The mission flyby description is now up.

975 km altitude, focusing on the southern hemisphere, lots of RADAR observations including a bit of SAR...

(sigh)...thanks for doing that, Del, was gonna do the same thing. (The sigh was missing Alex...)

These passes with lots of radar, gravity measurements and the like, are not nearly as immediately gratifying as the visual passes. But long term, we will learn more about the nature of the moons and the Saturn system.

I think the RADAR passes are the best. Granted we have to wait for processed data. But the SAR imaging always blows me away.

All the previous northern passes revealed the Titan winter lakes district. What will all these southern passes reveal? Now we know that liquid hydrocarbons condense out in the long northern dark.... what as been going on down south during the long southern summer?

Soon we will know.

Glorious.

Craig

No disagreement there from me, although overall balance is important



Actually I put it to you that we know no such thing. We 'know' (= 'are pretty sure that') there are liquid hydrocarbons in northern lakes, and there is evidence that the lake level changes. However, it is by no means certain that there
are appreciable lake level changes on seasonal timescales - could be mostly ethane slowly accumulating on geological
timescales, with methane merely tracking the ethane. And if there are seasonal lake changes, it isnt obvious
that there is accumulation in winter - after all, the rate of pan evaporation on Earth is higher in winter (windier, and dryer air - even though the precipitation is typically higher - it is precipitation minus evaporation that matters)

It's going to be fun to see the south (though T36 probably wont be far enough south to see lakes if they are
distributed in mirror image to the north) in future passes and trying to figure this all out....

R

Thanks for the correction rlorenz....

Very true that it is premature to jump to conclusions regarding seasonal effects. After all, we have not observed Titan over an entire seasonal cycle, nor will we in the near future.

Been eagerly awaiting these southern passes.

And I do not mean to negate the other instrument passes...... correct me if I am wrong, but RADAR cannot see the clouds, while VIMS can hint at composition.

What exciting times we live in.

Fun indeed!

Craig

The radar data frustrates the <expletive deleted> out of me, cause it's clear you really need much better than 100 meter resolution to really see the important geological details in most terrains. A future orbiter should plan to map all of Titan at 100 meter resolution, at worst, with sample capability <and the ability to build up local high-rez maps -- the whole return ultimately bandwidth-to-earth limited> at better than 25 meter resolution.

Of course, the CCD imaging frustrates me more, as we need a framing color camera with the same resolution in the 1.5 to 5 micrometer middle infrared. Impossible when Cassini was being built, possible now. We just can't see Titan's surface well enough, but we can see enough to make agonized progress and with swear-buckets full of qualifications. We're gonna have to make do for now. It's just that simple.

Testimony to how it's just not possible to design a one-size-fits-all interplanetary probe, mix up the sensors a bit, and fly the same thing to a different place every few years.

It's not just a matter of pulling one camera off and sticking another one on -- changing camera technology means changes to signal conditioning, data processing, transmission encoding, etc., etc. And that's not even considering the advances made from year to year in each of *those* technologies, either.

These things are designed to do certain things as efficiently as possible with not a milligram more mass than is absolutely necessary to do those things. That means they have to be specially designed to their tasks, each one unique to its mission.

If we were flying five to ten a year, an adjustable one-size-fits-all approach might work. But for flagship missions that fly every five to ten years? Nope.

-the other Doug

T36 approach RAWs are up

Some more images are up. This one is interesting.
http://saturn.jpl.nasa.gov/multimedia/imag...4/N00093734.jpg

Maybe tough to do, given that the thick atmosphere and huge scale height forces any orbiter to stay at a fairly high altitude.

Given the funding parameters, I don't think we'll see a Titan orbiter as the next mission there. I think it'll be an aerobot that observes from altitude along a long ground track (thousands of km), then sets down once on the terrain of choice and performs surface studies. Even better would be an aerobot that could make two or more surface stops, flying downwind each time. But that would be pricier.

That would provide very limited coverage, but very high resolution, with the hope that the track would cover representative terrains. Unfortunately, the northern lakes and the equatorial sand seas seem to be difficult to connect in one "trajectory" with the east-west Titanian winds.

