Splashdown on Titan?

by Paul Gilster on April 10, 2012

Getting to the stars may involve a sudden breakthrough — we can’t rule out disruptive technologies, nor can we predict them — but my guess is that interstellar flight is going to be a longer, more gradual process. I can see a sort of tidal expansion into the outer system, forays to Mars, for example, followed by reassessment, retrenchment, then one day deeper study of Jupiter’s moons with advanced robotics that can get under Europa’s ice. The search for life may become so provocative that we have to explore Titan and Enceladus with human crews, and the imperative for planetary protection may help us further tune up our deep space technologies.

The thing is, one wave of exploration inevitably begets another. Let’s put no timeframe on that kind of expansion because, like the tides, it may surge at times and then fall back, hostage to budgetary problems and waves of public interest that can as easily ebb. But I could see an eventual civilization that extends throughout the Solar System and, in shaping its essential infrastructure, pushes its propulsion and life support systems to begin exploring out into the Kuiper Belt and beyond. This assumes that we keep doing what we can right now, with resources that are stretched thin but may still give us something like the AVIATR airplane on Titan, or perhaps an instrument package that can splash down in one of Titan’s seas.

We build the Solar System infrastructure one step at a time, and our robotic missions have given us a glimpse of what is waiting for us. Imagine the scientific return when we can begin sending human crews to some of the places so far glimpsed only by our probes! But the probes come first and the Titan Mare Explorer (TiME), which Johns Hopkins Applied Physics Laboratory (JHU/APL) champions, is a cost-capped $425 million mission concept that would parachute a robotic boat right into Ligeia Mare, the second largest of Titan’s northern seas. Active mission time on Titan would be 96 days, with a launch between 2016 and 2018 if TiME is chosen over two competing proposals as a NASA Discovery-class mission. We’ll know the answer to that later this year.

Image: Ligeia Mare, in Titan’s northern polar region, could reveal its secrets to the TiME probe following a 2023 splashdown. Credit: NASA/JPL.

Every time we get a closer look at a distant world (think Cassini), we find compelling reasons to revisit the destination with ever more sophisticated technologies. Voyager and Galileo ramped up interest in Europa’s hidden ocean, and it’s likely that a Neptune orbiter would tell us things about Triton that might compel a future mission there. A major player in all this, of course, is the search for life, which makes Enceladus well nigh irresistible along with more likely targets.

As for Titan, it is already the site of the farthest landfall in human history, and it could now become the first place in which a probe lands in an alien sea. The interaction between liquid methane and ethane with Titan’s climate and weather patterns would be a prime area for study, but TiME would also look at the kind of complex organic chemistry that may be similar to what led to life’s formation on Earth billions of years ago. Says TiME project scientist Ralph Lorenz:

“These are disciplines that, to this point, have been strictly Earth science. How are heat and moisture exchanged between the ocean surface and atmosphere? How are waves generated? We have an opportunity to explore these processes in a completely different, alien environment.”

A 2009 presentation to the Decadal Survey by principal investigator Ellen Stofan (Proxemy Research) notes that the lakes and seas of Titan are probably at least tens of meters deep and may extend down beyond 100 meters, and they clearly play a major role in the overall methane cycle on the moon. Ethane has been detected in Ontario Lacus near the south pole, and the same lake shows changes to its shoreline over time that suggest seasonal effects. A key goal of TiME will be to examine the methane cycle and show its similarities and differences from the hydrologic cycle on Earth from the probe’s unique vantage point awash in Ligeia Mare.

Like AVIATR, the TiME mission would also offer a useful technology shakeout of the Advanced Stirling Radioisotope Generators (ASRGs) that would provide power for the probe, both in the deep space environment and in a non-terrestrial atmosphere. This first nautical exploration of an extraterrestrial sea could be providing science from Titan by 2023, including imagery from Ligeia Mare’s surface showing us clouds and rain moving across the moon’s orange skies. As I speculated last week, the choice of TiME would probably make the AVIATR airplane mission less likely to fly, given the inexorable logic of budgeting. We may be looking, then, at a choice between two compelling concepts to deepen our exploration of Saturn’s most intriguing moon.

