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KBO encounters
hendric
post Apr 15 2016, 10:49 PM
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I thought it might be because of the lower orbital velocity of MU69, but it turns out there isn't much difference, 4.67 km/s vs 4.48 km/s. The flyby speed will be slightly lower too I guess, with the extra years of the sun's gravity to slow NH down. I agree with Steve, it probably has more to do with a simpler slew operation, as well as a simpler "target" - they just need to capture the whole disk, not specific locations on the disk. Unless they happen to discover a moon before close approach! MU69 is in the same size range as Ida after all.


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Paolo
post May 18 2016, 10:00 AM
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meanwhile, NH has been busy observing KBO 1994 JR1
New Horizons Collects First Science on a Post-Pluto Object

anybody knows what is the other moving dot at the right edge of the pic? another reflection?
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HSchirmer
post May 18 2016, 12:35 PM
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QUOTE (Paolo @ May 18 2016, 11:00 AM) *
meanwhile, NH has been busy observing KBO 1994 JR1
New Horizons Collects First Science on a Post-Pluto Object

anybody knows what is the other moving dot at the right edge of the pic? another reflection?


Eh, it looks like 2007 UK126 (or) 2003 QX113 (are in the same general area and might be in) frame with 1994 JR1.
Lets see, New Horizons was about .75 AU away from JR1 for the picture, however, UK126 and QX113 would be around 40 and 70 AU away, likely to dim to see.


EDIT- looks like a reflection- there are several dots that move exactly in step with the lens flare
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Paolo
post May 18 2016, 12:44 PM
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after I posted I noticed that the dot is moving in the opposite direction to JR1 and in phase with the internal camera reflection. I guess it's likely to be another reflection
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alan
post May 19 2016, 12:43 AM
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Paper on arxiv:
Red, Rough, Fast, and Perturbed: New Horizons Observations of KBO (15810) 1994 JR1 from the Kuiper Belt
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HSchirmer
post May 19 2016, 01:52 PM
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QUOTE (alan @ May 19 2016, 01:43 AM) *


Very interesting,

So, 1994 JR1 (150km) was "observed by NASA's New Horizons spacecraft on November 2, 2015 from a distance of 1.85 AU".
Hmm, then it should be possible to do similar observations of Quaoar (1110 km) which should be about 13 AU away.
Might even be worth trying "snow white" 2007 OR10 (1280 km), but at 26AU, that might be a stretch.

But, just getting light curve data and refining the orbital parameters would be worth the effort.
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GS_Brazil
post May 19 2016, 01:53 PM
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QUOTE (Paolo @ May 18 2016, 09:44 AM) *
after I posted I noticed that the dot is moving in the opposite direction to JR1 and in phase with the internal camera reflection. I guess it's likely to be another reflection


Is see at least 4 other objects moving:

1) The clearest one on the right edge, +/- 3 o'clock.
2) Another clear one on the left edge, =/- 9 o'clock ( it visible in one frame, not in the other )
3) One in the middle of the image, roughly 1/3 from the center of the image in direction of the left edge
4) Other smaller, hardly visible changes

The 3 most visible objects move in exactly the same direction ( as well as the other less visible moving points ), so my conclusion is these are dead-pixels on the camera sensor or something else related to the sensor.
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TheAnt
post May 20 2016, 08:21 PM
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QUOTE (HSchirmer @ May 19 2016, 03:52 PM) *
...just getting light curve data and refining the orbital parameters (of Quaoar and Snowwhite/2007 OR10 ) would be worth the effort.


This announcement had me think in similar lines, slow moving as they are we do not know their exact orbits.
And that NH were able to do observations of such a relative small object of 150 km then the nearest of the major dwarfs planets also might be observed in the same manner.

Now I do not know if it would be possible, but the NH observation might reveal even more if NH were taking data in tandem with more or less simultaneous observations from Earth based telescopes or Hubble.
With quite some number crunching of the resulting light curves taken from two very different directions of observation. Would it not be possible to create the first very low resolution maps of lets say Quaoar?
(I assume the light from Weywot could be interfering to a small degree, though perhaps not that much to prevent us from getting some good data since it is relatively small.)
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HSchirmer
post May 21 2016, 03:08 AM
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QUOTE (TheAnt @ May 20 2016, 08:21 PM) *
And that NH were able to do observations of such a relative small object of 150 km then the nearest of the major dwarfs planets also might be observed in the same manner.


The extended mission proposal mentions observations of about 20 KBOs, so clearly NH team has been planning for this.

Earlier in this thread, Alan Stern explains the "distance to resolution relationship" in terms of object diameters

QUOTE
http://www.unmannedspaceflight.com/index.p...&pid=158572
Our best imager, LORRI, can resolve the size of an object from roughly 10^5 object diameters away. So for a 100 km object, for example, we have to be w/i 10^7 km just to resolved it; if you want crude shape information, cut that to 10^6 diameters, and if you want "geology," well, better come to approx 30,000 diameters or better.


Basically, NH will be far more than 10^6 diameters away from most KBO's, so they will be single pixels.
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Steve5304
post May 21 2016, 03:55 PM
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QUOTE (HSchirmer @ May 21 2016, 03:08 AM) *
The extended mission proposal mentions observations of about 20 KBOs, so clearly NH team has been planning for this.

Earlier in this thread, Alan Stern explains the "distance to resolution relationship" in terms of object diameters



Basically, NH will be far more than 10^6 diameters away from most KBO's, so they will be single pixels.



