First Microgravity Science Laboratory

Outline of First Microgravity Science Laboratory

The Microgravity Science Laboratory (MSL) program is a series of microgravity experiments using Space Shuttle/Spacelab proposed by the U.S. National Aeronautics and Space Administration(NASA). Five space agencies worldwide,which is NASA,National Space Development Agency of Japan(NASDA),European Space Agency(ESA),German Aerospace Center(DLR) participated in MSL-1 launched by STS-94 in July 1997 in order to conduct material experiments under microgravity. NASDA conducted material experiments with Large Isothermal Furnace(LIF).NASDA developed necessary technologies for the Space Station experiments by participating in this program.

Originally MSL-1 was launched as STS-83 in April 1997, however due to the malfunction of the fuel cell of the Shuttle its mission duration was shortened and as an re-flight of this mission STS-94 was planned.

STS-94 Mission Overview

Mission Overview Flight No. STS�|94 Launch date July 1 2:02 p.m.1997 (EDT) Launch Site Kennedy Space Center NASA U.S.A Orbiter Columbia Landing Date July 17 6:47a.m.1997(EDT) Landing Site Kennedy Space Center NASA U.S.A Orbital Altitude 270km Orbital Inclination 28.45 degrees Orbiter Attitude Shuttle cargo bay to the earth, Main engines to the flight direction. Duration 15 days,16 hours,46 minutes Crew 7 Number of Equipment 12 NASA=8, NASDA=1, ESA=1, DLR=2 Experiments 28

Features of Large Isothermal Furnace (LIF) :

The Large Isothermal Furnace used in the MSL-1 is a material science facility.It can heat up a sample homogeneously to high temperature. A variety of experiments such as solidification, sintering,etc. can be conducted�D

Experiment Themes and Principal Investigators (PIs) Using LIF

1. Diffusion of Liquid Metals and Alloys
   (Dr.Toshio Itami, Hokkaido University)
2. Diffusion of Liquid Lead-Tin-Telluride
   (Ms.Misako Uchida,Ishikawajima Heavy Industry Co.Ltd.)
3. High Accuracy Measurements of Impurity Diffusion Coefficients in Ionic Melts in Microgravity
   (Dr.Tsutomu Yamamura,Tohoku University)
4. Measurements of Diffusion Coefficients by Shear Cell Method
   (Dr.Shinichi Yoda, National Space Development Agency of Japan)
5. Liquid Phase Sintering
   (Dr.Randall German,Pennsylvania State University)
6. Diffusion Processing in Molten Semiconductors
   (Dr.David N.Mattiesen,Case Western Reserve University)

Diffusion, the Key word of MSL-1

Diffusion Coefficients measurement is the common experiment theme of all of the four MSL-1 experiments of Japan.

1. Why Diffusion Coefficients?
   In practical manner Diffusion Coefficient is used to determine the crystal growing best condition in order to produce high quality crystal with less defects. From academic point of view accurate Diffusion Coefficients are expected to be measured due to the fact that material diffusion mechanism hasn't been clarified as yet.
2. Why Diffusion Coefficients need to be measured in microgravity environment?
   It is well known that measuring accurate Diffusion Coefficients on the ground is very difficult. On the ground material movement is affected not only by diffusion alone but also by convection. Accurate Diffusion Coefficients measurement demands us to utilize microgravity environment so that material movement can be performed only by diffusion without the effects of convection caused by the gravity of the earth.

Last Updated : March 18, 1998