The Astral Express is a fictional train featured in the game Honkai: Star Rail. It serves as a mode of transportation for characters traveling across various worlds and dimensions. The train is equipped with advanced technology and is operated by a crew that includes notable characters like March 7th and Dan Heng. The journey on the Astral Express allows players to explore different locations, engage in battles, and uncover the game's storyline. The train symbolizes adventure and discovery, connecting players to the rich lore and diverse environments within the Honkai universe.