Amundsen and Scott were names for the DS2 microprobes, so that's out.

Argh...right, right...bummer!

Hmm. Wonder if there are any historical Aleut, Inupaq (sp?), or other "Eskimo" sailors? Should be; they were seafaring people, albeit limited in sortie length by environmental constraints. A name from that tradition would also be quite appropriate (esp. since the mission would be targeted for the north polar area of Titan).

Call it the Cuyahoga. Volatile organics and all that.

Do those count as real spacecraft?

How about the Fram?

http://en.wikipedia.org/wiki/Fram

Sailed further north and south than any other wooden ship.

They certainly weren't fake.

Obviously NASA can set the rules any way it wants. But for the Mars Exploration Rover naming contest, any name ever used for any spacecraft in the past was out, which eliminated what many considered the most obvious choices for their names: Lewis and Clark. (2005 was the bicentennial of the start of their expedition, so it would have been very appropriate.)

The names of the Vikings that discovered Greenland and North America about 1000 years ago are names that for obvious reasons look like obvious choices to me (although which spelling of their names to use (English, Icelandic, the spelling used 1000 years ago or even Norwegian) isn't totally obvious).

That said, I hope TiME gets selected. It looks like an extremely interesting mission, especially when keeping in mind that there's no flagship mission to Saturn in sight for the next 1-2 decades or more. I'm pleasantly surprised at how interesting/ambitious all three proposals look considering that these are 'only' Discovery missions. Chopper is my second choice (there has been a lot of Mars missions over the past 15 years).

Hey - we could call it TiME.

To be sure. The clock is indeed ticking; to answer my own question, the final selection apparently happens in June 2012.

I agree ! And I'd add soma other names to the list : Jean-Baptiste Charcot or his ship "Pourquoi-pas ?" ("why not ?" in english), or Jules Dumont d'Urville or his ship "L'Astrolabe"...

It would never happen in a gazillion years, I'm sure, but I'd love it to be called "Nautilus", after Captain Nemo's famous craft that battled the Kraken in Jules Verne's book...

Perhaps Champlain would be a good name, since he named/explored Lake Ontario.

They could, but they won't.

Not an explorer, but – Coleridge: “We were the first that ever burst / Into that silent sea”.

[EDIT for misquotation first time]

"Parachute Landing On Puddle"

PLOP!

Or maybe...

"Small Polar Landing And Sailing Heroically"

SPLASH!


Phil

(had to bring it down to my level eventually)

Titanic?

Or -- since Time is a raft -- Kon-Tiki. (It's the only famous raft name I could think of.)

How about the good ship ARGO. (I don't have to tell you what the team members will be called)

Huckleberry? Not the name of a raft itself...
But TiME allows for many more puns

Personally I like Fram and Endurance. These names looks really appropriate for such cold place.

A ship out on one of the Great Lakes in cold nasty weather... I've got it! How about the Edmund Fitzgerald?

Hmmm .... that one sank and was not heard from again ... sad to say.

So did the Endurance. But thanks to Shackleton's heroics, everyone on board survived.

I am still amazed every time I think of that feat. His ship crushed by the ice... no radio or communication of any kind with the outside world. Yet he didn't lose a single sailor. If you have never read that story, do yourself a favor and do it now.

For that matter, in his earlier expedition attempting to reach the South Pole, he turned back around 100 miles from his goal, based on consumption of their supplies, and the estimated time to return to their base. Scott later made it to the South Pole, and received posthumous honors for his bravery. (Everyone in the party died on the way back). But I would have preferred Shackelton as my leader.

David

Stu, We need to keep that name in reserve... for the first submersible explorer of Europa's oceans!

David

Though there's the sad story of Mrs Chippy, ship's cat.

Andy

Cat's are a law unto themselves, ours called "Chase" is no exception.

Heck, call it James Caird.

a technical question: any idea of the data rate of TiME and of the amount of data expected from the primary mission?
I get the impression that there will not be enough bandwidth for serious imaging

My concern too - coupled with the brief mission after a long silent cruise (no flyby science at Jupiter) - makes me prefer the other options.

Phil

On the other hand, it's gonna have gobs of power, WAY more than, for example, the MERs & other solar-powered spacecraft. I imagine that TiME might run dual-transmitter during the primary mission as is planned for NH, which should provide adequate bandwidth for image & data return.

