The crystal growth observation system (COS) is a payload for the third Japanese TR-IA sounding rocket launched on September 17, 1993. Equipment with the color Schlieren optical system was developed for in situ observation of freely growing dendrites of succinonitrile from the tip of a capillary tube. Provisions for precisely temperature control of the experimental cell and a Hi-8 8 mm VTR with higher spatial resolution were the two technical issues. They functioned well under microgravity conditions.
Combustion synthesis technology can be advantageously applied to high-temperature experiments under microgravity environments(MOE) not only as a direct synthesizing method for high-temperature materials but also as a super-heating chemical oven, because it is possible to get high temperatures more rapidly compared to conventional electric furnaces. In the present work, the combustion synthesis of ZrO2-A}zO3-Fe and TiB2-Al-B composite systems have been carried out using a TR-IA sounding rocket which provides about 10- 4 g0 for six minutes. As the former result, more uniform distribution and finer particles of ZrO2 could be attained under MOE, which would be caused from no disturbance in mass migration. As the latter, the composite layered particles composed of TiB2 and Al-B system synthesized under MOE were more uniform compared to those obtained on earth, which would result in the formation of denser cermet-like products.
We carried out a space experiment to investigate the interaction between EHD and Marangoni convections occurring under microgravity, using a TR-IA-3 rocket launched by the National Space Development Agency of Japan (NASDA). EHD convection was induced by impressing an electric field in a liquid column and the flow was reduced or enhanced depending on the direction of both the temperature gradient and the electric field.
We also carried out theoretical and numerical analyses. EHD equations were introduced and solved by the finite difference method . The numerical calculation agreed with the experimental result.
Ternary chalcogenide Si-As-Te amorphous semiconductors have been fabricated under a microgravity environment in the Spacelab J. The objective of the flight experiment was to fabricate homogeneous multi-component amorphous semiconductors in the microgravity en vironment in space, and to make a series of comparative characterizations of the amorphous structures as well as their electronic properties for materials prepared in space and under terrestrial gravity environment. In this paper, firstly the reasons for selecting this material system for FMPT (First Material Processing Test) experiment are explained, and discussed in association with essential advantages of Six(As2Te3) 1- x system in basic physics research and technological applications. Secondly, some details of the FMPT experimental procedure including a comprehensive description of tested materials are described. Finally, preliminary results on the electrical and optical properties as a new type of synthetic semiconductor are presented and discussed with a particular emphasis on the difference from terrestrial materials.
Bubbles in melt should be removed from the interface in the solidification under microgravity. Marangoni effect is one of the possible candidate to move bubbles under microgravity environment. The migration of bubble under temperature gradient is studied under the microgravity given by the drop shaft. Bubbles have moved from cooler region to warmer one, but the velocity of bubble given by experiment is slower than that predicted by Young et al. The reason why the velocity is slower than the expected one is also studied .
The Space Flyer Unit (SFU) is a multipurpose reusable free flyer for microgravity experiments, and is scheduled to be launched by the H- II No.3 rocket in February 1995 and retrieved by a Space Shuttle after mission completion.
The Institute for Unmanned Space Experiment Free Flyer (USEF) has been developing three types of furnaces and promoting experiments of compound semiconductor crystal growth under microgravity. This paper presents summary of SFU program, each furnace performance, experiments of com- pound semiconductor crystal growth and mission operations.