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

[cIclops]

Redux an earlier post. While browsing through the summaries of the recent Lunar and Planetary Science XXXVI (2005) Conference this paper about maximizing mission science return caught my attention. It outlines a successful flight experiment onboard the EO-1 spacecraft called the Autonomous Sciencecraft Experiment (ASE).

This type of software based intelligence demonstrated the capability to make decisions on instrument targeting and to optimize the data stored and transmitted. For the critical close encounter phases of the mission this may be extremely valuable.

no less than 287 days before launch

[Decepticon]

During the jupiter flyby will we be doing Moon science?

I would love to see any surface changes on Europa since the Galileo Mission.

[john_s]

During the jupiter flyby will we be doing Moon science?

I would love to see any surface changes on Europa since the Galileo Mission.

Yes, we'll be doing plenty of Jupiter moon science, though there are a few constraints that will limit what we can do. Primary constraint at the moment is limited onboard storage capacity, and the fact that we want to keep data management as simple as possible- we won't be able to do multiple write/download/erase/rewrite cycles on our solid-state-recorders, for instance. There's also the unusual problem that when your cameras are optimized to work at 30 AU, everything at 5 AU looks very bright, and we'll be saturating at minimum exposure on many of our targets. Our best views of Io are likely to be taken in Jupiter-shine rather than sunshine, for instance.

Despite these constraints, we'll be taking images and near-infrared spectra of all the satellites. Surface changes on Europa won't be a high priority, because the lack of changes between Voyager and Galileo epochs, in images at much higher resolution than we'll be able to get with New Horizons, make changes between Galileo and New Horizons unlikely. But we'll be cataloging surface changes, plumes, and hotspots on Io, and making near-infrared spectral composition maps of the satellites at higher spectral resolution than Galileo. We'll also be watching Jupiter eclipses of the satellites to study their atmospheres.

We can't make final plans till after launch, when we'll know the precise trajectory, the Jupiter flyby date, and the satellite viewing geometrys. Then we'll have a few months of hard work to come up with a detailed plan that makes the most of this unique opportunity.

[Decepticon]

Thanks for the quick answer!


As long as global imaging of Europa will be done, I'll be VERY happy!



I'm so excited about this mission.

[john_s]

As long as global imaging of Europa will be done, I'll be VERY happy!

Sorry, but it's unlikely that we'll get complete global imaging of Europa, because due to the overexposure problem we will only have a narrow strip of unsaturated terrain near the terminator in each image, so it would take too many images to build up complete coverage. Even on Io, where global imaging is higher priority, we probably won't achieve that goal. But we'll do our best...

Glad you're excited about the mission- so are we!

[Guest_Sunspot_*]

I want to see Io......

....I miss Galileo

[tedstryk]

I do too. I would like to see a Galileo-2 type mission. It could probably be developed more quickly than a Europa orbiter. With a high data rate and a very large data recorder, it could really send back some incredible shots. My bias against the Europa orbiter is basically my hands down rejection of the case that Europa is more interesting than the other moons. I think it is one member of a four part set that all need to be understood (in addition to the planet and inner moons) in order to understand the Jovian system (and outer moons, if they are not all captured asteroids).

[Decepticon]

I'm curious if there is a trajectory map is available threw the Jupiter system?


Also will any close encounters with asteroid's on the way out?



Sorry for all the questions, the main horizon page does not cover these questions in detail.

[djellison]

I'm curious if there is a trajectory map is available threw the Jupiter system?

As John said - not until after launch. The exact launch date will define where the jovian moons will be at the flyby - and launch windows and elv's being what they are - the only time you can guarentee when you're going to leave the ground is when you've done it :0

Doug

[cIclops]

With its 20cm scope NH will be able to perform a population survey of the Kuiper belt by direct imaging and by measuring dust debris, what search strategy will be used?

282 more days and nights before launch

[john_s]

With its 20cm scope NH will be able to perform a population survey of the Kuiper belt by direct imaging and by measuring dust debris, what search strategy will be used?

