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Unmanned Spaceflight.com > Outer Solar System > Pluto / KBO > New Horizons
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stevesliva
QUOTE (tasp @ Mar 10 2012, 07:34 PM) *
are there any unexpectedly large brightness variations among the images?

You have to remember that the discovery "images" on icehunters are not single images, but algorithmic mergers of several. I don't think you can address the questions you're raising from them.
tasp
OK, thanx for that.
centsworth_II
QUOTE (Seryddwr @ Mar 10 2012, 01:27 PM) *
... I'd like to help, but I can't seem to register for some reason.
I don't know about the registration problem, but there are no new images to analyze right now. From these posts in the IceHunters forum, I gather it may be weeks - or months (depending on what "a while" turns out to be) before new images are available and when they are, the search may continue at a different web site: http://cosmoquest.org./
Click to view attachment
Click to view attachment
Seryddwr
Thanks for the reply. It turns out I couldn't register due to the maddening technical hitch of my being unable to read simple English... rolleyes.gif

I managed it in the end, thank goodness. It's a fine site. I am thinking about helping out with the 'planet hunters' project in due course - or while we wait for another cache of KBO images!
alan
4 for me, one I missed being the first to spot by 3 seconds
antoniseb
I didn't figure out how to search just for ones that I'm listed on, but I looked through the roughly 150 confirmed KBOs and noticed my ID on three of them. I'd gone through about 20,000 images, so by the above suggestion should have seen about ten, but it is hard to know, and I'd have to say a large fraction of the images I searched were unusable... so maybe three is right.
stevesliva
^ The poster on the forum at icehunters said (s)he'd started late, so some of his 1-in-2000 "discoveries" were no doubt images be refloated to the top of the queue to get more looks. Indeed there were probably a lot of images that got skimmed by a few people and then thrown out of circulation.
centsworth_II
Just noticed the following in the IceHunters forum.
I used the starstryder@gmail.com address and got a form e-mail back saying Pamela was traveling. I see nprev on the Name Needed list in case anyone wants to get word to him.
Click to view attachment
centsworth_II
QUOTE (stevesliva @ Mar 9 2012, 03:36 PM) *
Gnsorgathon was the sole discoverer of one... I'm not sure how that sort of thing got followed up?...
Just found out myself. Clicking on the "?" in upper right on the catalog pages gives general information including, "Scientist Confirmation: Scientists review all marks - even those with a single click (but those are de-prioritized)." Objects with three clicks were reviewed first.
alan
SEARCHING FOR KBO FLYBY TARGETS FOR THE NEW HORIZONS MISSION
QUOTE
Results so Far: We have identified 24 KBOs in the 2004/2005 data, some with arc lengths up to 1 year, and so far about 18 unique KBOs in the 2011 data (Table 1), though analysis of the 2011 data is not yet complete. No KBO yet found is reachable by New Horizons, but the closest one to the NH trajectory would require less than twice the available onboard delta-V to be targeted
SFJCody
Will these get minor planet temporary designations?
Marz
QUOTE (SFJCody @ May 3 2012, 04:52 PM) *
Will these get minor planet temporary designations?


Here's the wording from the FAQ:

"How do the results get published?

Kuiper Belt Objects: All discovered KBOs will be submitted to the Minor Planet Center. The submission will be led by the scientists who are making all the observations, reducing the data, and calculating all the orbits. Within the submission, the name of every person who marked a discovered KBO will be listed. We will also maintain a catalogue on this site of all the discovered objects and all the discovery makers. Please note: Due to the restrictions on how things can get submitted, we can only include real last names and initials. We cannot use online alias.

Variable Stars: All discovered variable stars will be catalogued and submitted for publication in a to be determined journal. The submission will be led by team scientists and each object will be listed with the names of the individuals who discovered them.

