PURPOSE: To improve the construction workability of a cosmos structure article.

CONSTITUTION: An outer shell 2 is fabricated in the cosmos space. The inside of the outer shell 2 is filled with a liquid phase, and the water (liquid phase) inside the outer shell 2 is frozen (transformation) by the outside air temperature, and ice (solid phase) is generated inside the outer shell 2. Accordingly, the liquid phase inside the outer shell is transformed to a solid phase, and the rigidity of the outer shell is strengthened, and a truss structure is constructed, and the work carried out in the cosmos space can be reduced, and the rigidity of the outer shell is increased by ice, and a giant truss structure can be constructed, and the cost for the construction work for a cosmos structure article 1 can be reduced.