Active Experiments in Space Plasmas Proceedings of the D4.1 Symposium of Cospar Scientific Commission D, Held During the 30th Cospar Scientific Assembly, Hamburg, Germany, 11-21 July, 1994 - Advances in Space Research S.

The papers presented in this volume are derived from five sessions on Active Experiments in Space. The topics covered include ion and electron beams, ionospheric modification, spacecraft interactions, chemical releases, and plasma waves and other topics. Auroras and plasma emissions were reported from electron beam injection experiments on the EXCEDE III rocket and APEX satellite respectively. The important parameters affecting the charging of spacecraft during the operation of electron guns is now much better understood. A new mission called AMPAS (Active Magnetospheric Particle Acceleration Satellite) utilising dual-payload tethered satellites and both up and downward directed electron beams was proposed to study the magnetosphere.;Recent results and associated theories from the Sura, Arecibo and Tromso ionospheric heating facilities were presented. Results of E-region heating. VLF noise generation and VLF-ducts being affected by HF heating, and long period Doppler oscillations from the F-region were intriguing. Much progress has been made in coming to a fuller understanding of the many detailed features of stimulated electromagnetic emissions (SEE) produced by a powerful HF wave.;The effects of neutral gases on spacecraft charging was examined in a series of rocket flights. These studies as well as others investigating high voltage charged spacecraft are leading to a much improved understanding of interactions between spacecraft and the plasma environment.;Many results, both ground-based and from spacecraft, were presented from the Combined Release and Radiation Effects Satellite (CRRES) chemical release experiments. Electromagnetic wave emissions, ionospheric wave-like disturbances and aerosol clouds from the release were studied.