Deep Space and Interplanetary Exploration - The Universe is Timeless

[rebs]

Most of the Trans-Neptunian objects of note are too far apart for their own Grand Tour.  So I would be in favor of several more missions like this one.  One to Eris, one to Sedna while it is so very near on its 1,400 year orbit.  Maybe one to Haumea or Orcus or Quaoar... 

I'm still in favor of freezing myself for a Grand Tour, though.

At 700 million per pop that's gonna get pricy fast. For a couple billion we could just as well station a large telescope in say Uranus' orbit to watch the Kuiper Belt from half the distance...

I understand your point about getting pricey fast, but there are so many other ways that so much more money gets wasted every day, that we could talk about all kinds of them just before entering all of the rule four domains that exist in that territory.  Which I won't do, and I know nobody else here was planning to do, either.

A telescope in the orbit beyond Saturn sounds really good too, though.  One tuned for this purpose, and powered to last. 

Times like this and challenges like these are often what help lead to our great leaps in technology and science.  An obviously tangible reward is not there beyond the challenge, though, currently.  But knowledge about and experience in the newest frontier can only benefit us as this planet becomes smaller.

I'm a dreamer.  Bad.  Not everyone is like this, I know, but to me it makes sense, so it's a good clutch of dreams I have. 

[worktroll]

Really low delta-v requirements, thought. Can that really be correct? Even considering the flight time? ???

Remember, the point of a low-energy transfer orbit is to have you arrive not only at the same place as the target planet, but moving with the same velocity vector. And Pluto's not moving all that fast.  Get there travelling faster, and you need to slow down to make orbit/landing. Aerobraking is an option for Mars, or for the Jovians, but a little difficult around Pluto (or the Gallilean moons, for that matter).

Cyclic orbits (as proposed for Mars shuttling & the like) just have to get the place & time right, and use gravity to swing the cycler back around, and even then it's a long trip.

Ah, for the torch ships of Heinlen's early, non-sicko books. Heck, I'll settle for a VASIMR which lives up to the initial press. Reliable .1G is more than enough for my purposes!

W.

[ANS Kamas P81]

So riddle me this, science guys.  Pluto has light colored material at the poles, with a big streak of dark material around the equator.

Charon has a light equator with dark poles.

[Weirdo]

Delicious sciencey magic!

Anyone know when we're supposed to get the data dump from today's flyby?

What's the lightspeed lag from Pluto to here, for that matter?

[BirdofPrey]

Sometime late tonight, New Horizons is supposed to stay dark for 22 hours.
The communications delay is a few hours now (I think they said 2 and a half, but don't quote me on that)

[Wrangler]

Sometime late tonight, New Horizons is supposed to stay dark for 22 hours.
The communications delay is a few hours now (I think they said 2 and a half, but don't quote me on that)

Suppose to be hour from now (given take 10 minutes).  Hopefully it fared well and managed to get all the data it could.  That's such a unique situation zoom between two worlds orbiting each other.

[ANS Kamas P81]

So riddle me this, Batman.  How, without tidal stressing, does a body as cold as Pluto remain geologically active?  Because it is, no doubt about it.

[Maingunnery]

So riddle me this, Batman.  How, without tidal stressing, does a body as cold as Pluto remain geologically active?  Because it is, no doubt about it.

It has moons.

[RAW]

From what i've read, tidal stressing doesn't seem as strong as a force in Pluto's case, this isn't Europa or Titan we're talking about. There is some idea about underground oceans of some sort that have been cooling forever and day releasing heat to the surface causing geological activity.

[ANS Kamas P81]

It has moons.

That's just it, Charon's tidally locked - even if it was big enough for any notable tidal effects, it's not providing a changing stress.  And the other moons are Phobos-Deimos sized, they're tiny.

From what i've read, tidal stressing doesn't seem as strong as a force in Pluto's case, this isn't Europa or Titan we're talking about. There is some idea about underground oceans of some sort that have been cooling forever and day releasing heat to the surface causing geological activity.

It's gotta be something.  They haven't caught an eruption yet, but there's a lot of evidence for cryovulcanism on the surface of Pluto to explain its geological activity.

The planet of the dead is alive.

[worktroll]

And snow. Nitrogen probably subliming off the polar caps, cooling & crystallising, and falling near the equator.

Frickin' snow on Pluto! Whoo me some hooo, ladies & gents! Skied Mt Olympus? Passe. Skied the sulfur flows on Io? Hot stuff, but too many tourists. You want exclusive piste, I know just the place ...

[RAW]

Skie trip to Pluto.....it'll only cost you 18 years no problem , a small price to pay for the most exclusive slopes in the solar system.

[rebs]

So riddle me this, Batman.  How, without tidal stressing, does a body as cold as Pluto remain geologically active?  Because it is, no doubt about it.