If a single terrain had to be chosen for the next touchdown, it would probably be any sediment-rich area near the northern lakes that is not currently below the fluid line.

The cheapest mission plans for Titan run up estimates of approximately $1.6B, so any landed mission arriving also with an orbiter would run close to $3B.

Nothing's going to be cheap where Titan exploration is concerned. Drat it.

Narrow angle T36 mosaic at 2/3 original size, click to enlarge:


Further enhancement, 1/2 original size:


I don't think there's much more to pull out of the raws than this.

Context for the mosaic:

One word to you : bandwidth. An orbiter is the key element in any architecture - since Titan has
so much to explore, there is no single question to be posed to which there is a 1 bit, or 1 Gb answer -
you want to send Tb back, and that is hard without an orbiter as a relay. So you start with an orbiter
(which can, over 4 years, attain global coverage at 100m by SAR and at 2 microns) and add cool bits
from there.

I am pretty warmed-up on these questions - we (the APL/JPL/etc team) had our site visit from the
NASA review panel for the Flagship study - I myself got grilled for 3 hours.....

Flagship study reports should be released in the next month or so - that should explain everything.

stitched semi flat fielded images with various contrast skews for visual interest:

http://i225.photobucket.com/albums/dd78/al.../weirdorama.jpg

I thought the best ISS detail of the Huygens landing site was due to be taken on T35, and indeed there were some good ones there, but now it seems we have even better ones from T36. Does anyone know if this results from a change of plan or did I just misunderstand the plan in the first place? (Not important - just curious. I'm equally delighted to see them whenever they arrived!)

Does anyone else think they can see traces of dunes in these images?

If you're referring to my mosaic, that's vertical noise (mosaic is rotated 90 deg) in the original images. Different than the usual horizontal banding. The source of the noise wasn't characterized as of 2004 and it appears to be linked to camera telemetry mode - likely another form of electronic interference.

The following image shows why it's unwise to overinterpret raw ISS images (click to enlarge):


Exercise extreme skepticism when you see "features" perfectly aligned vertically or horizontally, especially on low contrast targets like Titan.

You won't see the dunes in these images. We can see dunes in some images with resolutions of 500 m/pixel, but this requires a lot of processing of the original, 12-bit data and requires sufficient contrast between dune and interdune areas.

First off thanks very much for the great mosaics - I should have said thet right away. I'm familiar with the vertical noise, which can indeed look cat-scratchy though its strict parallelism gives it away. No I'm seeing (or imagining) occasional vague hints of dark lines trending approximately 2 0'clock to 8 o'clock on your mosaic (and correspondingly rotated on the raws) though the precise azimuths vary somewhat. If nobody else picks up on it I'll easily dismiss it as wishful thinking.

OK thanks VP. I'll stop looking and wait for the professional publication!

I'll be excited to see those reports.

My fear is that a Titan orbiter will be the right plan but struggle with the planning and funding stage the way Europa Orbiter did. Of course, that worry isn't any less with other possible missions, so we have to pick the right mission first and then fight the good fight to get it aloft.

Using a Titan orbiter as a data relay seems to offer some new headaches. If the follow-on mission (aerobot, lander) is designed after data starts coming back from the orbiter, then it'll be one heck of a delay between the arrival of the orbiter and the arrival of the follow-on. The orbiter will have to have a very long lifespan to still be on the job.

On the other hand, if the follow-on is launched relatively soon after the orbiter, it makes it impossible to redesign the follow-on to accomodate new science. That's a minor concern -- a larger one is that we would have to fund two gigadollar missions to the same target in short order, and even Mars barely musters that level of funding (spread out over more missions).

The Titan program is going to have to be a Big Commitment from on high and win a second flagship mission against the field of other priorities in the outer solar system. It could be a battle royale between the tremendous interest inspired by Titan and the administrative inertia that makes such huge efforts difficult to undertake.

