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Posted by: exobioquest Jan 16 2006, 01:30 AM

After pluto and any other KBO its set to intercept, how far can NH go before it dies on use? Can it reach the heliopause? Does it have any means of analyzing the heliopause and interstellar wind beyond it?

Posted by: nprev Jan 16 2006, 01:37 AM

Just to add another question, have any candidate KBOs been identified for NH yet?

Posted by: alan Jan 16 2006, 01:54 AM

I wouldn't expect them to pick a KBO target right away. There are a couple of new survey telescopes under development which will significantly increase the options while New Horizons in on the way to Pluto. This one for example http://pan-starrs.ifa.hawaii.edu/public/science-goals/solar-system.html, projected to begin in 2009, is expected to find 20,000 KBO's.

Posted by: edstrick Jan 16 2006, 06:41 AM

They said on a press breifing today that they'd start the active search for KB objects about 2012. Post Pluto-encounter, the delta-V capability with the expected onboard fuel is a 1/10 degree wide cone expanding from the point of pluto-intercept. It's not worth the effort to search now for KB objects that will be in that narrow cone after 2015, when things like the Synoptic Survey Telescope will be deep-scanning the sky for KB objects by the hundreds of thousands and more.

Posted by: nprev Jan 16 2006, 07:47 AM

I see; thanks, Ed and Alan.

Makes sense; Pluto doesn't have enough mass to alter the spacecraft's course to any significant degree (ta-da, da!)

Posted by: abalone Jan 16 2006, 09:14 AM

I think it is a bit more than that. Delta V of say 100-150m/s when travelling at 13km/s equates to a cone of more like 1 deg rather than 1/10 deg

Posted by: edstrick Jan 16 2006, 09:16 AM

"....Pluto doesn't have enough mass to alter the spacecraft's course to any significant degree ...."

Even if it did.... the trajectory past Pluto is almost 100% "constrained". Primary mission science goals REQUIRE radio occultation by BOTH Pluto and Charon. There is essentially one trajectory that can give that result, with the main variation being which 6 1/2 <is that right> orbit of Chiron around Pluto puts it into the right position for the second occultation.

Posted by: abalone Jan 16 2006, 09:49 AM

Quick calculation. Max Delta V anticipated is about 210 m/s, this post Pluto-encounter wide cone expanding from the point of pluto-intercept of almost exactly 2.0 deg. Compare this to the moon as visble from Earth being about 1/2 deg.

That makes a cone 4X that apparaent diameter of the moon. The reason they are not searching yet is twofold.

1. they dont know where that cone will be until after launch
2. just as importantly, even after launch and the cone can be determined, where do you search for an object that will be in this cone in 9 years time. That of course depends on its orbit. The longer you leave the search, the smaller the area that needs to be searched

Posted by: Holder of the Two Leashes Jan 16 2006, 03:52 PM

When they do start that search, Pluto (and any KBO targets) will be smack in the middle of the milky way in Sagitarius. This is an area normally avoided by planetoid hunters in the past, because of the dense star field. I wonder how they're going to address this issue? You need very good resolution, on the order of nearly perfect seeing from the ground, to pull anything out of the background.

Posted by: ToSeek Jan 16 2006, 07:31 PM

Just because Pluto is there, does that mean that any KBO NH can fly by must also be there? I would think that with a years-long cruise ahead of it, there's a wide swath where a possible KBO could be, if it's at the right distance.

Posted by: 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.

Posted by: abalone Jan 16 2006, 09:04 PM

Yes that is true but the wide swath where a possible KBO could is all will be smack in the middle of the milky way in Sagitarius. It is not until about 2011 that the target field has moved into a more favorable location

Posted by: Holder of the Two Leashes Jan 16 2006, 09:13 PM

New Horizons will not have many years to live after Pluto, so the KBO's have to be fairly close. They didn't get as much plutonium as they wanted for the RTGs, and there was some question early on as to whether the spacecraft would be at full power even at Pluto. Even if the rendezvous point with the KBO clears the milky way, the object is not stationary in the sky and will have moved there from a point that was in a fairly dense sky background (unless it's in some very weird retrograd orbit). You need to have located it by the time NH reaches Pluto in order for a course change to have maximum effect.

Posted by: ljk4-1 Jan 16 2006, 09:15 PM

Any other gas giant planets conveniently along the way where NH could get an extra boost?

Posted by: 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. It would be fantastic if a gas giant were to found beyond Pluto and that would be in the narrow cone of possble post-Pluto trajectories.

Posted by: AlexBlackwell Jan 16 2006, 09:56 PM

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?

Posted by: AlexBlackwell Jan 16 2006, 09:58 PM

Yeah, I seem to recall from Astronomy 101 the following progression: Jupiter, Saturn, Uranus, Neptune, and then Pluto

Posted by: exobioquest Jan 17 2006, 05:21 AM

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

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?

