AMPTE, launched in 1984, was one of the most complex space missions ever. Three scientific spacecraft (each designed and built by a different nation) were carried into orbit by a single launch vehicle, deployed into different regions of space, and then operated to perform coordinated functions with one another. The German spacecraft, which was supplemented by a British spacecraft carrying a complementary set of instruments, orbited the earth outside the magnetosphere and released tracer ions into the solar wind, while the American spacecraft, which orbited inside the magnetosphere, attempted to detect the released ions in order to determine whether and how the solar wind "blows" ions into the earth's magnetosphere. The American spacecraft also made measurements of the natural environment within the magnetosphere, and the German spacecraft also released cometary ions to study the plasma physics of the interaction of solar wind with a cometary gas.
From the description of Active Magnetospheric Particle Tracer Experiment (AMPTE) (Space Science): Oral history interviews, 1992-1994. (American Institute of Physics). WorldCat record id: 82863021
