Titan Exploration Options

by Paul Gilster on October 8, 2012

One of the challenges of running a site like Centauri Dreams is that deep space news accumulates so swiftly that it’s easy to focus on one issue while another timely story slips away. I don’t want to get too far past the European Planetary Science Congress, which ended in Madrid on September 28, without mentioning the interesting discussion of Titan that took place there. A new proposal for landing on the moon and sampling Ligeia Mare, its largest lake, was put forward to join previous Titan exploration proposals, all of them challenging yet doable.

Titan Lake In-situ Sampling Propelled Explorer (TALISE) is the brainchild of SENER, a private engineering and technology group that has provided components and subsystems for a wide variety of space missions. The idea is to land a probe in the middle of Ligeia Mare, near Titan’s north pole, and embark on a six- to twelve-month cruise to the coast, gathering data all the way. TALISE team member Igone Urdampilleta explains what makes TALISE different:

“The main innovation in TALISE is the propulsion system. This allows the probe to move, under control, from the landing site in the lake, to the closest shore. The displacement capability would achieve the obtaining of liquid and solid samples from several scientific interesting locations on Titan’s surface such as the landing place, along the route towards the shore and finally at the shoreline.”

The image below shows one TALISE concept, using paddle wheels on either side of the probe, but SENER’s studies involve several propulsion methods including screws and wheels. Working in partnership with the Centro de Astrobiología (Madrid), SENER’s work is considered a Phase 0 Study which now moves into a feasibility study that will develop a preliminary mission architecture. What all that boils down to is that this is an extremely preliminary concept that is a long way from becoming an actual proposal in response to an ESA science mission call.

Nonetheless, TALISE is an indication of Titan’s continuing hold on the imagination, with its lakes and rivers of liquid hydrocarbons and its thick atmosphere more suggestive of a planet than a moon. This boat concept joins a Johns Hopkins Applied Physics Laboratory design called Titan Mare Explorer (TiME) as another potential craft on Ligeia Mare, offering us an in situ look at a lake that may be at least tens of meters deep, one whose shoreline changes over time in apparent response to seasonal effects. We looked at Titan Mare Explorer last April in Splashdown on Titan.

Nor should we forget AVIATR (Aerial Vehicle for In-situ and Airborne Titan Reconnaissance), a 120 kg airplane that takes advantage of Titan’s thick atmosphere (with atmospheric pressure one and a half times greater than Earth’s) to soar the skies of the moon for up to a year, backed by efficient Advanced Stirling Radioisotope Generator (ASRG) technology. Aerial methods like AVIATR and various balloon designs have the advantage of being able to roam widely over the surface but a long-term Titan strategy will incorporate both landers and aerial craft. See AVIATR: Roaming Titan’s Skies and A Closer Look at the Titan Airplane for more on the latter designs.

Image: An artist’s impression of Titan’s surface near the shore of one of its lakes, the kind of view we might eventually get from one of the boat/lander missions. Credit: SENER.

You’ll recall that the Huygens lander was designed to float for a time if it landed on a Titanian sea, an outcome mission planners considered a distinct possibility. The interaction between liquid methane and the moon’s weather patterns would be a major area of investigation for any floating probe, as would the complex organic chemistry that makes Titan a unique laboratory for the study of how life develops. Moreover, the sheer drama of operating a craft in an alien lake — or like AVIATR riding the currents of Titan’s thick atmosphere — could enliven public interest, providing a needed boost to deep space planners faced with chronic funding shortfalls.

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{ 12 comments }

Michael October 8, 2012 at 9:38

I am surpised a hoover craft design has not been looked at, it would be able to roam almost anywhere, land and lake’s.

Brie A. October 8, 2012 at 11:29

I didn’t know Huygens was designed to float! That’s neat. A boat on Titan is an intriguing idea…. though it does sound tricky. Regardless, it’s great to see that our ideas for unmanned exploration are becoming more and more advanced.

http://tranquilitybaseblog.blogspot.com/

Leo Behe October 8, 2012 at 12:32

Our current search for habitability takes place upon a planet at the edge of the habitable zone- Mars. Titan is a much more interesting prospect given the fact that it is so far removed from the habitable zone; if we were to find life on Titan, we would show the habitable zone only to be a general reference point for life rather than a requirement. Additionally, with proof of life arising from conditions so different from our own (perhaps most significantly by using methane as a solvent rather than water), we would essentially be proving that life is ubiquitous throughout the cosmos.

