A proposal to send a "boat" to explore the seas of Titan

December 19, 2009 12:44 PM

A proposal will be submitted to NASA to send a "boat" to explore the hydrocarbon seas of Titan
posted by Lobster Garden (65 comments total)

They should send a spacecraft that carries an apparatus that takes in Titanian methane to synthesize rocket fuel for a return trip.
posted by Anything at 12:49 PM on December 19, 2009

The problem would be synthesizing the oxidizer.
posted by dunkadunc at 12:51 PM on December 19, 2009 [1 favorite]

Will it be a whaling boat?
posted by Sys Rq at 12:51 PM on December 19, 2009 [4 favorites]

Titan has oceans full of rocket fuel? That's pretty awesome.
posted by empath at 12:52 PM on December 19, 2009

The Titanic?
posted by wolfewarrior at 12:57 PM on December 19, 2009 [11 favorites]

Also included in the proposal: Plans for a skipper, professor, millionaire, millionaire's wife, movie star, a delightful girl-next-door-type, and a semi-retarded deck hand.
posted by Cool Papa Bell at 1:01 PM on December 19, 2009 [12 favorites]

Why can't we ensure that T-Pain is on this boat?
posted by mightygodking at 1:10 PM on December 19, 2009 [4 favorites]

Wikipedia article

Since solar panels are out due to the thick atmosphere, they will have to use a radioisotope generators as mentioned in the BBC article. Unfortunately that is kind of a stumbling block. IIRC the Cassini mission had to push through a lot of negative PR because there were worries that if the launch had to be scrapped the RTG would fall back to Earth and disintegrate, spewing plutonium all over the place. Of course the flight paths are chosen so that this would happen over uninhabited ocean, but at the time I recall a lot of negative press from concerned environmentalists.
posted by Rhomboid at 1:10 PM on December 19, 2009

Will T-Pain be on this boat?
posted by blaneyphoto at 1:11 PM on December 19, 2009

But wait now -- aren't the seas and lakes dry at least part of the time? I thought they were at least somewhat seasonal. So would this "boat" be part walker as well?

Insert "I, Row-boat" joke here.</sla,,?
posted by Guy_Inamonkeysuit at 1:14 PM on December 19, 2009 [1 favorite]

Oops.
posted by Guy_Inamonkeysuit at 1:15 PM on December 19, 2009

Possibly related^SLYT

OK, not really. But it was the first thing I thought of...
posted by Decimask at 1:18 PM on December 19, 2009

Every time I submit a proposal to NASA they just send it back, with a note about the Sirens of Titan being fictional.
posted by scodger at 1:25 PM on December 19, 2009 [3 favorites]

Say hi to the Nommo while you're up there boys!
posted by mannequito at 1:38 PM on December 19, 2009

If I had a boat
I'd go out on the ocean
And if Matt gave us a pony
I'd ride him on my boat
And we could all together
Go out on the ocean
Me upon my pony on my boat
ON TITAN!!!!
posted by eriko at 1:38 PM on December 19, 2009 [1 favorite]

IIRC the Cassini mission had to push through a lot of negative PR because there were worries that if the launch had to be scrapped the RTG would fall back to Earth and disintegrate, spewing plutonium all over the place. Of course the flight paths are chosen so that this would happen over uninhabited ocean, but at the time I recall a lot of negative press from concerned environmentalists.

I don't know if this has changed recently, but I thought RTGs were designed so that they'll survive re-entry intact. In the late 60's, there was a launch failure of a NASA weather satellite, and they managed to fish the intact RTG off the ocean floor and re-used it for a later satellite.
posted by FishBike at 1:39 PM on December 19, 2009

They should send a spacecraft that carries an apparatus that takes in Titanian methane to synthesize rocket fuel for a return trip.

Rocket fuel includes it's oxidizer. Since there's none on titan, that would be kind of difficult. Although I suppose they could electrolyze the water in the ice that he lakes sit on, but that would take a lot of energy.

According to wikipedia Titan actually has a liquid water layer underneath the ice that the lakes sit on. You actually have hydrocarbons on top of ice, on top of water, on top of more ice.

What really interests me is the liquid water underneath the ice. Presumably titan could support life if there were any energy sources underneath the ice. (but would there be? probably not)
posted by delmoi at 1:44 PM on December 19, 2009

Sweet.
posted by From Bklyn at 1:47 PM on December 19, 2009

Rhomboid: "Wikipedia article

Since solar panels are out due to the thick atmosphere, they will have to use a radioisotope generators as mentioned in the BBC article. Unfortunately that is kind of a stumbling block. IIRC the Cassini mission had to push through a lot of negative PR because there were worries that if the launch had to be scrapped the RTG would fall back to Earth and disintegrate, spewing plutonium all over the place. Of course the flight paths are chosen so that this would happen over uninhabited ocean, but at the time I recall a lot of negative press from concerned environmentalists."

