A group of three spacecraft comprising a NASA and ESA mission to study the relationship between Earth and the Sun, the solar wind, and cosmic rays. ISEE-1 and ISEE-2 were launched on 22 October 1977 and ISEE-3 on 12 August 1978. The US contributed ISEE-1 and ISEE-3, and ISEE-2 was built and managed by ESA. In 1982, ISEE-3 was removed from its orbit about one of the Lagrangian libration points, eventually into a heliocentric orbit ahead of Earth that would intersect the comet Giacobini–Zinner, at which point the spacecraft was renamed International Cometary Explorer (ICE). It traversed the plasma tail of the comet in September 1985. ISEE-1 and ISEE-2 reentered the Earth’s atmosphere on 26 September 1987.
http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/isee3.html A joint ESA and NASA mission to study the Earth’s magnetosphere.