New Horizons: Pre-launch, launch and main cruise, Pluto and the Kuiper belt Options

[Alan Stern]

New Horizons is doing phase curves of Uranus, Neptune, Triton and Pluto (and later Charon) as we
cross the solar system and can look at these objects from illumination geometries only seen in the outer solar system. One does not need to resolve the objects to accomplish this unique science (which cannot be done from Earth or Earth orbit). That said, we *will* just marginally resolve Uranus, but no one should wet their pants, I am talking just over 1 LORRI resolution element (our highest resolution imager).

Alan

All-- The post above was edited to clarify that the imager is LORRI and that the targets are just over one LORRI *resolution element* in diameter (rather than pixel). LORRI's pixel scale is about twice as fine as its actual resolution capability.

-Alan

[Alan Stern]

I guess Titania and Oberon aren't bright enough for phase curves? Or is it a viewing-angle issue?

Rob- Smaller satellite phase curves could potentially be done (and have been discussed) but the image integration times we are using in ACO-2 aren't long enough-- our goals in ACO-2 are Uranus, Neptune, Pluto, and Triton.

-Alan

[Paolo Amoroso]

That said, we *will* just marginally resolve Uranus, but no one should wet their pants, I am talking just over 1 LORRI resolution element (our highest resolution imager).

Any Uranus/Neptune resolving opportunities further in the mission?


Paolo Amoroso

[Alan Stern]

Any Uranus/Neptune resolving opportunities further in the mission?


Paolo Amoroso

Yes, we plan to build up their phase curves by observing them annually. We have also searched for stellar occultations along our route-- checking for all four giant planets-- but to no avail. If any of you have valuable ideas the science team hasn't thought of, we'll consider them. Fire away!

-Alan

[Greg Hullender]

I've seen talk about looking for Neptunian trojans, but nothing about Uranian ones. I did a quick web search, and I see that it's thought there won't actually be any (or many) at Uranus:

http://www.aas.org/publications/baas/v33n3/dps2001/228.htm

But, given that we do have some time to kill :-) perhaps it would be worth taking a look anyway. If nothing is found, okay, that's what's expected. But if something is found, then that would be very significant.

--Greg

[Paolo Amoroso]

If any of you have valuable ideas the science team hasn't thought of, we'll consider them. Fire away!

Not science-related, but what about a Solar System family portrait similar to Voyager 1's?


Paolo Amoroso

[Ken90000]

That Voyager mosaic was very risky for the imaging system. They didn’t care if they ruined the camera because it was the last time it was to be used.

You aren’t going to get those New Horizons People to point their nearly-new equipment anywhere near that close to the Sun.

Also, the Voyager Family Portrait was taken while the Solar System was distant and the planets relatively close to each other. Right now, from NH’s point of view, the Solar System spans 360 degrees.

[john_s]

That Voyager mosaic was very risky for the imaging system. They didn’t care if they ruined the camera because it was the last time it was to be used.

You aren’t going to get those New Horizons People to point their nearly-new equipment anywhere near that close to the Sun.

That's correct- we will continue to image Uranus and Neptune, and we may also have a look at Saturn from somewhere near Pluto, but the terrestrial planets, and also Jupiter for most of the time, will be too close to the sun to image without an unacceptable risk to our cameras. Maybe we'll try looking at the terrestrial planets after our final KBO encounter, but not before that.

John.

[dilo]

Alan, thanks for this opportunity you're giving to us!
I was thinking to long-baseline parallax, using LORRI as astrometric telescope, but I guess resolution isn't enough to beat earth/satellite dedicated instruments, even though with 10-fold baseline increase... is it true?

[Alan Stern]

You heard it here first UMSF: The brain transplant was a success, and our new, improved C&DH software is running on NH's main computer out beyond Saturn! Go New Horizons!

-Alan

[Greg Hullender]

Does that mean Communications and Data Handling software? Can you share the highlights about the improvements?

--Greg

[just-nick]

Does that mean Communications and Data Handling software? Can you share the highlights about the improvements?

Indeed! I'm neck deep in dealing with bug fixes coming from software updates at work, so I'm very relieved that your process went smoothly. Mostly fixes for the surprise resets, I assume? Can you share what the source of that trouble was? Or were you updating NH's Twitter client software?

--Nick

[Alan Stern]

Indeed! I'm neck deep in dealing with bug fixes coming from software updates at work, so I'm very relieved that your process went smoothly. Mostly fixes for the surprise resets, I assume? Can you share what the source of that trouble was? Or were you updating NH's Twitter client software?

--Nick

Nick--

The new C&DH load (load 4.2) couple of dozen bug fixes and some new capabilities in terms of how we use the solid state recorder (easier indexing, for example). This coming week we put up a new and improved autonomy load (Autonomy 16). Then the week of the 2nd new Guidance & Nav flight software (load 4.1) goes up with one key bug fix that will improve scanning imaging for Ralph and a few more minor clean ups. Almost all of the fixes and improvements are based on Jupiter flyby and early ops experience we gained. We expect the new C&DH and G&C loads to be the ones we stay with the rest of the mission,

-Alan

ps. The C&DH resets are still w/o a root cause, but the new autonomy load has better response protection for when they do occur. Meanwhile, we are running ground testbeds very hard to trap out a reset and get to that root cause.

[hendric]

Alan,
Best of luck on that intermittent reset issue. I've had to debug intermittent issues before, and I can't imagine having to do that from billions of miles away! Does the reset occur on the testbed, and you're looking for a root cause, or does it not happen yet, and you're trying to duplicate it?

My favorite book on debugging is “Debugging: the 9 indispensable rules for finding the most elusive software and hardware problems” by David J. Agans. He has a free poster that I printed up for my cube at http://www.debuggingrules.com/ I wish it included the subheadings beneath the 9 rules, because that's where the really juicy hints can be found. Here's short presentation that has some of the details: http://www-sop.inria.fr/dream/seminaires/d...-16-11-2005.pdf

I've found that my best approach to solving bugs is to try and explain it to someone else. I usually end up thinking up 3-4 different possible causes just by trying to explain it, and I'm pretty lucky so far with those ending up being the real source. Works both ways too, I've had colleagues start describing a question to me for input, and before I even give an opinion, they realize they're missing something.

Anyways, I'm sure you've got the best team working on it and don't need my inputs!

[Alan Stern]

We're seen the resets on the bird, both pre-flight and in flight; now also on the simulator (test bed).
Because of slightly different manifestations these were not recognized as all the same thing until recently. So now the simulator is laced up with diagnostic tools to catch the next one in the act so we can, hopefully, get to root cause. As you say, we don't really have the option of debugging from the s/c resets ... We have very good people on this and have brought in outside experts from JPL, Marshall, the operating system code house, etc. for peer reviews of both the available data and the process we are using to get to the bottom of this. Of course, since the events are rare (MTBFs of months), it will likely be a while before we have a root cause. Hopefully, any events that occur up on NH will be similarly benign to the past ones, which our fault protection system (autonomy) has handled and recovered from well.

-Alan