Deep Space and Interplanetary Exploration - The Universe is Timeless

[Natasha Kerensky]

Juno, currently enroute to Jupiter.

ESA's JUICE mission will be solar powered, and NASA's Europa Clipper mission likely will be.  Both also going to Jupiter.

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

There's also been work on a small, uranium reactor to replace the RTGs and enable higher-powered missions.  But it's a billion dollars-plus to develop, and I doubt it will get funded in the current environment where NASA politics are dominated by local interests trying to keep the old Space Shuttle workforce employed on another big rocket.

FWIW...

[rebs]

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.

I think it was Worktroll or Kato who said it originally, by I would agree that a mission to Uranus or Neptune to study their moons would yield about the same results as another mission to a large Kuiper Belt Object.  Or at least from what you are saying.  Neptune and Uranus would also be much easier to get to.  (Also not counting the benefits of being able to study each of these outer planets long term)

At least we finally do have missions slated to Europa.  I know the US congress put their OK on a new mission not too long back this year.  JUICE also is going to be a great mission.

[kato]

It's Triton that's interesting in that regard. Especially now that we have data of a large KBO (or at least will have it by the end of the year), a comparison to the "caught KBO" Triton would be interesting.

Europa's ocean isn't all that special btw. It currently pretty much looks like about every large moon in the solar system has a global subsurface ocean in fact. Ganymede, Titan, Callisto, Europa, Triton, Titania, Rhea and Oberon are all considered to likely have one. Of those moons in the solar system above 1500 km diameter, i.e. larger than Iapetus, the biggest object not in hydrostatic equilibrium, only Io and Luna definitely don't have one - and both have (Io) or had (Luna) massive magma oceans instead.

[Natasha Kerensky]

At least we finally do have missions slated to Europa.  I know the US congress put their OK on a new mission not too long back this year

Congress has been throwing tens of millions of dollars annually at JPL for Europa mission studies, but Congress alone can't make a mission that takes years and billions of dollars of development and operations happen.  That requires the White House to budget for the mission in the outyears.  And that's what recently changed -- the White House gave their permission for Europa Clipper to enter formal design.

Unfortunately, Congress keeps trying to tie Europa Clipper to the Space Launch System, which Europa Clipper doesn't need and which poses a lot of technical, schedule, and budget risk to the mission.  Congress is keeping the old Space Shuttle workforce on life support via the Space Launch System, but it's a launcher that lacks missions and a lot of good stuff at NASA like Europa Clipper may get sacrificed on the altar of those Shuttle workforce votes.

Europa's ocean isn't all that special btw.

Yes and no.

Europa is special within the Jupiter system (more special than Callisto and Ganymede) because its ocean is likely a lot closer to the surface of Europa.  This makes Europa's ocean more accessible to future missions and gives Europa's ocean a better supply of impurities for starting/sustaining life.

Europa is also special in that the Jupiter system has the closest of these subterranean ocean worlds.  This make missions to Europa considerably easier, faster, and less expensive than at Saturn and farther out.  For example, we can execute some Europa missions without resorting to nuclear power sources, something that's not true at Saturn and farther out.

There are other subterranean ocean worlds, some of which have oceans close to their surfaces, like Enceladus.  But Europa's ocean is the one subterranean ocean that's both close to the surface of its parent world and close to us.

[kato]

The closest subsurface ocean is still on Ceres, unless Dawn decides to say otherwise sometime soon.

The big problem with the accessibility of Europa is that it's not so accessible at all due to Jupiter's radiation belts. Hence why Europa Clipper will only be a flyby probe and - during the same mission timeframe, concurrently even - will achieve much less than JUICE in orbit of Ganymede. None of the other underwaterworlds have that problem.

As for Enceladus, there's mission proposals for tapping that. Nuclear-powered.

[ANS Kamas P81]

It looks to me like nothing so much as a glacier plain, or else an iceberg field that's been frozen and broken and refrozen.

