There is a new contest sponsored by NASA's Ames Research Center.
MORE info HERE
It is aimed at "6-12th graders (11-18 years old) from anywhere in the world. Individuals, small teams of two to six, and large teams of seven or more (often whole classrooms with teacher leadership) may enter. Grades 6-9 and 10-12 are judged separately, except for the grand prize. Students develop space settlement designs and related materials. These are sent to NASA Ames for judgement. Submissions must be received by March 31, 2004."
Good Luck!!!