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Yes! We ARE going to Europa!


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  |Velocity| said:
Is that because they don't actually want it, or more likely, they thought there was no chance of getting it due to NASA's pitifully low funding levels? I suppose it also might be a little "early" to send of lander, we need to identify promising landing spots first, and determine whether the Europa "geysers" were real or not (unfortunately, right now it looks like they were probably just a transient cloud of water vapor following a small impact).

As a KSPer, I have to wonder why we couldn't send an orbital with a radar and powerful cameras and spectrometers, and identify the best landing spot, and THEN drop the lander down to the surface, all in one mission? If it's in a polar orbit, every spot on the surface is accessible, though the delta-V requirement to land is a little higher (at the least because of Europa's rotational speed, 32 m/s at the equator).

Orbiting at Europa is very complex due to the radiation levels-it's tough to get the actual instruments hard enough, and you can't meaningfully shield them while still allowing them to function.

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Pff. Two billion dollars is only 1/6th the cost of a Gerald R. Ford - class supercarrier. Uncle Sam's just cleaning out the couch cushions.

IIRC the Apollo, space shuttle and ISS programs were in the $100-200 billion range

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What are the DV requirements for Enceladus?

Depends how fast you want to get there. For a 2 year voyage the Dv is about 50km/s. (Source: Human mission to the outer solar system: designs and implementations)

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Any actual scientist will tell you that what you need is a good solvent for the given temperature range. At 300K of typical Earth life, you need pretty strong bonds in things like DNA and complex proteins to hold them together against thermal excitations. And to break these apart, you need a strong, polar solvent. Water is by far the best option, and the only available one that's naturally abundant. So at terrestrial temperature ranges, life means water.

In contrast, if you are at less than 100K, such as on Titan, hydrogen bonds are frozen solid. Your complex molecules will be held together by van der Waals forces. A polar solvent would ript that stuff to shreds, and no life would be possible. Fortunately, there are non-polar solvents, such as liquid methane. So if we are talking cryogenic life, life means liquid methane. And that makes Titan a perfect place to look for cryogenic life.

Granted, life at high temperatures has huge number of advantages. There are more potential energy sources, all of the processes are faster, and you can dump excess entropy way easier. Which means life will be more complex and far further evolved on Earth than it could ever be on Titan. I would not expect anything past simplest bacteria there. Something similar to Earth's Archaea.

So finding life on Titan would tell us two things. First, that our definition of "habitable" is a bit too narrow. Second, that two planets within a single star system have developed completely different life independently. And while former has very limited impact, because planets/moons like Titan are unlikely to ever produce complex life, that second statement is extremely powerful.

We live on Earth. Which means odds of us finding life on Earth are 100% ab initio. There is no way any species could ever find itself in a barren star system. Which means that us knowing that there is a habitable planet here is absolutely useless. Even if there is just one in all of the universe, we'd be on it. But two planets? Odds there being very few habitable planets out there, yet there being two, so vastly different, in our star system are minimal. If we find life on Mars or Europa, we'd still have to figure out if it had the same origin as life on Earth. For all we know, it did. Panspermia isn't very appealing on global scale, but within confines of a single star system, it's quite plausible. But if we find life on Titan, we know it didn't come from Earth. We know it's not contamination from one of the probes. Life on Titan cannot exist in water, and life from Earth cannot exist on Titan. Simple as.

If we find life on Titan, that's two data points from which we extrapolate a very simple fact. When you look up into the sky and look at the stars, more of the stars you see probably have life than don't. There is nothing we can find on Mars or Europa that would be anywhere close to this impact.

Life on titan, indeed, would be a greater discovery than on mars or Europa. However Europa is closer and easier to get to. To get to titan you need more Dv, Heat shields, Parachutes, and the knowledge you can't have a cheap-ish sample return because of the thick atmosphere. Europa has a very high potential, and even if its life came from earth millions of years ago, it still is alien life as it has spent millions of years adapting to its environment and becoming a new species.

