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New Images from Galileo
deglr6328 writes "New images of Jupiter's Moon Io, along with a false color image of the first isolated ammonia ice cloud discovered on Jupiter; were released yesterday on the Galileo Probe homepage. The probe is currently transmitting back (at it's maximum transmission rate of about 120 Bits per second!) data on previously recorded observations of Ganymede, Jupiter's main ring, Europa and the Jovian Aurorae. Magnetometer measurements that are now being taken in a 100 day survey of Jupiter's huge magnetosphere will be used in a joint investigation with the Cassini spacecraft, which will be making it's closest approach to Jupiter in about two months. After a broken antenna, 5 years in the Jovian environment, 2 extended missions and a total dosage of nearly 4 times the designed radiation exposure, Galileo is still doing spectacular science."
The reason for the low bitrate is the fact that they are not using the main antenna, which failed to open long ago. Instead the engineers ingeniously reprogrammed the craft to use a low-gain antenna to transmit scientific data. The high-gain antenna was meant to transmit 134,400 bits per second (about one imaging frame per minute). Many software tricks had to be applied, as well as the use of better receiving equipment on earth, for the mission to continue as planned. Prior to the software upgrades, the low-gain antenna had a bitrate of only 8-16 bits per second! See http://www.jpl.nasa.gov/galileo/hg a_f act.html.
http://minduploading.org
however, this image seems to indicate that there is life on Io and that they are using Lynx to surf our web :-)
I don't know what is more impressive:
1) NASA launching a spacecraft of this kind period
2) Having it still work at all
3) Having people smart enough to jury rig it to STILL WORK! Can you imagine trying to fix something MILLIONS of miles away? That's amazing...way to go NASA.
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Let me give you the lowdown
i mistakenly inserted an apostrophe, so friggin shoot me! i know the difference between it's=it is and its. but i still made the mistake WHY? because i was interested in the science not the grammar. you should feel lucky in the story i even used commas and capitals! :o]
- "Hear that?! The percolations are imminent! Cease your ingress!"
I guess thats not too suprising, the original Galileo did some pretty neat science as well. Must be a tradition with the name.
Just say no. Sigs are bad for your health.
Yep, it's here cuz they rejected my 1337 article!
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A feeling of having made the same mistake before: Deja Foobar
C'mon, that's uncalled for, the fact that you see space exploration as something useless doesn't automatically mean that it's "Wasting money"
I probably find 50% of your daily activities useless, does it mean that you shouldn't be allowed to practice them?
---- Stage 5 of drinking : Politics begin to appeal
So basically, what we're saying is that any manned missions to certain planets will be more or less impossible untill man can find a way to shield itself from radiation in a more effective manner than packing ourselves in tons of lead.......
Not that Jupiter would be parcticularly well suited for a manned mission to go, but still.......
---- Stage 5 of drinking : Politics begin to appeal
I am officially revoking the Geek Licenses of all you furby-collecting, Sailor Moon-watching social retards who didn't know that Gallileo's "paltry" 150bits/second transmissions are the result of a heroic rescue from yet-another-NASA-failure.
All kings is mostly rapscallions. -Mark Twain, The Adventures of Huckleberry Finn
i swear to god (actually im an atheist but you get the idea) i just finished watching 2001. had to introduce the gf to clarke. admittedly 2001 is a bit outdated now but at least clarke had a goal. he also had reality in mind when he wrote it. with the exception of hal we could probably do all the things that happen in that movie today. too bad americans just don't care anymore. oh and for everyone from the mars discussion a couple of posts back so concerned that we are wasting money on space that could be used on the poor i don't see the general public to damn concerned with the poor these days either. check your polls. the chances that a republican offering a hug tax cut will win are pretty fair. if we cut those taxes who do you think will lose out? space, children, the homeles, or corporate welfare? i don't see marlboro as being too worried at the prospect.
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It seems to be going not much faster than it was when it left Earth's gravity. Didn't they perform a number of gravity assists to speed it up?