Just because TiME will use an ASRG (or two) does not necessarily mean more power than a solar-powered soacecraft. It is independent of distance from Sun. But then it will also be at Saturn distance, not quite as far as NH will be, but still much farther out than MER. As with solar flux, comm power goes down by inverse square of distance, and TiME will not have a big high gain antenna. To a first order, my guess is TiME comm bandwidth will be an order of magnitude less than that of Cassini.

Since it will be out of line of sight to Earth for at least half of Titan's orbit, TiME may use rechargeable batteries to increase peak power during the times it can transmit to Earth similar to MSL for driving.

An extremely crude back-of-the-envelope calculation: Assuming an antenna/transmitter comparable to Cassini's but 10 times smaller you get approximately 1000 bps. That's over 10 times the typical Galileo rate on a spacecraft with fewer instruments where everything is designed with that data rate in mind, unlike the case with Galileo. Of course, lacking more information, this is all highly uncertain but it seems to me the data rate must lie somewhere between 100 and 10,000 bps and even the lower number gives you a great mission (just look at Galileo).

I'm on board. There's no fatal flaw with the mission. Bring it on and reveal the chemistry.

Thinking more about this, the Galileo LGA might be a better analogy than Cassini's HGA since it would probably be difficult to aim a narrowly focused signal to Earth. But even that should give you a respectable data rate for a mission like this.

And of course, as long as the descent imaging and initial panos can be stored, some have said the view might not change all that much.

Might be cool to watch for weather, though. Clouds and fogbanks. But that can be done with thumbnails and highly compressed images to see whether there's weather.

"any idea of the data rate of TiME and of the amount of data expected from the primary mission."

In very similar Titan Lake Probe study was DTE data rate 400 Mb/32 days. This is around 500 bits/s, relatively nice data rate from such great distance.
For 3-months primary mission it's approx. 1.1 Gb. For example, this is equivalent of 400 1 Mpix images with lossless compression or around 2000 images with lossy compression.

Except that the vast majority of the data will probably be GCMS results, which are a little less photogenic, albeit very scientifically valuable.

Maybe out of sight less than half Titan's orbit. How long would Titan actually be behind Saturn, or close enough to prevent communication?

Good point. Roughly speaking the Earth should be visible for about as long as the sun; from the polar regions basically 'round the clock until the next equinox. It will be getting pretty close to the horizon, though.

I suppose engineering specifics are way down the road on this, but I can't help but wonder what kind of materials and design they are going to use for the "hull" of this vessel. It's been a few decades since I studied materials science, but intuitively it would seem that it's going to be difficult to isolate the heat from whatever warm-electronics-box will be buried in the craft's interior, not to mention protruding instrumentation. Compared to the temperatures internal to most spacecraft, it wouldn't take much to nudge the outer structure a couple of degrees above the boiling point of the liquid it will be floating in (-250 -260 F or whatever the exact figure is).

The other issue that comes to mind is the mechanical characteristics of whatever outer cryo-materials will be used. They are going to need structural members that will survive launch vibration conditions and still retain or resist changing ductility and brittle conditions over such a wide temperature range during and post-EDL. It's going to be a fascinating process and I can't wait to read about the engineering challenges and solutions.

Titan will still go behind Saturn every 16 days as it orbits. But the actual time that Saturn blocks signals should be very short. Based on Saturn radius of 60,000 km and Titan orbit radius of 1,200,000 km, I calculate that Titan is blocked by Saturn for less than 1/60th of its orbit.
Click to view attachment

This only happens near the time of the Saturnian equinox as seen from Earth.

So it won't happen at all during the TiME mission?

No, it won't happen (unless you get a *very* long extended mission).

Dan - I wouldn't have thought that sort of temperature isolation would be an insurmountable technical challenge provided you don't want to put any active components on the outside of the hull. The JWST has active components sitting in the cryosection at around 35K connected to the ISIM (the Integrated Science Instrument Module) that operates at ambient (300K) via a 4m cable that requires some serious engineering so it is possible but I suspect that the mass of the multi-stage cooling system required to allow that would not be possible on TiME.

So, if TiME really is above the horizon (from Earth) for the length of the mission, and Saturn never blocks the line of sight, then TiME should be able to transmit data constantly throughout the three month mission. There may be technical or logistical reasons why this is not possible, I don't know, but it should be theoretically possible, I imagine.