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http://www.planetary.org/press-room/...t-Request.html

It's Official: We're On the Way to Europa.

President requests $18.5 billion for NASA in 2016, an increase of $519 million.

Posted by Casey Dreier

2015/02/03 02:55 UTC

NASA's Mission to Europa May Get More Interesting Still.

Posted by Van Kane

2015/04/11 21:08 UTC

http://www.planetary.org/blogs/guest...teresting.html

Wait, the American government actually wants this? Not sure if I should be grateful or suspicious...

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For those who are fascinated by a possible visit to Europa:

Europa Report.

2013 PG-13 CC

This is one of my favorite space films ever. Just sayin'

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  ChrisSpace said:

Life on titan, indeed, would be a greater discovery than on mars or Europa. However Europa is closer and easier to get to. To get to titan you need more Dv, Heat shields, Parachutes, and the knowledge you can't have a cheap-ish sample return because of the thick atmosphere. Europa has a very high potential, and even if its life came from earth millions of years ago, it still is alien life as it has spent millions of years adapting to its environment and becoming a new species.

Europa as higher potential than Titan only if we reach the Europa's deep underground Oceans.

And this is probably much harder than sailling the Titan's mares under the Sun.

- - - Updated - - -

  ChrisSpace said:

Wait, the American government actually wants this? Not sure if I should be grateful or suspicious...

Maybe they know something that increase the odds for an Europa mission? ^^

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  K^2 said:
There is nothing we can find on Mars or Europa that would be anywhere close to this impact.

We could find life on Mars or Europa that, while being water based, hae no homology with life on Earth, which would then have a similar impact to the speculative Titan result.

Scenarios:

Completely different amino acid set/chirality

completely different genetic material

different set of bases

same bases, completely different code for them

still has amino acids, but the proteins have zero homology to anything on Earth.

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I would not expect anything past simplest bacteria there. Something similar to Earth's Archaea

This sounds like you are promoting the view that archae are primitive and simple.

They diverged from the Eubacteria long, long ago. They are every bit as advanced, and are found outside of extremophile places (that was simply where they were first noticed). Modern sequencing technology has revealed they are all over the place, and very diverse.

The phylogeny is rather murky that far back... but some phylogeny has *US* as archaea - or rather, the product of Archaea engulfing a Eubacteria (specifically, a stem-alpha proteobacteria).

The Eubacteria became our mitochondria, and the Archaea (making use of a lot of Eubacterial genes that it gained access to), became the Eukaryotic host cell... ie, it became us.

If the above scenario is true (there is evidence, but then there it is also possible that the proto-Eukaryote[pre-mitochondria] and the archaea lineages are merely sister clades, and that archaea can be made monophyletic while still excluding Eukaryotes) - then we can't talk about archaea without talking about ourselves, or making arbitrary deviations from monophyly

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This isn't terribly relevant to current priorities anyway, as we don't have any single plausible chemistry for Titan life (like RNA/protein for water-based) so we have no real idea how to test for it's presence.

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  Kryten said:
This isn't terribly relevant to current priorities anyway, as we don't have any single plausible chemistry for Titan life (like RNA/protein for water-based) so we have no real idea how to test for it's presence.

We have something: http://advances.sciencemag.org/content/1/1/e1400067

"azotosomes" are natural life membranes that can form in the Titan's mares and duplicates the features of liposomes membranes of water-earth based life.

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  Exoscientist said:
I enjoyed the film, though I admit it had a Science Channel semi-documentary look to it.

I realize it is off topic but I thought I'd mention that I just watched Europa Report this evening. I had wanted to see it when it was first released but it didn't make it into any theaters in my area. Now that I've seen it I'd say that it was better than I expected. I was actually kind of impressed. In my humble opinion, it was better than both Gravity and Interstellar.

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  Kryten said:
That's something that's possibly present anyway from abiotic processes. It doesn't give us a specific test.

And as you mentioned earlier: a plausible hereditary molecule is still lacking. A plausible class of enzymatic molecules, is still lacking.