IIRC, Galileo sat in storage for a couple of years during the launch moratorium which followed the Challenger disaster. When it was time for prepare for the long-delayed launch, no one thought to see if mechanical stuff still worked, like unfurling the main antenna. It was reported that it was thought that the lubrication seized up, preventing deployment of the main antenna. I believe that they even spun the Galileo trying to deploy the main antenna. As someone has already observed, it was a magnificent accomplishment to jury rig things with the small, omnidirectional antenna so many millions of miles away. Kinda late, I know, but I've been having beaucoup computer problems. Just hadda say it.
That being said, I'm a little worried about Bush's tax cuts overheating the economy at this particular point in time, even though I'm going to vote for Bush.
Even if the story provided you with nothing *cough* all the trolls *cough*. Atleast you can enjoy the images. That's one cool gallery. For example this one Enjoy!
I'm sorry, but you're wrong here. It may be a nitpick, but the middle layer is hydrosulfate, NOT hydrosulfide. Additionally, a substantial portion of the middle layer of clouds is comprised of various and sundry nitrogen and carbon compounds.
Yow. That's awful. I wonder if it at least uses some kind of compression?
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Username taken, please choose another one.
It's hydrogen sulfide. It's the same compound that makes all those pretty white swirls you see in pictures of Jupiter. Don't believe me? Would you believe google? A search for jupiter+"hydrogen sulfate" turns up only 4 matches, whereas a search for jupiter+"hydrogen sulfide" turns up 10 screens of matches.
-- Anne Marie
First posting isn't trolling. It's...first posting.
on the hydrogen sulfide point.
Translated, this would read: "at it is maximum transmission rate of about 120 Bits per second!", which is just plain wrong.
Use "its", not "it's" as a possessive pronoun.
"Ancillary does not mean you get to rule the world." --U.S. Circuit Judge Harry Edwards, speaking to the FCC's lawyer
First posting isn't trolling. It's...first posting.
Why, the answer to your question lies, as always, with the great sage:
To alcohol... the cause of, and solution to, most of life's problems. -H.J. Simpson [paraphrased]
So there you go. Your answer is: yes, and therefore you should drink more.
"You'd think for a few hundred million dollars they'd find something better than an AOL account?"
Galileo was launched in 1989 and probably took
two tears to build. Also keep in mind that "dependable" is far more important than "cutting edge" technology so they would have used older tech. ( I think the space shuttle is just now upgrading to pentiums from 486 'puters).
120bps is pretty impressive.
AdFuel
where's this post going? Well let's think about it ... if you're going to go somewhere wouldn't you want to know as much about the place as possible before you got there?
yep hence why there's probes. As for the 120 bits per second ... let's see ... how old is gallileo? Yeah that's what I thought ... and is it still working? exactly.
You don't see people whipping out their tandys and saying "hey this will work just fine for me ... it can type add and print" nope ... not NASA ... they've got a rather pricey old POS in space that even if you make fun of it ... it still rocks.
So rock on gallileo ... and would everyone quit whining about the technical specs of a device SO old. BTW ... you can't imagine a beowulf cluster on one of them ... and it doesn't run linux.
Ignore the "p2p is theft" trolls, they're just uninformed
gave the area of compression algorithms in mathematics something of a kick in the ass, so to speak. IANAMathematician but Galileo doesuse some extremely clever tricks to achieve its mission. Three main types of compression functions are used:
1.)a low-complexity integer cosine transform algorithm, which is an integer-based version of discret cosine transform (ie. JPEG)compression, ICT algorithm, this is new and was developed at JPL.
2.) 2x2 summation mode (which includes a factor of 2 hit on resolution).
3.) Bit Adaptive, Rate-Controlled compression(BARC) a lossless compression
A science virtual machine was created in the the command and data subsystem(main computer) and integrated into the existing operating system to support editing, compression, and packetization of the science data. So Galileo was REPROGRAMMED FROM EARTH (using an upload speed of about 10 bits/second!!) on it's way to Jupiter, with the new compression algorithms. I think those scientists deserve a huge amount of credit for thier achievments.
