There have been a surprising number of spacecraft
sent to study comets - both past and present.
Missions of the Past:
The first probe to visit a comet was the
ISEE-3/ICE probe. Launched in 1978, the probe
was sent to study comet Giacobini-Zinner. The
mission proved the "dirt-snowball" theory, that
comets are composed of mixed rock and ice. The
mission ended in 1981 and is now in a heliocentric
orbit that will bring it close to
Earth in 2014.
There are plans to capture the probe for display in
the
Smithsonian Institution.
The next probe to visit a comet was Japan's
Sakigake probe. Launched in 1985, the probe
reached comet Halley in 1986. Its closest approach
was 7 million kilometers. The European Space
Agencies first deep space mission was
Giotto. This remarkable probe was able to study
two comets: comet Halley in 1986 and comet
Grigg-Skjellerup in 1992. Its closest approach to a
comet was only 200 km. Japan's second probe,
Suisei, was also sent to study comet Halley in
1986. This mission was a direct result of the
success of
Sakigake. While not a cometary probe, the
Galileo spacecraft did capture the impact of
comet Shoemaker-Levy 9 in 1994. The
Ulysses probe - designed for Solar studies - did
pass close to comet Hyakutake in 1996. The result
was the study of the longest tail ever - composed of
ions, gas and dust. NASA's
Deep Space 1 was a probe designed both a comet
and an asteroid. Launched in 1998, the probe studied
comet Borrelly in 2001. On July 3, 2002, the
CONTOUR probe was launched to study two comets.
Contact to the probe was lost after only a month in
the mission. Current Missions: The
Stardust mission is a return sample mission.
Launched in 1999, the probe encountered comet Wild 2
in 2004 and captured particles surrounding the
comet. It is currently returning to
Earth and is
planned to enter the atmosphere on January 15, 2006.
The European Space Agency's
Rosetta probe was launched in 2004 to study
comet 67P/Churyumov-Gerasimenko. It will attempt a
first ever landing on a comet when it reaches its
target in November of 2014. Just recently launched
on January 12, 2005 was NASA's
Deep Impact probe. Its purpose is to send a
projectile to the comet creating an impact crater so
the main craft will perform
spectroscopy of the
internal structures. Its target: comet Tempel 1.
The Future: There are no proposed missions
for visits to comets.
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