Nuclear-Powered Mission to Neptune Could Answer Questions About Planetary Formation

http://gtresearchnews.gatech.edu/new...se/neptune.htm

For Immediate Release
Georgia Tech
December 9, 2004

Solar System Secrets: Nuclear-Powered Mission to Neptune Could
Answer Questions About Planetary Formation

In 30 years, a nuclear-powered space exploration mission to Neptune
and its moons may begin to reveal some of our solar system's most
elusive
secrets about the formation of its planets -- and recently discovered
ones that developed around other stars.

This vision of the future is the focus of a 12-month planning study
conducted by a diverse team of experts led by Boeing Satellite Systems
and funded by NASA. It is one of 15 "Vision Mission" studies
intended to develop concepts in the United States' long-term space
exploration plans. Neptune team member and radio scientist Professor
Paul Steffes of the Georgia Institute of Technology's School of
Electrical
and Computer Engineering calls the mission "the ultimate
in deep space exploration."

NASA has flown extensive missions to Jupiter and Saturn, referred to as
the "gas giants" because they are predominantly made up of hydrogen and
helium. By 2012, these investigations will have yielded significant
information on the chemical and physical properties of these planets.
Less is known about Neptune and Uranus -- the "ice giants."

"Because they are farther out, Neptune and Uranus represent something
that contains more of the original - to use a 'Carl Saganism' - 'solar
stuff' or the nebula that condensed to form planets," Steffes said.
"Neptune is a rawer planet. It is less influenced by near-sun
materials,
and it's had fewer collisions with comets and asteroids. It's more
representative of the primordial solar system than Jupiter or Saturn."

Also, because Neptune is so cold, its structure is different from
Jupiter and Saturn. A mission to investigate the origin and structure
of
Neptune -- expected to launch between 2016 and 2018 and arrive around
2035 -- will increase scientists' understanding of diverse planetary
formation in our solar system and in others, Steffes noted.

The mission team is also interested in exploring Neptune's moons,
especially Triton, which planetary scientists believe to be a Kuiper
belt object. Such balls of ice are micro planets that can be up to
1,000
kilometers in diameter and are generally found in the outermost regions
of our solar system. Based on studies to date, scientists believe
Triton
was not formed from Neptune materials, like most moons orbiting planets
in our solar system. Instead, Triton is likely a Kuiper belt object
that
was accidentally pulled into Neptune's orbit.

"Triton was formed way out in space," Steffes said. "It is not even a
close relative of Neptune. It's an adopted child. We believe Kuiper
belt objects like Triton were key to the development of our solar
system, so there's a lot of interest in visiting Triton."

Though they face a number of technical challenges -- including entry
probe design, and telecommunications and scientific instrument
development -- the Neptune Vision Mission team has developed an initial
plan. Team members, including Steffes, have been presenting it this
fall
at a variety of scientific meetings to encourage feedback from other
experts. On Dec. 17, they will present it again at the annual meeting
of
the American Geophysical Union. Their final recommendations are due to
NASA in July 2005.

The plan is based on the availability of nuclear-electric propulsion
technology under development in NASA's Project Prometheus.
A traditional chemical rocket would launch the spacecraft out of Earth
orbit. Then an electric propulsion system powered by a small nuclear
fission reactor - a modified submarine-type technology -- would propel
the spacecraft to its deep-space target. The propulsion system would
generate thrust by expelling electrically charged particles called
ions from its engines.

Because of the large scientific payload a nuclear-electric propelled
spacecraft can carry and power, the Neptune mission holds great promise
for scientific discovery, Steffes said.

The mission will employ electrical and optical sensors aboard the
orbiter and three probes for sensing the nature of Neptune's
atmosphere,
said Steffes, an expert in remote radio sensing of planetary
atmospheres. Specifically, the mission will gather data on Neptune's
atmospheric elemental ratios relative to hydrogen and key isotopic
ratios, as well as the planet's gravity and magnetic fields. It will
investigate global atmospheric circulation dynamics, meteorology and
chemistry. On Triton, two landers will gather atmospheric and
geochemical information near geysers on the surface.

The mission's three entry probes will be dropped into Neptune's
atmosphere at three different latitudes - the equatorial zone, a
mid-latitude and a polar region. Mission designers face the challenge
of
transmitting data from the probes through Neptune's radiowave-absorbing
atmosphere. Steffes' lab at Georgia Tech has conducted extensive
research and gained a thorough understanding of how to address this
problem, he noted.

The mission team is still discussing how deep the probes should be
deployed into Neptune's atmosphere to get meaningful scientific data.
"If we pick a low enough frequency of radio signals, we can go down to
500 to 1,000 Earth atmospheres, which is 7,500 pounds of pressure per
square inch (PSI)," Steffes explained. "That pressure is similar to
what
a submarine experiences in the deep ocean."

However, that depth will probably not be required, according to the
mission team's atmospheric modelers, Steffes said. The probes will be
able to obtain most information at only 100 Earth atmospheres, or 1,500
PSI.

------------------------------------------------------------------------

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Georgia Institute of Technology
75 Fifth Street, N.W., Suite 100
Atlanta, Georgia 30308 USA

MEDIA RELATIONS CONTACTS: Jane Sanders (404-894-2214); E-mail:
); Fax
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).

TECHNICAL CONTACTS: Paul Steffes, Georgia Tech, (404-894-3128); E-mail:
); or
Bernie Bienstock, Boeing Satellite Systems, (310-416-2503); E-mail:
)

WRITER: Jane Sanders

ha scritto nel messaggio
ups.com...
http://gtresearchnews.gatech.edu/new...se/neptune.htm
snip
Also, because Neptune is so cold, its structure is different from
Jupiter and Saturn. A mission to investigate the origin and structure
of
Neptune -- expected to launch between 2016 and 2018 and arrive around
2035 -- will increase scientists' understanding of diverse planetary
formation in our solar system and in others, Steffes noted.

I'm so angry, almost 20 years to reach Neptune...
Where are all the wormholes, the entanglements, the Star Trekkers...
In 2035 I'll be 77 years old, or more likely I'll be dead, so I won't see
anything of this interesting mission...
How many millenniums to see something a bit faster (only a bit) travelling
in space?

Luigi Caselli

I well be 80 year old. with 4 to spare.
You well have the internet.
and ?V( what to come)_ each there own:
Neptune:
nuclear powered mission?
I well all ways look at all the time you can spend to learn what is
allready know of planets,
because as we all know. earth is such a great place to live.
and the people are so loveing: and they all share all they have. as we
all are so happy as we ride into the sun set every terminations. and the
night we pray to the lord and jesus because life is the best it can
be.... becuse of our country leaders. I love them all so much.........
I heard this some were today.