One thing to consider is that TiME will require VERY long periods of DSN use since the bitrate is going to be relatively low. That may be as much of a limiting factor as anything else.

I'm glad to see that you lot are thinking about all this - fun, isnt't it?

Obviously I'm not going to go into specifics but it is possible to address some of the questions that have
come up in very general terms.

Materials/temperatures - guys, come on. Huygens operated in this environment until its batteries ran
out. Launch vehicles - to say nothing of the liquified natural gas industry - deal with cryogenic fluids
all the time. Of course heat leaks and insulation need to be designed appropriately, and material
properties at the relevant environment must be considered, as they do on Mars and Venus or in vacuo.

Communications - some cogent discussion on the thread. This has been thought about a lot for Titan
balloons too. I'll remind readers that many cruise ships, and drones for that matter, use gimballed
antennas for satellite communications. Again, not trivial, but a familiar and soluble problem.

As for data - have a look at the Huygens or Pathfinder or any other mission's balance of data volume
between imaging, composition, meteorology etc. On any mission this balance gets struck somehow (and
indeed it can often be tuned during the mission)

Thanks for responding Ralph. My actual concern was not so much the low temperatures affecting the TiME craft as the other way around. If it drops down in that hydrocarbon sea and then sets it boiling and steaming that would seriously affect instrumentation's ability to collect data would it not? If nothing else images would be difficult. With respect to terrestrial cryogenic industrial uses, to the best of my knowledge none of that equipment is required to go through launch vibration tests at STP and then transition to high loads and stresses in cryogenic environs. My armchair recollections are that materials which are strong and ductile at one end become fragile and brittle at the other end and vs. vs. Certainly the temperatures we are dealing with are substantially lower than any of the Mars craft were designed for, and then finally the whole notion of the vehicle in contact with an ocean of liquid adds a heat capacity component to the materials calculations that is barely a factor in the gaseous 0.01 atm on Mars.

I'm certainly not questioning your knowledge or understanding of the conditions (I read your book), just outlining my line of thinking that caused me to pose (perhaps in-artfully) the previous question.

Dan

I realize your questions are well-intentioned and motivated by your excitement about this mission (an excitement
that is widely shared). The fact is that any measurement perturbs its subject (qv quantum theory)
and this applies to a warm lander on Titan, a warm lander on a comet, or a geophysical lander on Mars that couples
wind energy into the ground.

It is also a fact that a Phase A study is just that, a study. Only one of the three missions under study is likely to fly (and NASA
reserves the right not to fly any of them!). Remember too that USMF is read by many in the planetary science community.
Thus people who may be reviewing study reports in the future and deciding what flies could be reading your question.
Developing a full answer that satisfactorily addresses your question (or any other from someone else) may require more text than
most people want to read, more of my spare time than I can afford, or may require details that are proprietary to
my employer or one or more of the industrial/agency/academic partners in the project. So a complete answer cannot
be given, and an incomplete answer may be seen as indicating a weakness that may not exist or may be otherwise
taken out of context.

Thus by asking a question of a mission in competition in a public forum you actually may make
the mission less likely to happen. There does not exist at present a 'people's court' wherein missions under competition
can be probed by the public in an equable manner, appealing as such a notion may be (and it may not appeal for example
to industry). And probing at concepts under study in an ad-hoc manner, wherein all concepts under competition are not probed
equally, could be prejudicial to the decision-making process. So I ask your understanding that I cannot discuss such details.

All I can say is the challenges of doing science in an exotic environment are recognized by a team that has successfully
addressed such challenges before. The detailed plans for doing so will be evaluated in NASA's formal review process.

And let me take this opportunity to remind readers that (roughly) for every scientist out there doing cool stuff like studying
pictures on Mars, or analyzing bits of asteroids, there's another (nameless) scientist who doesnt get their name on papers, or appear
on TV, but who had to sit on a tedious peer review panel for a week in some dreary hotel, and read hundreds of pages of dense proposal
material to help judge which 1 of 5 scientists should be picked to work on the team, or which mission should fly, when
actually the top 3 out of the 5 would all be superb. A painful decision, and an onerous duty, but one that is rarely
recognized outside the field.