With the recent touchdown of the Mars rover, Curiosity, the beginning of the school year would be a great time to ignite your students’ curiosity about space exploration.  On the Follow Your Curiosity site, NASA has provided 5 lesson plans with student and teacher guides for grades 6-8.  I think that you could modify them for a bit lower or higher grades on either end, though.  The site includes video clips and many hands-on activities, including a simulation activity of a Mars rover and the creation of a 3-D Mars community.  Visit Follow Your Curiosity for a great selection of Rover Resources!