concept is proposed to realize quick access to space via pico-satellite. A satellite is devided into two parts; one is a cube comprised of bus components, called SatelliteCore, the other a volume containing mission components, called Container. SatelliteCore and Container are able to be separated physically, and then a Container can be replaced with another one with different mission system. In fact, SatelliteCore concept has been applied to develop a APD (avalanche photodiode) charged-particle-detector demonstration satellite, which is a derivative of Cute-1.7 + APD.

To share experiment opportunities using real satellite with space engineering enthusiasts.

Advantages of microsatellites include low cost and short term development. Also microsatellite development in universities is a great opportunity to get real experience in space engineering education. It is not realistic, however, that every university or laboratory run a microsatellite development project. Some are interested in control method rather than fabricating a microsatellite. With these facts in mind, Cute-1.7 + APD is planned to have magnetic torquers in order to provide experiment opportunity of attitude control. Magnetic torquers are considered as suitable to microsatellite because of its simplicity. And new control algorithms are propsed to allow microsatellites to have advanced attitude control, such as three axis stabilization.
In addition, Cute-1.7 + APD will have a digipeater open to public and will be equipped with functionality to evaluate several types of radio communication protocols. Since we have developed a new protocol, Simple Radio Link Layer, to demonstrate on the previous satellite, CUTE-I, its characteristics will further be examined.

Project Overview PowerPoint(Created at 2004-01-25, subject to change)
Mission Scenario PowerPoint(in Japanese)
Details of Simple Radio Link Layer

Amateur radio satellite

Amateur Frequency Use

Cute-1.7 + APD project team proposes using an amateur radio frequency for communication between the satellite and its ground station. We will operate our satellite, recognizing that radio-frequency spectrum is a precious finite resource and that an amateur satellite should be operated for the purposes stated in IARU's guidlines, that is

To provide communication resources for the general amateur radio community and/or
To conduct technical investigations in all respects consistent with the Radio Regulations.

About Cute-1.7 + APD's digipeater with store-and-forward functionality.

Frequency coordination for Cute-1.7 + APD project was completed by IARU at December 5, 2004. Cute-1.7 + APD will use:

437.385MHz, CW Beacon
437.505MHz, GMSK or FM/AFSK AX25 Downlink
1268.500MHz, GMSK AX25 Uplink

Papers and Presentations

Katsutoshi Imai, Naoki Miyashita, Masafumi Iai, Kuniyuki Omagari, Masashi Asami, Wataru Miyazawa, Hideyuki Yabe, Kei Miyamoto, Takeshi Usuda, Ken Fujiwara, Shinji Masumoto, and Saburo Matunaga, Tokyo tech small satellite development projects -"Cute 1.7" and "TSUBAME," Workshop for Space, Aeronautical and Navigational Electronics, Daejeon, Korea, March 4, 2005. Conference Homepage Paper Presentation
Masafumi Iai, Shinji Masumoto, Saburo Matunaga, "Electrodynamic Tether System of Pico-Satellites for Orbital Debris Mitigation," JSME 13th Space Engineering Conference, Tokyo, January 21, 2005. Conference Homepage
Masafumi Iai, Kazuya Konoue, Koji Nakaya, Kyoichi Ui, Naoki Miyashita, Masashi Asami, Wataru Miyazawa, Kuniyuki Omagari, Yusuke Funaki, Katsutoshi Imai, Kei Miyamoto, Hideyuki Yabe, Ken Fujiwara, Shinji Masumoto, Takeshi Usuda, "Tokyo Tech's second microsatellite, Cute-1.7," Mechanical Engineering Congress 2004 International Symposium, September 6, 2004. Conference Homepage
Masafumi Iai, Yusuke Funaki, Hideyuki Yabe, Ken Fujiwara, Shinji Masumoto, Takeshi Usuda, Saburo Matunaga, Jun Kataoka, Tatsushi Shima, "A PDA-Controlled Pico-Satellite, Cute-1.7, and its Radiation Protection," 18th AIAA/USU Conference on Small Satellites, SSC04-IX-8, Logan, USA, August 12, 2004. Paper, Presentation, Conference Homepage, Pictures.

Public Relations

Japan International Aerospace Exhibition 2004 held at Pacifico Yokohama. Poster1, Poster2, Exhibition Homepace.
Space Development Forum 2004 held at National Museum of Emerging Science and Innovation. Poster, Forumm Homepage.
Ham Fiar 2004 held at Tokyo Big Site. Ham Fair Homepage.

Why 1.7?

The name of this project is Cute-1.7 + APD Project. You might think 'CUTE-II' seems suitable for the name of the second project after CUTE-I project. But when a new idea of this project came up, there already existed CUTE-II project in progress, where a satellite will be larger and its launch date will be later. Because this project expected earlier launch date than CUTE-II, a number greater than one and less than two was needed. It was finally named as Cute-1.7 + APD, one with a lucky number seven.

Cute-1.7 + APD II Project - Overview -

Small Satellite Program (SSP)

Laboratory for Space Systems (LSS), Tokyo Institute of Technology