Slashdot Mirror
Nuclear Powered Mission to Jovian Moons
Skyshadow writes "The San Francisco Chronicle has an article about NASA's new project, the JIMO (Jupiter Icy Moons Orbiter). The probe is designed specifically to search for liquid water and signs of life on Europa, as well as making detailed observations of Callisto and Ganymede. Planned for a 2010 liftoff, this new probe makes all previous interplanetary probes look wussy: it'll be 300 feet long and powered by a next-gen fission reactor (as opposed to nuclear batteries). Sure beats blowing money circling the earth over and over again..."
Had to be said, what with a 2010 liftoff date (actually 2011 if you read the article.)
The ship even looks quite a bit like Discovery.
And I bet the NSA lies to this onboard computer too.
Is this truly the only Earth I can live on?
The grass is only greener, if you don't take care of your own lawn.
NASA will also launch a satellite to search for liquid water and signs of life over Arizona sometime late next year.
can we call it GZK? to any who have not read Arthur C Clark's and IBM's "discussion" about the naming of HAL ignore this. actually just ignore it anyway :)
"Yeah, Yeah, Yeah." - Lennon, McCartney
did anyone else read that big long link in the title as "looking for signs of life in europe"?
Selling software wont make you money, selling a service will.
I wonder, specifically, what instruments this thing'll have that will require their own little nuke plant as opposed to batteries. Articles were a bit sketchy on the details...
Every year during my review, I just pray the words "slashdot.org" aren't mentioned.
What if there is a failure of some sort around Europa and the probe ends up crashing on the planet?
That nuclear material could have an unmeasureable detrimental effect on any life there is there, so NASA needs to be damn certain that this baby will not contaminate the surface even if the worst case scenario was to occur.
Remember, recent NASA missions to the other planets have not all gone smoothly, so this is a very big concern.
"Accept that some days you are the pigeon, and some days you are the statue." - David Brent, Wernham Hogg
We all know the REAL reason we're going there.
TO NUKE THE MONOLITH IN 2010.
this sig limit is too small to put anything good h
Wonder what the monday-morning-quarterbacking will be like when something bad happens?
I hardly believe that a space station is a waste of money. There is much we still don't know about how humans react in 0 gravity and without an ozone layer. If we ever hope to have any type of manned exploration vehicles for our solar system we've got to "do our homework" first.
Does "Mir" ring a bell with you at all?
GF.
Lots of petrified grits
In the 1970s, the Soviet Union launched several dozen fission reactors on naval radar satellites, most of which are still whizzing over our heads. (These orbits are expected to decay within the next couple of centuries.)
Actually, a new fission reactor loaded with fresh fuel would be no big deal if it blew up. Uranium isn't all that radioactive before you start splitting it. With just a little bit of depletion, it's regarded as safe enough to spew liberally over battlefields (for some definition of safe). If you don't switch the reactor on until you're safely in orbit, you won't have much to worry about.
The radioisotope thermal generators (RTGs) that many of our current probes use are far more dangerous. They carry a considerable amount of a highly radioactive isotope of plutonium that has a half life of a few decades. The decay (not fission) of this isotope generates the heat to generate electricity with a thermocouple.
A fission reactor starts out with almost no radiation, and it builds up as the fuel burns. An RTG starts out with maximum radiation, and it slowly decays over time. Clearly, the first choice would be better to strap into a rocket.
It is just tantilizing that out there, in our solar system, is another ocean.
One in which you could actually swim (lack of oxygen aside and all)! geniune water, at a comfortable temperature...well, at least in a thin layer (below which is seething boiling death and above, vacuum-of-space freezing).
The chances that this moon harbors life seem high. After all, we are all familiar with deep oceanic hydro-thermal vents and the bleached beasties that find the lightless life appealing.
It is my dearest hope that someday a probe will melt down a few miles, pop into this blackened world, and turn on it's lights to discover mile-long whale-like creatures.
Of course, it's most likely we will only find bacteria and other single celled dudes. But complex organisms are so much more cool...and kinda freaky.
