Astronomy and Space Science Summer Institutes for Elementary and Middle School Teachers is a twenty-four month program which will introduce fifty elementary and fifty middle school teachers whose school districts already own planetariums to experiences and resources for teaching astronomy and space science through classroom activities. Lawrence Hall of Science, in conjunction with New York Hall of Science, will conduct two three-week summer institutes and develop a series of Guides to the Active Planetarium to support teacher's efforts in conducting inservice workshops and fully utilizing planetariums to supplement classroom instruction. During the two year period following the NSF funding cycle, participants will have follow-up meetings at major science teacher conferences with funds provided by Learning Technologies, makers of portable planetariums.