In the spring of 1989 an extensive campaign will take place at the Arecibo Observatory in Puerto Rico. This study on the dynamics of the mesosphere and lower thermosphere will combine the largest collection of instruments ever assembled at one location to study this important region of the atmosphere. This award provides for the inclusion of a meteor radar and a low-light-level optical imager in this campaign in order to maximize the participation and obtainable science in this endeavor. The overall program will include the Arecibo incoherent scatter radar, coherent radars, meteor radars, optical imagers and spectroscopic, interferometric and photometric instruments distributed at a number of locations in Puerto Rico.