International Cometary Explorer flies through Giacobini-Zinner comet's tail 1985

The International Cometary Explorer (ICE), launched in August 1978, passed through the Giacobini-Zinner comet on September 11, 1985 and conducted a flyby of the comet's nucleus at 4800 miles. 

 

International Cometary Explorer launched 1978

The International Cometary Explorer (ICE), also known as the International Sun-Earth Explorer 3 (ISEE-3), was launched August 12, 1978.  It became the first spacecraft to visit a comet, when it encountered Comet Giacobini-Zinner in September 1985.

It made a flyby of Halley's Comet in March 1986, but the closest it got to the comet's nucleus was 28M kilometers.  By comparison, Earth's minimum distance was 20.8M kilometers.

Contact with the probe was lost September 16, 2014.

Sakigake, Japanese space probe to Halley's Comet, launched 1985

Japan launched its first interplanetary spacecraft Sakigake on January 7, 1985 to explore Halley's Comet during its 1986 visit to Earth.   It was the first deep space probe to be launched by a country other than USA or the Soviet Union.

Sakigake was developed by two entities who became part of the Japanese Exploration Agency (JAXA).  It made a flyby of the comet in March 1986 at just under 7 million kilometers.  It did not carry any imaging instruments. 

Japan planned for it to do a flyby of comet 21P/Giacobini-Zinner but the idea was abandoned due to lack of propellant.

Telemetry was lost in November 1995 but its beacon signal was received until January 7, 1999.