International Cometary Explorer: ICE Meets Ice
The first spacecraft encounter with a comet occurred in September 1985, when the International Cometary Explorer (ICE) flew through the tail of Comet Giacobini-Zinner.
The International Sun/Earth Explorer 3 (ISEE-3) satellite, launched in 1978, was designed to monitor the interaction between the solar wind, a stream of charged gas emanating from the Sun, and the Earth's magnetic field. Because of this mission, the spacecraft was not equipped with a camera system, but with numerous instruments to measure the characteristics and composition of the solar wind. When the decision was made to change the trajectory for a comet intercept, the spacecraft was renamed the International Cometary Explorer.
116k GIF - 51k JPEG
Photo by Terry McCrea.
A Plasma Wave Detector similar to the one pictured here on display in the National Air and Space Museum is aboard the ICE spacecraft, and measured radio waves produced by ionized gases near Comet Giacobini-Zinner over a period of 24 hours. Gift of Fred Scarf, TRW Space and Technology Group
Comet Halley Missions
Mission Launch Date Encounter Date Distance from
Vega-1 Dec. 1984 Mar 1986 10,000 km 13 Vega-2 Dec. 1984 Mar 1986 3,000 km 13 Suisei Aug. 1985 Mar 1986 200,000 km 2 Sakigake Jan. 1985 Mar 1986 10,000 km 3 Giotto Jan. 1985 Mar 1986 596 km 10
The Giotto Mission
112k GIF - 39k JPEG - NASA Image
The Giotto mission, carrying 10 instruments, came closest to the nucleus of Comet Halley. It flew by the comet 596 kilometers (375 miles) from the nucleus, and returned pictures in visible light, as well as other wavelengths. Giotto was guided in its course by data supplied by the Soviet Vega spacecraft and Earth-based tracking from the US Deep Space Network. See Encounters with Comet Halley for imagery from Giotto.
113k GIF - 41k JPEG - NASA Image
The Soviet Vega mission consisted of two identical spacecraft (Vega 1 and Vega 2) launched in December of 1984. Each spacecraft deployed a lander and a balloon at Venus in 1985 and then used a gravity assist at Venus to fly by Comet Halley on March 6, 1986.
Spacecraft orbiting Venus and Earth were used to examine the nucleus and tail of Comet Halley. The International Ultraviolet Explorer (IUE) satellite measured variations in ultraviolet light and found times of brightening that were caused by release of carbon dioxide. Also in Earth orbit, the Solar Maximum Observatory (Solar Max) took pictures of the nucleus in ultraviolet wavelengths.
The Pioneer Venus Orbiter, in orbit around Venus from 1978 to 1992, also provided data on Comet Halley. This spacecraft observed the comet at the time the comet and the Earth were on opposite sides of the Sun, and when the comet was closest to the Sun.
Future Comet Missions:
- STARDUST - NASA's Discovery Program mission to collect cometary dust from Comet Wild-2 in 2003.
- Future Comet and/or Asteroid Missions
For more comet mission information, see the COMET LINKS page.
Historical Records || Origin & Orbits || Anatomy of a Comet || Comet Observations
Comet Names || Halley's Comet || Spacecraft Encounters
Meteor Showers || Shoemaker-Levy 9 || Comet Links
©2002 National Air and Space Museum