Just think those will be the best images for the next 60 years.. tongue.gif
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HSchirmer
post May 21 2016, 08:14 PM
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QUOTE (Steve5304 @ May 21 2016, 04:55 PM) *
Just think those will be the best images for the next 60 years.. tongue.gif


Not necessarily.
US is launching next generation spy-sats from Vandenberg in 2018.
Um, yeah, those SpaceX heavy lift boosters don't just aim for Mars...

Anyway, that suggests that several US spy satellites should be retiring soon.
Well, rather than just sitting there like last-year's-smartphone-in-your-desk-drawer,
we can hope that the US will donate them to astronomy.

Remember a couple years ago, US military donated two Hubble class KH-11 spy satellites to NASA? Well, it seems there were a total of sixteen KH-11 launches, and only two donations (so far) to NASA. That sugests that there is quite a bit of fast-glass in the Kh-11s still up there in orbit. If science is lucky, they'll be decomissioning some of the KH-12s in a bit

Real interesting thing is whether they can be synchronized, like the VLA, as a synthetic aperture array. Would be really interesting to have a 10 telescope array functioning as a 13 million meter telescope.
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dvandorn
post May 21 2016, 11:02 PM
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Umm... USAF donated unflown optics from recon satellites that were never launched. In specific, the one I recall is the donation of the mirrors from the first MOL (which was also a spy sat) for scientific purposes.

You won't be able to just decommission a KH-11, hand it over to NASA and say "Here's another Hubble." I don't believe those cameras can even be set to focus out to solar system objects, much less other galactic and extra-galactic targets. And trust me, it will cost a heck of a lot less to build new mirrors than to harvest mirrors already in orbit.

So, yeah, I don't think the old KH-11's can be converted to astronomical telescopes. If I'm wrong, I'd love to hear about it. But I don't think I'm wrong...

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scalbers
post May 21 2016, 11:47 PM
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Speaking of telescopes operating in synchrony I still like to keep the momentum going for the Terrestrial Planet Finder (TPF) and Planet Imager (PI - a free floating interferometric network of TPFs) proposals from 10-20 years ago. Even though they were designed to show details on extrasolar planets, I suppose the KBOs would be fitting as well. It's hard to find info on these proposals online presently, particularly for PI.


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HSchirmer
post May 22 2016, 12:08 AM
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QUOTE (dvandorn @ May 22 2016, 12:02 AM) *
Umm... USAF donated unflown optics from recon satellites that were never launched.

In specific, the one I recall is the donation of the mirrors from the first MOL (which was also a spy sat) for scientific purposes.

You won't be able to just decommission a KH-11, hand it over to NASA and say "Here's another Hubble."
I don't believe those cameras can even be set to focus out to solar system objects,
much less other galactic and extra-galactic targets.
...


Well, things might not be that impossible.

QUOTE
http://www.americaspace.com/?p=20825
(snip)
As NRO telescopes, the optics were designed for looking at objects on Earth to provide up to 3.9 inch resolution from 200 mi. altitude or higher.
...
Matt Mountain, director of the Space Telescope Science Institute, has visited the NRO hardware several times at its manufacturing plant , the ITT Exelis manufacturing facility in Rochester, N.Y. After seeing the NRO telescopes he came away calling them “Stubby Hubbles” because the focal length is shorter.

The shorter focal length means the NRO telescopes can image at high resolution an area 100 times bigger than Hubble’s Wide Field Camera-3, a visible / infrared instrument that has become Hubble’s most advanced and heavily used sensor. And by imaging areas 100 times larger in a single image the more galaxies and objects in the cosmic zoo can be studied with a single image.
...
Another key benefit is unlike Hubble, the secondary mirror on the NRO telescope can be moved by either ground control or on board instruments. This can be used to bring the image to an extremely fine focus. The secondary mirror is supported by 6 struts and there are servo motors at the bottom of each strut. The six motors can maneuver all those struts to tweak the secondary mirror to achieve the finest focus possible.


Anyway, my point was, we probably won't need to wait 60 years to get getter pictures of KBO objects. We've got some really nice glass already in orbit. No, we don't have the space infrastructure to repurpose them now, or next year, but when you start to think about what aerospace tech should be in the next decade- 3d sintered metal, telepresence, lightsails, the era of satellite repair and repurposing is coming.
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hendric
post May 23 2016, 03:40 PM
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QUOTE
As NRO telescopes, the optics were designed for looking at objects on Earth to provide up to 3.9 inch resolution from 200 mi. altitude or higher.


One is slated for WFIRST, but the second donated mirror is un-allocated. One proposal is to send it to Mars to replace MRO, with about 4x the resolution, as well as support for outer solar system objects. The proposal focused the mission on brighter objects, since adding the necessary fine guidance for faint objects would significantly increase the budget. This article is dated, but I couldn't find any more recent information on the AFTA proposals. I think NASA is holding off proposal development until WFIRST is further along, to understand better the requirements and limitations in the mirrors.

http://www.space.com/21064-nasa-donated-sp...scope-mars.html

A report on WFIRST/AFTA is available free at the National Academies Press.

http://www.nap.edu/catalog/18712/evaluatio...nd-astrophysics

Edit:

Ah, nevermind, it looks like NASA passed on all the ideas presented at the workshop, including Mars-Orbiting Space Telescope, because they weren't in line with recent priorities. They might revisit the decision though.

http://spacenews.com/35628only-nasa-astrop...-telescope-for/



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