Posted by: abalone Jan 17 2006, 06:53 AM

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

Posted by: Analyst Jan 17 2006, 08:51 AM

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.

Posted by: djellison Jan 17 2006, 08:58 AM

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

Posted by: edstrick Jan 17 2006, 09:38 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.

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.

Posted by: abalone Jan 17 2006, 10:46 AM

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

http://www.spaceflightnow.com/atlas/av010/060108spacecraft.html

Posted by: David Jan 17 2006, 11:16 AM

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.

Posted by: edstrick Jan 17 2006, 11:25 AM

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.

Posted by: belleraphon1 Jan 17 2006, 02:07 PM

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

Posted by: ljk4-1 Jan 17 2006, 03:35 PM

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.

Posted by: djellison Jan 17 2006, 03:40 PM

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

Posted by: ljk4-1 Jan 17 2006, 03:55 PM

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?

Posted by: mchan Jan 17 2006, 07:23 PM

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

(Ducks)

Posted by: abalone Jan 17 2006, 09:42 PM

No. It does not have any landing capability and no-one to open the bonnet

Posted by: Bob Shaw Jan 17 2006, 10:50 PM

Yes, and your point about Donald *was*?

(REALLY ducks - and hides!)

Bob Shaw

Posted by: Jeff7 Jan 17 2006, 11:50 PM

Ok guys, stop being Goofy!


*also ducks*

Posted by: punkboi Jan 18 2006, 02:00 AM

You guys seem too hyper. Let me slip you a Mickey.

*Really really really ducks*

Posted by: exobioquest Jan 18 2006, 02:13 AM

ooooooooooookkkkkkkkkyyyyyyyyy...

so how long will NH last and how far could it get?

(fires alot of mortor rounds)

Posted by: dvandorn Jan 18 2006, 03:52 AM

This isn't really a full-fledged pun war. It's more of a Minnie-war.

*ducks faster than you can scrub a launch attempt*

-the other Doug

Posted by: edstrick Jan 18 2006, 07:56 AM

beware of quantum ducks: QUARK! QUARK!

Posted by: Bart Jan 21 2006, 12:53 AM

Sorry to hijack this thread back to something serious, but...

I was looking at a plot of where stuff is in the outer solar system at http://cfa-www.harvard.edu/iau/lists/OuterPlot.html (link provided so graciously by edstrick on the Pioneer/Asteroid Belt thread), and I noticed that there is a big gap in the Kuiper Belt right where New Horizons is headed.

Is this some kind of an observational bias, or is there a real dynamic effect, some kind of scattering by Neptune, that is clearing out the exact part of the belt that we're going to visit? Does this mean that NH is less likely to find a big juicy target after Pluto?

Bart

Posted by: Alan Stern Jan 21 2006, 02:04 AM

That's just an observational effect. NH is headed toward Sagitarius, the galactic center.
The starfields are dense there, so observers avoid them to ease their needle
in the haystck hassles in finding KBOs. The KB itself has no such gap.

-Alan

Posted by: Alan Stern Jan 21 2006, 03:11 AM

Posted by: edstrick Jan 21 2006, 09:33 AM

A random note on that outer planets plot: There is a lot of "structure" in the Kuiper belt that consists of approximately radial lines of objects separated by zones with fewer objects. This is an amusing selection effect... wher objects were found in a deep search, separated by areas where the search wasn't as deep.

Even more amusnig....some of the line-ups are NOT radial toward the sun.... because the inner objects have moved slightly further in their orbits since that radial zone of objects was discovered than the objects further out.

Posted by: Holder of the Two Leashes Jan 21 2006, 07:48 PM

Perhaps now would be a good time to reask a question I asked earlier:

Posted by: stevesliva Jan 21 2006, 11:15 PM

I find the animation of the orbits of the discovered objects to be amusing:
http://cfa-www.harvard.edu/iau/Animations/OuterSmall.gif

Lots of comets that were discovered in the inner solar system extrapolated back in time... very clearly indicating how much must be undiscovered.

Posted by: stevesliva Jan 21 2006, 11:20 PM

http://en.wikipedia.org/wiki/Pan-STARRS ... apparently will be able to find just about anything that moves.

Posted by: ljk4-1 Jan 22 2006, 12:48 AM

In Arthur C. Clarke's novel The Hammer of God, a bomb is detonated that reveals where every minor body is in the Sol system. I cannot remember the details much beyond this, can someone help here and would such a plan be feasible?

http://en.wikipedia.org/wiki/The_Hammer_of_God

Posted by: just-nick Jan 22 2006, 02:21 AM

And, pending funding, there's this even bigger bad boy:

http://www.lsst.org/lsst_home.shtml

Though I do take points away for the name.

--Nick

Posted by: Holder of the Two Leashes Jan 22 2006, 05:59 AM

Thank you, stevesliva. I read the article, and found it interesting in several respects. I always consider Wikipedia a little suspect, but I have no reason to believe that anything in particular in this article is not factual.

