The players travel the Sol-System (between Earth, Luna, Venus and Mars) and try to accquire Property Cards with allow them to build space stations, rockets, landing crafts or atom reactors. The players have to pay a fee, if they land on a space that belongs to another player, even more it that player has already build something on this space or if the player has several properties on this planet. The last payer who has any money left or the player who has the most money after an agreed upon playing time, wins the game.