Due to a significant leap in the science and technology, the manned space exploration that has started with suborbital flights is now being expanded into the deep space. The space superpowers such as the U.S. and Russia have been making an effort to further develop the manned space technology. Among such technologies, the fire safety technology in microgravity has recolonized as one of the most critical factors that must be considered for the manned space mission design since the realistic fire broke out onboard the Mir station in 1997. In the present study, the flame characteristics such as flame ignition, shape, spread, and extinction that are critical to understand the fire behavior under microgravity conditions are described and discussed. The absence of buoyancy in microgravity dominates the mass transport driven by diffusiophoretic and thermophorectic fluxes (that are negligible in normal gravity) and influences the overall flame characteristics-flame ignition, shape, spread, and extinction. In addition, the cabin environments of the pressurized module (PM) including the oxygen concentration, ambient pressure, and ventilation flow(which are always coupled with microgravity condition during the ISS operation) are found to be the most important aspects in characterizing the fire behavior in microgravity.