But sadly, as it is with this universe, I have the sinking suspicion that europa will ultimately yield nothing more than the biggest cache of sterile water known to man.
Let us not also forget, intelligent life evolving in an environment where the outside universe is completely obscured by miles and miles of pitch-black ice might not be ready for the rest of the universe just yet.
When NASA and its contractors can pull together a big project that works, I'll believe it. Until then I doubt their proposals. Since Apollo and Skylab, we've had an expensive shuttle, several failed shuttle replacements (over ten billion dollars wasted trying) and spam-in-a-can ISS. Manned space missions have turned into grandiose, miserable failures.
On the other hand, the small unmanned projects with limited and well-defined goals have had some success. The microprobe analyses from the little Mars rover were very interesting. Viking did good work. Probes have left the solar system and still work. And there is the propect that the next Mars landings will do some good science.
This proposal just smells of another huge project to keep funding and billing rates high for the sake of government jobs and contractor profit. No concrete details and a promise to Fundamentally Change Life on Earth.
Stick with KISS -- Keep It Simple, Stupid.
I'm saddened by the fact that this thing will probably come under some extreme environmental protest simply because it contains the words "nuclear" or "reactor".
Not to mention that the reactor is probably sturdy enough to survive an liftoff abort destruct, or falling back to Earth. These things aren't engineered to be large radation hazards.
Besides, nuclear material goes up on a lot of spacecraft and the world hasn't ended yet.
this is my sig
When scientists look for life out side the solar system, why don't they focus on moons of Jupiter like planets instead of finding Earth like planets. These Jovian planets could harbor moons that could sustain intelligent life. If you look at our solar system, two planets are good candidates for life (Earth and Mars) while three moons are good candidates (Callisto, Ganymede and Europa.)
In the external solar systems we've found, most have had a Jupiter like planet orbiting near the star. This would expose it's planets to a similar amount of heat that the earth is exposed to.
BU's Center for Space Physics had a seminar speaker talking about this a month or so ago. So, to answer questions:
-The reactor will be started up in orbit and, like all missions carrying nuclear material, it's well-shielded and, even if it weren't, basically huggable without detrimental effects
-The goal here is to provide a deep-space probe with a much larger energy budget than possible with RTG's. It's not really a LOT of power; just that RTG's are very little power. One interesting consequence of this design is the propulsion: ion drive, as tested on Deep Space 1.
-Instrument package is by no means finalized yet; it's basically pie in the sky. That includes what exactly will happen with a lander
-"What if something goes wrong" scenarios tend to be based on the idea that stuff can "fall out of the sky." It can't. The people running the mission know where things are going
-To the poster who said "small cheap missions are better": the manned program tends to be the money sink (as were all the examples you quoted). The really small cheap unmanned missions have a sadly high failure rate. This is more like Galileo or Cassini or Magellan: big, expensive, and incredibly valuable in scientific return. There's a place for small and cheap, but outer planets missions are expensive no matter what. You can't afford two baskets, so you make a *really good* one.
In short, this is a chance to do a pure science probe the likes of which we haven't seen before. It's incredibly exciting and pushes our true exploration of the solar system further.
This picture specifies a 20m boom, which appears to be over half the length of the spacecraft. I didn't find any reference to 300ft (or metric equivalent) at the JPL website (but feel free to correct me if it is there.) Eyeballing the picture, 20m for the boom implies about 35m total length. By comparison, 300ft is about 90m.
The 300ft figure is in the newspaper article. Possibly it is an error, possibly the reporter knows more than I do.
I am curious as to how they will launch something so long. Presumably it will be collapsed in some way, and expand after launch. Allowing the (presumed) heat-pipe connections between the reactor and the radiators in a collapsable configuration sounds like a challenging engineering problem.There is no indication of how it would collapse - telescoping and folding seem the most obvious.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
I think it's just been done.