Asteroids: Most of the objects noted by this project do not have sufficient data to calculate orbits. If sufficient data is achieved for any of our asteroids, they will be submitted to the Minor Planet Center and the discovery team will be allowed to name the object. "


FYI: there's new images to work on at http://cosmoquest.org/iceinvestigators/
centsworth_II
An interesting video display of KBOs so far found along New Horizon's path. Right now there are no new images to view in the KBO search... more coming in the future.
Click to view attachment
Explorer1
Anyone else getting a real Star Wars vibe from those sound effects and visuals?
Just need a lost TIE fighter now...
john_s
Also, check out the webcast videos on the New Horizons web site, about our July 2011 KBO search observing run on the Subaru telescope on Mauna Kea:
http://www.pluto.jhuapl.edu/gallery/videos/podcast.php

John
Paolo
posted a few minutes ago on NewHorizons2015 twitter:

QUOTE
FLASH! Possible distant but interesting New Horizons KBO flyby in Jan 2[0]15, BEFORE Pluto!

remcook
Oh, that would be nice! Looking forward to the details.
tedstryk
Looking forward to seeing what this is...distant flyby can mean a lot of things.
Phil Stooke
"FLASH! Our possible KBO encounter in Jan 2015 is not a close flyby-75 million km off-but there's science in it no other observatory can do! "

Not a close-up!


Phil

Paolo
also:

QUOTE
About the Jan 21o5 KBO, It's VNH0004; need orbit refinements to make sure & see if we can weave it in: Pluto flyby also starts in Jan '15! About the Jan 21o5 KBO, It's VNH0004; need orbit refinements to make sure & see if we can weave it in: Pluto flyby also starts in Jan '15!


QUOTE
And by the way, VNH0004 is our own unofficial designation for the KBO, no IAU tag yet.
stevesliva
Just light curves? Or something more like resolving satellites?
Paolo
probably characterization of a KBO at phase angles impossible from Earth
algorimancer
I wonder whether it would be feasible/worthwhile to have the New Horizons spacecraft itself performing an ongoing active search for targetable objects, then perform an autonomous imaging campaign, kind of like the MER rovers could be configured to scan for dust devils and record them. Possibly this mode would be better left until after the Pluto flyby. Years ago this thought occurred to me with regard to the Voyager probes, but that was shortly after they permanently disabled their cameras.
Phil Stooke
I would have thought it could not possibly go as deep as a big ground or orbital telescope... and it wouldn't work during hibernation periods.

Phil
algorimancer
QUOTE (Phil Stooke @ Aug 21 2012, 01:55 PM) *
...thought it could not possibly go as deep as a big ground or orbital telescope... and it wouldn't work during hibernation periods.


Agreed, but it could potentially catch smaller/darker objects which the ground/orbital telescopes would miss, when it is close enough to them -- which is why it would likely need to be a fairly active search, with capability for quick response. No, this would not work during hibernation periods, but presumably once past Pluto -- since it is nuclear powered and need not ration power -- it can simply be set in an active/automated mode where it regularly looks ahead seeking nearby objects which will be made obvious by rapid changes in brightness/position, then images them as it passes by. This would require little energy, and probably no active maneuvering beyond orienting the cameras to follow an object during flyby.
john_s
Right, our camera aperture is small enough that even though we're closer to the KBOs there's no advantage to searching from the spacecraft. Plus our maximum exposure time is 10 seconds compared to the hours we can integrate from the ground, and it takes thruster fuel to hold the spacecraft steady during those 10 second exposures, so we can't take too many of them. Oh, and because of the need to use thrusters to hold the spacecraft steady, our best spatial resolution for those long exposures is about 4 arcseconds, compared to the ~0.6 arcseconds we can get from the Earth (on a good night). The lower spatial resolution makes it difficult to distinguish and KBOs from all the background stars.

New Horizons would have a sensitivity advantage for KBOs that are very small and close to the spacecraft, as algorimancer says, but we don't think there are many of those, and we don't have the onboard smarts to find them autonomously in the images onboard the spacecraft, and we don't have the bandwidth to send enough of them back to Earth for processing even if we could afford the fuel for all those long exposures...

So we'll just have to keep searching with the big telescopes here on Earth.