[Natasha Kerensky]

The closest subsurface ocean is still on Ceres, unless Dawn decides to say otherwise sometime soon.

True, but Ceres is likely too small to have had a heat engine long enough to drive the complex chemistry necessary for the development of life in its ocean.

The big problem with the accessibility of Europa is that it's not so accessible at all due to Jupiter's radiation belts.

It's a problem, but it's addressable with shielding.  The mission that New Horizons stole budget from would have orbited Europa.

As for Enceladus, there's mission proposals for tapping that. Nuclear-powered.

Enceladus is second right behind Europa in terms of habitability and potential for life.

[Natasha Kerensky]

It looks to me like nothing so much as a glacier plain, or else an iceberg field that's been frozen and broken and refrozen.

It looks like it was melted for only a brief period, in probably a very shallow liquid layer.  It doesn't look like there was enough time or enough circulation for one ice sheet to slide under another and create subduction zones.  That would seem to indicate an temporary event like an impact or the freezing out of a lower layer, rather than something sustained like internal radioactive heating.  But I'm spitballing -- the New Horizons team and their reviewers will have the final say.

[rebs]

But these endeavors are worthwhile nonetheless, if not for the value of discovery alone, then for future technologies and industries that could now spring from the drive the simply do these things, and keep alive a spirit of achievement for all of us.

And btw, I love all pics of Europa or Enceladus.  Can't draw them like French girls, probes and missions are needed to see these beauties for what they really are.   ^-^

[BirdofPrey]

Unfortunately, Congress keeps trying to tie Europa Clipper to the Space Launch System, which Europa Clipper doesn't need and which poses a lot of technical, schedule, and budget risk to the mission.  Congress is keeping the old Space Shuttle workforce on life support via the Space Launch System, but it's a launcher that lacks missions and a lot of good stuff at NASA like Europa Clipper may get sacrificed on the altar of those Shuttle workforce votes.

Sounds like the same crap NASA pulled with the Space Shuttle.  They did what they could to shoehorn every single mission they could into a space shuttle mission to justify the expense of their terrible new launch system, and it was only really after the loss Challenger, that they stareted going back to using alternate launch vehicles for certain missions.

Realistically, only the Spacelab, and ISS missions demanded a shuttle, the former because the lab was also reusable and needed to be flown home, and the latter, since the CanadaArm is useful for assembly of the station (which is why ISS has its own arm now).  Maybe a few other things that involve the return of things from space.  Aside from that, the shuttle itself eats into the payload capacity by far too much.


I don't anticipate the SLS will suffer the same problems since it's supposed to be a heavy launch vehicle and is supposed to be somewhat able to be tailored to the payload requirements of the specific mission, but at the moment, there aren't a whole lot of proposed missions that need heavy launch capability (though, that may be in part that people aren't keen on planning missions that won't even get off the ground for lack of appropriate launch vehicle).  Still, trying to shoehorn something onto the SLS that can be flown on any of the numerous existing launch platforms is silly and screams of the same sunken cost fallacie that kept the shuttle in service for so long.


I'm eternally disappointed Energia/Buran was shelved due to the collapse of the Soviet Union.  The Buran shuttle was batter than the US Space shuttle, most notably having higher payload and being capable of autonomous operation, but more than that, the Energia itself was a fully self contained heavy lift launch vehicle with multiple proposed variants for differing payload capacities (2-8 strap on boosters and the potential for an upper stage plus the suggestion of altering the number of engines on the core stage itself); in that manner the Buran was just another payload.

[kato]

Realistically, only the Spacelab, and ISS missions demanded a shuttle, the former because the lab was also reusable and needed to be flown home, and the latter, since the CanadaArm is useful for assembly of the station (which is why ISS has its own arm now).  Maybe a few other things that involve the return of things from space.  Aside from that, the shuttle itself eats into the payload capacity by far too much.

The entire truss structure would have been a real bitch to assemble without a "cargo truck" where you could just have the "crane" pick it off the "truck bed" and place it in position.

