Transformable spacecraft: Feasibility study and conceptual design

Yoshiki Sugawara, Toshihiro Chujo, Yuki Kubo, Yasutaka Sato, Masatsugu Otsuki, Ryota Ikeda, Kotaro Ikeda, Masahiro Fujita, Kenichiro Sawada, Kohji Tsumura, Shuji Matsuura, Takayuki Kotani, Ahmed Kiyoshi Sugihara, Ayako Torisaka, Osamu Mori, Shigeo Kawasaki, Junichiro Kawaguchi

Research output: Contribution to journalConference articlepeer-review

2 Citations (Scopus)


Transformable spacecraft under development is an innovative system that consists of several structural components, such as panels, connected together by internal force actuators. The spacecraft can change its structure drastically by driving installed actuators and achieve the following four features simultaneously. The first feature is "attitude change by internal force using non-holonomic characteristic of the system". It is possible to orient the spacecraft to an arbitrary direction by repeating the deployment of the panel in an appropriate order by the internal force actuator. The second feature is that "change of the structure enables the multiple functions by switching modes". Two telescopes will be installed for scientific missions utilizing the features of the transformable spacecraft and used to realize two different observation modes. One is a mode in which each telescope is oriented to different directions to perform wide-field observation (single telescope mode). The other is a mode in which two telescopes are pointed in the same direction. This mode enables the spacecraft to work as an interferometer (interferometer mode). The third feature is "orbit control and orbit keeping by controlling the solar radiation pressure on the spacecraft with the use of change of spacecraft structure". Since the spacecraft can change its structure by the internal force actuator, the orbit control and orbit keeping are achieved without fuel consumption. By utilizing this feature, the spacecraft will be injected into an artificial halo orbit around Sun-Earth Lagrangian point L2, and the technology demonstration of the transformable spacecraft and the observation mission will be performed in the orbit. The fourth feature is "passive cooling of observation equipment by use of panels as sunlight shield". In the observation mode, observation in the infrared region is performed and sufficient cooling is required. Appropriate arrangement of panels enables shielding of sunlight, and then the passive cooling of the observation equipment is realized. As a result, disturbance due to refrigerator is eliminated, which contributes to precise observation in addition to the contribution by non-holonomic attitude control without disturbance. This paper shows the analysis and experimental results for feasibility studies and conceptual designs of above four features. Furthermore, development status of the system and each subsystem to realize the spacecraft are introduced.

Original languageEnglish
JournalProceedings of the International Astronautical Congress, IAC
Publication statusPublished - 2020
Externally publishedYes
Event71st International Astronautical Congress, IAC 2020 - Virtual, Online
Duration: 2020 Oct 122020 Oct 14


  • Artificial HALO orbit
  • Non-holonomic turn
  • Passive cooling
  • Transformable

ASJC Scopus subject areas

  • Aerospace Engineering
  • Astronomy and Astrophysics
  • Space and Planetary Science


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