John
elakdawalla
John, I was talking to someone at LPSC (and now I can't remember who it was) who was dismissing the usefulness of obtaining lightcurves at high phase angles. Obviously people do think it's useful because New Horizons and Cassini have been doing lots of high-phase-angle observations of unresolved objects. Could you explain what it is you (by which I mean planetary astronomers in general, not just the New Horizons team) hope to learn with these lightcurve studies?
machi
Light curves are useful for many things.
This is citation from abstract Rotation Periods of Irregular Satellites of Saturn, which describes observations of small irregular moons from Cassini.

"Motivation is the determination of basic
properties of these objects like rotation periods, polar
axes orientations, object sizes and shapes, phase
curves, colors, or the search for binaries."

Another field of research is about asteroids and analyzing their light curves for determination of their physical properties.
I saw comparison between two shape models of Lutetia. One was obtained by modeling from light curve and second from Rosetta OSIRIS camera.
Both of them were almost identical (basic shape in low resolution).
High phase observations are useful for Hapke modeling of surface properties as surface roughness etc.
But I think that usefulness of this technique strongly depend on quality and quantity of images.
paxdan
Motivation is the determination of basic
properties of these objects like rotation periods, polar
axes orientations, object sizes and shapes, phase
curves, colors, or the search for binaries

reads like amazing blank verse.
algorimancer
QUOTE (john_s @ Aug 22 2012, 11:13 PM) *
...need to use thrusters to hold the spacecraft steady....don't have the onboard smarts to find them autonomously in...


Thanks for clearing that up. I had assumed that reaction wheels were used for adjusting orientation, if thrusters are needed this is clearly a non-starter. I was also a bit concerned that communication would require re-orienting to point at Earth, which would add additional complications. Perhaps someday a similar approach might be tried on a subsequent mission.
john_s
QUOTE (elakdawalla @ Aug 22 2012, 09:46 PM) *
John, I was talking to someone at LPSC (and now I can't remember who it was) who was dismissing the usefulness of obtaining lightcurves at high phase angles. Obviously people do think it's useful because New Horizons and Cassini have been doing lots of high-phase-angle observations of unresolved objects. Could you explain what it is you (by which I mean planetary astronomers in general, not just the New Horizons team) hope to learn with these lightcurve studies?


Actually we're more interested in the phase curves than lightcurves per se (lightcurves would be interesting too, to get rotation periods and shapes, but can be done from HST). A rotational lightcurve at high phase angles may be hard to interpret in terms of shape, but is fine for getting the rotation period, which I think is the prime motivation for the Cassini lightcurve observations. For Cassini, I don't *think* there's any preference for high phase angle observations- the phase angle is just whatever it happens to be when there's a block of time available for the observations.

Phase curves (which can't be done from Earth for KBOs) are useful for constraining surface textures. However we also have a practical interest on New Horizons, because we will need to acquire our flyby target KBO at higher phase angles (maybe 20 degrees) than can be observed from Earth, so we'd like an estimate of how bright it will be at that phase angle. The dimmer our KBO is, the less time we will have between our first onboard OpNav and the encounter, and the more fuel we'll need to hold in reserve for final targeting.

John
john_s
QUOTE (algorimancer @ Aug 23 2012, 06:10 AM) *
Thanks for clearing that up. I had assumed that reaction wheels were used for adjusting orientation, if thrusters are needed this is clearly a non-starter.


Yes, no reaction wheels on New Horizons (I think because they would have required too much mass and power). Thrusters are better than reaction wheels for the rapid slewing we'll need to do at Pluto- they just aren't as good at keeping a spacecraft rock-steady for time exposures, and of course they use fuel.

John
TheAnt
Well at least I did not expect any images taken of "VNH0004" since it will be at a distance comparable to Mars at opposition.
It would take one huge telescope to get a good spectra and even less to resolve anything even if it had been located in the inner solar system.

