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- (CNN) -- Just nine days after scrapping one comet
exploration mission over cost concerns, NASA announced a similar mission
with exactly the same price tag to exactly the same comet.
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- The new mission, Deep Impact, aims to crash a 500 kilogram
(1,100 pound) copper spacecraft into Comet Tempel 1 in 2005, creating a
crater as big as a football field and as deep as a seven-story building.
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- The earlier mission, Champollion or Deep Space 4, was
to map the icy surface of the comet, land a small spacecraft there in 2005
and collect samples for on-site analysis and a later return to Earth.
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- NASA attached $240 million price tags to both missions
and Deep Impact, like Champollion, will be managed by NASA's Jet Propulsion
Laboratory.
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- Jay Bergstralh, NASA's program scientist for the division
that includes Deep Impact, said Friday that the newer mission is unique
in that it will sample the comet's core. He said the decision to can Champollion
was "not in any way predicated on the selection of Deep Impact."
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- "We think that the pristine matter in comet nuclei
is the stuff that the solar system is made of," he said. "These
are fossils. If we can get through this processed crust and look at the
pristine matter beneath it we think we'd have a better idea of the chemicals
that were in the nebula, the cloud of gas and dust that the solar system
formed from."
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- Champollion grew beyond original scope
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- The phasing of costs over time was one reason Champollion
got the ax, Bergstralh said.
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- "Champollion was supposed to be principally a technology
demonstration program and it had grown outside that envelope," Bergstralh
said.
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- "Deep Impact is a qualitatively different kind of
mission," he said. "It doesn't do the same kinds of things Champollion
was intended to do."
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- Both missions aimed for Comet Tempel 1 because it is
a handy target in the asteroid belt between Mars and Jupiter that rotates
slowly, making for easier landings, and spews less gas and dust than other
comets, he said.
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- The earlier mission was headed up by NASA's Brian Muirhead,
leader of the Mars Pathfinder mission. The new mission will be led by Michael
A'Hearn at the University of Maryland in College Park.
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- That move follows a NASA cost-cutting trend to put more
aspects of missions in the hands of university researchers and contractors.
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- Another coincidence?
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- The day after NASA scrapped Champollion, the European
Space Agency grabbed media attention by unveiling a model of the Rosetta
spacecraft, set for a 2012 rendezvous and landing on the comet Wirtanen.
That feat would have made them the first agency to land on a comet given
the cancellation of Champollion.
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- NASA's Deep Impact will precede the European landing
-- although it's clear that a controlled crash is not quite the same as
a landing.
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- Bergstralh said NASA planned months ago to announce the
Deep Impact mission in July. As for whether the European Space Agency timed
its unveiling to upstage NASA following the death of Champollion, Bergstralh
wouldn't venture to say.
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- Deep Impact, which shares its name with a 1998 movie
about a comet crash on Earth, is set for a January 2004 launch (Champollion
was set for a 2003 launch). The plan is to put a camera and infrared spectrometer
aboard Deep Impact to collect data on the icy spray from the crash, which
is set to occur July 4, 2005.
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- The impact date hearkens to the Pathfinder landing of
July 4, 1997.
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- NASA's other missions involving asteroids and comets
include:
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- * Deep Space 1, set to pass by asteroid 1992KD on July
29.
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- * The Near Earth Asteroid Rendezvous mission, set to
enter orbit around asteroid Eros on Valentine's Day, 2000.
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- * The Stardust mission to gather samples of comet dust
and return them to Earth.
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- On Wednesday, NASA also announced a $286 million mission
to Mercury, set for a spring 2004 launch. The mission marks NASA's first
return to Mercury since the Mariner 10 flybys in 1974 and 1975. Mercury
is the planet closest to the sun.
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- The Messenger mission will be designed to look for water-ice
in Mercury's polar craters, following a flight path that includes two fly-bys
apiece of Mercury and Venus and an orbital tour of Mercury to start in
September 2009.
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