Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Groundbreaking Solar Mission Faces Chilly Death

timothy posted more than 6 years ago | from the hardly-knew-ye dept.

NASA 134

iamlucky13 writes "Over 17 years ago, the Ulysses spacecraft was launched aboard the space shuttle Discovery for a unique NASA/ESA mission. While nearly all other probes travel along our solar system's ecliptic plane, Ulysses used a Jupiter gravity assist to swing 80 degrees out of plane, carrying it over the sun's poles for an unprecedented view. During a mission that lasted four times longer than planned, it has flown through the tails of several comets, helped pinpoint distant gamma-ray bursts, and provided data on the sun and its heliosphere from the better part of two solar cycles. Unfortunately, the natural reduction of power from its radioisotope thermal generator means it is now unable to even keep its attitude control fuel from freezing, and NASA has decided to formally conclude the mission on July 1."

cancel ×

134 comments

Sorry! There are no comments related to the filter you selected.

I need better (2, Funny)

oldhack (1037484) | more than 6 years ago | (#23794091)

attitude control.

Re:I need better (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23794161)

A few years ago, while browsing around the library downtown, I had to take a piss. As I entered the john, a big beautiful all-American football hero type, about twenty five, came out of one of the booths. I stood at the urinal looking at him out of the corner of my eye as he washed his hands. He didn't once look at me. He was "straight" and married -- and in any case I was sure I wouldn't have a chance with him.

As soon as he left, I darted into the booth he'd vacated, hoping there might be a lingering smell of shit and even a seat still warm from his sturdy young ass. I found not only the smell but the shit itself. He'd forgotten to flush. And what a treasure he had left behind. Three or four beautiful specimens floated in the bowl. It apparently had been a fairly dry, constipated shit, for all were fat, stiff, and ruggedly textured. The real prize was a great feast of turd -- a nine inch gastrointestinal triumph as thick as a man's wrist. I knelt before the bowl, inhaling the rich brown fragrance and wondered if I should obey the impulse building up inside me. I'd always been a heavy rimmer and had lapped up more than one little clump of shit, but that had been just an inevitable part of eating ass and not an end in itself.

Of course I'd had jerkoff fantasies of devouring great loads of it (what rimmer hasn't?), but I had never done it. Now, here I was, confronted with the most beautiful five-pound turd I'd ever feasted my eyes on, a sausage fit to star in any fantasy and one I knew to have been hatched from the asshole of the world's handsomest young stud.

Why not? I plucked it from the bowl, holding it with both hands to keep it from breaking.

I lifted it to my nose. It smelled like rich, ripe limburger (horrid, but thrilling), yet had the consistency of cheddar. What is cheese anyway but milk turning to shit without the benefit of a digestive tract? I gave it a lick and found that it tasted better then it smelled. I've found since then that shit nearly almost does. I hesitated no longer. I shoved the fucking thing as far into my mouth as I could get it and sucked on it like a big brown cock, beating my meat like a madman. I wanted to completely engulf it and bit off a large chunk, flooding my mouth with the intense, bittersweet flavor. To my delight I found that while the water in the bowl had chilled the outside of the turd, it was still warm inside. As I chewed I discovered that it was filled with hard little bits of something I soon identified as peanuts. He hadn't chewed them carefully and they'd passed through his body virtually unchanged. I ate it greedily, sending lump after peanutty lump sliding scratchily down my throat. My only regret was the donor of this feast wasn't there to wash it down with his piss. I soon reached a terrific climax. I caught my cum in the cupped palm of my hand and drank it down. Believe me, there is no more delightful combination of flavors than the hot sweetness of cum with the rich bitterness of shit. Afterwards I was sorry that I hadn't made it last longer. But then I realized that I still had a lot of fun in store for me. There was still a clutch of virile turds left in the bowl. I tenderly fished them out, rolled them into my hankercheif, and stashed them in my briefcase.

In the week to come I found all kinds of ways to eat the shit without bolting it right down. Once eaten it's gone forever unless you want to filch it third hand out of your own asshole -- not an unreasonable recourse in moments of desperation or simple boredom.

I stored the turds in the refrigerator when I was not using them but within a week they were all gone.

The last one I held in my mouth without chewing, letting it slowly dissolve. I had liquid shit trickling down my throat for nearly four hours. I must have had six orgasms in the process. I often think of that lovely young guy dropping solid gold out of his sweet, pink asshole every day, never knowing what joy it could, and at least once did,bring to a grateful shiteater.

Re:I need better (1, Funny)

Anonymous Coward | more than 6 years ago | (#23794339)

Troll or not, that was a gripping narrative.

Re:I need better (0)

Anonymous Coward | more than 6 years ago | (#23794513)

Hahahahahahahhaahahahhaa!

A gripping narrative . . . (0)

Anonymous Coward | more than 6 years ago | (#23794697)

with just a hint of deja vu.

yeah but (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#23794097)

does it run linux?

if not, I don't care

Refreshing summertime treat... (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#23794119)

Just like mom used to make with an ice-cube tray, mice and popsicle sticks.

Re:Refreshing summertime treat... (-1, Redundant)

Anonymous Coward | more than 6 years ago | (#23794219)

-1 Offtopic? Jeez, someone has no sense of humor. Besides it is ON TOPIC. The fucking thing is dying an icy cold death just like the mice with popsicle stick stuck up their tiny mouse anii.

Re:Refreshing summertime treat... (0, Funny)

Anonymous Coward | more than 6 years ago | (#23794237)

Cry me an icy river

solar power? (5, Funny)

Anonymous Coward | more than 6 years ago | (#23794165)

They should have put solar panels on it.

Re:solar power? (2, Informative)

Anonymous Coward | more than 6 years ago | (#23794485)

it does not provide thrust. for that you need to throw out some mass. or use HUGE solar sails.

Re:solar power? (1)

fr4nk (1077037) | more than 6 years ago | (#23794907)

The RTGs don't provide thrust either... as TFS states, it's used (among other things) to keep the hydrazine tanks for attitude control from freezing. Also, solar panels wouldn't help much, because it's orbit extends as far as Jupiter's (with the periapsis being a little outside Earth's orbit).

Re:solar power? (4, Informative)

NathanBFH (558218) | more than 6 years ago | (#23795461)

While this was certaintly true 17 years ago, it's interesting to note that we are now able to sufficiently power science craft with solar panels even as far as Jupiter. Check out Juno: http://en.wikipedia.org/wiki/Juno_(spacecraft) [wikipedia.org]

Re:solar power? (2, Informative)

hubie (108345) | more than 6 years ago | (#23796823)

"Sufficiently power," of course, depends on your mission goals as well. An RTG will give you consistent power for a long time, whereas the solar cells will have issues managing eclipses and long-term degradation from radiation exposure. A Voyager-like flyby would be better suited for an all-solar approach rather than a Galileo-type orbit (and eclipse) all the time in strong radiation belts. History has also shown that it is far from trivial to deploy large solar arrays, even when you have humans present, and the size of these arrays are huge.

A very nice summary [usra.edu] of solar cell technology and future plans can be found over at the USRA site.

Re:solar power? (2, Insightful)

Wandering Wombat (531833) | more than 6 years ago | (#23794979)

It doesn't need to provide thrust. Read the article. They need energy to keep the fuel warm.

Re:solar power? (5, Funny)

inamorty (1227366) | more than 6 years ago | (#23795331)

No man, it's an attitude problem.

it is now unable to even keep its attitude control fuel from freezing
Instead of chilling out, it should apply itself more.

I heard it passed Tim Russert on the way to the (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#23794169)

I heard it passed Tim Russert on the way to the Great Beyond !!

OK, enuf of Russert already !!

Not really as bad as the blurb sounds (4, Insightful)

the_humeister (922869) | more than 6 years ago | (#23794173)

The mission lasted 4 times longer than was planned. Not too shabby (unless you compare to those Mars rovers that just keep going and going...). Sure beats having the mission end prematurely due to stupid things like not having enough fuel or computer errors.

Re:Not really as bad as the blurb sounds (1)

the_humeister (922869) | more than 6 years ago | (#23794203)

Come to think of it, it's even lasted longer than those Mars rovers.

Re:Not really as bad as the blurb sounds (4, Funny)

Anonymous Coward | more than 6 years ago | (#23794329)

Come to google it, it's even lasted longer than those Mars rovers
fixed.

So long Energizer Bunny (5, Funny)

dreamchaser (49529) | more than 6 years ago | (#23794211)

those Mars rovers that just keep going and going

I am waiting for Energizer to ditch that obnoxious rabbit and license the Mars Rovers for their advertising.

Re:So long Energizer Bunny (1)

antdude (79039) | more than 6 years ago | (#23795185)

Or have both. Energizer would win. :P

Re:So long Energizer Bunny (4, Funny)

ckaminski (82854) | more than 6 years ago | (#23795291)

If you noticed, the rabbit's pink. The whole marketing program is a mind-numbingly awesome appeal to women to use Energizer batteries to power their vibrators.

Re:So long Energizer Bunny (2, Funny)

jc42 (318812) | more than 6 years ago | (#23795691)

Hmm ... I can see the ad slogan: It keeps going and going, so you'll keep coming and coming.

Maybe I oughta copyright the slogan before they try to use it (if they haven't already).

Re:So long Energizer Bunny (-1, Redundant)

Anonymous Coward | more than 6 years ago | (#23796995)

You know the bunny keeps going and going and going...

and what's the opposite of going...

Re:So long Energizer Bunny (1)

Xyrus (755017) | more than 6 years ago | (#23797625)

Wow...and I thought I spent too much time on slashdot.

~X~

Re:So long Energizer Bunny (0)

Anonymous Coward | more than 6 years ago | (#23795389)

I wonder if aliens could collect enough high energy photons from their nuclear whessels to refill the RTGs?

These old probes are going to be worth a fortune a few hundred years from now.

Am I the only one that... (5, Funny)

Anonymous Coward | more than 6 years ago | (#23794249)

...gets a little choked up thinking about that poor abandoned craft out there floating to oblivion with no one to talk to it.

Ok, back to masculinity-land...

Re:Am I the only one that... (0)

Anonymous Coward | more than 6 years ago | (#23795127)

Ok, back to masculinity-land...
In a similar way to Charlton Heston landing on an Earth run by apes, you appear to have landed in Geek territory. And you have NO WAY BACK!

The Real Ulysses (5, Funny)

gihan_ripper (785510) | more than 6 years ago | (#23794251)

As the Greek Geeks will know, the real (legendary) Ulysses (aka Odysseus [wikipedia.org] ) went on a ten-year odyssey returning home after the Trojan war. All assumed that Ulysses had died and his former wife was preyed upon by suitors seeking her hand in marriage.

To cut a long story short, Ulysses killed all the suitors when he got home and was especially cruel to a turncoat goatherd, Melanthius. Ulysses cut off his nose and ears, pulled out his genitals for dog food, then sliced off his hands and feet.

Let's home the satellite doesn't come back and find us messing about with the ISS.

Re:The Real Ulysses (5, Funny)

DNS-and-BIND (461968) | more than 6 years ago | (#23794395)

So, Ulysses was a neocon, eh?

Re:The Real Ulysses (0)

Anonymous Coward | more than 6 years ago | (#23795107)

So, Ulysses was a neocon, eh?
See, that's just a stupid thing to say.

Re:The Real Ulysses (1)

Hektor_Troy (262592) | more than 6 years ago | (#23794433)

Let's home the satellite doesn't come back and find us messing about with the ISS.THEY did it! *points to Bush, Cheney, Rumsfeld and Rize*

Re:The Real Ulysses (2, Insightful)

nfk (570056) | more than 6 years ago | (#23794519)

"the real (legendary) Ulysses"

Hmm, so this probe is actually the real Ulysses.

Re:The Real Ulysses (1, Interesting)

the_other_chewey (1119125) | more than 6 years ago | (#23794749)

As the Greek Geeks will know, the real (legendary) Ulysses (aka Odysseus) went on a ten-year odyssey returning home after the Trojan war.

Yeah, because he sucked at navigation.
Additionally, he was an idiot: All the things the gods warned him not to do because
they would turn out to be bad, he did - and they went bad. I never understood why this
moron is considered a hero, and what the gods liked about the guy.

Re:The Real Ulysses (0)

Anonymous Coward | more than 6 years ago | (#23795385)

Just goes to show that despite the odds and what common sense might tell you, stupid endures.

Re:The Real Ulysses (1)

andrikos (1114853) | more than 6 years ago | (#23795589)

Just goes to show that despite the *Gods* and what common sense might tell you, stupid endures.

Re:The Real Ulysses (0)

Anonymous Coward | more than 6 years ago | (#23796281)

Yeah, because he sucked at navigation.

I don't think navigation skills help all that much when Poseidon is angry at you.

Additionally, he was an idiot: All the things the gods warned him not to do because
they would turn out to be bad, he did - and they went bad. I never understood why this
moron is considered a hero, and what the gods liked about the guy.

It's been a while since I've read the Odyssey, but I don't remember it quite like that. After the battle of Troy, Poseidon got angry, and Odysseus didn't offer a sacrifice to the gods, so he wasn't sufficiently humble. The other gods offered him help in an attempt to teach him humility (which he did learn and proceeded to offer sacrifices to the gods after every victory on his way back to Ithaca). Poseidon just wanted him dead.



I do remember his crew doing things that made the situation worse, like opening the bag of winds.

Re:The Real Ulysses (1)

flyingfsck (986395) | more than 6 years ago | (#23795021)

No, I read the Odyssey - it is on my book shelf, together with many other classics. Odysseus did give the goat herd a sucker punch that cracked a bone in his face (for good reason), and the rest of what you said is simply not true. The suitors attacked Odysseus and he fought them off successfully. I suggest that you read the book. It is in every library.

Re:The Real Ulysses (2, Interesting)

gihan_ripper (785510) | more than 6 years ago | (#23795153)

Well, I don't know what version of the Odyssey you have, but I can quote from the Samuel Butler translation of Book XXII at the Project Gutenberg [gutenberg.org]

As for Melanthius, they took him through the cloister into the inner court. There they cut off his nose and his ears; they drew out his vitals and gave them to the dogs raw, and then in their fury they cut off his hands and his feet.
Here 'they' refers to Ulysses, Telemachus, and some cronies, as you'll find if you read further up the page. I can only imagine you have a censored version that took out the gory bits.

Re:The Real Ulysses (1)

Petrushka (815171) | more than 6 years ago | (#23797589)

Odysseus did give the goat herd a sucker punch that cracked a bone in his face (for good reason), and the rest of what you said is simply not true

You're thinking of Iros, the beggar, in book 18 (though we're told that he too was going to get the same punishment: 18.86-87). The punishment of Melanthios, the goatherd, is in book 22 (22.474-477). If it's any comfort the OP isn't wholly correct either, as it's not Odysseus himself who does the dismembering; the context makes it sound like it was his son, Telemachos, assisted by the "good" herdsmen. It's the bit just after Telemachos hangs a bunch of maidservants for having sex with the suitors.

Re:The Real Ulysses (2, Insightful)

Tablizer (95088) | more than 6 years ago | (#23797273)

Ulysses cut off his nose and ears, pulled out his genitals for dog food, then sliced off his hands and feet.

I find it humorous how ancient writers went into great detail about how torture was done. It makes them sound obsessed with violence. I wonder if that was the style, or whether its just that such info tends to survive longer?

In 2500 years, will people be reading the same kinds of things about Guantanamo Bay and CIA water-boarding and think the same thing?
   

It can't die, it wasn't alive (-1, Offtopic)

Nova Express (100383) | more than 6 years ago | (#23794267)

Using animate metaphors for inanimate objects is the Pathetic Fallacy [wikipedia.org] .

Re:It can't die, it wasn't alive (1)

maxume (22995) | more than 6 years ago | (#23794319)

Which fallacy is linking to fallacies on wikipedia?

Re:It can't die, it wasn't alive (0, Offtopic)

owlnation (858981) | more than 6 years ago | (#23794431)

Is that a fallacy x fallacy, or a fallacy raised to the power of fallacy?

The latter, I think?

Re:It can't die, it wasn't alive (1)

maxume (22995) | more than 6 years ago | (#23794517)

I think it divides, so that you end up multiplying your argument by the identity, but people wonder why you stuck in that extra step.

Re:It can't die, it wasn't alive (1)

cp.tar (871488) | more than 6 years ago | (#23795131)

Which fallacy is linking to fallacies on wikipedia?

Ad Wikipediam?

Re:It can't die, it wasn't alive (1)

ricebowl (999467) | more than 6 years ago | (#23794341)

Using animate metaphors for inanimate objects is the Pathetic Fallacy.

Does it offend you that much? Really? I'm not sure of the exact terms, but if the metaphor helps commmunication, without confusing people, then what's the harm?

Re:It can't die, it wasn't alive (3, Funny)

oldhack (1037484) | more than 6 years ago | (#23794619)

Shut up you ricebowl.

Re:It can't die, it wasn't alive (2, Insightful)

risk one (1013529) | more than 6 years ago | (#23795253)

It's not a fallacy unless you're using it as an argument. This is just metaphorical language.

Bad Boy Probe (1, Funny)

timbudtwo (782174) | more than 6 years ago | (#23794291)

They must be retiring it because of its serious attitude problem. It is a teenager after all.

attitude control (0)

Anonymous Coward | more than 6 years ago | (#23794387)

it is now unable to even keep its attitude control fuel from freezing
You're fired!

I'd send it into the sun for one last splash (5, Interesting)

crovira (10242) | more than 6 years ago | (#23794461)

If the fuel's going to freeze forever after this orbit, I'd send it into the sun with all instruments lit up and see what it can record on the way down.

Re:I'd send it into the sun for one last splash (3, Interesting)

endlessoul (741131) | more than 6 years ago | (#23794649)

The mods may have found this funny, but I find this interesting. Is it possible to modify the trajectory? Is it simply too far away to get to the sun? If the fuel already too frozen to be utilized?

If it's going to be an orbiting piece of frozen metal, we may as well send it to a fiery and possibly information gathering demise.

Re:I'd send it into the sun for one last splash (2, Informative)

PMBjornerud (947233) | more than 6 years ago | (#23794867)

"Attitude control" means the thrusters to change its orientation, as opposed to changing the course. You could likely make the probe spin real fast. Not sure if that would give you any more exciting data, though.

I think you can safely assume the engineers on the project have gone through the possible options.

Re:I'd send it into the sun for one last splash (1)

Fred_A (10934) | more than 6 years ago | (#23795495)

Not sure if that would give you any more exciting data, though.
Dizzying data then, maybe ?

Re:I'd send it into the sun for one last splash (2, Insightful)

mortonda (5175) | more than 6 years ago | (#23794893)

since it used a gravity assist to get into this orbit, I highly doubt it can in any way adjust its orbit enough to make it useful, unless another planet happens to stumble by... and since it intersects the orbital plane only twice per orbit, that's pretty bad odds too.

Oh it will probably get to the sun eventually, if it doesn't run into something else, but it will be dead long before.

Re:I'd send it into the sun for one last splash (4, Informative)

cyclone96 (129449) | more than 6 years ago | (#23794905)

To change the orbit to intersect the sun, a tremendous amount of velocity would need to be removed from the current orbit. It would take more propellant to get it to the sun than it took to launch it from the earth in the first place.

It's actually quite difficult to "hit the sun", the Messenger [jhuapl.edu] spacecraft will need to do one earth, two Venus, and 3 Mercury flybys over 7 years to "slow down" enough so that it can finally brake into orbit around Mercury with it's insertion motor.

Re:I'd send it into the sun for one last splash (4, Informative)

u38cg (607297) | more than 6 years ago | (#23794965)

Absolutely no way, is the short answer.

Long answer - in order to get it into the sun, you have to reduce its rotational velocity from numerous miles per second down to zero. You'll remember your 0.5mv^2 - that's how much calorific energy has to be in those tanks to achieve that. Also, at those kind of distances, almost any kind of rotational velocity will be enough to achieve orbit - meaning the damn thing will almost certainly miss and turn into a rather odd comet, which will no doubt baffle our ancestors.

Re:I'd send it into the sun for one last splash (4, Funny)

gihan_ripper (785510) | more than 6 years ago | (#23795263)

which will no doubt baffle our ancestors.
so that would be our time-travelling ancestors?

Re:I'd send it into the sun for one last splash (1)

CartoonFan (1285946) | more than 6 years ago | (#23795933)

In order for our ancestors to travel through time, wouldn't we have to send a time machine back to the past?

Re:I'd send it into the sun for one last splash (0)

Anonymous Coward | more than 6 years ago | (#23796535)

Well yes, but it's a forgone conclusion that time travel will-is-was(will have been, is being, was going to be, etc) invented simultaneously throughout history. Don't worry, it all fits together like a jig-saw puzzle.

Re:I'd send it into the sun for one last splash (1)

X3J11 (791922) | more than 6 years ago | (#23797151)

which will no doubt baffle our ancestors.
so that would be our time-travelling ancestors?

Unless it swings around the sun, achieves a speed multiple times that of light, and travels back in time itself.

At least it won't have to save any whales.

Re:I'd send it into the sun for one last splash (1)

metamechanical (545566) | more than 6 years ago | (#23795305)

It'll only baffle our ancestors if it performs the time-travel slingshot maneuver while going backwards around the sun.

Re:I'd send it into the sun for one last splash (1)

denzacar (181829) | more than 6 years ago | (#23795393)

It does not work without Spock's precise calculations.

You have to be very careful with time traveling solar-slingshots.
Forget a decimal point or two and it might end up as another Tunguska event...

Heeey...

Oh and... (1)

denzacar (181829) | more than 6 years ago | (#23795421)

Warp speed...

It needs to be going towards the Sun at warp speed.

Re:I'd send it into the sun for one last splash (0)

Anonymous Coward | more than 6 years ago | (#23795371)

... which will no doubt baffle our ancestors.
I find the idea of our ancestors being baffled by a modern day artificial satellite baffling. But maybe your ancestors have a time machine.

Re:I'd send it into the sun for one last splash (4, Informative)

ozbird (127571) | more than 6 years ago | (#23795043)

It doesn't carry anywhere near enough fuel for a sun dive.

Most of the energy to get into its current orbit came from its PAM-S and IUS solid rocket boosters, with Jupiter kicking it out of the ecliptic. Until New Horizons was launched recently, Ulysses was the fastest ever artificially-accelerated object - that's how much energy we're talking about. Ulysses started out with 33.5kg of hydrazine maneuvering fuel, and was down to 8.4kg in May 2002. In a nutshell, you could use up all of the remaining fuel and not get anywhere near the Sun (perhelion distance is around 1 AU.)

Re:I'd send it into the sun for one last splash (1, Insightful)

Anonymous Coward | more than 6 years ago | (#23794865)

I'd expect getting it to hit the sun anytime soon, would be a large delta-v maneuver, which it probably can't make anyway.

Re:I'd send it into the sun for one last splash (1)

RealGrouchy (943109) | more than 6 years ago | (#23795125)

Yes, we could paint it black and have a really loud concert with terrible, terrible music!

"Ship! Sun! Wham bang!"

- RG>

NASA-style journalism (4, Insightful)

TrueJim (107565) | more than 6 years ago | (#23794471)

You can always tell when a story is based on a NASA press release. If the spacecraft exceeded its mission expectations, it's a "NASA spacecraft." But if it failed, it's a "Lockheed-built spacecraft" (or whichever contractor they decide to blame).

For a change it would be nice to see NASA give kudos to whatever contractor built the successful spacecraft for them.

Re:NASA-style journalism (3, Insightful)

eggman9713 (714915) | more than 6 years ago | (#23794561)

It's just like they said in the Dilbert TV series, "credit travels up, blame travels down."

Re:NASA-style journalism (1)

barzok (26681) | more than 6 years ago | (#23796389)

You mean "shit rolls downhill."

Re:NASA-style journalism (1, Informative)

Anonymous Coward | more than 6 years ago | (#23795179)

Except in this case it isn't even a NASA spacecraft, sure NASA lauched it and did lots of the science equipment, but the spacecraft itself was built by the ESA.

Re:NASA-style journalism (0)

Anonymous Coward | more than 6 years ago | (#23796915)

I have found it much more accurate if you replace "NASA" with "JPL." When the spacecraft is successful at Mars (or wherever), it is the big press ado at JPL with their logo everywhere. When it fails spectacularly, it is the NASA press room talking about how JPL will head the review board to understand why the NASA mission was a failure.

Control moment gyros (2, Funny)

heroine (1220) | more than 6 years ago | (#23794477)

Control moment gyros would have failed after 1 year & needed 17 servicing missions + 1 protest on capitol hill. U can't beat rocket fuel.

Why not closer orbit? (1, Interesting)

Anonymous Coward | more than 6 years ago | (#23794587)

Or crash it into the sun and take data as long as you can?

RTG lifetime (4, Interesting)

Richard_J_N (631241) | more than 6 years ago | (#23794775)

Quite a few spacecraft seem to run out of power due to failing RTGs. Admittedly, these are the ones that already perform *much* better than their design-lifetime (so Kudos to the designers), but why not just equip them with a little more of the relevant isotope? After all, the mass required is really quite small, and when the missions succeed, it would be great to have a 50+ year lifespan. Is there a good reason why the amount of isotope is limited, or is it just that nobody ever expected the craft to function so well and for so long?

Re:RTG lifetime (2, Insightful)

Waffle Iron (339739) | more than 6 years ago | (#23794885)

but why not just equip them with a little more of the relevant isotope?

Because then you'd need a bigger heavier radiator to keep the RTG from melting early in the mission.

Re:RTG lifetime (0, Offtopic)

32771 (906153) | more than 6 years ago | (#23794949)

This is a silly comment.

This kind of knowledge must come in handy when designing your nuclear powered waffle iron.

Re:RTG lifetime (1)

Richard_J_N (631241) | more than 6 years ago | (#23794951)

I hadn't thought of that. I assumed it was just a case of adding another 1kg or so of whatever isotope is used. But actually, if you doubled the mass of RTG, and used an isotope with a longer half-life, you wouldn't need a larger radiator.

Re:RTG lifetime (2, Informative)

Free the Cowards (1280296) | more than 6 years ago | (#23797333)

And if wishes were horses we'd all be eating steak.

It's easy to say things like, just double the mass of the RTG and just use an isotope with a longer half-life. It's much harder to actually find an isotope with that longer half life (the isotopes which have an appropriate half life and can be synthesized in the appropriate quantities, and to actually change the design of the spacecraft to accommodate the extra mass.

It's an extremely complex engineering problem with a lot of tradeoffs involved. If they could get more life "for free" then they certainly would, but unfortunately it's far from free when you get into the details.

what about.... (2, Interesting)

ztcamper (1051960) | more than 6 years ago | (#23796411)

keeping active components of RTG at a distance and as they gradually decay bringing them closer together. Additionally a gradually increasing concentration of neutron reflective materials can be added as components get closer together. This would slow decay of radioactive materials and reduce temperature in the beginning potentially reducing size of radiators. This should also increase period of time for which RTG can be active by using variably reflective neutron mirrors.

Re:RTG lifetime (4, Informative)

deglr6328 (150198) | more than 6 years ago | (#23795051)

Because the problem of failing RTGs is not due to radioactive decay. RTGs use Pu-238 which has a half life of 88 years. It's just as hot as when it launched. The problem is dopant migration in the semiconductor heterojunctiontions (peltier junctions) of the part that creates the electricity. They degrade over time and put out less electricity for the same reason an LED fails gradually over time slowly emitting less and less light for the same amount of energy put in.

Don't know how to mod this (4, Funny)

Fross (83754) | more than 6 years ago | (#23795351)

It's either very informed indeed, or complete rubbish. I mean, "heterojunctiontions"?

Well done, I'm completely stumped.

Re:Don't know how to mod this (2, Informative)

Pathwalker (103) | more than 6 years ago | (#23795483)

What term would you use for the ions in the junction of two different metals than "heterojunction ions"?

Seems perfectly clear to me.

Re:Don't know how to mod this (3, Informative)

jschen (1249578) | more than 6 years ago | (#23796255)

Definitely informative. Slowly failing RTG's due to degradation of the thermocouples that convert heat into electricity is a likely cause of the eventual end of the Voyager missions. More info at http://voyager.jpl.nasa.gov/spacecraft/spacecraftlife.html [nasa.gov]

Re:Don't know how to mod this (1)

deglr6328 (150198) | more than 6 years ago | (#23796301)

typo!

Re:RTG lifetime (1)

deblau (68023) | more than 6 years ago | (#23795401)

Is there a good reason why the amount of isotope is limited, or is it just that nobody ever expected the craft to function so well and for so long?
From Wikipedia [wikipedia.org] , the best fuel to use is Pu-238 (as in, zomg Plutonium, atomic bombs). Read the article for the technical explanation.

Re:RTG lifetime (1)

dwye (1127395) | more than 6 years ago | (#23797237)

> From Wikipedia, the best fuel to use is Pu-238 (as in, zomg Plutonium, atomic bombs)

No, fission uses Pu-239, not 238. Alas, I only know how to produce Pu-239 (oblig. bwah, hah, hah!) or I would write how different they are.

Mission's over? (3, Insightful)

192939495969798999 (58312) | more than 6 years ago | (#23794863)

I think the mission shouldn't officially be over unless useful data stops coming back, and I would assume a probe even just floating around aimlessly might still broadcast back some kinda data.

Re:Mission's over? (5, Informative)

Anonymous Coward | more than 6 years ago | (#23795101)

Did you see that big dish on it? "Floating around aimlessly" = not pointing at the earth. You can't transmit to the earth without attitude control.

Re:Mission's over? (3, Insightful)

Anonymous Coward | more than 6 years ago | (#23796229)

The only problem with maintaining the mission is that the Deep Space Network has a limited capacity for data transfer, if the equipment is utilized to monitor the Ulysses, it can't receive data on other, more useful probes. My guess is that NASA, in order to allocate resources for missions still streaming huge amounts of valuable data, it's better to cut this one loose and focus on the others.

I remember (3, Interesting)

32771 (906153) | more than 6 years ago | (#23794881)

My astronomy teacher told us about it when I was still in school. Must have been around '92.

She taught astronomy at the local observatory+planetarium. Her name was the German word for Fox so she had her own constellation = Vulpecula.

Idiotically our local Christian democrat government canceled astronomy lessons in 2007. This used to be a required course for the 10th grade in Eastern Germany since 1959. (Its probably the money)

Anyway, old satellites never die, and sometimes their orbits won't even decay.

sex with a Dick (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#23796585)

Groundbreaking Solar Mission Faces Chilly Death (0)

Anonymous Coward | more than 6 years ago | (#23796853)

and NASA has decided to formally conclude the mission on July 1."

And at that point Nasa will change the name from Ulysses to Useless

Go get it. (1)

Sun.Jedi (1280674) | more than 6 years ago | (#23796877)

Since it's built so well as to exceed expectations x4, why doesn't someone go get it, and bring it back for an refit/upgrade and a new mission?

Worst case would be that it just looks damn good on someones front lawn.

Re:Go get it. (1)

Zosden (1303873) | more than 6 years ago | (#23797029)

Only because it would take forever to get it and then returning it would be a big ??? Also do you even know where it is located NASA is having problems getting to the moon let alone correct me if I'm wrong (I'm on my iPhone) but isnt it past Pluto.

Congratulations, NASA! (1)

drolli (522659) | more than 6 years ago | (#23797371)

This is great! The systems worked well up to the point until a fundamental limit, which could not be overcome, hits. The fact that they had overdimensioned it already that the system worked four times longer than planned shows that the right design decisions have been made.
Load More Comments
Slashdot Login

Need an Account?

Forgot your password?

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>