- "Hear that?! The percolations are imminent! Cease your ingress!"
Alright, before I hear any more complaints about the data rate, keep in mind that Galileo is 50 light minutes from Earth. It's one thing to get 100Mbps over twisted pair copper between machines a kilometer apart, but quite another to do it by radio over about 900,000,000 times that distance (by some quick back of the envelope calculations) with a broken antenna.
Bottom line: don't mess with NASA -- chances are one of their engineers wrote your network driver.
Corgha
When Galileo was built, NASA put a Big Huge Beefy antenna on there, that would deploy like a flower bloom, and provide Lotsa Data.
Now, this is a directional antenna - it puts out lots of data but only in a narrow cone. So they needed a backup antenna, for when the main one was not deployed or if it was not pointed right, just for basic communications (i.e., "Galileo, point main antenna towards earth"). So this antenna is omnidirectional but very small bandwidth (since you don't need bandwidth, after all.)
Yeah, the big one broke. So they have to use the dinky one for all the _data_ communication, too. :-P
This would be like your monitor burning out and having to figure out a way to use your PC speaker to do file management.
Well, I'm sure that a lot of people would love to increase its transmission ability. But one slight problem ... exactly how do you intend to make this upgrade?
It would be really nice if we could consistently create probes with this kind of durability and usefulness. If we're getting this kind of data with 1989 (?) technology, then wouldn't it be a good idea to spell off the old probe with something with better instruments?
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
If you watch the Quicktime of Ganymede's plasma waves, you can actually make out a sinusoidal curve in the wave spectrum graph, compliments of special relativity.
120 characters isn't enough to explain it.
For the record, I don't think NASA can be completely blamed for the failed main antenna on Galileo.
Earlier this year I heard Bob Mitchell speaking about Galileo and Cassini - he's pretty much been at the top of both missions. One of the reasons that the main antenna failed to open was because it had to open in the first place, so it was a lot more complicated. (Ideally they would have built it fixed open, like Cassini is designed.)
It had to be redesigned and sent up with the antenna folded up so they could fit it in the space shuttle cargo bay. The reason it had to go up in the space shuttle was because of political interference where people wanted the shuttle to be used for some high profile missions to revive it a bit from the Challenger blowing up in 1986.
Cassini couldn't have the same problems because it was launched with the antenna open. Instead of the space shuttle, they just threw it on the back of one of these, which would have been preferable for Galileo aswell, since they can get much more effective propulsion to kick it off.
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I fear it wasn't the first time for such a problem.
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Gleepy the Hen. More intelligent than the average hen.
Remember the Van Allen radiation belts around Earth? They're composed of energetic charged particles (protons and electrons), excited to high energies by the magnetosphere, and are held in their spiraling paths by the terrestrial magnetic field. Before they were discovered (in the late 50's, by James Van Allen), people like Werner Von Braun had planned to put manned satellites in a two-hour orbit -- about 1075 miles up. This turned out to be in the lower Van Allen belt, and the radiation hazard was far too great for safety, so manned spaceflight now is generally in orbits below 250 or 300 miles.
But it's Jupiter we're talking about, and the jovian magnetic field is much stronger than Earth's; the jovian equivalent of the Van Allen belts are millions of times more energetic than the terrestrial belts. Just to give you an idea of what this means to people, compare the exposure at Jupiter (say, in the neighborhood of Io) to that around Earth.
When the Apollo astronauts went to the moon, they had to penetrate the Van Allen belts twice, going out and coming back; in doing so, they received about 2 rem radiation dose. This isn't too much: the U.S. limits radiation workers to about 25 times this, each year, based on the cancer risk. When you talk acute doses -- say, you do a pass by Io, which is in the middle of the jovian belts -- the whole-body exposure which is 50% fatal within 30 days (when untreated) is around 250-300 rad (under these circumstances, 1 rad ~ 1 rem).