When one consider that it will have to be for one object that receive ~1000 times less sunlight (about 900 times less at Neptune) it become one daunting task indeed. Even to coerce information out of any possible post-Pluto encounter, that might 'only' be some few millions of kilometers will be quite an achievement - we need to find a possible candidate for anything such first though. smile.gif
Tom Tamlyn
QUOTE (vjkane @ Aug 5 2008, 12:38 PM) *
The Voyagers and Pioneers had capable particles and fields instruments. Anyone know if NH's SWAP and PEPSSI instruments would be good for exploration of the heliopause? Also, NH left Earth with a smaller than expected payload of plutonium. How far could it go and still (1) operate the instruments and (2) call home?


QUOTE (Alan Stern @ Aug 5 2008, 01:39 PM) *
We could probably run the s/c and 1 instrument to the mid-2020s to explore the heliosphere 50-70 AU, but that's not the mission-- the mission is to maximize the KB science, and that means spending all the fuel to do that.

Voyager's 35th anniversary got me thinking about a possible particles and fields terminal mission for New Horizon, and I was working on some follow-up questions when I discovered that Alan had answered most of them in a recent PI Perspective.

QUOTE
It's possible that NASA could approve a second extended mission, allowing New Horizons to explore the deep heliosphere as the two Voyager spacecraft are doing now. Although we won't get as far as the Voyagers before we run out of power, we expect New Horizons can operate successfully out to about 90 or 100 times as far from the Sun as Earth.

That would allow us to probe this area of our planetary system with our Solar Wind Around Pluto (SWAP) and Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instruments – the most sophisticated and sensitive space plasma instruments ever flown to this distant region – and to explore the distribution of dust in this region for the first time using the Venetia Burney Student Dust Counter (SDC). Other science involving our LORRI and Ralph imagers, Alice ultraviolet spectrometer, and our radio science experiment (called REX) will also likely be possible.


I'm curious why NH won't last as long as the Voyagers. Of course it has a substantially smaller RTG, but the decay rate should be roughly comparable. Perhaps NH's spacecraft housekeeping takes proportionately more of its power than is the case for the Voyagers?

Edit: I've belatedly realized that "last as long" and "get as far" are different questions, because the Voyagers are traveling faster than New Horizons. But Alan indicates that "New Horizons has the power and technical capabilities fly late into the 2020s or even into the 2030s if its health remains good," and I still wonder why the shorter life-span.
Alan Stern
New Horizons has 1 RTG, not 2 as the Voyagers do.Also, some will recall we got shorted on Pu-238 owing to two closures of LANL during the mission build-- we launched with 25 watts less power (read: 10+ years lifetime) than we originally hoped for. Double that with 2 RTGs and you have the basic answer to your question.
Tom Tamlyn
OK, I finally get it (less margin), and I apologize for being dense. Thanks as always for taking the time to monitor this thread.
Tom Tamlyn
As I was thinking about Alan’s answer, I remembered that the SwRI site for New Horizons has a comprehensive collection of freely downloadable technical papers written by scientist and engineer participants in the mission, found at http://www.boulder.swri.edu/pkb/, the kind of basic information that you have to scrounge for with most missions.

One paper, Fountain, et al., The New Horizons Spacecraft (02 Feb 2007) contains a four-page discussion of the NH power system. In particular, Figures 10 and 11 at p. 25 were particularly helpful to me in visualizing the relationship between the RTG’s initial power output and the mission’s lifespan.

Click to view attachment


It’s immediately obvious how an extra 25 watts of initial power would have translated into 10 more years of fully operational lifespan.

TTT (when I figure out how to convert the 90k attachment into an inline image or thumbnail, I'll do it)
stevesliva
I suppose it's worth asking whether the instruments on NH measure anything that the Voyagers and IBEX don't. Certainly another in-situ measurement is good, but I wonder, in terms of measuring empty space, what's new?
imipak
The NH power charts Tom posted, inline:
Click to view attachment
o`
Tom Tamlyn
Thanks imipak! Looks great, just what I wanted.