Although the Tuesday SF Chronicle article (referred to in this slashdot article) claims that Jimo will be up to 300 feet long, Both the astrobio.net article, (also referred to here) and a Monday SF Chronicle article (pointed to by today's SFC article) refer to Jimo being 60-100 feet long.
I'm thinking that somebody saw 100 feet, and thought metres. Hopefully they're not the engineers for the current mission.
Free Software: Like love, it grows best when given away.
Chemical engines are only capable of a theoretical max of ~400 seconds of specific impulse, with 175-300 seconds about as good as it gets for commonly-used propellants.
Ion engines in production easily achieve 3000+ seconds of impulse. So, once you're in orbit, ion engines are the way to go.
Cut your fuel mass by an order of magnitude, and enjoy. All you need is that handy nuclear reactor for power, and they build 'em pretty light nowadays.
"We have to go forth and crush every world view that doesn't believe in tolerance and free speech." - David Brin
Why doesn't NASA just give up and announce that they've discovered large oil reserves on Europa?
We'll have humans there in two years!
The US Army: promoting democracy through unquestioned obedience
One good way to get from Europe to the US is to get in a row boat and start rowing.
Another is to go work someplace for a month and use the salary to buy a plane ticket.
NASA's rowing. I've taken the time to read the Space Elevator Phase II NIAC paper. For a good many years now, composite fabric with a higher and higher percentage of carbon nanotubes loading(hence a higher and higher tensile strength) is produced each year. Moreover, each year the scale of production jumps higher and in a very non-linear fasion. They were at 5% CN loading in March 2003 (as of the writing of the NIAC Phase II summary paper), promising 15% in a few months and techniques that will allow 25% and higher.
According to the current estimates, this will get us to elevator-worthy fiber in mid-2006.
If NASA really wanted to get to Europa, they'd funnel the 10 bil at CN research, building power-transmission lasers, hammering out the political hurdles and building a working elevator. Then they could send a manned boomer sub to Europa if they wanted, probbably for less money than this new idea of a white elephant.
For those too lazy to go read the paper, here's the piece that'll interest us:
"The University of Kentucky has published and patented on fibers 5 km long with 1% carbon
nanotube loading that achieved a tensile strength increase from 0.7 GPa to 1.1 GPa. Recent
results have included producing fibers with tensile strengths of 5GPa with ~5% CNT loading.
Steel has a strength of 3 GPa and Kevlar is at 3.7 GPa. This process used multi-walled carbon
nanotubes. This implies a roughly 100 GPa carbon nanotube strength or an interfacial adhesion
roughly 1/3 of theoretical. However, we must remember that in the current process only the
outer nanotubes are being functionalized and attached to, the inner tubes are not being fully
utilized. Understanding this implies that by finding a method to utilize the inner shells would
enable production of material performing close to theoretical maximum. A complimentary
technique now being developed at Rensealler Polytechnic Institute allows for the pinning of
the walls in the multi-walled tubes together so that all of the tubes can be used. Techniques at Foster
Miller will also allow for dispersion and implementation of the carbon nanotubes in the
composite at much higher loadings. Loadings over 25% have been demonstrated and higher
levels are possible. By combining these techniques the resulting material should have a tensile
strength near theory of 150 GPa for 50% loading. Material at 12 GPa (4 times stringer than
steel) is expected in the coming months and the full strength materials should be available within
two years at the current research rate."
"Hear that, NASA? That is the sound of inevitablity..."
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Has everyone already forgotten about Cosmos 954?
At the time then President Carter called called for an agreement with the Soviets to prohibit earth-orbiting satellites with atomic radiation material in them. Unfortunately this was never enforced.And for a little history of Nukes in space.
- SR
One of the "Making of 2001" type books describes the design process for the Discovery.
At one point it had a nuclear pulse ("Orion") drive.
There was serious thought to giving it whopping big radiators, which would make it look even more like this probe . . . but they didn't want people thinking they were wings!
The design of this probe is a "classic," in the sense that it looks a lot like design proposals for nuclear-ion rockets circa 1960. One of the science encyclopedias I had when I was a kid had nifty pictures of 'em.
Stefan