The International Cometary Explorer (ICE) spacecraft (designed and launched as the
International Sun/Earth Explorer 3 (ISEE-3) satellite), was launched August 12, 1978,
into a heliocentric orbit. It was one of three spacecraft, along with the mother/daughter pair
of ISEE-1 and ISEE-2, built for the International Sun-Earth Explorer (ISEE) program, a
joint effort by NASA and ESRO/ESA to study the interaction between the Earth's magnetic field
and the solar wind.

ISEE-3 was the first spacecraft to be placed in a halo orbit at the L1 Earth-Sun Lagrangian point.
Renamed ICE, it became the first spacecraft to visit a comet, passing through the tail of Comet Giacobini-Zinner
within about 7,800 km of the nucleus. NASA suspended routine contact with ISEE-3 in 1997, and made brief status
checks in 1999 and 2008.

On May 29, 2014, two-way communication with the spacecraft was reestablished by the ISEE-3 Reboot Project,
an unofficial group[4] with support from the Skycorp company. On July 2, 2014, they fired the thrusters for the
first time since 1987. However, later firings of the thrusters failed, apparently due to a lack of nitrogen
pressurant in the fuel tanks.[8][9] The project team will pursue an alternative plan to use the spacecraft to
"collect scientific data and send it back to Earth.