But now we also have the issue of Russia being all stingy with their plutonium.
posted by Science! at 1:48 PM on December 19, 2009

space boat!
posted by Jon_Evil at 1:51 PM on December 19, 2009

I thought RTGs were designed so that they'll survive re-entry intact.

That could very well be the case; I've always been personally dismissive of the naysayers in these cases. I seem to recall that their argument acknowledged that it was exceedingly unlikely, but nevertheless there was resistance. Maybe my memory is exaggerating their impact.
posted by Rhomboid at 1:52 PM on December 19, 2009

Sea of hydrocarbons, eh?

Name it the Condoleezza Rice II.
posted by mr_crash_davis mark II: Jazz Odyssey at 1:55 PM on December 19, 2009

Put deployable heated electrodes on it. Splash down. Deploy electrodes. Electrolyze the water ice into hydrogen and oxygen.

Spark.

Watch the fireworks without a telescope, from Earth.

What?
posted by Splunge at 1:55 PM on December 19, 2009 [2 favorites]

What really interests me is the liquid water underneath the ice. Presumably titan could support life if there were any energy sources underneath the ice. (but would there be? probably not)

Doesn't ice-water-ice suggest that something is making the water warmer than the surrounding ice?
posted by weston at 2:16 PM on December 19, 2009

Space boats? Well then that means the possibility of SPACE PIRATES!
posted by Ron Thanagar at 2:23 PM on December 19, 2009 [1 favorite]

Go, robots, go! I'll be quite old when this lands (asuming no delays) but I'm still behind this one.
posted by chairface at 2:27 PM on December 19, 2009

Consider me educated regarding oxidizer. Now, let me put forth my hypothesis that there are hot nude photographs in the moon's core melting the ice from the inside.
posted by Anything at 2:27 PM on December 19, 2009

Doesn't ice-water-ice suggest that something is making the water warmer than the surrounding ice?

I think there are some pretty large gravitational tidal forces there, yes? The liquid water might just be under a lot of pressure.
posted by echo target at 2:40 PM on December 19, 2009

Doesn't ice-water-ice suggest that something is making the water warmer than the surrounding ice?

Lake Vostok is a liquid water lake under 3km of antarctic ice.
posted by neuron at 3:23 PM on December 19, 2009 [2 favorites]

The Searcher by James P. Hogan
posted by Confess, Fletch at 3:44 PM on December 19, 2009 [2 favorites]

Lake Vostok is a liquid water lake under 3km of antarctic ice.

I just mentioned that in another thread. (The one about the 'ghost mountains') Seems like there's a lot of similarity between Titan and Antarctica.
posted by delmoi at 3:57 PM on December 19, 2009

Fletch: The only bad thing about all this Titan research is that it has incontrovertibly moved The Code of the Lifemaker from the might-happen column to the yep-it's-fiction column.
posted by localroger at 4:08 PM on December 19, 2009

Will the Titan MeFites please register their latitude and longitude for the meetup. Who wants to walk into a Titan bar looking for MetaFilter blue T-shirts?
posted by Cranberry at 4:33 PM on December 19, 2009

I thought RTGs were designed so that they'll survive re-entry intact.

They are now -- Apollo 13's LEM had one for the ALSEP package that was to be left on the moon. It's now near the bottom of the Tonga Trench.

However, in 1968 (IIRC), a Transit satellite failed on launch. It almost made orbit, and then burned up on reentry, destroying the SNAP-9 RTG onboard. ²⁴⁰Pu was definitely detected in the atmosphere, so there's no question that that particular RTG failed open into the atmosphere.

Nowadays, they're all built to survive reentry from earth orbit, but there was some question with the Cassini probe. It was fine on a launch failure, but there was a later gravitational boost pass of Earth, at significantly higher velocity than orbital, and there was some discussion of what if the probe hit the atmosphere at that speed.

The chances were very low (and became none after the Venus pass -- when the probe's orbit was analyzed, we knew it wouldn't hit Earth.) but possibly not zero -- the RTG may not have survived a high speed reentry.

