Abstract: A stereostructure spacecraft of the present invention comprises multiple deployable beam members, multiple tension members, and a spacecraft for storing the deployable beam members and the tension members. The stereostructure spacecraft is formed by deploying the deployable beam members and the tension members around the spacecraft. The deployable beam members stored in the spacecraft are deployed and arranged equidistantly in directions of multiple rotational symmetry axes, the rotational symmetry axes being rotational symmetry axes of a virtual polyhedron that is formed to have a substantial center of the spacecraft as an origin. The tension members support two end portions of two adjacent deployable beam members with tension. The respective end portions of the deployable beam members are simultaneously supported by three or more of the tension members.

Abstract: An artificial satellite system according to the present invention includes first and second artificial satellites. An antenna of the first satellite transmits a radio wave (transmission signal) to the second satellite. An antenna of the second satellite receives the transmission signal. A software defined radio of the second satellite generates a signal having the same frequency and phase as the transmission signal has. The antenna of the second satellite transmits a radio wave of a signal generated by the second satellite to the first satellite. The antenna of the first satellite receives the radio wave (reception signal) transmitted by the second satellite. A data processing device of the first satellite determines a relative distance between the first and second satellites by using the difference between a transmission time of the transmission signal and a reception time of the reception signal and the phase difference between the transmission and reception signals.

Abstract: The space structure control system includes: a space structure; an artificial satellite connected to the space structure; and a propulsion device installed on the artificial satellite and configured to control an orbit and an attitude of the artificial satellite, in which the space structure includes a film-like structure, a solar reflectance control device that controls a spatial pattern of a solar reflectance in a reflecting mirror provided in the film-like structure, and a shape retaining device that is connected to the film-like structure, the propulsion device rotates the film-like structure to generate a centrifugal force, the solar reflectance control device controls a solar reflectance in the reflecting mirror to control a solar radiation pressure to be applied to the reflecting mirror, a three-dimensional shape of the film-like structure is controlled based on the centrifugal force generated by the rotation of the film-like structure and the solar radiation pressure, and the shape of the film-like st

Abstract: An electric-power conversion device receives an electromagnetic wave transmitted from space and converts the electromagnetic wave into electric power. The electric-power conversion device includes: an electric-power conversion portion for receiving an electromagnetic wave transmitted from space and converting the electromagnetic wave into electric power; a propelling device or driving device for moving the electric-power conversion device; a positioning device for determining the position of the electric-power conversion device; a control device for controlling the propelling device or the driving device based on information about the position and the electric power received by the electric-power conversion portion; and an electric-power supply device for supplying the electric power received by the electric-power conversion portion to an electric system.