This chapter reviews a series of microgravity experiments on the thermocapillary convection in a liquid bridge of high-Prandtl-number fluid (i.e., MEIS, Marangoni-UVP, and Dynamic Surf projects), which has been conducted in the Japanese Experiment Module—Kibo—onboard the International Space Station. The silicone oils with the Prandtl number of \(\textrm{Pr}=67\text {--}207\) were used as the test liquid, and the liquid bridge was formed between the disks with diameter of \(10\,{mm}\) to \(50\,{mm}\) . The driving force of convection was generated by imposing the temperature difference between these disks, and the resultant thermocapillary convection was observed with various measurement techniques. The first experiment started in 2008 and continued until 2020, during which period many findings and important experimental data were obtained. Starting with general information about the project, the experimental equipment, procedures, and typical results are introduced in this chapter. It contains the onset conditions of thermocapillary-convection instability for a variety of experimental conditions, the measurement results of velocity and temperature fields, the dynamic behavior of the liquid-bridge free surface, the transition process to the chaotic or turbulent states, and so on. In addition to the experimental results, the related numerical simulations and theoretical analyses are also introduced.