How did you do that? I tried copying the attachment url into the "insert image" tool, but I got an error message about dynamic links. I know zippo about html ....
dilo
Based on these plots, they should be able to make correction maneuvers and science activities until early 2024 (59 au) and downlink data until 2029 (74 au).
Moreover, if mission extension will be financed, I'am pretty confident they will be able to further improve these margins by optimizing operations (as done on Voyager)
hendric
Alan,
Do those power margins account for shutting down unnecessary systems as NH ages? Or is the technology good enough now (I'm an embedded engineer myself) that a low-power mode for an instrument is essentially near-zero power?
Alan Stern
The figures in Glen Fountain's paper do not include measures we can take to extend mission duration, which we now estimate will take us to the mid-late 2030s. However, those measures do not generally include low power instrument modes, as most NH instruments do not have them.


QUOTE (hendric @ Sep 9 2012, 02:04 AM) *
Alan,
Do those power margins account for shutting down unnecessary systems as NH ages? Or is the technology good enough now (I'm an embedded engineer myself) that a low-power mode for an instrument is essentially near-zero power?

Paolo
this in interesting: the search for candidate KBOs continues to provide some "collateral" discoveries
Discovery and Characterization of an L5 Neptune Trojan in the Search for a New Horizons Encounter Candidate
and it may also receive some distant (180 million km) observations
morganism
Am a big fan of the KBO post encounter, and threw in some time at Ice Hunters, but would trade it all for a trajectory change to get more info on Uranus or Neptune.

That red trojan looks interesting tho, and nearly a 30 deg inclination is crazy!

Am specifically interested if there are any flux tube re-connections out there.

OPAG doesn't look like they will be chosen in time to still have any specialty scientists still around to study an ice giant.....
Tom Tamlyn
QUOTE (morganism @ Sep 10 2012, 06:36 PM) *
Am a big fan of the KBO post encounter, and threw in some time at Ice Hunters, but would trade it all for a trajectory change to get more info on Uranus or Neptune.

<cough>

I've attached a diagram showing the positions of the outer planets at the time of New Horizon's Pluto encounter, together with a cone indicating the outer limits of NH's ability to change course after the encounter. The diagram is figure 14 from Guo and Farquhar, New Horizons Mission Design (2007), available at http://www.boulder.swri.edu/pkb/.
Click to view attachment*
Keeping in mind the narrowness of the cone, the positions on the diagram of Uranus and Neptune, and of course the fact that Uranus and Neptune will continue to march, "rank on rank," as members of "[t]he army of unalterable law" ** further counterclockwise from the Pluto rendezvous point ... what kind of trajectory change are you talking about?

TTT

_______
* I've looked at BB Code Help, I've searched the forum, I've googled (per Chairman's advice), and I've looked at page source, but haven't figured out how to post an inline image. I'm sure it's only a few characters of code with a simple syntax, but I'm not able to intuit what those words and syntax are. To avoid threadjack. I'll start a thread in EVA/Chit Chat or EVA/Image Processing Techniques.

** Apologies to George Meredith.
TheAnt
QUOTE (Tom Tamlyn @ Sep 11 2012, 08:13 AM) *
... what kind of trajectory change are you talking about?


I guess that would have to be the kind of trajectory change that involved the reverse gear. rolleyes.gif
udolein
Candidate for post-Pluto encounter - Plutino 15810:

A possible post-Pluto flyby target for NASA’s New Horizons spacecraft?

Cheers, Udo
centsworth_II
QUOTE (udolein @ Sep 20 2012, 02:09 PM) *
Candidate for post-Pluto encounter - Plutino 15810...

The amateur search for post Pluto targets is no longer hosted by Zooniverse as mentioned in both the linked article and the Planetary Society blog post (linked in the article). It is now at http://cosmoquest.org/ as Ice Investigators.

In any case there are not currently any images available to search in. I guess Pamela Gay has her work cut out getting word out about Cosmoquest.
brellis
Looks like there is a pre-Pluto target smile.gif PS article on the Ice Hunters
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