But given the fact that we dumped the SNAP9 on Madagascar, and we didn't see millions of deaths, I think the risk was basically ignorable.
posted by eriko at 4:43 PM on December 19, 2009 [4 favorites]

Is there any way to ensure S. Palin is on the "boat"?
posted by Balisong at 5:17 PM on December 19, 2009 [1 favorite]

All they are going to find are statues of three beautiful women.
posted by drezdn at 6:01 PM on December 19, 2009

Earth saw clmate chnge4 ions;will cont 2 c chnges.R duty2responsbly devlop resorces4humankind/not pollute&destroy;but cant alter naturl chng

From here


Can we vote her off the planet now?
posted by Balisong at 6:08 PM on December 19, 2009

Earth saw clmate chnge4 ions;will cont 2 c chnges.R duty2responsbly devlop resorces4humankind/not pollute&destroy;but cant alter naturl chng

Jesus fucking Christ. Can we get a referendum going to vote on flying Sarah Palin and her brood directly into the heart of the sun?
posted by Blazecock Pileon at 6:27 PM on December 19, 2009

Isn't Titan supposed to have an average temperature of - 290 degrees Fahrenheit, around twenty degrees Fahrenheit above nitrogen's boiling point? I wonder what kind of craft would be able to endure two years on the surface of Titan and be able to operate to send data back to earth.
posted by millardsarpy at 6:33 PM on December 19, 2009

One chock full of plutonium, I suppose.
posted by ryanrs at 6:36 PM on December 19, 2009 [1 favorite]

I wonder what kind of craft would be able to endure two years on the surface of Titan and be able to operate to send data back to earth.

It's an interesting engineering problem. Those radiothermal generators we've been talking about produce a fair bit of waste heat, which could be quite useful combined with really good insulation. I suspect it's a much easier problem than trying to reject heat into a super-hot environment, like you'd have to do to make something survive for a long time on the surface of venus, say.
posted by FishBike at 6:40 PM on December 19, 2009

Generally speaking, space is cold. But we seem to have solved that problem, what with Voyager probes and Mars satellites zooming around doing useful science. A mission to Titan will have many unique engineering problems, but low temps aren't one of them.
posted by ryanrs at 6:48 PM on December 19, 2009

Generally speaking, space is cold. But we seem to have solved that problem

That's because space may technically be cold but because it is near vacuum it doesn't act like what we think of as "cold". There is no thermal conduction of heat; heat loss only occurs by radiation. So despite space technically being cold overheating would be a far greater problem. You don't need to insulate, you need to enhance heat dissipation.

Cooking inside your spaceship is more likely than freezing.
posted by Justinian at 7:43 PM on December 19, 2009

Well, if the craft heats up to much, wouldn't it cause the hydrocarbons to boil, or the ice to melt underneithe it? Seems like we would need something that could not only keep itself warm, but not enough to cause melting/evaporation.
posted by delmoi at 7:49 PM on December 19, 2009 [1 favorite]

So regular aluminum finned heat sinks don't work in space? My Raedion G-force 5000 will hate it out there.
posted by Balisong at 8:44 PM on December 19, 2009

Heat sinks work but at a far lower efficiency so you'd need REALLY REALLY MASSIVE heat sinks.
posted by Justinian at 8:54 PM on December 19, 2009

Is there any way to ensure S. Palin is on the "boat"?

Not an issue. You can see it from Alaska. She'll probably walk there to hunt from a helicopter.
posted by Splunge at 9:57 PM on December 19, 2009

Cooking inside your spaceship is more likely than freezing.

That's not true. The Ulysses probe ceased operation when its hydrazine fuel froze. The last spacecraft we sent to Saturn, Cassini-Huygens, needed 117 radioisotope heaters to maintain its temperature (82 on the orbiter, 35 on the lander).

You underestimate heat loss due to radiation. Using the Stefan–Boltzmann law, I calculate that a black body at 0°C and far from the Sun will radiate 316 W/m². Deep space probes have an electrical power budget of several hundred watts and a surface area ≫ 1 square meter. Thus the problem is one of too little heat, not too much.
posted by ryanrs at 12:03 AM on December 20, 2009 [3 favorites]

As a completely pedantic aside, interplanetary space is technically very very hot. Being a near-vacuum, however, it has very little capacity to hold and conduct heat, so you mostly end up exchanging heat with the sky, not with the space near you. As anyone who's spent a night in the desert has found out, the black parts of the sky are very cold. 3 Kelvin, mostly. (The sun is hot enough, though, that if it occupies very much of your sky at all it skews the average temperature way up, as anyone who's spent a day in the desert has found out.)
posted by hattifattener at 1:09 AM on December 20, 2009

