US-12620693-B2 - Stereostructure spacecraft

US12620693B2US 12620693 B2US12620693 B2US 12620693B2US-12620693-B2

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.

Inventors

Yosuke TANABE
Tsukasa FUNANE
Koichi Watanabe
Hisatoshi KIMURA
Makoto Ito

Assignees

HITACHI, LTD.

Dates

Publication Date: 20260505
Application Date: 20240304
Priority Date: 20230628

Claims (8)

1 . A stereostructure spacecraft comprising: multiple deployable beam members; multiple tension members; and a spacecraft for storing the deployable beam members and the tension members, wherein the stereostructure spacecraft is formed by deploying the deployable beam members and the tension members around the spacecraft, wherein 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, wherein the tension members support two end portions of two adjacent deployable beam members with tension, and wherein the respective end portions of the deployable beam members are simultaneously supported by three or more of the tension members.
2 . The stereostructure spacecraft according to claim 1 , wherein the rotational symmetry axes are three orthogonal axes orthogonal to one another, wherein the deployable beam members include first deployable beam member and second deployable beam member, and wherein the first deployable beam member and the second deployable beam member are arranged equidistantly in positive-negative direction of the rotational symmetry axes, the rotational symmetry axes being formed to have an origin that is a substantial center of the spacecraft.
3 . The stereostructure spacecraft according to claim 1 , wherein the rotational symmetry axes are three orthogonal axes orthogonal to one another, wherein the deployable beam members include first deployable beam member and second deployable beam member, and wherein the first deployable beam member and the second deployable beam member are arranged equidistantly in positive-negative direction to have each longitudinal direction orthogonal to the rotational symmetry axes, the rotational symmetry axes being formed to have an origin that is a substantial center of the spacecraft.
4 . The stereostructure spacecraft according to claim 1 , further comprising: a thin film included in a plane, the plane being formed by three or more of the tension members connecting the respective end portions of the deployable beam members, wherein the deployable beam members, the tension members, and the thin film include one or more antenna structures for radiating or receiving electromagnetic waves.
5 . The stereostructure spacecraft according to claim 4 , wherein the spacecraft receives and analyzes electromagnetic waves including rotation information by receiving the electromagnetic waves with rotating along the multiple rotational symmetry axes, and the spacecraft identifies characteristics of the electromagnetic waves and positions of sources of the electromagnetic waves.
6 . The stereostructure spacecraft according to claim 5 , wherein the spacecraft downlinks an analysis result to a ground station, and the ground station examines an analysis pattern change according to an orbit condition of the spacecraft and the rotation information.
7 . The stereostructure spacecraft according to claim 1 , further comprising: a thin film included in a plane, the plane being formed by three or more of the tension members connecting the respective end portions of the deployable beam members, wherein the deployable beam members, the tension members, and the thin film include a photon-energy receiver for receiving photons.
8 . The stereostructure spacecraft according to claim 1 , further comprising: a thin film included in a plane, the plane being formed by three or more of the tension members connecting the respective end portions of the deployable beam members, wherein the deployable beam members, the tension members, and the thin film include a photon-energy reflector for reflecting photons.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority from Japanese Patent Application JP 2023-105999 filed on Jun. 28, 2023, the content of which is hereby incorporated by reference into this application. BACKGROUND OF THE INVENTION The present invention relates to a stereostructure spacecraft. An electromagnetic wave radiated by accelerated motions of electrons is absorbed and scattered by various atoms in the propagation process, and newly induces emission of electromagnetic waves. Electromagnetic waves include various kinds of information about not only electronic anthropogenic activities on earth or in outer space but also substances of celestial bodies such as fixed stars, planets, and nebulas as well as actions and formation processes of those substances. Observation of the electromagnetic wave, and analysis of a radiation source and a propagation process of the electromagnetic wave may be of significant help to understand the anthropogenic activities and global environment, and clarify the celestial activities and the celestial formation processes. Recently, in the case of the visible light and the electromagnetic wave with a nearby wavelength of the visible light, the progress of constellation in the low orbit earth observation satellites has made high frequency/resolution observation data available. In order to grasp the state of the radiation source and the propagation path in the distance, or those which cannot be grasped by the visible light, the artificial satellite mounted with an antenna has been used for observing electromagnetic waves (hereinafter referred to as radio waves) with wavelength longer than that of infrared. When executing a radio wave observation in outer space, it is necessary to identify radio radiation sources in various directions at various distances at a high resolution so that necessary information is only analyzed. Development of technologies for enlarging aperture of the space antenna has been in progress on a world scale to attain high resolution by making the aperture area of the antenna deployable in outer space sufficiently large relative to the wavelength. As the technology for enlarging the aperture of the space antenna, application of the thin film deployment structure is advantageous to attain the space antenna which reduces the space transportation cost by making the payload compact and light in weight, and ensures high form accuracy. Document JP 2008-236500 discloses the spacecraft mounted with an antenna. The patent literature aims at provision of the deployable antenna reflector for the spacecraft, which is deployable with high reliability. The deployable antenna includes a metal mesh which constitutes a radio wave reflection surface of the antenna, a network cable constituted by a shape-retaining cable for retaining the shape of the metal mesh, a back cable, and a tie cable which connects the shape-retaining cable and the back cable, multiple deployment masts which are constituted by multiple deployment ribs and deployment hinges for deploying the deployment ribs, and deploy the metal mesh and the network cable from the folded state for holding the metal mesh and the network cable after the deployment, and a tendon cable for connection between the deployment masts. The deployment rib and the network cable are disposed separately while being disconnected from each other, and deployed independently upon deployment of the deployment mast. Document JP 2008-236500 discloses provision of the deployable antenna reflector for the spacecraft, which is deployable with high reliability. The disclosed deployable antenna, however, still needs to be improved for forming the space antenna with large aperture to ensure both lightness and the form accuracy of the thin film surface. In order to form the large aperture antenna with high form accuracy through extension of the cantilevered deployment rib from the spacecraft, the cross-sectional area of the deployment rib has to be increased for enhancing bending rigidity of the deployment rib. This may result in weight increase. In order to improve the omnidirectional space antenna having directivity in all directions, the planar antenna is formed by extending the cantilevered deployment rib from the spacecraft in the planar direction. The resultant structure exhibits high directivity in the direction vertical to the plane, but fails to realize the omnidirectional antenna having directivity in all directions. Accordingly, the radio wave radiation sources existing omnidirectionally in all directions cannot be identified at high resolution. SUMMARY OF THE INVENTION It is an object of the present invention to provide a stereostructure spacecraft which allows formation of an omnidirectional space antenna that ensures lightness and the form accuracy of the thin film surface, observes incoming radio waves from the omnidirection, and identifies the radio wave sources existing at various distances in various