ISEE-2

The International Sun-Earth Explorer 2 (ISEE-2) was a space probe used to study magnetic fields near the Earth. ISEE-1 and ISEE-2 were launched on October 22, 1977, and they re-entered on September 26, 1987. The instruments on board ISEE-2 were designed to measure electric and magnetic field properties.

Mission
The space probe was part of a program consisting of three spacecraft: a mother/daughter pair (ISEE-1 and ISEE-2) and the ISEE-3 spacecraft (later renamed to International Cometary Explorer). The program was a cooperative mission between NASA and ESRO (later ESA) designed to study the interaction between the Earth's magnetic field and the solar wind. At least 32 institutions were involved, and the focus was on understanding magnetic fields. ISEE-1 (a.k.a. Explorer 56) and ISEE-3 were built by NASA, while ISEE-2 was built by ESA. All three had complimentary instruments supported by the same group of over 100 scientists.