However, the problem here is one of pulling faint (mag 22-24) objects out of a somewhat bright background. At 1 to 2 arc sec resolution, as I'm assuming these telescopes will have, you are seeing small variations in brightness as the KBOs move around over the milky way, rather than faint but distinct objects moving over a black starry background. Within the Wikipedia article, it mentioned that times around full moon would have to be avoided because of the brightly lit sky. The milky way forms a kind of permanent nearly "full moon" type sky in it's location, and it's at it's widest and brightest near Sagittarius.

I'm wondering how even Pan-STARRS will cope with the background noise. Hubble, I'm sure, has the resolution, but it's field of view is too narrow to do the kind of survey required.

Posted by: SFJCody Jan 22 2006, 09:15 AM

There's a ppt about the search problems here:
http://www.boulder.swri.edu/~spencer/nhkbosearch/plutokbofind4web.ppt

Posted by: Holder of the Two Leashes Jan 22 2006, 07:15 PM

That's exactly the sort of summary I was looking for. However, having read it, I'm still a little unsettled.

An overview of the conclusions seems to be this: "We're pretty sure we can do this, by brute force if necessary. There's going to be better technology and techniques down the road in any case. There are some dust lanes in some search areas that won't be so bad. And maybe it WOULD be a good idea to use Hubble on occasion."

Ooookaaayyy. I say good hunting to them. I mean that sincerely.

(And I'll be back in a few years to say I always had faith in them)

Posted by: john_s Jan 22 2006, 11:15 PM

Thanks for the good wishes! Your summary is fairly accurate, though Hubble's of limited use for the search because of its small field of view. Though once we've found some candidates, Hubble may be able to help up pin down their orbits. Pan-STARRS has a wide field of view but is limited by its fairly small aperture. We're counting on big telescopes with big cameras to do this job right. We already have a bunch of data from the Subaru telescope, covering the search area with fairly short exposures, in case there are some particularly bright targets, and we're grinding through that data now. Fortunately we've got nine years before we need the results from the full survey.

John Spencer.

Posted by: BruceMoomaw Jan 24 2006, 02:55 AM

One of the main arguments for New Horizons 2 is that it could fly by a really big second known KBO with a large moon (as well as flying by Uranus and its moons fairly near their equinox). This wasn't quite strong enough an argument for me to push it in print as I did NH 1 -- although, if the manned program hadn't been eating up NASA's budget like popcorn, I WOULD have pushed it. But it's a safe bet that virtually every probe launched to solar escape velocity from now on will take advantage of the opportunity to fly by at least one already-known KBO, given the extreme importance of observing a fair-sized sampling of them (which the seminal 2002 Decadal Survey report actually described as more important than flying by Pluto specifically).

In particular, there's a good chance that at least one or two of the future New Frontiers missions in the next decade or two will fly by one of the giant planets and drop off one or more atmospheric entry probes -- and it would be insane not to then use that craft to visit a KBO as well. (Plus a Centaur object or one of Jupiter's Trojan asteroids, should the opportunity for either present itself.)

Posted by: tasp Jan 24 2006, 06:24 AM

Is it feasible that during the last 2 or 3 years of the trek to Pluto the NH cameras could be used to image the KBO near the exit cone of the NH flight path?

If the cameras can be set for long exposures, relatively dim objects might be seen. We would be interested in the brighter (larger) objects anyhow, for possible flybys.

Also, the rapid motion of the craft will result in long baselines for blink comparing images (shades of Mr. Tombaugh!) (or just let the computers do it) to discern the possible encounter objects.

My understanding is the exit cone for post Pluto is not all that large, so there should not be large numbers of pictures to take, anyhow, if this is feasible.

Posted by: djellison Jan 24 2006, 08:59 AM

That discussion re: using NH to search for KBO's has been had I think, Alan confirming that given the apeture of LORRI, compared to the apeture of ground based observatories, even given the proximity of NH to the target, the maths just doesnt add up and ground based obs are a much much better way to do it.

Doug

Posted by: ljk4-1 Jan 24 2006, 04:57 PM

Is it too early to ask what stars New Horizons will be passing relatively nearby in the coming millennia?

Posted by: Aldebaran Oct 19 2014, 06:38 AM

I've heard Ross 248 being mentioned but a lot depends on the final trajectory. The closest it can come is around 2 LY in around 30,000 to 40,000 years from now. That may sound close, but when you consider that Voyager 1 has only travelled 0.002 LY so far it puts it in perspective.

The window is between 30,000 and 40,000 years due to the rapid motion of Ross 248. In 40,000 years, NH will have travelled about 1.5 LY, so it may be closer to Ross 248 than the Sun at some stage. At that stage, Ross 248 will probably be the closest star to the Sun.

Posted by: jman0war Jul 22 2015, 03:15 PM

Would they please send a Rover, like MSL to Pluto?

Preferably within my lifetime.