Well the individual molecules can be several thousand degrees, since there's so few if them that they haven't lost much speed due to collisions since being shot out from the surface of the sun. But when it's averaged out with the blackness, it's still about 2.75 degrees Kelvin. The definition of temperature is the ability of the object to give off thermal energy. If any object hotter than 2.75 degrees is radiating heat into space rather than vice-versa, space really is that cold, pedantry or no.
posted by Zalzidrax at 9:43 AM on December 20, 2009

ALL THESE WORLDS ARE YOURS
EXCEPT TITAN
WHICH IS AN EXCLUSIVE YACHTING CLUB
MEMBERS ONLY
posted by panboi at 10:44 AM on December 20, 2009 [3 favorites]

There was enough enthusiastic interest in the idea that I've gone ahead and put the plan in motion.
posted by well_balanced at 11:59 AM on December 20, 2009

No, that's not quite right either. It doesn't make sense to assign a temperature to a system that isn't in thermodynamic equilibrium. For example, what's the temperature of a warm glass of water with an ice cube in it? The water is warm and the ice cube is cold. You have to wait until the ice cube melts before you can determine the temperature of the combined system.

Interplanetary space is not in thermodynamic equilibrium. It's mostly protons, but there are so few of them, they rarely bump into each other. The mean free path (the average distance between particle collisions) is similar to the distance from the Earth to the Sun. So there isn't much averaging going on with respect to particle speeds. And since the temperature of a gas is related to average particle speeds, it doesn't make much sense to talk about the temperature of space. Space isn't hot or cold; space is a bunch of hot and cold particles zipping about independent of one another.

One of those particles is your spacecraft. For the sake of this example, we'll assume you forgot to fill it with fuel and didn't turn on the electronics (you suck!). With no power to keep things interesting, the temperature of your dead spacecraft will be determined by the net energy flow between it and the rest of the universe. Energy absorbed, such as light from the distant stars, increases your temperature. Energy lost, such as your own infrared glow, decreases your temperature. When these energy flows are equal, your temperature will be in equilibrium.

There are not many ways to lose energy in space. The most significant by far is black body radiation. Like all things with a temperature above absolute zero, your dead spacecraft glows. At normal operating temperatures, this glow is in the deep infrared. The infrared photons you emit each carry away a minute bit of energy, cooling you. The closer you get to absolute zero, the less you energy you emit. Absent any incoming energy, this radiative process will cause your temperature to fall to 0 K.

However, incoming energy is not zero. In the inner solar system, you'll pick up a ton of energy radiated by the Sun. That incoming radiation will warm you up quite a bit. Alternatively, you might find yourself further afield, orbiting one of the outer planets. Like you, these planets glow in the deep infrared. If you're nearby, this infrared light will dominate your incoming energy flow. But assuming you're far from any planets, the dominant energy you'll absorb will be the Cosmic Microwave Background Radiation. This background radiation is the faint afterglow of the Big Bang. The entire sky shines dimly in the microwave frequencies, peaking at about 160 GHz.

At 0°C, your spacecraft will be emitting a whole lot more energy in the infrared than it will be absorbing from the microwave background. Thus you will have a net outflow of energy and your temperature will fall. But as your temperature decreases, so too will your infrared emissions. Eventually you will reach a temperature where the black body radiation you emit will equal the cosmic background radiation you absorb. When that happens, you will have reached the magic temperature that brings you into thermodynamic equilibrium with the rest of the universe. And that temperature is 2.725 K.

Tl;DR: Space doesn't have a temperature, but if you stick a thermometer in it, it'll read 2.725 K.
posted by ryanrs at 12:25 PM on December 20, 2009 [5 favorites]

I'm stowing aboard 'er and will hoist the Jolly Roger when we make moonfall. Who's with me?
posted by Halloween Jack at 1:28 PM on December 20, 2009

Heh, I was going to go into the temperature-is-not-well-defined-without-equilibrium thing but I decided that might be too pedantic even for me. Good explanation though.

Still, you are saying the same thing as I was: the temperature of the space you're in isn't what affects the temperature of your spacecraft; the temperature of the sky you see is what determines the temperature of your spacecraft. The sky's temperature is dominated by averaging the 3-Kelvin black parts and the 5800-Kelvin surface of the Sun. Though, if you're near Earth or another planet, you need to take that into account as well.