All we have, is a plausible container...

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  KerikBalm said:
And as you mentioned earlier: a plausible hereditary molecule is still lacking. A plausible class of enzymatic molecules, is still lacking.

All we have, is a plausible container...

We have a container and a solvant (Liquid methane).

And abundance of carbonates: simples like methane, and complexs form in the upper atmospher and fall back to surface (with help of the sun winds on methane) http://en.wikipedia.org/wiki/Atmosphere_of_Titan

And a unexplained methan cycle in the Titan atmospher, and some carbon dioxyde.

We have all the main elements for some enzymes capable of methanization, and even ARN.

Science about Titan is just at the beggining, the "plausible container" discovered only a few months ago.

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The Miller–Urey experiment and several following experiments have shown that with an atmosphere similar to that of Titan and the addition of UV radiation, complex molecules and polymer substances like tholins can be generated. The reaction starts with dissociation of nitrogen and methane, forming hydrogen cyanide and acetylene. Further reactions have been studied extensively.[17]

In October 2010, Sarah Horst of the University of Arizona reported finding the five nucleotide basesâ€â€building blocks of DNA and RNAâ€â€among the many compounds produced when energy was applied to a combination of gases like those in Titan's atmosphere. Horst also found amino acids, the building blocks of protein. She said it was the first time nucleotide bases and amino acids had been found in such an experiment without liquid water being present.[18]

In April 2013, NASA reported that complex organic chemicals could arise on Titan based on studies simulating the atmosphere of Titan.[19] In June 2013, polycyclic aromatic hydrocarbons (PAHs) were detected in the upper atmosphere of Titan.[20]

Look interressing to me. Probably enough for a little test, at least ^^

Edited by baggers
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  Hcube said:
Why is everyone talking about the SLS as a launcher for this mission ( if ever it gets funded) when the PDF the OP linked is talking about the delta4 or delta4 heavy as a launcher ?

Did i miss something ?

It's less a case of "we need to have SLS in order to do this mission", but rather "we need to have a mission for SLS between EM-1 and ARM".

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The difference is between 6.5 years (and multiple Venus flybys) for a non-SLS launcher, to 2 years for a SLS. Aka- 4.5 year difference in transit time. BTW, you're probably going to have to get used to this- Mars Sample Return is supposed to launch on SLS if the proposal gets approved for a 2024 launch date.

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I saw 3920 and thought it was the pricetag of the proposed mission in millions of dollars.

Then I started thinking and concluded it couldn't be, with congress involved it's going to cost a lot more than that and be abandoned because of cost overruns...

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  billbobjebkirk said:
It's less a case of "we need to have SLS in order to do this mission", but rather "we need to have a mission for SLS between EM-1 and ARM".

Well, if they can make it - I'd be really pleased. 7 year gap between these EM-1 and EM-2 is rather ridiculous.

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Falcon heavy doesn't exist yet, NASA doesn't want to design an important payload around an uncertified vehicle. Also the performance would be marginal for this application, it would likely require a third stage of some sort.

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  Kryten said:
Falcon heavy doesn't exist yet, NASA doesn't want to design an important around an uncertified vehicle. Also the performance would be marginal for this application, it would likely require a third stage of some sort.

SpaceX could strap two second stage boosters on to the second stage and call it the Falcon Heavier.

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  Robotengineer said:
SpaceX could strap two second stage boosters on to the second stage and call it the Falcon Heavier.

And then two more for the 'Heaviest'....Sorry, was going for a 'Murican theme.

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I read this just today, the instruments planned for the Europa trip...

http://www.universetoday.com/120446/nasa-selects-mission-science-instruments-searching-for-habitability-of-jupiters-ocean-moon-europa/

45 close fly-bys, the closest of which will be around 16 miles (25km) from the surface. It will not be orbiting Europa, but Jupiter itself, with encounters about every 2-3 weeks. This is all according to the article, however, things could change by the time it actually happens.

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