Proposed NASA Mission Would Sail the Seas of Titan 197
The BBC has a report on a proposal that will be submitted to NASA for funding — a mission to Saturn's moon Titan that would deposit a lander on its hydrocarbon sea. (We recently discussed the widely-circulated photo of sunlight glinting off one of Titan's seas.) "The scientific team behind the idea is targeting Ligeia Mare, a vast body of liquid methane sited in the high north of Saturn's largest moon. ... 'It is something that would really capture the imagination,' said Dr Ellen Stofan, from Proxemy Research, who leads the study team. 'The story of human exploration on Earth has been one of navigation and seafaring, and the idea that we could explore for the first time an extraterrestrial sea I think would be mind-blowing for most people,' she told BBC News. ... The Titan Mare Explorer (TiME) has already been under study for about two years. It is envisaged as a relatively low-cost endeavor — in the low $400m range. It could launch in January 2016, and make some flybys of Earth and Jupiter to pick up the gravitational energy it would need to head straight at the Saturnian moon for a splash down in June 2023."
Are any non-profits doing anything like this? (Score:3, Interesting)
I would seriously be interested in donating maybe a hundred dollars toward something like this, and I can't be the only one. Are there any non-profit organizations that fund similar missions?
Titan Landing Probes (Score:5, Interesting)
Picture (Score:4, Interesting)
Wikipedia has a picture [wikipedia.org] showing the probe floating on Titan.
One question I can immediately see an answer to is whether the ASRG [wikipedia.org] generates as much power in vacuum as it will on the surface of Titan. My assumption is that having a weaker heat sink will reduce power output but I can't confirm that.
Re:Titan Landing Probes (Score:4, Interesting)
I suppose another way would be to build a balloon borne probe, probably using hydrogen for buoyancy. It could compress the hydrogen to land, and release hydrogen to lift.
hydrocarbons (Score:1, Interesting)
Where did this methane come from? The common wisdom is that terrestrial hydrocarbons come from old dead stuff. Maybe not?
This is exactly what we should be doing (Score:3, Interesting)
This idea is beyond awesome. Sending a "ship" to sail the seas of another world. And the price... $400 million... is uber-cheap in the world of space exploration.
Unless we can send a man to a near-Earth asteroid, this is the kind of exploration NASA should be doing... not manned attempts at Mars. Not yet.
Re:This is exactly what we should be doing (Score:3, Interesting)
What exactly are your prerequisites for a manned mission then?
Re:This is exactly what we should be doing (Score:5, Interesting)
What exactly are your prerequisites for a manned mission then?
My concerns here about manned exploration are twofold:
One, unless we're going to build a real, permanent base on the moon, and actually keep men there for extended periods of time, then we shouldn't be going back to the moon right now. It'd be a waste, and nothing more than reliving old glories without breaching new frontiers. And with declining budgets, if we actually did go back to the moon, we wouldn't stay. Again, it would essentialy be doing it just to say that we still could. A waste. So the first argument is about needless waste of funds.
Two, as far as the other oft-proposed trip... to Mars... we shouldn't do it because of cost, but mostly, because the technology just isn't there. Specifically, we're lacking a way to keep astronauts fed and healthy for the very long trip. Suspended animation is still science fiction at this point, so unless a true breakthrough in space travel speed is found, we currently have no way to send a bunch of men on a months-long journey to another planet and back, at least not in a manner that we can afford.
The asteroid mission right now is the only place we can actually land a man involving fairly short distances, and with the virtue of it being real exploration, literally where no man has gone before.
Re:Titan Landing Probes (Score:5, Interesting)
What's missing from this discussion, and so far as I can see from any proposal site discussions on this mission, is how to get the data back from the probe! If this is going to be a lander without an orbiter, you have a SERIOUS problem of how to get data back to earth. We talked about this very topic 5 years ago here [slashdot.org] after Huygens landed. People are going to want high-res images, audio and at least some video in addition to all the other basic science data from this mission. That is a HUGE amount of information to get back to earth from a billion miles out, while floating on a lake of CH4 under a thick atmosphere. The Huygens probe had 2 redundant, 8 watt, medium gain (partially directional) on board radio transmitters that sent all the data from the probe through the Cassini orbiter relay system. It took VLBI aperture synthesis, simultaneously using ~20 of some of the largest radio telescopes around the world JUST TO HEAR THE CARRIER SIGNAL of Huygens as it descended on Titan. We couldn't get any actual data directly from Huygens, we couldn't hear modulation of the signal clearly from that far away.