(As a thought experiment, though: take a chunk of interplanetary medium and put it in a perfectly insulating box and wait for it to thermalize. What is its temperature? Answer: very hot. What is its heat capacity? Answer: very little.)
posted by hattifattener at 1:54 PM on December 20, 2009

So how do they intend to A) keep the "sea" from boiling from the craft's heat; and B) prevent the thing from sinking? Said sea likely to be of very low density, lower that of water.
posted by Guy_Inamonkeysuit at 2:11 PM on December 20, 2009

Hattifattener, my disagreement was with the comment following yours. Not even disagreement, exactly. I just wanted to explain how space can be both cold and hot at the same time.

(I was also going to make a joke about Sweden, but I chickened out.)
posted by ryanrs at 5:03 PM on December 20, 2009

Cooking inside your spaceship is more likely than freezing.

Yep. On the cruise to the moon, the Apollo CSM would be put into a 3 degree per second roll to prevent on side of the spacecraft from overheating. The crews called it "Barbeque mode"

If the shuttle cannot open the cargo bay doors after launch, it will reenter and land as soon as possible -- inside the doors are the radiators needed to keep the Shuttle cool.
posted by eriko at 5:22 PM on December 20, 2009

That's not true. The Ulysses probe ceased operation when its hydrazine fuel froze. The last spacecraft we sent to Saturn, Cassini-Huygens, needed 117 radioisotope heaters to maintain its temperature (82 on the orbiter, 35 on the lander).

It is true. There's a vast difference between a probe and a manned vehicle. See eriko's post above. "Barbeque mode".
posted by Justinian at 5:29 PM on December 20, 2009

Guy_Inamonkeysuit, the answer to both your questions is foam, or perhaps aerogel. That is, the craft will be lightweight and well-insulated.
posted by ryanrs at 5:30 PM on December 20, 2009 [1 favorite]

More importantly, there's a vast distance between Earth and Saturn. Hang out near the Sun and you'll get hot.
posted by ryanrs at 5:36 PM on December 20, 2009

Just to add a little bit more pedantry, the equilibrium temperature of an object in space even depends on the material and finish of its surface. Materials always emit and absorb equally well at any particular wavelength (their "emissivity"), but can have different emissivity at different wavelengths. Or put more simply, not everything is grey throughout the whole spectrum.

The spectrum an object radiates is a function of its temperature, and its emissivity at each wavelength. Being cooler than the sun, an object in space wants to radiate a different spectrum than it's receiving from the sun. Specifically, the sun radiates more in the visible light range, while a colder object radiates more in the infrared, relatively speaking.

So if you, for example, coat it with something that has low emissivity in the visible light spectrum ("looks white"), but high emissivity in the infrared, it will radiate heat well, but won't absorb it from the sun very well. The result is a relatively cold equilibrium temperature. White teflon is an example of such a material.

Whereas the same object, coated in paint with high emissivity for visible light ("looks black"), and low emissivity in the infrared, will absorb heat from the sun quite well, but won't radiate it very well. It'll be quite hot as a result.

It gets even more interesting when the object is something that also generates its own heat internally--but even in that case, materials like white teflon make relatively good radiators even when the sun is shining on them, whereas (for example) paint that's also "white" well into the infrared does not.
posted by FishBike at 6:16 PM on December 20, 2009

FishBike, what if you make a hot object and a cold object as you describe, then connect a heat engine between them? That shouldn't work, should it? It feels kinda illegal. If you're exploiting anisotropic illumination to segregate two heat reservoirs, then it's not going to work well with CMB.
posted by ryanrs at 6:55 PM on December 20, 2009

FishBike, what if you make a hot object and a cold object as you describe, then connect a heat engine between them? That shouldn't work, should it? It feels kinda illegal.

No more illegal than putting a heat engine between two objects, one of which shades the other from the sun (so the sun-lit object gets hotter than the shaded one).

If you're exploiting anisotropic illumination to segregate two heat reservoirs, then it's not going to work well with CMB.

This effect definitely relies on illumination from objects of at least two different temperatures, such as the sun and the cosmic background radiation. The radiative equilibrium temperature must be somewhere between the temperatures of those two things, and messing around with emissivities that vary with wavelength just allows you to adjust where the equilibrium temperature will be within that range.

No violating the laws of physics by making something hotter than the sun or colder than the cosmic background is possible this way. And if everything the object can "see" is the same temperature (e.g. cosmic background in really deep space), then that's what the equilibrium temperature for the object will be, too. In that case, it works out that the effect can never be quite large enough to maintain a temperature difference, and we are saved from having to explain how something could be permanently hotter or colder than its surroundings.
posted by FishBike at 8:41 PM on December 20, 2009 [1 favorite]

Great thread. I can hear all the sf writers hereabouts (me included) sharpening their pencils.
posted by Guy_Inamonkeysuit at 12:36 PM on December 21, 2009