UPI Exclusive: Bush OKs new moon missions

"Jorge R. Frank" wrote in
:

"Kaido Kert" wrote in
:

As there is no pressing need or particular hurry to get those
close-up photos of Plutos surface, deferring such "missions" say .. a
couple of decades should be a no-brainer, if this money is needed for
somewhat more practical developments closer to current frontier.

It's not the pictures of the surface that are important. Pluto is
moving away from perihelion and its atmosphere will soon freeze out.
Deferring this mission a couple of decades means we won't get
measurements of Pluto's atmosphere until the next perihelion, which is
over 200 years away.



Which is important because...?

Apart from sheer monkey curiousity, what can be learned from the
atmosphere of Pluto that needs to be understood in the next 200 years
(which assumes that we don't get smart enough in the intervening time to
send a mission there with a drill bit and spectrometer)?

The justification for this mission has always struck me as primarily
"Well, we've been to the other 8 -- what about poor Pluto?" Which isn't
really the same thing as "important"...

--
Reed

Reed Snellenberger wrote in
.119:

"Jorge R. Frank" wrote in
:

"Kaido Kert" wrote in
:

As there is no pressing need or particular hurry to get those
close-up photos of Plutos surface, deferring such "missions" say .. a
couple of decades should be a no-brainer, if this money is needed for
somewhat more practical developments closer to current frontier.

It's not the pictures of the surface that are important. Pluto is
moving away from perihelion and its atmosphere will soon freeze out.
Deferring this mission a couple of decades means we won't get
measurements of Pluto's atmosphere until the next perihelion, which is
over 200 years away.

Which is important because...?

Pluto is the largest Kuiper belt object. Many such objects have their
orbits deflected into the inner solar system and become comets. Since Pluto
is still within the Kuiper belt, it is more likely to be in a pristine
state. Studying Pluto's atmosphere will give us clues to the composition
and lifecycle of Kuiper belt objects, which will become valuable once we
start trying to exploit near-Earth asteroids, many of which are suspected
to be extinct comets. It may even come in handy trying to figure out how to
deflect such near-Earth objects from collisions with Earth.

The justification for this mission has always struck me as primarily
"Well, we've been to the other 8 -- what about poor Pluto?" Which isn't
really the same thing as "important"...

But it is, if Pluto is materially different from the other 8 - which it
most definitely is.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

Jorge R. Frank wrote:

It's not the pictures of the surface that are important. Pluto is moving
away from perihelion and its atmosphere will soon freeze out. Deferring
this mission a couple of decades means we won't get measurements of Pluto's
atmosphere until the next perihelion, which is over 200 years away.

I suspect we'd get measurements of the atmosphere sooner than that --
by landing on the planet itself and examining the frozen gases. 200 years
is a long time.

Paul

"Jorge R. Frank" wrote in
:

Reed Snellenberger wrote in
.119:

"Jorge R. Frank" wrote in
:

It's not the pictures of the surface that are important. Pluto is
moving away from perihelion and its atmosphere will soon freeze out.
Deferring this mission a couple of decades means we won't get
measurements of Pluto's atmosphere until the next perihelion, which
is over 200 years away.

Which is important because...?

Pluto is the largest Kuiper belt object. Many such objects have their
orbits deflected into the inner solar system and become comets. Since
Pluto is still within the Kuiper belt, it is more likely to be in a
pristine state. Studying Pluto's atmosphere will give us clues to the
composition and lifecycle of Kuiper belt objects, which will become
valuable once we start trying to exploit near-Earth asteroids, many of
which are suspected to be extinct comets. It may even come in handy
trying to figure out how to deflect such near-Earth objects from
collisions with Earth.


Which still doesn't suggest that analyzing Pluto's atmosphere would be
near-term useful. We can analyze the volatiles in comets either via
spectroscopy or by missions like Giotto & Stardust, so I still don't
understand the urgent need to look at Pluto while *it's* atmosphere is
gaseous. If we're going to exploit the the near-Earth asteroids (what
does that mean, anyway?), we can do it by actually going to some near-
Earth asteroids and get more meaningful data. And if it's the surface
composition you're interested in, take a close look at the Stardust
aerogel samples.

Furthermore, what is the lifecycle of a Kuiper-belt object in-situ? Dead
as a doornail gets my vote -- these objects don't even begin to be active
until they are perturbed into the inner solar system. And, once they're
down there they'll be much more accessible (as comets) -- if only by
observation that by actual close-up inspection.

The really critical questions near-term about the Kuiper belt objects
wouldn't be answered by the Pluto probe -- what is their spatial size
distribution, is there a "Nemesis" planetoid and, if so, what is its
orbit. We've already seen, from Giotto et al, that they can be large and
rocky...

The justification for this mission has always struck me as primarily
"Well, we've been to the other 8 -- what about poor Pluto?" Which
isn't really the same thing as "important"...