Huygens had a power budget from its NaS batteries of ~250W, you're not going to do much better than that with a sterling radioisotope generator for this proposed mission. So you have maybe 20W of radio power to use on this mission in order to get all your data back from Titan, you NEED to use a directional (high gain) antenna to do that. How the hell do you accurately and consistently point a high gain antenna directly at earth when rotating and bobbing around wildly while floating over the waves of a Titanian lake?!
Re:Are any non-profits doing anything like this? (Score:2, Interesting)
A better place to donate for space projects would be the Planetary Society's solar sail proof-of-concept project.
Re:Sailing the myriad seas? (Score:3, Interesting)
Well, conditions on the earth vary dramatically with location, even ignoring biological and biogenic variation. It seems to me that a vessel capable of performing tests over a wider area can't help but provide better data. One of the big downsides of the Mars rovers is that they're restricted to such a small portion of the planet's surface, especially since for the Titan mission this can apparently be achieved on a low budget. I mean, what reason do we have to think that the chemical composition of the ocean and atmosphere don't vary with location? What about things like currents, and winds? Maybe we'll find something that's entirely unexpected!
Maybe Star Wars was right and planets other than earth are all 'desert' planets or 'ice' planets with uniform conditions all around, but if not, this seems worthwhile!
Re:Sailing the myriad seas? (Score:5, Interesting)
There are a number of good reasons for doing this.
The primary objective of the mission would be to determine the precise chemistry of one of these lakes; but also to do meteorology, to help scientists better understand how the "methane-ologic cycle" on Titan actually works.
It would give scientists the opportunity to study shared climate processes at work under very different conditions.
"If we have models that will work on Earth and on Titan then we can be much more confident that those models understand the fundamentals of what's going on," explained the researcher from the Johns Hopkins University Applied Physics Laboratory.
"The photogenic appeal and the mystique of exploring a sea on another world speak for themselves, but there is a genuine practical application to do with the science that will help us address problems here on Earth."
Plus it's already been under study for two years, and it would test a "novel power system," the Advanced Stirling Radioisotope Generator.
ASRGs would give TiME sufficient energy to support a very capable instrument suite and a direct-to-Earth communications system to get its data home.
Not to mention that Titan looks like one of the best nearby candidates for life, specifically in its seas and not on its surface. Landing on Titan's shores is apt to be far less interesting than in its seas.
Europa or bust -- Titan sucks.. (Score:4, Interesting)
Maybe our agencies don't want to find life yet, as some societal and religious aspects of there being life somewhere else would drive the religious folk crazy, or maybe they don't want to contaminate Europa. Whatever the reason they need to get off of their collective rear ends (asses) and do a mission there before even going back to Mars. I just get tired of the new bright and shiny and unpaid for missions, and some of the more dumb funded one that just go in circles snapping images of useless real estate, when Europa truly deserves, on all levels, a serious series of missions that bring light to what resides under the ice.
Re:Sailing the myriad seas? (Score:1, Interesting)
And then of course there's the whole "exploring for the sake of exploring" thing. To get any real data we need to land something on Titan, and the most obviously interesting places are the methane lakes. You could land on a shore but with the dense atmosphere there's probably going to be waves and it's easier to just go ahead and build a boat then to build a crawler that can also tolerate being under water.
Re:Sailing the myriad seas? (Score:3, Interesting)
Re:Sailing the myriad seas? (Score:4, Interesting)
> Sail around to find more liquid methane?
Sail around and observe thousands of miles of shoreline. Study the atmosphere and seabottom at widely separated points. This ship will travel farther in a day than a Mars rover can in a month.
