IPB

Welcome Guest ( Log In | Register )

4 Pages V  < 1 2 3 4 >  
Reply to this topicStart new topic
After Pluto...
Guest_AlexBlackwell_*
post Jan 16 2006, 09:56 PM
Post #16





Guests






QUOTE (ljk4-1 @ Jan 16 2006, 07:37 PM)
Here's some real heresy:  Why flyby Pluto when more interesting KBOs will likely be discovered between now and 2015?  Can NH be retargeted for them?  How about some of the interesting ones we know now, including the one that is bigger than Pluto (I will NOT say its unofficial name)?  I think we should use Jupiter to whip NH out of the ecliptic to it.
Aside from the power issues mentioned previously, your idea, in addition to being "heresy," doesn't make a whole lot of scientific sense. The Pluto flyby alone will allow for exploration of four KBOs (Pluto, Charon, S/2005 P1 and S/2005 P2). You want to give up that opportunity to fly to a "more interesting" (whatever that means) KBO? And one that is further away?
Go to the top of the page
 
+Quote Post
Guest_AlexBlackwell_*
post Jan 16 2006, 09:58 PM
Post #17





Guests






QUOTE (mchan @ Jan 16 2006, 09:52 PM)
After Jupiter, there are no gas giants to help further on the way to Pluto.  Beyond Pluto, there are no known gas giants.
Yeah, I seem to recall from Astronomy 101 the following progression: Jupiter, Saturn, Uranus, Neptune, and then Pluto tongue.gif
Go to the top of the page
 
+Quote Post
Guest_exobioquest_*
post Jan 17 2006, 05:21 AM
Post #18





Guests






Hey, be nice and answer stupid question like they are smart ones, respect the retarded and you will be blessed with good karma. wink.gif

So what’s the max life span of NH? Expected to die in?... 2020,2025,2030, when? How much power would it need to run a minimum of instruments (say for heliopause observations, if any instrument on board can do that)? How far would it get roughly by then?
Go to the top of the page
 
+Quote Post
abalone
post Jan 17 2006, 06:53 AM
Post #19


Member
***

Group: Members
Posts: 336
Joined: 12-June 05
From: Kiama, Australia
Member No.: 409



QUOTE (exobioquest @ Jan 17 2006, 04:21 PM)
Hey, be nice and answer stupid question like they are smart ones, respect the retarded and you will be blessed with good karma.  wink.gif

So what’s the max life span of NH? Expected to die in?... 2020,2025,2030, when? How much power would it need to run a minimum of instruments (say for heliopause observations, if any instrument on board can do that)? How far would it get roughly by then?
*

Just roughly from memory.
Power at launch is just over 200w and it degrades at 3.5w/year. Minimum power required to operate is 100w? I dont know what it will be able to run on this. So lifespan about 25 years.

Even at Pluto flighby it will be down to about 190-200w and not enough to run all instruments at the same time
Go to the top of the page
 
+Quote Post
Guest_Analyst_*
post Jan 17 2006, 08:51 AM
Post #20





Guests






Power at Launch is about 240w. I believe Alan Stern posted here 190w are needed to operate including the science instruments (encounter). No idea about the minimum power needed just to live.
Go to the top of the page
 
+Quote Post
djellison
post Jan 17 2006, 08:58 AM
Post #21


Administrator
****

Group: Chairman
Posts: 13806
Joined: 8-February 04
Member No.: 1



QUOTE (abalone @ Jan 17 2006, 06:53 AM)
Even at Pluto flighby it will be down to about 190-200w and not enough to run all instruments at the same time
*


I dont think you've got that right. If you go back and read Alan's PI-Persp's, I see no mention of rolling instrument operation a-la Voyager.

Doug
Go to the top of the page
 
+Quote Post
edstrick
post Jan 17 2006, 09:38 AM
Post #22


Senior Member
****

Group: Members
Posts: 1869
Joined: 20-February 05
Member No.: 174



My understanding is that they were able to get more plutonium than they expected to after all the security-screwup work-stoppages at Los Alamos, but they didn't get a full load. I think they're able to do 100% duty cycle at Pluto, but the further out a KB object they flyby is, the more they'll have to cycle power usage as the levels decline.

There's also probably some small uncertainty on the degradation rate of the RTG. The half life of the plutonium is pretty well known, but much of the degradation is due to radiation damage of the bimetallic junctions in the thermocouples that generate power, and that's going to be very hardware dependent. This is a spare.. was it from Cassini?.. so that should be pretty well but not perfectly known.
Go to the top of the page
 
+Quote Post
abalone
post Jan 17 2006, 10:46 AM
Post #23


Member
***

Group: Members
Posts: 336
Joined: 12-June 05
From: Kiama, Australia
Member No.: 409



QUOTE (djellison @ Jan 17 2006, 07:58 PM)
I dont think you've got that right.  If you go back and read Alan's PI-Persp's, I see no mention of rolling instrument operation a-la Voyager. 