Related: Planetary Lake Lander is an attempt to study these technologies right here on Earth, with implications for what could fly aboard the TiME mission. From Five Steps Toward Future Exploration, in Astrobiology Magazine:

The Planetary Lake Lander project is led by Principal Investigator Nathalie Cabrol of NASA Ames Research Center and the SETI Institute, and involves a three-year field campaign at Laguna Negra (Black Lagoon) in the Central Andes of Chile. Here the team will test mission scenarios and technologies for deploying a floating, robotic platform that can perform scientific studies remotely while swimming the waters of Laguna Negra. Ultimately, this work will pave the way for a lake lander mission to Saturn’s moon Titan. NASA has never attempted a lake landing before, so this field campaign is an essential first step in identifying the challenges that mission developers must contend with when they turn their sights toward the methane lakes of Titan.

You can follow the ongoing work of the Planetary Lake Lander project here. From the most recent blog entry (December 15, 2011), as the team prepared to return to the US, leaving the robotic device behind to monitor Laguna Negra:

Our plane takes off at 9:15 pm the following evening, and we are back in the US and home by 11:00 am on December 17. The morning air is clean and brisk, not unlike that of the lake, where for now, PLL is a reminder that we were there. It is logging data every hour and calling “home” (at NASA Ames) every evening, sharing more knowledge about melting glaciers and climate change. In a few months, it will be proactively monitoring the environment at Echaurren, as a precursor to what, maybe some day, another Lake Lander will do on Titan.

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{ 14 comments }

James D. Stilwell April 10, 2012 at 10:05

Little baby steps…
CONTACT
Keep going…
JDS

Mark April 10, 2012 at 10:26

If they do “land” a boat I hope they’ll put some sort of tethered undersea camera on it to view what’s under the surface. Imagine landing on a lake here on earth and looking around, you’d miss almost all of the action which is below the surface. Of course it would have to have some serious lighting on it to illuminate the murky depths.

What materials would the hull of such a boat have to be made from to withstand the severe cold? Maybe something like the space shuttle tiles?

ljk April 10, 2012 at 12:19

I really like the design of the Planetary Lake Lander patch, to say nothing of the idea of something from humanity being able to float in an alien lake. What is the actual difference between a lake and a sea? Is it just the size?

It is a shame that our current culture may force us to choose between either a flying or floating mission to Titan. Both projects together would cost only a bit more than what we have been spending each month in Iraq. Our priorities continue to remain skewed, to use a polite word about it all.

Phil April 10, 2012 at 13:27

How will mission planners monitor Titan’s surface for TiME in order to choose a landing site? Cassini is scheduled to be done in 2017 and this doesn’t launch until 2016, or 2018 and land until 2023. Are they that sure that surface features won’t change while the probe is en route?

Michael April 10, 2012 at 14:10

AHovercraft is a must.

Joy April 10, 2012 at 16:18

I like AVIATR as well, but TiME is cheaper and has less technological risk, therefore more hope of funding. Go TiME! Of course, on an alternative Earth where the nations are not crippled by servicing mountains of debt, both missions could easily be funded.

Rob Henry April 10, 2012 at 20:30

Unlike Apollo, we know we have the technology and economic resources to complete this incredible mission, but ljk and Joy point out reasons that we can be gloomy.

To ljk I say that many of the same factors that drive us to war drive us to also drive discovery adventure and expansion. Our high expenditure on war proves that we can find surpluses for tasks that can only benefit our wellbeing in the very distant future, if at all.

To Joy, I point out that the economic structures that are in place are there because they have worked so far and have proved reasonably stable. Perhaps they are amenable to total collapse, but perhaps not. All of us realise the we could do better, but we must have consensus on how before anything can be done.

If those here focus on what we can achieve, we might well redirect all our energies to encourage a mission that has potential to inspire humanity and, in turn, refocus it on how extraordinary our own world is, and how petty our own differences. Also how important far distant goals are.

Kenneth Harmon April 10, 2012 at 22:48

Paul,

I certainly agree with the path you laid out in your article, especially in terms of what can be accomplished in the 21st Century. If one believes the Web Site 21st Century Waves, and despite todays pessimism based on todays thinking there will be 2 Maslow windows in the 21st Century to really push forward both manned and unmanned Space exploration, and even colonization. These are approximately 2015-2025/2027 and `2071-2081/2085. The other decades will simply extend and enhance what is achieved in those Maslow Window time periods of roughly 10-15 years (The last one was 1959-1972, and they happen about every 56 years from the start of the previous one) so that by the end of the 21st Century, and barring a major Global catastrophe that sets back Human Civilization we should have the beginnings of a Solar System wide Civilization even without any Kurzweilian Singularity. The only quibble I have with your article is that in your tentative Space Exploration and Colonization “Road Map” of sorts you do not include unmanned and even manned exploration of the Alpha Centauri system as a “stretch goal” and even without some sort of fundamental breakthrough in Physics.

