The third spacecraft of the International Sun–Earth Explorer (ISEE) program began its work in an orbit between the sun and Earth. From its position there, ISEE 3 monitored cosmic gamma-ray bursts and solar flares before being rechristened the International Cometary Explorer (ICE) in 1982. ICE flew from its original orbit to a rendezvous with Comet Giacobini-Zinner in 1985 and then investigated Comet Halley the following year.

In 1997 operations for the ISEE 3/ICE spacecraft finally concluded. But its stable orbit allowed NASA's Deep Space Network to locate and contact the spacecraft in September 2008. ISEE 3/ICE is making its way back and should approach Earth's vicinity around 2014; the spacecraft's former flight director Robert Farquhar says it should still be in good shape. With enough fuel left to maneuver the spacecraft, Farquhar would like to see ISEE 3/ICE revived and returned to its original orbit between the sun and Earth, where it could become a relatively inexpensive space project for students to work on.