Kill the alien life while looking for it? (Score:3, Interesting)
The story of human exploration on Earth has been one of navigation and seafaring
The story of human exploration on Earth has also been one of spreading disease and wiping out indigenous populations. Bacteria are known to survive the radiation and vacuum and cold of space quite nicely, thank you. I do not think this is a good way of looking for alien life.
Re:Are any non-profits doing anything like this? (Score:4, Interesting)
http://en.wikipedia.org/wiki/Student_Space_Exploration_&_Technology_Initiative [wikipedia.org] might be closest to what you want, they are building lunar orbiter, to be launched in 2012 (and they already have some major successes http://en.wikipedia.org/wiki/SSETI_Express_Satellite [wikipedia.org] ); though I don't know if there's a way to donate, or if they even need it.
Or pick one of the teams from Google Lunar X PRIZE; not only you should find some with great chance of success, but also accepting donations.
Re:Why titan? (Score:3, Interesting)
Titan is interesting because, in many ways, it is probably similar to primordial Earth, frozen in time. Even with low temperatures still the most similar place to our planet in the Solar System.
Re:Titan Landing Probes (Score:4, Interesting)
I don't know about the "small influx of energy," that's basically one of objects of research here. The Sun is definitely far away, but Saturn is close, and its gravitational interference should be considerable, so far that Titan is locked in position just as our local Moon is. There are also clouds forming and dissolving, which must influence the weather.
perhaps the lander will use strong signals transmitted to it from Earth as a beacon?
Let's say the distance from Earth to Saturn is 10 A.U. (it varies, obviously). That would be 149.60×10^10 meters. The path loss (using the Friis transmission equation [wikipedia.org]) is 300 dB at 30 GHz. Antennas of Deep Space Network give you gain of 80 dB. The antenna on the lander, as a guess, will give you 40 dB at best [wikipedia.org] if it is a fixed parabolic dish. 300 - 80 - 40 = 180 dB (in either direction.) If we transmit from Earth at 1 MW [wikipedia.org], that would be 90 dBm. Then the signal at the front end of the receiver on Titan will be -90 dBm. This is not a problem in itself, modern receivers can work with even smaller signals. A ham receiver (like K3 [elecraft.com]) will detect a signal at -136 dBm within 500 Hz.
But there is still a problem. High gain antennas have, by definition, a narrow beam. It's like a telescope. But you can't look through a telescope to find a star! Your field of vision is too small. But if you make the beam wider the signal disappears! So here is the catch 22 - you can receive the signal from Earth only if you already know where it is coming from :-) Phased antenna arrays are kind of convenient for beam-forming on the fly, but they are typically not as good as a simple dish (or else we'd all use only them.)
There may be a way to do it still. First of all, you may make your receiver so good that it will detect the signal even with antenna configured for a wide beam. You only need a few bits per second at that stage. It helps a lot that you are swimming in the sea of cryogenic liquid, you can cool your front stage somewhat - not as He would allow, but still -160C is better than nothing.
Alternatively, look for a signal with a wide beam, but that signal won't be coming from Earth. Find a stronger signal - from the Sun, or from some pulsars, or from anywhere else that can be used as a good astronomical marker. That assumes that your communication system covers the right frequency band.
But all in all, it's too much risk for such a trivial [today] problem. Your mission may easily fail just because the lander can't find Earth - and that happened more than once with other probes, it's not unusual. Especially when you don't have a clue what you are landing into. If I were to plan the mission, I'd splurge on a proper set of one orbiter and one or two landers. It's a good distance to Saturn, many years in transit, so you want to make one mission count. Cost should not be such a concern when you are doing the most complex rocket science that there is.
Re:Sailing the myriad seas? (Score:3, Interesting)
Or it could be like a Swiss cheese: round, flat, and hollow at the same time.
Re:don't just sail it, mine it (Score:3, Interesting)
> But if we do run out of oil here, we'll have to get the raw materials to
> make plastics from somewhere. Titan seems as good a choice for that purpose
> as any.
Much cheaper to simply use water, air, and any handy source of carbon.