I certainly understand that there is an order of magnitude difference in distance and therefore difficulty and cost to reach the Alpha Centauri system, especially by 2100 CE. However, if something of real interest is detected there through various observation methods it seems to me that a major “demand pull” will ensue, and a means will somehow be found to get there since it can be done even with known Physics. In essence, the Alpha Centauri system is just close enough to be “workable” or brute forced with known technology and likely engineering advances in the 21st Century, i.e it is more of an Engineering problem then a Physics problem. This is in contrast to a destination that may be very interesting or highly desirable, but where given known physics it is simply to far away to be “brute forced” somehow if required even if it were as little as 7-10 Light Years away.

Bottom line, while Alpha Centauri would clearly be an Interstellar journey (even if we followed a stepping stone approach), and therefore would require a quantum leap in technology and engineering from current levels, given its proximity it should be included as part of any enhanced Solar System wide exploration/colonization program for the 21st Century as an extension or transition phase objective to true Interstellar exploration. If we find some sort of habitable planet this close, and as hard as the challenges will be, we will get there and much quicker then is generally believed to be feasible today. The demand pull will drive Human ingenuity assuming a habitable planet is detected.

anooo April 11, 2012 at 0:47

Too bad that moon-sized lake methane can’t help the earth on its energy crisis problem that is happening right now………..

Paul Gilster April 11, 2012 at 8:03

Kenneth Harmon writes:

The only quibble I have with your article is that in your tentative Space Exploration and Colonization “Road Map” of sorts you do not include unmanned and even manned exploration of the Alpha Centauri system as a “stretch goal” and even without some sort of fundamental breakthrough in Physics.

I take your point, Kenneth, but I was really thinking just in Solar System terms in the article because the focus was on the Titan lander. Alpha Centauri — assuming we find interesting planets there — is much a part of the road map I have in mind as we proceed further out, and I do believe we’ll get there one day, though I’m very dubious of the idea that it will be in this century.

henk April 11, 2012 at 12:38

Paul Gilster

what if we find a marslike planet there is it still just as interesting to go there ?
I think it is but how will other people think about it. Are we only going to alpha centauri if there is a habitable planet arount one of those stars.

what if the closest habitable planet is to far away. What are we going to do then ? and still if we find a planet like earth doesn’t mean we can walk on that planet like we can walk on earth because it have a different evolution.

we need to be open to all possibilities

Kenneth Harmon April 11, 2012 at 20:56

Essentially what I am arguing is that the Alpha Centauri system given its relative close proximity to Sol/Terra is potentially a unique case that straddles Interplanetary and Interstellar Exploration. Therefore, if something of major interest is found there it should be thrown into the “Extended Interplanetary Exploration” category as part of any comprehensive road map and “stretch goal” for “Interplanetary Exploration and Colonization” in the 21st Century. This is not simply an argument about labels. Instead, it is an argument to perhaps think about the problem a little differently from today, especially as we set longer term Space Exploraton goals for the 21st Century. By placing Alpha Centauri unmanned and manned exploration within the circle of very hard, but still feasible, albeit just barely, it will start to be taken much more seriously in future technology planning, investment and development. Consequently, if some sort of Global Interplanetary Exploration Institute is established within the next couple of decades as some have proposed, the unmanned and manned exploration of the Alpha Centauri System should be included in its charter as an ultimate objective and as a precursor to the Interstellar Era. Admittedly, the only thing that would warrant such an inclusion in the relatively nearer term “feasibility circle” of “Extended Interplanetary Exploration” in the 21st Century would be if a habitable planet or clear evidence of an Alien Civilization was found around Alpha Centauri, and the Aliens were then deemed to not pose a danger.