Realistically, looking over all 133 successful ISS missions:

4.5% (6) were initial commissioning/R&D flights, various flights without science platform or truncated flights
12.0% (16) were free-flyer return or satellite repair work/servicing
27.8% (37) were satellite deployments

7.5% (10) were Shuttle-Mir, including delivery of components
20.3% (27) were SpaceLab, SpaceHab, Astro, Atlas, SR
27.8% (37) was ISS assembly and supply/crew incl. MPLM

About 50% of the overall STS missions did demand a shuttle (half the Mir flights could have done without). Another 20% were missions that would have been complicated with another platform.
Before Challenger (i.e. in the first 18% of flights) half the missions were satellite deployment, 60% if you don't count the commissioning flights.

[Lazarus Jaguar]

I saw an article once, from an anual science book from the mid seventies, describing the planned space shuttle.  If you saw what we were promised and then look at what they gave us, it was a real comedown

Wish i could find that book again.  But, pretty aure my parents have it

[rebs]

I remember mention in an article with a timeline that I read probably right after the Challenger accident that working Aerospace vehicles would be reality by 1990. 

But then, here we are now with the promise of private venture capital stepping in to the Space Race, and it seems to be happening - just not in the slick 80's science art kind of way. 

[worktroll]

Photo never taken before.



Pluto from behind.

[Maingunnery]

Wasn't that picture taken for analyzing Pluto's atmosphere (if it has one)?

[worktroll]

Yes that would have been one of the reasons, and yes it demonstrably does.

160km of thin haze, rapidly freezing out.

I suspect most of our expectations for Pluto will have been made in no clear understanding of how cryogeology works. Not that we know that yet, but at least we have a beginning.

[rebs]

www.planetary.org/blogs/emily-lakdawalla/2015/07241705-looking-back-at-pluto.html

And here is a link to a fine article with this and many other photos at The Planetary Society.

What a great series of shows we've been treated to this year!

[Kovax]

What's the general opinion about the "earthlike" world recently discovered by (I believe) the Kepler probe?

The guesstimate of around 40% larger diameter than earth means somewhere around 2x to 4x the total mass, so anyone weighing 200 pounds here could find themselves at an unhealthy 500+ there.

Worse, at a speed in the general neighborhood of that reached by current probes, it will take something on the vague order of 1.4 million years to reach.  That's a even more of a potential problem for any travelers who have gotten used to the low-G or zero-G conditions over the course of their trip, and are "out of shape".

I'm definitely not booking a hotel reservation there for my next vacation (even if the travel services offer GREAT rates); I don't get anywhere near enough time off for the round trip, much less have an interest in letting the excessive gravity and potentially toxic or caustic atmosphere kill me in the middle of my peaceful round trip, at least not until they open a Starbucks there.  How about a possible carbon dioxide atmosphere that traps heat, and getting a hot cup of coffee at an awkward 700 degrees Farenheit?  "Earthlike?", yeah, right.

[ANS Kamas P81]

They can do a spectral analysis on the atmosphere, I think they've got some data that argues against that.  As far as surface gravity, remember that it's a function of both distance from the center of mass and the actual mass of the planet.  Jupiter may be far more massive than earth, but IIRC a radius of 110,000km gives a surface of just about 1g anyway.

[Lazarus Jaguar]

Except Jupiter has no surface, so its hard to tell where to measure from when determining the distance from center

[rebs]

The James Webb telescope should be of help once it gets put into space.  I'd love to see more projects like it escape the crushing gravity of gov't bureaucracy, procedure, and whatnot.

[kato]

The guesstimate of around 40% larger diameter than earth means somewhere around 2x to 4x the total mass, so anyone weighing 200 pounds here could find themselves at an unhealthy 500+ there.

Gravity doesn't scale geometrically with mass. g = m/r². Given similar density m scales with r³, therefore g scales with r.

