A simpler, one-player version of Starship Catan can be played online after registration (which is free) on Playcatan. In this version, the game lasts for 18 turns. Like the two-player version, the player starts with 25 Astro, but unlike it, the player only starts with one booster and no cannons. At the beginning of the first turn, a booster or cannon is chosen, for free. Before the second turn and every three turns after that (fifth, eighth, etc.), a booster or cannon may be bought for three Astro, or a command or logistics module for one Astro. Before the first, second, and seventeenth turns, the modules may not be chosen. The modules cannot be upgraded to level II. If a fourth booster or cannon is bought, two of them become level II boosters/cannons and the third disappears; it is impossible to buy more than five of either.