What I am attempting to argue is that if (and admittedly this is a big if) a habitable planet was found right next door to Sol/Terra in the Alpha Centauri system this would be such a major “prize” that it would create a major discontinuity from the normal evolutionary approach to exploration and technology development. The “demand pull” function from this discovery would spur basic scientific, technical, and engineering investment and developments decades and perhaps even a Century or more before they would normally occur, especially on an more evolutionary path. In essence a true “Black Swan” event for which a placeholder should be created just in case. I suspect that serious development of Antimatter propulsion would be first up on the agenda as a race of sorts developed to find ways to get to Alpha Centuari within the following 50-75 years even if things had to be brute forced with extensive risk. Such a “prize” almost within our fingertips would become simply irresitable to Human plans and schemes starting with those of “visionary Politicians”.
This situation is in contrast to finding a habitable planet say 20 LY’s out that while it is still close is going to be very hard to get to no matter how much we may want to. No doubt if such a habitable planet were found 20 LY’s from Sol/Terra the hunt would be on for various breakthrough physics concepts, and there would be extensive investment in such areas. Unfortunately, there would not be a sense of real urgency or a race to get there like there would be if something just close enough was found, and while very, very hard to reach was viewed as still feasible. In essence, proximity would drive demand while something even a little further out would be seen as “unobtanium” until there was some physics breakthrough which could take Centuries.
In the past calculations have been made by Freeman Dyson and others that an Interstellar Spaceraft would cost somewhere between $1 Trillion and $10 or even $100 Trillion. While one can argue the $100 Trillion figure, to gain access to a new planet for a mere $10 Trillion might be very tempting indeed or as they say in the trade, “the juice would be worth the squeeze”. Finding a habitable planet or evidence of a non hostile Alien Civilization in the Alpha Centauri system would turn something that may seem dubious now for the 21st Century into something that was much more practical in retrospect. In essence, even as a “near Kardashiev 1 Civilization” circa the late 21st Century we could get to Alpha Centauri, although it might be very expensive and risky. And if by some chance Pete Kurzweil is right about some sort of Singularity occuring by 2045-2050 then we should certainly be able to do this by 2100 CE if not before, but only if there is a driving reason to do it.
However, it should also be noted that there might be a huge down side risk to finding a habitable planet or a friendly Alien Civilization right next door to us. With two Solar Systems to work with including one with a Trinary Star system, interest may diminish for many Centuries to come in exploring anything else in detail except through remote observation. In essence, for those who dream about some sort of Star Trek situation developing circa 2200-2500 CE, the discovery of a habitable world so close in the Alpha Centauri system could be both a blessing and a curse as everything is focused on this as a practical end state objective using known technologies and engineering. Under this scenario planet X around Alpha Centauri becomes “the new Mars” and this stretch goal along with the even more practical Interplanetary Exploration and Colonization goals becomes the almost exclusive focus to the detriment of everything else. In short, why even think about something as hard as 20 or 50 LY’s out when there is a lot to keep us pre-ocupied for many Centuries to come in our immediate neighborhood or right next door. At that point there might be a tremendous temptation for Humanity to “go short and go long” with the long focused on the truly exotic to the detriment of everything else in between.

Eniac April 12, 2012 at 20:09

Kenneth,

I certainly understand that there is an order of magnitude difference in distance and therefore difficulty and cost to reach the Alpha Centauri system, especially by 2100 CE.

More like three orders of magnitude, really, which makes it quite awkward to lump one in with the other.

ljk April 21, 2012 at 11:05

African Lake Has a Twin on Titan

by Jason Major on April 19, 2012

A large lake on Saturn’s cloud-covered Titan seems very similar to the Etosha Pan, a salt-encrusted dry lakebed in northern Namibia that periodically fills with water. As it turns out, Titan’s “great lake” may also be temporary.

Ontario Lacus, so named because of its similarity both in shape and size to Lake Ontario here on Earth, was first discovered near the south pole of Titan by the Cassini spacecraft in 2009. Its smooth, dark appearance in radar images indicated a uniform and reflective surface, implying a large — although likely shallow — body of liquid.

Full article here:

http://www.universetoday.com/94706/african-lake-has-a-twin-on-titan/

To quote:

The inherent otherworldly nature of Etosha Pan is further underlined — and perhaps foreshadowed! — by its use as a backdrop in the 1968 sci-fi film 2001: A Space Odyssey.

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