At 3 M(E) mass and 1.4 r(E) radius a planet would have around 1.5g. At 2 M(E) mass and 1.4 r(E) radius a planet would have 1.0g, but would need a lower density (of around 4.0g/cm³, which is still reasonable for "rock").

[Jal Phoenix]

http://www.examiner.com/article/german-scientists-confirm-nasa-results-of-propellentless-impossible-em-drive

A friend just posted this to Facebook.  Damn BOP drive.  There goes NASA, giving Chip credibility, and now the Germans are helping. How can this be anything but Chip holding these scientists hostage?    [face palm]  My entire worldview hinged on three things: The potato is always watching you, Gary Coleman may not be the anti-christ, and Herochip is always wrong.  I'm feeling very disoriented right now. 

[worktroll]

it's important to remember a couple of things:

- that the NASA tests in vacuum produced significantly less thrust than the tests in atmosphere
- that any vacuum humans can produce in a pressure vessel on Earth is still considerably "dirty".

The odds of a reaction process using ambient reaction mass remains high.


I'd personally love for this to be a real thing. And I'm hoping someone's rigging up a mini-satellite with an EM drive that that can be sidecarred on a commercial launch for real testing. (Note - the environment around the ISS would not be suitable; far too dirty with outgassing & assorted urine dumps. Geosynch is the place to go.) And if I were Steve Allen or Richard Branson, I'd be getting in the ground floor right now fundign that with a couple of hundred million from my petty cash drawer.

Still not drinking the attractively-coloured fruit drink - quite yet, anyway.

[ANS Kamas P81]

Still not drinking the attractively-coloured fruit drink - quite yet, anyway.

Agreed on the need for testing, but I'll chug one for you - because this opens up a need to explain a clearly verified experimental result that doesn't fit the classical model.  Which means it's SCIENCE TIME.

And if they manage to make a powered-by satellite, spank it on the butt, and send it off into the deep like they did the ion-drive and solar-sail designs?  I'll buy the kool-aid myself.

[worktroll]

The article says Pluto in 18 months. By extension,

1) Mars in a couple of weeks. Which is "forget the biosystems, just pack more lunch and poo-bag" territory. We can do that now. There's so much that a couple of guys with shovels can uncover - let alone a mechanical digger.

2) 18 months for a lander on Pluto? All the planning for Mars One suddenly is perfectly applicable for Pluto One (or Triton One, Europa One, Ceres One ... you name it!)

I would love this to be true. But I'll wait.

That said, if I had billions, I'd drop a hundred million for the chance for a percentage of the royalties.

[kato]

There goes NASA, giving Chip credibility, and now the Germans are helping.

The German abstract culminates in "we can neither confirm nor deny the previous findings". A confirmation looks different. As for the oh-so-controlled experimental conditions, they used a commercial waveguide from a microwave oven.

[Sabelkatten]

Awhile ago I discussed the EM drive with a physicist  friend. We came to the conclusion that it might actually be possible to squeeze the thing into classical physics if we assumed that the thrust was produced by pair production at the rear end of the device (Hawkins radiation FTW!).

Problems? Well, as far as we could figure you shouldn't be able to get any more thrust than a conventional photon drive...

So I'll remain skeptical, thought it would be real cool if it turns out there is something real!

[BirdofPrey]

Here's a thought though.  If it IS producing thrust due to what little remains of an atmosphere in the vacuum chambers used for testing, then even if it is useless for deep space, it could still prove useful for spacecraft not designed to go past LEO for counteracting atmospheric drag.

[Wrangler]

I was reading a article here at Spaceflightnow! about close up on Pluto's "heart" region, Sputnik Planum.

Terrain is fasinating look at, i'd wonder if we event sent a rover or human explorers if rugged landscape would be even passable.
The place is size of Texas, which i kind find it ironic that place which resembles a heart.  :))

I'd like give reward to the person who convinced the scientific community to name region next to Sputnik, Cthulhu Regio.  :D