Simulation model for the closed plant experiment facility of CEEF.

The Closed Ecology Experiment Facilities (CEEF) is a testbed for Controlled Ecological Life Support Systems (CELSS) investigations. CEEF including the physico-chemical material regenerative system has been constructed for the experiments of material circulation among plants, breeding animals and crew of CEEF. Because CEEF is a complex system, an appropriate schedule for the operation must be prepared in advance. The CEEF behavioral Prediction System, CPS, that will help to confirm the operation schedule, is under development. CPS will simulate CEEFs behavior with data (conditions of equipments, quantity of materials in tanks, etc.) of CEEF and an operation schedule that will be made by the operation team everyday, before the schedule will be carried out. The result of the simulation will show whether the operation schedule is appropriate or not. In order to realize CPS, models of the simulation program that is installed in CPS must mirror the real facilities of CEEF. For the first step of development, a flexible algorithm of the simulation program was investigated. The next step was development of a replicate simulation model of the material circulation system for the Closed Plant Experiment Facility (CPEF) that is a part of CEEF. All the parts of a real material circulation system for CPEF are connected together and work as a complex mechanism. In the simulation model, the system was separated into 38 units according to its operational segmentation. In order to develop each model for its corresponding unit, specifications for the model were fixed based on the specifications of the real part. These models were put into a simulation model for the system.     

A space station experiment on large antenna assembly and measurement

The large assembly antenna in space can meet future requirements of both high frequency and large aperture. This paper proposes an experiment on assembling a large antenna at the Space Station, and discusses a realizable procedure of the experiment. The objective of this experiment is that a large antenna of a 10-m diameter is assembled in space and at the same time problems occurring in the assembling process are clarified by conducting the following experiments: assembly of test articles by manipulators, measurement of both mechanical and electrical performance of the assembled antenna, test of the pointing control system, and operational test. In the operational test, the weather radar development test and the large aperture microwave radiometer development test are conducted. Furthermore, the problem areas and items of further study are discussed in this paper.     

Numerical and experimental study on the shaped charge for space debris assessment

This paper proposes a numerical analysis method to simulate jet formation and penetration process by the ‘low-velocity’ (67 km/sec-class) inhibited shaped charge launcher, in order to assess the protection capability of the bumper structure against orbital space debris impacts on the spacecraft. The present simulations by a two-dimensional hydrocode (AUTODYN-2D), which was performed by an improved method on the basis of our former works, were compared with the test results based upon the experimental method that we had proposed in our another work. The both results were in fairly good agreement, and the feasibility was ascertained of the calibration between the inhibited CSC jet and solid spherical projectile by the numerical method. Consequently, the accuracy of the ballistic limit curve at 1015 km/sec is expected to be enhanced by making use of the present method hereafter.     

EVA-related activities in Japan

Recognizing the importance and fertility of the extra vehicular activity technologies in future space development and utilization, some related research activities have been conducted in Japan, though it has not committed itself to developing its own manned space flight capability. The purpose of this paper is to introduce and evaluate these EVA-related activities and to indicate the next step for Japan to get into the era of manned space activities including EVA in reality.