JoeP October 8, 2012 at 13:48

I do think the last couple of sentences in the article here resonate: the psychological impact of high resolution photos (or even video) of such a craft operating on the surface of Ligeia Mare is a worthy goal, the science aside. And, of course, the science value is immense as well.

While I am constantly fascinated by all the data and photos returned from the various Mars landers of the past, a craft operating as a boat on an alien sea is opening a completely new faucet in exploration.

Waves? Wind? Storms? Methane rain? Perhaps some microbiological life forms to be seen via an onboard microscope in a sample of Ligeia Mare’s liquid?

Daniel Suggs October 8, 2012 at 15:53

I may be naive here, but, if we were going with one, why not both on the same mission? Also, why not design the ‘boat’ to be amphibious so we could do some ‘land’ sampling too? Wouldn’t we get more ‘bang for the buck’ by miniaturizing and doubling up?

Rob Henry October 8, 2012 at 16:15

I like the way this article uses “the complex organic chemistry that makes Titan a unique laboratory for the study of how life develops” as a motive for study, and not just the search for life.

There may well be no life on Titan, but its strange surface chemistry would still be almost as interesting as if there was. What are the most complex organics that develop there? Is there any stereochemical preference in any of it? How is all that hydrogen being absorbed, acetylene reduced, and thiolin destroyed.

Such studies have their own intrinsic fascination. The fact that they have potential to revolutionise or currently extremely poor understanding of processes involved in abiogenesis is just the icing on the cake.

It is true that there is also a remote possibility that there is life here, but we are best to downplay its search as a factor in sending a probe. Besides, if that reverse hydrogen flow data is correct and due to life, Titan’s biosphere should be so powerful that all but the most trivial investigations should find life if landing in one of its more suitable habitats.

Sedjak October 8, 2012 at 17:19

Poor Europa. Closer and with a chemistry we are more familiar with. A rover(s) could just trundle along to one of its infamous cracks and possible find signs of life.

If we do a Titan mission, then be sure to make space on the rocket for an adjunct satellite to study the spray of Enceladus.

ljk October 10, 2012 at 12:12

We could afford to do this mission and so many others if we wanted to. But our culture is still too backwards and insular, to say nothing of short-sighted, to have such a mission to Titan become reality any time soon.

Of course there are individuals and groups that do want this and look beyond our limited lives on Earth, but they have achieved neither the numbers or the clout to seriously affect the rest of society. We really do only have so much time before humanity wakes up; after that a few lucky ones may escape but the rest will be stuck here to watch our species and our civilization start regressing.

Earth cannot sustain our current civilization or our population numbers, and it certainly cannot handle an increase of both which is bound to happen without something critical giving way. But many people still think this won’t happen any time soon and the alpha males in charge have no interest in changing the status quo.

Yes, this is about much more than an academic study of a robotic mission to Titan, because its existence hangs on whether we can think and act cosmically or not.

JoeP October 12, 2012 at 16:01

I was thinking about this article again today, in light of the more recent articles and comments on the hopeful expansion of humanity into the whole solar system.

Which brought me to further contemplate manned exploration of this moon. How interesting and fun would that be! I imagine that a pressure suit is even not needed. A very well designed heating suit and oxygen might be all you need to get out and start exploring. Might even pack a picnic have a barbeque with an oxygen powered campfire; sort of an inverse gas grill. :) Just don’t go swimming the lakes or get caught out in the rain. (How fat would raindrops be in this gravity? Like grapes?) And flying is probably also quite easy to do with human power due to the low gravity and the density of the air.

Rob Henry October 14, 2012 at 22:42

Joe, you have really opened my eyes to the possibilities. And here was me thinking of the first explorers would be huddled behind thick protective walls.

The lakes would be particularly dangerous because of their low density, but if everyone had hydrogen filled “water wings” even swimming should be fine given sufficiently amazing insulation.

Methane is not so toxic that small whiffs of it would be noticeably toxic, but how do you prevent very cold air getting into you suit along with the piping hot BBQ chicken. Perhaps they would have an input area in the suit’s chest, and somehow use counter-current flow to solve the problem. As long as you can have one hand active outside the suit, and one hand inside the suit, it could be just like a conventional BBQ. Remarkable for you to have thought of that.

ljk October 16, 2012 at 16:31

16 October 2012

** Contact information appears below. **

Text & Images:

http://www.jpl.nasa.gov/news/news.php?release=2012-326

WHAT’S BAKING ON TITAN?

Radar images from NASA’s Cassini spacecraft reveal some new curiosities on the surface of Saturn’s mysterious moon Titan, including a nearly circular feature that resembles a giant hot cross bun and shorelines of ancient seas. The results were presented today at the American Astronomical Society’s Division for Planetary Sciences conference in Reno, Nev.

