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NASA plans to launch a spacecraft to Titan

theatlantic.com

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Re: NASA plans to launch a spacecraft to Titan

#91

Post by aeorgnoieang »

plutonorm wrote: post #67

What. How are they going to detect life on titan? They can't even detect life on mars. I mean to say, even when we know the kind of life we are looking for we get confused about how to confirm or deny its existence. So they want to design a small flying drone that works in extremely hostile conditions, that also has the kinds of sophisticated instruments needed to look for life? And not just life, life of potentially…

I think you need to relax the idea of 'detecting life' towards 'detecting evidence of life', i.e. evidence of populations of locally-entropy-defeating systems that reproduce.

Once you relax the requirement that 'answers' must be 'yes or 'no' to 'more likely' or 'less likely', it should be clearer how one would go about searching for life. For one, is there chemical activity one wouldn't otherwise expect if there was no life?

Re: NASA plans to launch a spacecraft to Titan

#92

Post by martinald »

T-hawk wrote: post #63
jvanderbot wrote: post #7

Earlier quoted context omitted.

The data rate from the surface of titan is abysmal. Even with a relay, we won't get much video, but man, I hope we get some.

From a scientific standpoint, there's really no value in downlinking video as opposed to still images. It costs several multiples worth of scarce downlink bandwidth, for a tiny gain in what there is to see of the same rocks at slightly different angles. Same reason we didn't have New Horizons at Pluto or the various Mars rovers do any video.

Why is bandwidth so scare still? Satellites in geosynchronous orbit on earth can do terabit/sec of total capacity now.

Obviously latency is going to be extremely high, but I can't really understand why data rates are still so low?

Re: NASA plans to launch a spacecraft to Titan

#93

Post by foota »

MereInterest wrote: post #80
AnIdiotOnTheNet wrote: post #57

Earlier quoted context omitted.

Mercury's whisper thin atmosphere won't be much use for cooling anything, though possibly the surface would be. However, the real problem is that Mercury isn't actually tidally locked anyway.

You could have the facility move constantly to keep the facility straddled across the sunlight line. At the equator, this would require constantly moving at about 7 mph, though you could reduce the speed necessary by moving to higher latitudes.

Reminds me of the book Absolution Gap

Re: NASA plans to launch a spacecraft to Titan

#94

Post by akozak »

MereInterest wrote: post #80
AnIdiotOnTheNet wrote: post #57

Earlier quoted context omitted.

Mercury's whisper thin atmosphere won't be much use for cooling anything, though possibly the surface would be. However, the real problem is that Mercury isn't actually tidally locked anyway.

You could have the facility move constantly to keep the facility straddled across the sunlight line. At the equator, this would require constantly moving at about 7 mph, though you could reduce the speed necessary by moving to higher latitudes.

Appears in 2312 by Kim Stanley Robinson.

Re: NASA plans to launch a spacecraft to Titan

#95

Post by QuotedForTruth »

Robotbeat wrote: post #66
dflock wrote: post #45

Earlier quoted context omitted.

The delta-v required for a trip to Titan, according to this[1], is 28.43 km/s. Optimistically, a fully re-fuelled startship in LEO has ~10km/s of delta-v to spend, afaik. [1]( https://www.reddit.com/r/space/comments/1ktjfi/deltav_map_of... )

Starship can do better than that if stripped down to expendable use. About 13km/s: https://twitter.com/elonmusk/status/1111798912141017089 Also, you're reading that delta-v map completely wrong. The red arrows mean you can aerobrake. So it only takes about 4.1km/s to reach Saturn if you start out at a highly elliptical (near escape) Earth orbit and do a large departure burn at perigee. (See here: https://en.wikipedia…

So it would work! Thanks for the analysis.

Re: NASA plans to launch a spacecraft to Titan

#96

Post by disconnected »

saagarjha wrote: post #25
cwkoss wrote: post #17

Earlier quoted context omitted.

In addition to lack of solar energy, I wonder if nuclear power source is necessary to keep batteries or other electronics warm enough to function properly. Conversely, on Titan, we won't need to worry about heat sinks as everything is kept at ~94K in a bath of liquid and frozen methane. Perhaps in a few hundred years AWS's most popular region for intensive compute will be under Titan's methane sea. High spin up cost,…

Super fast compute, but awful ping…

To put it into perspective:

https://solarsystem.nasa.gov/moons/saturn-moons/titan/overvi...

According to this (at the time of reading) a one way trip at the speed of light is ~75 minutes, so you will have approximately two and a half hours of ping.

Ouch.

Still, it raises an interesting question: how would a hypothetical Earth-Titan network protocol work?

Re: NASA plans to launch a spacecraft to Titan

#97

Post by eloff »

eindiran wrote: post #64
magnamerc wrote: post #44

Earlier quoted context omitted.

I find it kind of funny that you think AWS will still be around in a hundred years.

This paper company was founded 771 AD: https://www.shinise.ne.jp/j_kyoto/voices/vol/48/48-d.html It's not even the longest-lived company in the world. This construction company was founded in 578 AD and continuously operated until 2006 when it was bought by a larger company: https://en.wikipedia.org/wiki/Kong%C5%8D_Gumi 100 years ago was only 1919 -- here are some random companies from 1919 that I found on Wikipedia…

A company lasts just 11 years on average on the S&P 500 now. Companies are surviving for shorter time periods now then they used to.

Re: NASA plans to launch a spacecraft to Titan

#98

Post by UncleSlacky »

dsfyu404ed wrote: post #9

I can't believe it's been that long since Huygens was sent to Titan. I remember listening to some radio show (NPR?) that was broadcasting the touchdown live. Also, it's interesting that since they can't study Titan very well visually (you can't point a telescope at it and map the surface like you can with Mars) they're planning on sending a rover that can cover far more distance since they have less idea what will be…

I worked on prototypes of the experiments in the Surface Science Package at uni in 1991 - boy do I feel old!

Even then we were speculating on flying or floating probes for future missions there. At the time it was assumed that the surface could well be entirely liquid.

Re: NASA plans to launch a spacecraft to Titan

#99

Post by UncleSlacky »

Robotbeat wrote: post #90
droithomme wrote: post #32

Venus and Titan have in common that probes landing there tend to only operate a few minutes before failing due to the extreme conditions. A helicopter sounds great, but perhaps it would make sense to try to simply make a probe that can stay alive there long enough to do anything other than send a couple pictures back.

This is not true. The only reason the previous probe (Huygens) only lasted a few hours is because it was battery powered (and the battery wasn't particularly large). This probe will carry a power source powered by the radioactive decay of Plutonium 238 (virtually all the radiation being alpha particles, which are easily blocked by the casing of the power supply and thus will not hurt the electronics or ground crew) t…

As I mentioned elsewhere in this thread, before Huygens we expected that the surface might well be entirely liquid, giving us at best only a few minutes to run the experiments and return the data before it sank. There was no point carrying too much battery capacity in that case.

Re: NASA plans to launch a spacecraft to Titan

#100

Post by heavenlyblue »

redcalx wrote: post #29
newsoul2019 wrote: post #26

Earlier quoted context omitted.

Perfect for mining bitcoin

Not really; if you find a block it will mostly likely have been beaten by someone else's block by the time yours reaches most nodes...unless there is a Saturn based side chain or similar.

It depends if the "most nodes" are on Mercury or on Earth.
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