Hmmm... Even in a gravitationally locked system, the orbital resonance with Charon could play a strong role keeping an internal ocean churning, providing heat through friction.  Europa, Io and Ganymede all benefit from orbital resonance, and are also tidally locked bodies.  edit: Of course, the Jupiter system is likely a poor comparison to what we are seeing out at Pluto right now.   :)

It would not take that much friction to keep Nitrogen above its freezing point, unless I am mistaken.

[RAW]

Aren't you forgetting the celestial body that is known as Jupiter, that is the primary reason for tidal forces on Europa. Same reason Mercury has such strong tidal forces in it, something with a hell of a lot of mass is very near by.

[worktroll]

The masses involved in Jupiter & Europa are slightly different than the ratio between Pluto & Charon. Given they're similar sizes, and locked, any such tidal stresses will have settled down by now, one would think.

This is when science really advances - not "Eureka!", but "Hmmm ... that looks odd ...."

W.

[RAW]

That's my point exactly, tidal forces are far less likely responsible for what is going on with Pluto I was using Europa and Mercury as examples of real significant tidal forces at work looks like. I'm interested to see all the data collected from horizons pass.

[Wrangler]

Too bad the New Horizon wasn't equipment with a secondary micro satellite of some kind, that could remain in Pluto-Charon system to continue to observe the planets.

[rebs]

That's my point exactly, tidal forces are far less likely responsible for what is going on with Pluto I was using Europa and Mercury as examples of real significant tidal forces at work looks like. I'm interested to see all the data collected from horizons pass.

But it would only take a fraction of the frictional heat from tidal forces to keep liquid Nitrogen in a ready to erupt state, as compared to water, for example.  So the orbital resonance of the Pluto/Charon system could most certainly play a part in this. 

[Lazarus Jaguar]

Lets have these guys do the naming

http://xkcd.com/1551/

[kato]

Too bad the New Horizon wasn't equipment with a secondary micro satellite of some kind, that could remain in Pluto-Charon system to continue to observe the planets.

Just for the idea per se: That satellite would have had to break by some 20 km/s delta-v. Which is about a hundred to a thousand times what one could reasonably put into a "microsatellite".

[Natasha Kerensky]

So riddle me this, Batman.  How, without tidal stressing, does a body as cold as Pluto remain geologically active?  Because it is, no doubt about it.

At least three possibilities:

1) Radioactive decay.  There may be interior deposits of radioactive elements that are heating up Pluto and melting/slushing its icy crust.

2) Recent impact(s).  Pluto may have been smacked recently (geologically speaking) by another (or other) Kuiper Belt objects that melted/slushed its crust.

3) Subterranean phase changes.  If underground layers of Pluto recently (again, geologically speaking) froze out, the transport of the heat through Pluto's crust may have temporarily melted/slushed it.

So riddle me this, science guys.  Pluto has light colored material at the poles, with a big streak of dark material around the equator.

Charon has a light equator with dark poles.

Different composition, but it's way to early to know what's driving the differences, and New Horizons probably won't settle the resulting debates.  Could be trace impurities, thin surface layer deposits, or totally different ices.  And those compositional differences could be driven by different origins (Charon may be captured), history of movement through the solar system, Pluto's eccentric orbit around the Sun, impacts, underground liquid transport, transport in Pluto's periodic atmosphere, etc.  Geophysicists could probably name a dozens other causes.

Hope this helps.

[Wrangler]

Is possible that with Pluto spinning together with Charon, that the gravitational pressure of pull of each other is enough to keep squeezing Pluto enough to keep it's inner working "warm" despite the deep freeze of near edge of the Solar System?

It was also suggested that Pluto is cooling down after it's disaster that created it and Charon's weird orbital states.

[rebs]

At least three possibilities:

1) Radioactive decay.  There may be interior deposits of radioactive elements that are heating up Pluto and melting/slushing its icy crust.

2) Recent impact(s).  Pluto may have been smacked recently (geologically speaking) by another (or other) Kuiper Belt objects that melted/slushed its crust.

3) Subterranean phase changes.  If underground layers of Pluto recently (again, geologically speaking) froze out, the transport of the heat through Pluto's crust may have temporarily melted/slushed it.

Different composition, but it's way to early to know what's driving the differences, and New Horizons probably won't settle the resulting debates.  Could be trace impurities, thin surface layer deposits, or totally different ices.  And those compositional differences could be driven by different origins (Charon may be captured), history of movement through the solar system, Pluto's eccentric orbit around the Sun, impacts, underground liquid transport, transport in Pluto's periodic atmosphere, etc.  Geophysicists could probably name a dozens other causes.

Hope this helps.

Agreed, it would take relatively little radioactivity to keep Nitrogen fluid, even at Pluto's aphelion. 

And that does help.  All of the dynamics in play must be accounted for, certainly.   :)

[BirdofPrey]

All this discussion makes me wonder if Pluto has suddenly become interesting enough for them to start thinking about another probe.