Steam from baking often causes the top of bread to lift and crack. Scientists think some similar process involving heat may be at play on Titan. The image showing the bun-like mound was obtained on May 22, 2012, by Cassini’s radar instrument. Scientists have seen similar terrain on Venus, where a dome-shaped region about 20 miles (30 kilometers) across has been seen at the summit of a large volcano called Kunapipi Mons. They theorize that the Titan cross, which is about 40 miles (70 kilometers) long, is also the result of fractures caused by uplift from below, possibly the result of rising magma.

“The ‘hot cross bun’ is a type of feature we have not seen before on Titan, showing that Titan keeps surprising us even after eight years of observations from Cassini,” said Rosaly Lopes, a Cassini radar team scientist based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “The ‘bun’ may be the result of what is known on Earth as a laccolith, an intrusion formed by magma pushing up from below. The Henry Mountains of Utah are well-known examples of this geologic phenomenon.”

Another group of Cassini scientists, led by Ellen Stofan, who is based at Proxemy Research, Rectortown, Va., has been scrutinizing radar images of Titan’s southern hemisphere. Titan is the only place other than Earth that has stable liquid on its surface, though the liquids on Titan are hydrocarbon rather than water. So far, vast seas have only been seen in Titan’s northern hemisphere.

A new analysis of Cassini images collected from 2008 to 2011 suggests there were once vast, shallow seas at Titan’s south pole as well. Stofan and colleagues have found two good candidates for dry or mostly dry seas. One of these dry seas appears to be about 300 by 170 miles (475 by 280 kilometers) across, and perhaps a few hundred feet (meters) deep. Ontario Lacus, the largest current lake in the south, sits inside of the dry shorelines, like a shrunken version of a once-mighty sea.

Scientists led by Oded Aharonson, another radar team member based at the California Institute of Technology in Pasadena, think that cycles analogous to Earth’s Croll-Milankovich cycles, which explain climate changes in terms of the way Earth orbits around the Sun, are at play on Titan, too. Such cycles on Titan would cause long-term transfer of liquid hydrocarbons from pole to pole. By this model, the south pole could have been covered with extensive seas less than 50,000 years ago.

“The seas on Titan are temporary hosts for experiments in prebiotic chemistry, and we know they are cycling from one hemisphere to the other over 100,000 years,” said Stofan. “I’d love to get a closer look at the seas of the north or these dry seabeds to examine the extent to which this prebiotic chemistry has developed.”

The Cassini team has confirmed some of the stability of Titan’s northern seas by looking at radar images from Cassini taken about one Titan season (in this case, six Earth years) apart. The newer images, from May 22, 2012, on the same flyby as the hot cross bun images, show the shorelines stayed about the same, indicating the northern lakes are not transient weather events, in contrast to the temporary darkening of parts of the equator after a rainstorm in 2010.

Contact:
Jia-Rui C. Cook
Jet Propulsion Laboratory, Pasadena, Calif.
+1 818-354-0850
jia-rui.c.cook@jpl.nasa.gov

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and ASI, the Italian Space Agency. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. The Cassini orbiter was designed, developed and assembled at JPL. The RADAR instrument was built by JPL and the Italian Space Agency, working with team members from the US and several European countries. JPL is a division of the California Institute of Technology in Pasadena.

ljk October 18, 2012 at 9:14

Wednesday, October 10, 2012

Too Exciting to Die? And Good Reads

Probably a couple dozen times a year or so, I come across a talk or a paper proposing a new planetary mission concept. If the idea is truly novel, or just really intrigues me, I’ll write about it in this blog. Usually, these ideas die as nothing more than paperware, victims of the winnowing of the many, many ideas proposed and the very few planetary missions that actually fly.

Recently, though, one concept mission received coverage in a number of blogs and news outlets. Interestingly, the mission is new only in proposing a twist on a mission that has been proposed and considered seriously several times before.

I’m talking about the TALISE Titan lake and shore probe presented atthe recent European Planetary Science Congress. At the time of the presentation, the concept remained in the early conceptual phase where many basic tradeoffs such as the instrument compliment remain to be decided.

What was novel about this proposal was the idea of attaching paddles, wheels, or screws to the lander so that after a period floating on a Titan lake, the probe could haul itself onto “dry” land to measure a different surface.

Full article here:

http://futureplanets.blogspot.com.es/2012/10/too-exciting-to-die-and-good-reads.html

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