Doug
*

It may be wrong or out of date but here is where I got the info

http://www.spaceflightnow.com/atlas/av010/...spacecraft.html
QUOTE
Typical of RTG-based systems, as on past outer-planet missions, New Horizons does not have a battery for storing power. At the start of the mission, the RTG will supply approximately 240 watts (at 30 volts of direct current) - the spacecraft's shunt regulator unit maintains a steady input from the RTG and dissipates power the spacecraft cannot use at a given time. By July 2015 (the earliest Pluto encounter date) that supply decreases to 200 watts at the same voltage, so New Horizons will ease the strain on its limited power source by cycling science instruments during planetary encounters.
Go to the top of the page
 
+Quote Post
David
post Jan 17 2006, 11:16 AM
Post #24


Member
***

Group: Members
Posts: 809
Joined: 11-March 04
Member No.: 56



QUOTE (ljk4-1 @ Jan 16 2006, 07:37 PM)
Here's some real heresy:  Why flyby Pluto when more interesting KBOs will likely be discovered between now and 2015?  Can NH be retargeted for them?  How about some of the interesting ones we know now, including the one that is bigger than Pluto
*


Pluto is still the most interesting KBO out there -- if only because we know a little bit more about it than the other ones. I think that a very distant, very cold, rather small planet that still somehow manages to have an atmosphere has got to have interesting things going on on it.
Go to the top of the page
 
+Quote Post
edstrick
post Jan 17 2006, 11:25 AM
Post #25


Senior Member
****

Group: Members
Posts: 1869
Joined: 20-February 05
Member No.: 174



It's not really a practical target untill we can lob something bigger considerably faster, but Sedna is going to eventually be a very high priority target.. Much further out, with orbital dynamics that suggest a radically different origin is possible (possible capture during stellar flyby as the star forming region the solar system formed in broke up). If nothing else, Sedna's been in a deeper freeze than anything we know other than Oort cloud comets.
Go to the top of the page
 
+Quote Post
belleraphon1
post Jan 17 2006, 02:07 PM
Post #26


Member
***

Group: Members
Posts: 732
Joined: 29-December 05
From: NE Oh, USA
Member No.: 627



Right now the Pluto/Charon binary planet is the most interesting KBO. And it should indeed remain the focus for New Horizons.... one of the big attractions at Pluto is the presence of an atmosphere that is slowly freezing out.

Note this report form
http://www.spaceref.com/news/viewpr.html?pid=18769

Researchers have identified spectral features that hint at possible atmospheres on
2003 UB313 and 2005 FY9.

As for what we will find out there in the Kuiper Belt as NH heads out ..... I have read some reports that believe there could be Earth sized KBO's out there....

Craig
Go to the top of the page
 
+Quote Post
ljk4-1
post Jan 17 2006, 03:35 PM
Post #27


Senior Member
****

Group: Members
Posts: 2454
Joined: 8-July 05
From: NGC 5907
Member No.: 430



This thread discussed the theory that no really large KBOs exist:

http://www.unmannedspaceflight.com/index.php?showtopic=1546

Of course we won't know for certain until we can send some dedicated KBO probes out there.

I certainly understand that Pluto is the best known of all the KBOs, but I get the feeling there are even more interesting ones out there. Their only "flaw" is that they are more distant from Earth.


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

Go to the top of the page
 
+Quote Post
djellison
post Jan 17 2006, 03:40 PM
Post #28


Administrator
****

Group: Chairman
Posts: 13806
Joined: 8-February 04
Member No.: 1



Pluto gives us 4 bodies for the price of one, that we know to be reachable, targetable, and interesting.

To even entertain the idea of targetting elsewhere is just crazy.

Doug
Go to the top of the page
 
+Quote Post
ljk4-1
post Jan 17 2006, 03:55 PM
Post #29


Senior Member
****

Group: Members
Posts: 2454
Joined: 8-July 05
From: NGC 5907
Member No.: 430



QUOTE (djellison @ Jan 17 2006, 10:40 AM)
Pluto gives us 4 bodies for the price of one, that we know to be reachable, targetable, and interesting.

To even entertain the idea of targetting elsewhere is just crazy.

Doug
*


I was referring in my most recent post to later probe missions with more power, better instruments, and a future improved astronomical knowledge of other KBOs.

We are just touching the tip of the iceberg with KBOs right now. And let's not forget the Oort Cloud, of which we know even less. Literally billions of worlds out there to explore, ones presumably untouched since the formation of the Sol system.

Pluto and its moons are just for starters.

Would this be the place to discuss what we would need in a probe to properly explore multiple KBOs?


--------------------
"After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
I see that such intercourse long continued would make one thoroughly prosaic, hard,
and coarse. But the longest intercourse with Nature, though in her rudest moods, does
not thus harden and make coarse. A hard, sensible man whom we liken to a rock is
indeed much harder than a rock. From hard, coarse, insensible men with whom I have
no sympathy, I go to commune with the rocks, whose hearts are comparatively soft."

- Henry David Thoreau, November 15, 1853

Go to the top of the page
 
+Quote Post
mchan
post Jan 17 2006, 07:23 PM
Post #30


Member
***

Group: Members
Posts: 593
Joined: 26-August 05
Member No.: 476



QUOTE (edstrick @ Jan 17 2006, 01:38 AM)
My understanding is that they were able to get more plutonium than they expected to after all the security-screwup work-stoppages at Los Alamos, but they didn't get a full load.  I think they're able to do 100% duty cycle at Pluto, but the further out a KB object they flyby is, the more they'll have to cycle power usage as the levels decline. 
*

Since NH is going by Pluto anyways, can't it pick up some more plutonium there?

(Ducks)
Go to the top of the page
 
+Quote Post

4 Pages V  < 1 2 3 4 >
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 26th October 2014 - 12:18 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is a project of the Planetary Society and is funded by donations from visitors and members. Help keep this forum up and running by contributing here.