SpaceX Discussion Thread in Science & Spaceflight Posted November 22 10 minutes ago, magnemoe said: Wonder if it would be practical? I imagine you would have an outer niobium skin then a gap before the steel tank. using pins to connect the skin to tanks. Think its more an question if it manages the heat. Its used on the cone of the falcon 9 vacuum engines but reentry is even more demanding. Now I thought spaceX has thought about it they use it in engines after all, don't think it would be heavier than the tiles as it would not be structural. And its so much simpler than the tiles. A niobium heat shield for Starship would be vastly heavier than the tiles. The tiles are extremely lightweight. Also, heat management would still be a problem. The limiting factor for Starship is the temperature on the back of the heat shield, where it radiates to the steel. Niobium radiates and conducts heat very well, which makes it great for radiatively-cooled engine nozzles in a vacuum but not so great for a thin heat shield attached to steel.