I really, really like the idea of a coupled orbiter-lander(balloon) mission to Titan.

This could be pretty similar to the Viking missions. The orbiter could give you SAR-RADAR, radiometry and further upper atmosphere chemistry studies plus would serve as data relay for the surface science package.

A real nicety would be to mount a SHARAD-type RADAR on the orbiter capable of penetrating 0.5-1 km below the surface to identify features buried below the dune sands, washed in sediments, or buried under the temperate polar schizzle.

IMHO the best surface science package would come from a balloon that would be capable of a reasonably sustained flight along an equitorial track. "Simple" hyperspectral imaging from below the cloud deck with less methane interference would give you data that would be able to identify and characterize a variety of different terrain types found in the Equatorial zones. [Xanadu continents, tectonic ridges and mantles, craters, cryovolcanoes, bright channels, dark channels, impact craters, bright center-dark halo objects, rotten terrain, dune sands].

The amount of characterization and detail from the Huygen's data when coupled with the SAR-RADAR data is incredible: Imagine doing this again for a different region or over a longer track?

If the balloon were able to "toe dip" and drag or touch a surface package onto the surface, nice instruments could include RAMAN and IR spectroscopy, GCMS, or some type of LCMS that could help "taste" Titan's surface and try to sort out the products there. Again, following the Viking missions, it might be possible to design experiments that would carry out chemical modifications then subject the resulting broth to chemical analysis to determine post-degradation components. Hopefully, this would give results that could work back to figuriing out the original chemical components.

[I don't think the "ping and fling" method of chemical analysis (direct injection into LCMS) is going to work on Titan. I think we need to do the "pour and roar" beforre we do the "ping and fling" (boil sample in 0.1N aq. HCl (for example), elute through SPE cartridge, then LCMS of isolated bands)].


A perfect track for a balloon would be right along the spine of Quivra. That region offers a really diverse target-rich environment. Starting at Sotra facula and tracking E, you'd hit a cryovolcano (Sotra Facula), channel, dune sands, dark channels, blue ice sand bay and shore margin, tectonic ridges, bright center dark halo objects and craters all packed in a 500 km ground track. (If we're willing to blow off Sotra facula and the W Quivra channel, you can get most of the above in a 125 km downwind ground track along Quivra.)

I will bet that there will be new terrain types that will show up as well as maybe even more exciting targets as Cassini unfolds. (Keep a watch on NE Shangri-La and W Senkyo basins).

-Mike

I like it too, but will the money be there?



I think real compositional data is going to require direct contact between the probe and the balloon. IR spectroscopy doesn't give us clear answers for Ganymede, which has no atmosphere. It could be useful, as you say, for mapping terrain types, with two to five touchdowns needed to ground-truth the IR data.

I think the mobility goal would be to start in an equatorial track and apply constant low thrust to the north so that the noodle of the ground track would spiral north, with the ambient winds providing the longitudinal motion. The ultimate would be to sample both the sand seas and highlands as well as the sediments, etc., seen around the arctic lake district.

Note that nightfall would put a damper on imaging the ground track. Maybe we'd want it to land every evening and take off again in the morning, if that didn't have too much engineering risk.

All three elements (Orbiter, Lander, Balloon) can fit on a single Atlas V

Oooo... ...aahh! Is that my spidey sense tingling as it does when I detect a Flagship proposal?

New press release, lakes near the south pole!

http://saturn.jpl.nasa.gov/news/press-rele....cfm?newsID=782

T36 RADAR Swath
Click to view attachment

hehe, finally! Will have this and T39 up on my RADAR swath page within one hour plus an ISS map with these swaths added

This swath is now added to my RADAR swath page:

http://pirlwww.lpl.arizona.edu/~perry/RADAR/

including the full-res version

There are some hisar swaths in T36 and T39 that I have not added, but will try to get to in the next few days. One of the T36 Swaths includes Selk, an impact crater first observed by ISS on T28.

Additional T36 RADAR Swath
Click to view attachment

Oh, what a beautiful crater.
Click to view attachment

Selk does look pretty nice: