Cassini Alters Path. Phoebe Now In Sight! 186
Anonymous Explorer writes "This week the Cassini-Huygens
Spacecraft finally entered
the Saturn system and made its first
main-engine burn in five years in preparation of for the Phoebe flyby. This long
journey
has been one filled with much promise and peril. Launched in 1997,
Cassini is expected to have a rendezvous with
the moon Phoebe
on June 11. For those of us who are lazy, that's just a tad under two
weeks away. After the Phoebe flyby, it's on to the ringed planet, with an
anticipated July 1
ground orbit insertion. The ESA's
Huygens probe will descend into the atmosphere of Titan a few months
after Cassini is inserted into orbit. This mission
promises to be
one that brings a very psychedelic and beautiful area of our solar
system into clearer focus. This multinational
mission is one the
most ambitious scientific explorations yet undertaken and promises some
truly otherworldly images in the near future. With 31 moons/natural
satellites thus far discovered orbiting Saturn, there should be a lot
to keep us occupied. Anyone else excited about the journey
to a ringed world? Lets all enjoy this ride. It promises to
be a unique one as much as for the scenery as for the science. Informal
discussion regarding the Cassini-Huygens mission can be found at
#cassini on irc.freenode.net."
Whoooaaa (Score:1, Funny)
Heeeey man..
I'll be sure to tell my cat (Phoebe). . . (Score:4, Funny)
She gets a little freaked when things flyby without warning (although I've rather been looking forward to it myself).
I'm still trying to figure out though, why I, as the more massive of the pair, appear without question to be the captured object.
KFG
DOOM (Score:2, Funny)
By then, we better have BFG
Re:I'll be sure to tell my cat (Phoebe). . . (Score:2)
Hence, your belief in being the more massive of the two objects is incorrect. =)
Phoebe flyby (Score:3, Funny)
Re:Phoebe flyby (Score:1)
protests (Score:4, Interesting)
Remember cassini is nasa's deadly space probe [animatedsoftware.com]. It is nice to see that these groups have other stuff to protest these days. Hope that stuff is not as deadly as cassini...
Al Sharpton (Score:1, Informative)
Re:protests (Score:5, Interesting)
We've been using nukes in space for 30 years without significant problem. If we could have used them on MER, the damn things could run for years.
This subject needs a Penn & Tellerish "Bullshit!" show
Re:Haha - yes, those "stuupid" environmentalists (Score:5, Insightful)
Anyway, I didn't say "environmentalists" are stupid. Most mean well, and some are even well informed and productive. Unfortunately, many mistake passion for evidence, and can't be bothered to investigate opposing viewpoints.
RTGs are hardened and designed to withstand explosion and extreme temperatures. They do not explode, and I believe that they do not even become active until after launch. Radiation has been "The R Word" since the 50's, but we actually use it all the time and know how to handle it. Only in cases of extreme incompetence and lack of precautions (see Chernobyl - 1986) do we need to be concerned.
Returning to the planet, a nuclear plant is far less likely to cause ANY harm than most power technologies or chemical processes (See Bophal, India). We KNOW that radiation can be dangerous, hence the extreme precations we take.
Incidently, NOTHING is 100% safe... along with fearing (and guarding against) the risk, you should consider the rewards.
public policy and democracy (Score:3, Insightful)
Because, while RTGs m
Re:public policy and democracy (Score:2)
Re:public policy and democracy (Score:2)
What happened with Cassini was harmful to the relationship between science and the public.
Re:public policy and democracy (Score:4, Informative)
The greater damage was done by irrational fearmongering than any launch.
This silly thing where "my side need only be plausible, your side needs to be 100% concrete" is stupid. I think we're done.
Re:public policy and democracy (Score:2)
Yes, RTGs probably are very safe, but that is not the point. The point is how ordinary people, whose lives might be affected by them, get to the point of being convinced of that.
In economics, information itself has a cost. Now, lets say, you are a scientist and you want to perform some experiment which involves dangerous materials and has little perceived benefit to most people.
Re:public policy and democracy (Score:2)
I think your use of rational is as a deductive argument. As had been demonstrated by deductive argument, with finite axioms, deductive arguments are not a path to truth.
As to using the term rational as a modifier on economic arguments, it makes me think of game theory. From where I sit, that is a severe criticism.
Looking broadly at your argument, it can never be economically justified to perform basic research. Nor can large infrastructure projects be implemented.
Looking specifically a
Re:public policy and democracy (Score:2)
So we need only convince ordinary people whose lives might be affected by it? We don't have to convince ordinary people who definitely won't be affected but who are terrified anyway because of the nasty N-word?
Or do we have to convince every superstitious idiot on the planet that they absolutely won't die horribly as a result, before we do anything at all anywhere?
Re:public policy and democracy (Score:2)
Turns out that people have the right to have extremist/reactionary opinions. It is then the duty of opposing viewpoints (the more rational, im my opinion) to respond to them. Theoretically, that's the best way to get to the truth.
Unless of course this is slashdot "you-can't-have-an-opposing-opinion-because-I-don ' t like-it" conversation #5,123,234 , in which case I don't give
missing the point (Score:2)
While many people may be afraid of the potential harm from nuclear power plant accidents, the real problem with them is that nobody has figured out what to do with the waste.
Bhopal may have been a terrible chemical accident, but the chemicals that were released can be destroyed fa
Re:missing the point (Score:2)
Personally, I use a lot of energy (I drive a not particularly fuel efficient vehicle in California). I made that choice when I bought it, and thus can't bitch too much about _paying_ for said energy...
Re:missing the point (Score:2)
We just gotta hold out for 2050 when we get the spiffy fusion plants.
Re:Haha - yes, those "stuupid" environmentalists (Score:5, Informative)
This doesn't mean they're dangerous. They are all quite capable of surviving reentry and impact, and in one case (the NASA Nimbus B1 satellite in 1968) an RTG was recovered and actually reused in another spacecraft!
Furthermore even if one did break up in the atmosphere and somehow vapourise despite being made in a ceramic form that would stay in a few lumps, it would cause bugger all damage. Plutonium isn't especially radioactive, although it is moderately chemically toxic. The small amount in an RTG completely pales in comparison to the plutonium in the environment from all the nuclear tests, and those make up literally 0.5% of the radiation we receive each year. (The rest comes mostly from natural sources but a significant amount also from medical xrays.)
Re:Haha - yes, those "stuupid" environmentalists (Score:2)
Re:Haha - yes, those "stuupid" environmentalists (Score:4, Informative)
They're also really damn expensive because you have to make the fuel in a nuclear reactor. Probably not suitable for home use. Also, there hasn't been much success making them really really tiny like you'd want for portable equipment.
Re:Haha - yes, those "stuupid" environmentalists (Score:3, Informative)
Do you drive a car? Do you use a computer? Do you smoke? All of th
[OT your sig] Re:protests (Score:2, Insightful)
You want to give us the slightest shred of evidence for that?
I hate unsubstative, emotional, unable to be backed up sigs. Especially stupid ones.
It's comin' right for us! (oh, false alarm?) (Score:2)
risk (Score:4, Insightful)
The protests were about a risk, that is, an accident that could have occurred with a certain probability. Everybody pretty much agreed that the risk of an accident was at least fairly low. What people disagreed on was the cost should such an accident acctually occur. The fact that a fairly low-risk event didn't occur does not tell you anything about whether it was prudent to engage in the activity in question.
I'm sorry that such elementary scientific and economic concepts as "risk" and "cost" elude you. Without an understanding of those concepts, you are simply in no position to even participate in such debates.
Re:risk (Score:5, Interesting)
It seems that you don't understand the concepts of risk and probability.
You never have a "certain probability". All you have is probability. Probability is a best guess in cases such as this since there are numerous factors to take into consideration.
72 lbs. of plutonium re-entering the atmosphere BY ITSELF without shielding would cause insignificant damage at best. It would be vaporized and scattered in the upper atmosphere, where cosmic radiation would rapidly turn most particles into unstable elements that breakdown even faster.
In fact, the chances of said particles reaching the surface of the earth is minimal. And even if it did, we are talking fractions of microcuries at best.
BUT IT WILL DAMAGE THE ENVIRONMENT! 36 kg of plutonium vs. 6.14X10^24 kg of Earth? With the way people make radiation sound, you'd think it was magical death wraith just waiting to be set loose on the poor undefended Earth.
And while we're talking about probabilities, I think you should be more concerned with your fellow drivers than an errant space probe. You're far more likely to die in a car crash than any sort of radioactive accident, least of all from a space probe.
To put it in perspective, you have a risk when you take a shower in the morning. There's a risk that you could slip, crak your head and die. The risk is small, but it's there. Does this mean you shouldn't take showers? Do you do a risk/cost analysis everytime you step in the shower? Do you have life insurance, a will, savings, etc. for anyone left behind? Do you estimate how much a funeral will cost? What taxes will be due? How much lawyers will cost? What about your job? The cost it would take to replace you? The list goes on. And this is all just based on you taking a shower.
Do you trully know your risk/cost? I doubt it. It's not possible to know all the repercussions of your demise because no one can predict the future. If you were smart though, you would be prepared as you could be for such a thing and you'd go on living your life and taking showers.
You're just one person. NASA has hundreds who run computer simulations, analysis, environmental impacts, emergency scenarios, etc. . The probe was launched in 1997, but they were probably testing the hell out of it for at least a decade. And NASA has been doing this since the 60's.
They are not infalliable, but they have numbers to back up their claims. And I would take a 100 scientist recommendation over an elitest snob.
~X~
missing the point (Score:2)
Beyond that, you are just reiterating the usual arguments that the risk was low. I happen to agree with that. But arguing, as the original poster implied, that absence of deaths resulting from the Cassini launch suggests
Re:risk (Score:3, Informative)
Sure you do. The expression just means "some well-defined but unknown probability value" and suggests it is different from zero. It's common usage in statistics and stochastics. Search on Google for examples (about 19300 of them).
Re:risk (Score:2)
I heartily agree about the risk/cost issues. The Cassini Probe [flosat.be] was worth $1.5 billion before launch [gpnj.org]. Now that it's been taken out of the package, the value to collectors will go WAY down. As anybody who collects pristine government space probes knows, once you turn it on, it's never like new again. And you know that nodoby's gonna put out another limited edition big science probe [techdirections.com] like Cassini.
I mean, how can all that knowle
Re:protests (Score:2)
Re:protests (Score:4, Funny)
That is great. I hadn't heard that common referral before, so I googled the quote. Just to check their facts. I did the I Feel Lucky search. Lo and behold, I did find an article about the deadliest substance known to man. Apparently, it is not plutonium as is commonly referred. It is in fact dihydrogen monoxide [heraldguide.com]
Re:protests (Score:1, Offtopic)
If not, I have a buddy you HAVE to meet.
Re:[ot]Re:protests (Score:5, Insightful)
Re:[ot]Re:protests (Score:2, Insightful)
Well... (Score:5, Funny)
Guess the mission engineers took the brown acid. Bummer.
Re:Well... (Score:5, Funny)
"Gimme an Ph!"
And it's one, two, three, what's this Cassini for?
Don't ask me I don't really care,
I suppose just 'cause Titan's there
And it's five, six, seven, open up the pod bay doors.
There ain't no time to wonder why,
Whoopee! It's a Phoebe flyby.
KFG
Re:Well... (Score:2)
ROFL! Well done, nice filk!
and the images from Cassini will no doubt induce shock and awe among us pointy-headed types
SB
water on earth (Score:5, Funny)
Re:water on earth (Score:4, Funny)
Re:water on earth (Score:2)
Re:water on earth (Score:2)
Saturnian Surgeon General: We all need 8 glasses of CH4 a day to live! And the nearest sources is...
Saturnians (looking up):
And that's before you consider ther day is only ~10 hours.
Images (Score:5, Informative)
Map and Images of Titan [arizona.edu] from Hubble Space Telescope
Nasa Titan Photojournal [nasa.gov]
Saturnian Satellite Fact Sheet [nasa.gov]
Phoebe [space.com] best image so far, from Voyager2 in 1981!
Odyssey 2004 (Score:5, Funny)
"My God! It's full of pixels!"
Re:Images (Score:1)
Then download the model and the trajectory information of the cassini probe from some able contributors!
Re:Alll look shithouse to me (Score:2, Interesting)
It had rings last time I looked at it through a telescope.
Guess I may have been hallucinating or perhaps my memory is not what it was.
How do we know anything?
Paul
Photographic mission (Score:5, Informative)
However, based on Voyager flybys, Saturn's moons are not quite as photogenic as Jupiter's. Titan is covered with a thick feature-poor haze and most of the other moons are too small to have many of the interesting tidally-caused features of the Jupiter moons. But there are still some interesting features on some of the moons.
And, Cassini will drop a probe into Titan's atmosphere that should return some interesting images and data. Titan may have a methane ocean and the Titan probe may possibly land in it and float for a few hours. The ocean may have giant waves because the gravity is so weak compared to Earth, similar to the way that sand-dunes are easier to make on Mars because of the lower gravity there. Things can get taller and weirder under low gravity. It would be the first time liquid could be seen from the surface of another world (aside from the Apollo Tang drippings).
Re:Photographic mission (Score:5, Informative)
Re:Photographic mission (Score:2)
I would love to see NASA slap a standard interface on the back of these devices. A standard probe framework would be nice too.
Then anybody could just grab a NASA catalouge and order up a probe for their X Prize launch.
I mean, many of these sensor systems were on the bleeding edge of desi
Re:Photographic mission (Score:2)
Though I hope it doesn't.
Re:Photographic mission (Score:2, Informative)
It may float for an eternity, but its batteries will run out only a few (possibly ony three, depending on how long the trip through the atmosphere lasts) minutes after the impact/splashdown. See the mission timeline on the esa webpage [esa.int].
Re:Photographic mission (Score:3, Insightful)
Of course, it will get even closer and do much more that take picture, but I thought that said a lot for the Hubble.
I've been waiting for this... (Score:4, Interesting)
I more than half expected the channel to be Slashdotted, as happens to all websites when their address is mentioned here. But strangely, there are only about ten people over there right now.
On another note, I am very excited about the upcoming part of this mission. I was finishing high school when they launched this thing, and when they talked about it, it seemed like it would be forever before that thing reached Saturn. Needless to say, it has been a lot less than forever.
I wish the fine engineers at Nasa the best of luck in accomplishing this portion of the mission.
Ummm (Score:5, Interesting)
All the gas giants have rings, not just Saturn. They're not as easy to see, but they have been detected.
Re:Ummm (Score:2, Insightful)
Everyone knows which one is the "ringed planet". If one of the outer planets is slightly red-tinged will you object to us calling Mars the "red planet" ?
Re:Ummm (Score:5, Interesting)
Beauty is important (Score:5, Insightful)
Hubble Heritage (Score:5, Informative)
Re:Beauty is important (Score:5, Interesting)
On "Beauty" (Score:2)
With Cassini actually passing through a gap in the inner rings during its orbit insertion it's hard to imaging the spectacular images that await us.
I'm sorry, but goatse.cx has made it impossible to utter phrases like that without a collective cringing. The only way you could have made that more mentally disturbing is if this were a mission to Uranus.
Re:Wow (Score:2)
Kinda makes the CGI from the movie 2010 (which was amazing back then) look pathetic, doesn't it?
I have a new wallpaper...now if I could persuade someone to print a wall-sized poster of that, well
SB
Re:Beauty is important (Score:3, Interesting)
Some European space scientist said that space exploration is necessary for a society for the same reason an art gallery is.
lazy people first (Score:5, Funny)
Does this mean that those of us who are not lazy have to wait a few more weeks before we can learn about Phoebe's observations?
Re:lazy people first (Score:2)
hrm. (Score:3, Funny)
This, as we all know, is the spaceship equivalent of a middle aged man gettin' some for the first time in a long while.
Re:hrm. (Score:3, Interesting)
This burn was only for 56 seconds, (insert joke here), and changed Cassini's velocity by about 78 mph.
June 30 is the real show when Cassini performs its orbit insertion burn for over 90 minutes, resulting in a delta-v change of in the area of 1,400 mph.
What's remarkable is that because of the distance between Earth and Saturn, there is an hour and 20 minute lag, so Cassini is pretty much on its own for this (and most other) maneuvers.
Reporting as ordered -- (Score:3, Funny)
Its amazing. (Score:5, Interesting)
Re:Its amazing. (Score:5, Interesting)
Re:Its amazing. (Score:2)
Re:Its amazing. (Score:2)
wonderful (Score:4, Interesting)
Re:I wouldn't expect a landing (Score:2)
Approaching Phoebe (Score:3, Funny)
"Smelly probe, sme-elly probe..."
(Unless it's the other Phoebe. Meh, she does nothing for me. Wake me up when the probe approaches Piper.)
Re:Approaching Phoebe (Score:3, Funny)
Re:Approaching Phoebe (Score:2)
"Smelly probe, sme-elly probe..."
Now it's on Planet Joey to bring 'Drina back to life!
(Unless it's the other Phoebe. Meh, she does nothing for me. Wake me up when the probe approaches Piper.)
Paging Paige....
How does one orbit a ringed planet? (Score:3, Interesting)
Re:How does one orbit a ringed planet? (Score:5, Informative)
There is a preliminary plot of Cassini's possible orbital tour here [nasa.gov]. According to it, Cassini will make around 69 orbits during its planned mission. Note that one of Cassini's primary targets, Titan, orbits at around 40 Saturn radii, well outside the rings.
Oh, and, look for all the pretty pictures from Cassini to be posted over at CICLOPS [arizona.edu] (Cassini Imaging Central Laboratory for Operations).
Re:How does one orbit a ringed planet? (Score:2)
I haven't heard or read about any ring-crossing, so I am assuming not b/c it seems like a bad idea to take a multibillion dollar probe through a rock garden where the rocks are flying at a few kilometers a second. If anyone knows different though, I'd be interested though.
Sorry about the self-reply.
Re:How does one orbit a ringed planet? (Score:2)
Are they going to check Iapetus for a 1Km tall black monolith?
Re:How does one orbit a ringed planet? (Score:5, Informative)
misinformed mods (Score:4, Informative)
The ring plane extends out to infinity, and so even the Earth passes through it occasionally. The ring plane is considerably tilted with respect to the ecliptic, so it would have been impossible for the Voyagers to not pass through the ring plane. Both went well outside the rings, not, as you imply, through the rings (In Saturn radii: closest approaches V1=3.09 & V2=2.67, outer ring lies at ~2.3) Someone has already pointed out your misinformation about the Cassini orbit. Your links are interesting, but none support your assertions.
Kudos to the mapmaker (Score:5, Insightful)
[only a] 78 mph change in speed
One thing that comes out again here, but only by implication, from these reports, is the amazing accuracy and precision (still amazing to me anyhow) of the ephemerides (~ solar system maps) used to plan these missions. They knew where Mars would be for MER to within, what, was it about a meter or two? Maybe not that close for Saturn but still good enough not to need main-engine course corrections in five years
Kudos to the chief JPL mapmaker Dr Myles Standish and his crew!
-wb-
Re:Kudos to the mapmaker (Score:2)
"It was no coincidence Farquhar had visited his first wife's grave that morning [the date of the main engine burn to decelerate]; December 20 was Bonnie Farquhar's birthday. January 10, 1999, the day the spacecraft was due at Eros, was the fifth anniversary of his civil marriage to his second wife, Irina. The mission's nominal completion date, February 6, 2000
What? We call this news? (Score:3, Funny)
What about the other moons? (Score:2)
Excited? Pictures of Phoebe? 31 moons?
When do they get pictures of Rachel? That would be some moon! I like that one better than Phoebe, at least to look at, but Phoebe is more entertaining to listen to. You can skip Ross, Joey and Chandler but take a few of Monica mooning while you're at it. That will get me excited
Re:What about the other moons? (Score:2)
With 31 moons, Saturn is the "Baskin-Robbins" of planets.
My favorite is Butter Pecan...
Anyone else excited ... (Score:3, Insightful)
Saturn history (Score:3, Informative)
http://www.jnocook.net/saturn/
The things that move us forward... (Score:2, Interesting)
Shadows (Score:3, Interesting)
Hmmm how about an artist-impression of that... :-)
#cassini Chat available to all... (Score:4, Informative)
We have a room on the irc.freenode.net servers called #cassini which is available to all who are interested in the Cassini [nasa.gov] project. Here you will find a wide range of interests discussed, from the informal to the most scientific details of the mission. Some of the Cassini staff have shown interest in participating to further support the project's public interest so don't be surprized to meet them there.
We also support the ' Maestro [telascience.org] ' program which is the Public-Outreach software [telascience.org] created for the Mars Exploration Rover Project [nasa.gov] from JPL [nasa.gov]. As a result, we helped maintain the #maestro room (also on freenode.net) which is still in operation today.
With such high interest building as Cassini-Huygens [nasa.gov] approaches orbital insertion and the Phoebe flyby, we expect a bigger rush in the next weeks. Join in and share the experience!
If you are not sure how to do 'IRC' there are many good primers [irchelp.org] online to help and you can visit http://freenode.net [freenode.net] for details about connecting as well as links to assist you to set things up to chat online.
See all "/.'ers" there... ;^)
Pandelirium
http://www.pandelirium.net [pandelirium.net] irc.freenode.net
#cassini
#maestro
#pandelirium
Huygens not released until December (Score:2)
The submission isn't really wrong, 5-6 months could still be considered a 'few' months but the Huygens probe [nasa.gov] won't be released until December, 2004, and won't reach Titan until January, 2005.
Re:I prefer.... (Score:3, Funny)
queue the obligatory rant (Score:3, Interesting)
Re:Massive telescope versus deep space probe (Score:2)
Ah, could it be that when they built Vogager's camera's they didn't what to look for? They didn't know the nature of Titan, so how could they build cameras to look for it?
My point is this. If the probe doesn't land on the surface .. it's useless.
Ah, again, I don't think any space or land based telescope is going to be able to directly sample the makeup of the Titan atmosphere... you know actually measure the parts? Nor will remote sensors be able to measu
Re:Well we can still hope (Score:2)
Re:does anyone else feel the need... (Score:2)