But it is, if Pluto is materially different from the other 8 - which
it most definitely is.


Once again, I don't question that we'd learn something -- I just haven't
seen a convincing argument that says we have to go *now* to take
advantage of some special characteristic of Pluto-with-an-atmosphere.
Admittedly, the nuclear propulsion initiative would be a beneficiary of
the Kuiper mission -- but this new initiative may provide even more
benefits (what's the minimum Earth-Mars transit time for nuclear/ion
propulsion - useful for re-supply missions - and what would be required
to man-rate such a system - useful for Mars missions that don't require
three years).

--
Reed

Reed Snellenberger wrote:

Which still doesn't suggest that analyzing Pluto's atmosphere would be
near-term useful. We can analyze the volatiles in comets either via
spectroscopy or by missions like Giotto & Stardust, so I still don't
understand the urgent need to look at Pluto while *it's* atmosphere is
gaseous.

It might be useful to know the temperature of the exobase on
these bodies. This governs the rate at which low atomic number
gases can escape, which in turn would tell us how small a KBO
has to be in order to retain helium in its atmosphere. A KBO
that retained helium could be the best place in the solar system
to mine 3He (once we have fusion rockets to get there).

Paul

Reed Snellenberger writes:

Which still doesn't suggest that analyzing Pluto's atmosphere would be
near-term useful. We can analyze the volatiles in comets either via
spectroscopy or by missions like Giotto & Stardust, so I still don't
understand the urgent need to look at Pluto while *it's* atmosphere is
gaseous.

Because Pluto's surface and atmosphere have hopefully not been _as_
"processed" as comets already passing through the inner solar system.

By the time Giotto and Stardust look at a comet, most of the more volatile
materials have already been stripped from its outer surface. What you're
left with is a mixture of (grossly simplifying) silicates, coal dust, and
asphalt like substances surrounding a core with all of the above mixed with
clathrates of water ice, ammonia ice, and methane ice.

Looking at Pluto is an easy way of looking at a comet's _core_, without
having to dig through hundreds of meters of baked-over crust on the surface.



--
Phil Fraering
http://newsfromthefridge.typepad.com

"Jorge R. Frank" wrote:

"Kaido Kert" wrote:

As there is no pressing need or particular hurry to get those close-up
photos of Plutos surface, deferring such "missions" say .. a couple of
decades should be a no-brainer, if this money is needed for somewhat
more practical developments closer to current frontier.

It's not the pictures of the surface that are important. Pluto is moving
away from perihelion and its atmosphere will soon freeze out. Deferring
this mission a couple of decades means we won't get measurements of Pluto's
atmosphere until the next perihelion, which is over 200 years away.

Hasn't Pluto's atmosphere already partially frozen out? Pluto's orbit
was inside Neptune's orbit from 1979-1999, so it is already headed
outward further from the Sun.

--
Scott M. Kozel Highway and Transportation History Websites
Virginia/Maryland/Washington, D.C. http://www.roadstothefuture.com
Philadelphia and Delaware Valley http://www.pennways.com

In article ,
john doe wrote:

"Greg D. Moore (Strider)" wrote:
Remember, just to develop the industrial base on the Moon to make this
possible you're going to have to have cheap launch from here on Earth.

And more importantly, have a way to return to earth the ore that you have
mined on the Moon, and all of this should be cheaper than the ore that is
mined on earth.

Um, no. The point of mining stuff in space is not to ship it to the
Earth. Except for energy, that makes no sense. The point of mining
stuff in space is so you can use it in space, without having to ship it
up *from* the Earth.

,------------------------------------------------------------------.
| Joseph J. Strout Check out the Mac Web Directory: |
| http://www.macwebdir.com |
`------------------------------------------------------------------'

In article ,
"Greg D. Moore \(Strider\)" wrote:

Oh, I have it straight. I'm just pointing out the idea makes no sense.

No, I don't think you do. You're saying "Building a lunar
infrastructure in order to launch scientific craft is not going to be
cheaper than launching those craft from Earth." And I agree, but that's
not the point. The point is, once you've already built the lunar
infrastructure for other reasons, *then* you can do a variety of things
in space (including launching scientific craft) more cheaply than you
could without that infrastructure.

"Space science" is not a reason to build the infrastructure, of course
-- it never was a good reason for a space program. But the more we
develop our space infrastructure, the cheaper (and better) the
scientific results will get, as a minor side benefit.

,------------------------------------------------------------------.
| Joseph J. Strout Check out the Mac Web Directory: |
| http://www.macwebdir.com |
`------------------------------------------------------------------'

I suspect we'd get measurements of the atmosphere sooner than that --
by landing on the planet itself and examining the frozen gases. 200 years
is a long time.

Paul

Well its been how many years since the last apollo mission? At this rate we
might make pluto before the sun burns itself out!