[ANS Kamas P81]

All this discussion makes me wonder if Pluto has suddenly become interesting enough for them to start thinking about another probe.

Considering it's breaking a lot of expectations and has some fantastic discoveries noone thought was coming, I'd say the unanimous answer from the New Horizons team would be 'Yes and soon!'

[worktroll]

Apple currently has cash reserves of around one trillion US dollars. That's not assets, that's bank account.

Surely it would be worth dropping a measly billion for the sake of calling it iPluto? Give them naming rights for a successful automated landing.

[Wrangler]

Hopefully they'll consider another probe, but one biggest obstacles is US Congress.  New fuel I believe is chief problem, if they think their going be able to use solar panels to keep a vehicle going on Pluto, i believe there sadly mistaken. 

I read couple years ago, there dwindling supply of nuclear materials available to produce deep space problems, which was using overstock from the nuclear weapons program.  Aside from protesters paranoid of a rocket explosion causing a nuclear disaster on Earth, NASA needs produce some new fuel or get some with a limit budget to power any deep space probe. 

I hope they manage to get some, Space is my opinion the future of mankind, especially if we want our humanity grow and think more about how pay the bills next month.

[BirdofPrey]

I can't think of any outer solar system probe that wasn't powered by radioisotope thermal generators.
Apparently, when they did finally manage to convince Congress to fund New Horizons, they actually got TWO probes financed, but they couldn't make the second since they didn't have enough plutonium for a second RTG.  Of course, that's far from the only fuel you can use; since you only need it radioactive rather than actually fissile, your choices are much broader than for proper reactors.
It would be fascinating if they DID launch a reactor, though, then they might be able to power a fancy electrical propulsion drive. 

Beyond that, though, there's a lot of extra red tape to put hazardous materials on top of a rocket.

You are right of course, that paranoia is always a problem.  It seems like every time they try to launch an RTG into space, protesters show up because nuclear is a bad word, and they are too misinformed to know the actual risks.
====
I'm sure SOMEBODY has already been wanting to send another probe to Pluto, and other Kuiper belt objects (again, a second New Horizons was on the budget to go elsewhere, but wasn't build), but if they started working on a new probe today, I can't see the next flyby happening any sooner than 15-20 years from now since it takes several years to design and build a probe and the flight time alone is nearly a decade.

[kato]

I read couple years ago, there dwindling supply of nuclear materials available to produce deep space problems, which was using overstock from the nuclear weapons program.

NASA issued a contract with the DoE to resume Pu-238 production in 2013. Planned stable output is 1.1 kg/year, beginning from 2021 - enough for a mission requiring a RTG every five years. Current stocks are 35 kg.

Pu-238 RTGs are realistically highly inefficient for long-cruise missions like Pluto due to the low halflife of the fuel material. Britain is working on far-longer-lived Americium-241 RTGs for ESA, which can be harvested at Sellafield from spent fuel rods in a comparably easy cycle. Lower output-to-mass ratio, but virtually identical output over decades hence none of that vast oversizing NASA does for RTGs. Tentative introduction mid-2020s.

I can't think of any outer solar system probe that wasn't powered by radioisotope thermal generators.

Juno, currently enroute to Jupiter.

Apparently, when they did finally manage to convince Congress to fund New Horizons, they actually got TWO probes financed, but they couldn't make the second since they didn't have enough plutonium for a second RTG.

NASA has enough Pu-238 for three NH-style missions left at the moment. It's saving those for Mars missions though.

[Natasha Kerensky]

All this discussion makes me wonder if Pluto has suddenly become interesting enough for them to start thinking about another probe.

I hope not.  Pluto may be a fascinating object on its own, but it does little to inform the big questions in planetary science about the origins of planets and life.

Pork barrel politics in Congress gave us this Pluto mission by giving up/delaying by decades a mission to confirm and map the suspected water ocean under Jupiter's moon Europa.  The existence and nature of such an extraterrestrial ocean in our solar system's backyard has huge implications for our understanding of extraterrestrial life and the origins of life.  We knew going in that there would be nothing comparable in the Pluto system.

Kuiper Belt Objects like Pluto are important repositories of information about the early solar system's composition and the building blocks of the planets.  But you want to study smaller KBOs that are unprocessed and undisturbed since the early stages of the solar system.  We knew going in that Pluto and Charon were too big and would be highly processed, ruining any evidence that they once had of the solar system's original chemical and physical building blocks.

It's interesting that Pluto/Charon exhibit no craters and have different colored surfaces.  But even when we answer why that is, it will tell us little to nothing about where we and our solar system come from and the potential for life beyond Earth.  Those are the big questions in planetary science, not whether a particular planet's smooth surface or surface color is driven by radioactives or impacts.  And those big questions require data from different planetary targets, not Pluto.

My 2 cents... YMMV.