The space development is our big dream. One of this is foray into deep space. And so we must have too large amount of power because missions in space is highly-developed and protracted, and in addition, devices are complicated and big with the space development. Nuclear power generation is good choice to these problems since it has such good points as big electric-generating capacity in the proximity of scale and weight of the facility. There our laboratory has researched about a nuclear spaceship. Especially this paper deals with living space in a nuclear spaceship. For example space has big difference in temperature and nuclear reactor releases radiation. The crew is needed to protect from such danger. First we did reproductive experiment of big difference in temperature in space as a basic experiment of heat insulation and researched the possibility of insulation by insulating material of urethane foam. Next we tried a design of shielding system by using a calculation code.