Combined Release and Radiation Effects Satellite (CRRES) dumps chemicals in space while a ground-based microwave antenna in Arecibo, Puerto Rico heats them to study and modify the ionosphere. The Arecibo heater was later destroyed by a hurricane then rebuilt as the Enhanced HF Ionospheric Heating Instrument. 
The Combined Release and Radiation Effects Satellite, CRRES, was a joint program of NASA and the Department of Defense launched in July of 1990. The spacecraft was placed in a highly elliptical orbit and conducted uniqely active experiments involving the release of chemicals at various locations where the complex interactions between solar radiation and the fields and particles in Earth's magnetosphere could be observed. Roger R. Anderson of The University of Iowa was the PI of the Plasma Wave Experiment on CRRES which was part of the Air Force Geophysics Laboratory's SPACERAD project. The mission ended in October of 1991. 
CRRES Program Experiments Release Release Experiment no. Chemical Location Altitude Period ____________________________________________________________________________________ SATELLITE EXPERIMENTS Critical Velocity Critical Velocity G-13 Strontium Am. Samoa 270-360 mi. Sept. 1990 Ionization Barium G-14 Calcium Am. Samoa 270-360 mi. Sept. 1990 Barium High-Altitude Magnetospheric Diagmagnetic Cavity, G-1 Barium N. America 1.3 Re* Jan-Feb 1991 Plasma Coupling G-2 Barium N. America 1.8 Re Jan-Feb 1991 G-3 Barium N. America 3.5 Jan-Feb 1991 G-4 Barium N. America 5.5 Jan-Feb 1991 Stimulated Electron/ G-5 Lithium N. America >6.0 Re Jan-Feb 1991 Aurora Production Stimulated Ion- G-6 Lithium N.America >6.0 Re Jan-Feb 1991 Cyclotron Waves and Ion Precip. Ion Tracing G-7 Lithium N. America >6.0 Re Jan-Feb 1991 and Acceleration Velocity Distribution G-9 Barium Caribbean June-July 1991 Relaxation Caribbean Perigee Grav. Instability G-8 Barium Caribbean 270-480 mi. June-July 1991 Field Equipotentiality Field Line G-10 Barium Caribbean 270-480 mi June-July 1991 Tracing and G-11 Barium Caribbean 270-480 mi June-July 1991 Equipotentiality G-11A Barium Caribbean 270-480 mi June-July 1991 G-12 Barium Caribbean 270-480 mi June-July 1991 G-12A Barium Caribbean 270-480 mi June-July 1991 *Re=Earth radii CRRES PROGRAM EXPERIMENTS Release Release Experiment no. Chemical Location Altitude Period __________________________________________________________________________________ SOUNDING ROCKET EXPERIMENTS Kwajalein Equatorial AA-5 SF6* Kwajalein 240 mi Jul.-Aug. 1990 Instability Seeding AA-6A SF6 Kwajalein 150 mi Jul.-Aug. 1990 AA-6B SF6 Kwajalein 150 mi Jul.-Aug. 1990 Puerto Rican Rockets F-Region AA-1 Barium Puerto Rico 150 mi June-July 1991 Irregularity Evolution HF Ionospheric AA-2 Barium Puerto Rico 150 mi June-July 1991 Modification of a Barium Plasma E-Region AA-7 Barium Puerto Rico 150 mi June-July 1991 Image Formation HF-Induced Ion AA-3 Barium Puerto Rico 90-240 mi June-July 1991 Striation/Differential Barium Puerto Rico 90-240 mi June-July 1991 Ion Expansion Barium Puerto Rico 90-240 mi June-July 1991 SF6 Puerto Rico 90-240 mi June-July 1991 Ionospeheric AA-4 SF6 Puerto Rico 210-240 mi June-July 1991 Focused Heating *SF6=Sulfur hexafluoride 
If any of the links above do not work, copy the URL and paste it into the form below to check the Wayback Machine for an archived version of that webpage.