282 more days and nights before launch

We don't plan to use New Horizons for Kuiper belt population studies by searching for individual KBOs. Even though it will be much closer to its little piece of the Kuiper Belt than ground-based telescopes, that won't make up for its lack of aperture compared to the 10-meter class telescopes back on Earth, and the narrow data pipeline back to Earth will also limit the area that we could cover. We'll be directly sampling the dust in the Kuiper Belt with the Student Dust Counter, which has no particular strategy- it simply records the dust particles as we run into them. It's also possible that we'll be able to image the sunlight scattered by Kuiper Belt dust, as you suggest, though I don't think we've studied this possibility in detail yet- the likely faintness of the "zodiacal light" at such large distances from the sun will be a challenge. The dust is particularly interesting because it can be directly compared to the dust we see in the "Kuiper Belts" around other stars, where we have no hope of seeing individual asteroid-sized bodies.

New Horizon's biggest contribution to our understanding of the Kuiper Belt will of course come from its close-up studies of Pluto, Charon, and the other one or two KBOs that we fly past- an area where ground-based facilities can't hope to compete.

[hendric]

John,
I never saw an answer to a previous question about using NH's position to take astrometry. Would it be a worthwhile thing to do?

[cIclops]

We don't plan to use New Horizons for Kuiper belt population studies by searching for individual KBOs.  Even though it will be much closer to its little piece of the Kuiper Belt than ground-based telescopes, that won't make up for its lack of aperture compared to the 10-meter class telescopes back on Earth, and the narrow data pipeline back to Earth will also limit the area that we could cover.  We'll be directly sampling the dust in the Kuiper Belt with the Student Dust Counter, which has no particular strategy- it simply records the dust particles as we run into them.  It's also possible that we'll be able to image the sunlight scattered by Kuiper Belt dust, as you suggest, though I don't think we've studied this possibility in detail yet- the likely faintness of the "zodiacal light" at such large distances from the sun will be a challenge.  The dust is particularly interesting because it can be directly compared to the dust we see in the "Kuiper Belts" around other stars, where we have no hope of seeing individual asteroid-sized bodies.

Yes NH has only 20/1000 of the resolving power of Keck but Keck has to peer through the atmosphere and NH will be right inside the Kuiper belt. What is the smallest KBO resolvable by Keck at 60AU - 100 kms? NH will have better resolving power than Keck for at least an AU in all directions *continuously* for several years. An automated onboard survey would greatly reduce the load on that narrow data pipe. Imaging the Kuiper dust should yield information about the object density assuming that it is generated by collision processes.

A survey of smaller KBOs should be possible with NH that is beyond Keck's capability to compete. In any case NH needs something to keep it busy once it has finished its KBO flyby

[Alan Stern]

The major contribution NH will make to understanding the size distribution of KBOs
will be documenting the crater size-frequency distributions on Pluto and Charon (and
KBOs--if we get that far--as we hope we will).

Our 1 km-resolution maps will allow us to count craters due to impactors
as small as 100 m-- something one can't detect from Earth, even at 40 AU.
The hi-res LORRI images near C/A will get craters as small as perhaps
50 m, thus due to impactors of scale 5 m size!

Most interestingly to me, Pluto's rapid atmospheric escape should have generated
one to several km in surface loss over 4 Gyr. This is thought to have, "wiped
the slate clean" over time, so that Pluto's surface should show only craters
from the "present-day" KB. Charon, with no atmospheric loss, should however show
the time-integrated history of impacts stretching back almost to its formation, when
the KB is thought to have been much more massive. Comparison of the two should
be fascinating.

-Alan

[john_s]

John,
  I never saw an answer to a previous question about using NH's position to take astrometry.  Would it be a worthwhile thing to do?

You mean astrometry of stars for parallax determination? It's possible we could do something useful in that area. Our highest-resolution imager, LORRI, has pixels about 1 arcsecond in size, and we can measure star positions to an accuracy of a few tenths of a pixel. This is pretty good, though we can't compete for precision with specialized satellites like Hipparcos in Earth orbit, which though it only had a 2 AU baseline to work with, compared to the 30 or 40 AU we'll get from New Horizons, could measure star positions to 0.001 arcsec or better. We do have one advantage over Hipparcos, though- we can look at much fainter stars, magnitude 16 or fainter compared to Hipparcos' limit of about magnitude 12. So maybe we could get some useful parallax measurements of a few high-priority targets that were too faint for other techniques (if technology at 1 AU hasn't caught up with us by 2015!). But we couldn't do a wide survey- it would take too much bandwidth and maneuvering fuel that we need for our prime mission.

Good questions- keep 'em coming!