Jupiter's radiation belts are millions of times stronger than Earth's, so if an astronaut spent the same time in them (about 3 hours total on a lunar mission -- but Jupiter's much larger, and so your speed would have to be hugely greater to make the transit in that time) they'd get an exposure of millions of rem. In other words, they'd be dead almost immediately -- an exposure of mere seconds would probably be lethal.
Galileo is radiation-hardened, since it was intended to survive in this environment; however, it's been there for almost three times its design limit, and it must be getting pretty fried by now. As a matter of fact, last year when it made its first really close flyby of Io, there was concern that the radiation would corrupt the computer memory and cause it to go into safe mode, or blind the camera's CCD. When that didn't happen, everyone was relieved -- and they promptly did it again!
The radiation environment is severe enough that they actually expect the spacecraft to be physically destroyed in a few hundred million years, if they left it in Jupiter orbit.
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Politics is about making compromises. Religion isn't. --Michael Horton
Were any government functions being underserved in 1984? Certainly the country was in good enough shape that the challenger for the Presidency in that year only won his home state, so the American people must have thought things were pretty good.
You see, if you take the 1984 budget (minus 1984's debt interest) in 1999 constant dollars, increase it for the amount the U.S. population has increased, and use that (plus 1999's debt interest) as your 1999 budget, the U.S. would have run a $740 billion surplus in 1999.
You know what that means? We could have in 1999, while spending as much per citizen as we did in 1984, cut all government revenues by 33%, and still have had a surplus of $131 billion, as opposed to the actual 1999 surplus $154 billion.
Huge tax cut? No major-party candidate has proposed one since 1980.
There's no "we" in team, only "me"
what is about sig11 and annemarie et al that rub sensibility the wrong way? mebbe they're the handful in a couple hundred thousand folks who will abuse *any* system in an almost interesting way....
This the next place we'll loose a lander to then?
Jovian clouds are generally understood as comprising three distinct cloud layers: an upper layer of ammonia crystals, a middle layer of ammonium hydrosulfide, and a thick bottom layer of water and ice crystals. It's good finally to see some corroboration from the trenches.
-- Anne Marie
a hell of a lot, considering that the Galileo mission has gone on for much longer than it was really supposed to. Also, empty space does not provide a good barrier to radiation, no matter how you cut it.
rough conversion:
transcontinental airplane flight = 10 - 100 chest exrays. Realize that a) Galileo has been in space for a lot longer than you are on an airplane flight and b) Galileo can't have much more shielding than you would have in that plane (airplane skin + atmosphere + earth's magnetic field)
The aliens that finally find that little satellite will have to take care so that they don't burn their fingers!
-inq
The value of data alone that the probe is obtaining is well worth the value of increasing the transmission ability.
The slow transmission speed is due to the fact that the main (high-gain) parabolic-dish antenna failed to open correctly on its way to Jupiter. According to the JPL web site, the main antenna was supposed to be capable of up to 134 Kbps.
Instead, they had to use the less powerful, omnidirectional backup antenna, which has worked admirably over the years. Go JPL.
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Is it okay to cry "Movie!" in a crowded firehouse? --Steve Martin
I'm kinda wondering why they couldn't transmit the data via laser or a simililar mode of transmission. At 120 bps, there's quite the antiquity of technology! The value of data alone that the probe is obtaining is well worth the value of increasing the transmission ability.
"Haha, stupid whore, I bet you've never used a twenty-million dollar dildo!/iL
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303infinity Rocks, buy their CD's.
You'd think for a few hundred million dollars they'd find something better than an AOL account?
For crying out loud! When are they going to get @home installed on that thing??
One future, two choices. Oppose them or let them destroy us.
Did anyone notice the comet in image 115-A? Look to the right of Eurpoa, above the third star, and you can see it. You can hardly make it out, but once you do, it's quite spectacular. Did anyone else notice this?
Something wonderful will happen Dave.