ICE is returning to Earth; but do we have the will to regain control?
In 1978, the International Sun-Earth Explorer (ISEE-3) spacecraft began its mission to study Earth’s magnetosphere from a position at one of the Earth-Moon Lagrange points — specifically, the L1 point, located between Earth and the Sun where the two bodies’ gravity cancels. In 1983, ISEE-3 was renamed the International Cometary Explorer (ICE) and used the Moon’s gravity to send it on to encounter comet Giacobini-Zinner, which it encountered in 1985. Later, ICE performed distant observations of comet Halley. Ever since then, it’s been in solar orbit, traveling slightly faster than Earth. It has outdistanced us, traveling very close to 31 times around the Sun in the time that it has taken us to complete 30. And now it’s approaching us from behind. It will make its closest approach again in August, 2014.