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Cassini's Huygens Probe Rendezvous with Titan
im333mfg writes "Tonight at 7:08pm PST, the Cassini spacecraft will be releasing the much anticipated Huygens Probe for a rendezvous with the Saturn moon Titan. It will be making a 22 day journey to the moon, and end up entering the atmosphere sometime on January 14th. 'Titan is one of the remaining puzzles of the solar system - while Cassini's imaging cameras and radar instrument have begun to reveal the details of its surface, the Huygens probe will be the first spacecraft to venture beneath Titan's thick clouds.'"
Plus: Europa-the-planet. Water beneath the ice. Lots of critters.
I am anxiously awaiting the Jan 13th entry into Titan's atmosphere. Apparently there are huge electrical storms on Titan, and to top it all off with gooey, sugary icing, Huygens has a fricking microphone on it. Now that is going to be sweet. The only thing that I don't particularly like about it is that my mission, Deep Impact, could have our launch pushed back a day due to DSN coverage for the descent, but what the hell, it's *so* worth it.
We learn a lot more from a single one of these probes than we do from having a couple of starving astronauts endlessly orbiting the earth in a big tin can full of their own garbage.
cheap labor conservatives - they want to keep you hungry enough to be thankful for minimum wage.
...in this 1.3 MB PDF, which includes timelines for both the release and Titan encounter, and some pretty in-depth discussion of the science instruments on Huygens.
That's the great thing about Physics though - it's not only cosmology - it's also quantum physics and the others. And we were nowhere near our present understanding of physics at the turn of the last century.
This is slightly OT...
Now this probe did cost a bit: At 350 kg and $600m, its cost is way above gold (5.000.000) and only slightly below diamond ($1.75b at $1000/carat). So much for "diamond fever".
You will be able to watch this on one of you CSPAN channels tonight.
I can summarize what you will see. Since there will be no images of the seperation until a day or so later, at which time it would only be a distant speck, you will see a bunch of nervious nerds watching their monitors. And...
if the separation goes well:
"Yeah! We did it!"
if the separation is zarked:
"Oh shit! There goes my life's @&#* work!"
The odd thing is that once separation happens, there is only one-way communication with the probe and Huygens has no guidence rockets. In fact, it will be sleeping via timer until just before entry. There is no way to alter it's course, change parameters, or nothing. If we found out between that time that it will land in a pile of quicksand or the atmospheric models are totally off (messing up parachute timing), there is no retargeting or changing the mission plan.
It is considered primarily an atmospheric mission, and landing is more or less a bonus. But I think the coolest thing would be to land in an oil sea and see giant waves. The waves can be taller on Titan because of lower gravity. They could be giant and slow-rolling. It will be a great mission if it makes it to the surface while transmitting, but a lot can go wrong. Parachutes have been a problematic technology in the past. I hope some bone-head did not put something on backward, like they did that Utah-crashing probe. Galileo's Jupiter penetrator also had parachute problems, but luckily recovered by shear chance. And, they already found a transmitter problem in the probe. They compensated for it by changing Cassini's flight path to avoid too much Dopler shifting.
I wish they split it into two smaller probes which shared instruments between them to reduce the chance of complete loss. But, that is generally still more expensive than one bigger probe.
Good Luck, Little Probee
Table-ized A.I.
"Personally, I'd much rather see these things with chemical propulsion until something else non-radioactive (solar, fusion, ?) becomes feasible. There's always a chance that something could fail, and if it burns up in the Earth's atmosphere there could be some nasty fallout."
If the launch vehicle crashed, the worst that could happen would be the release of less uranium than coal power plants already release on a regular basis. Uranium just isn't that radioactive.
The reactor would only be activated when the craft was already in orbit, and a catastrophic crash at that point is very unlikely. To crash, the engines would have to deorbit the craft, which would take a long time. I don't know how long, probably days at least.
You should also be aware that probes to the outer solar system require nuclear power anyway, just not in the form of reactors. They use highly radioactive plutonium to generate heat and electricity. A crash with that would be much more damaging because Plutonium is much more readioactive, and it's already radioactive at launch time. Unused Uranium fuel just isn't that dangerous compared to Plutonium.
I rarely criticize things I don't care about.
I wish they split it into two smaller probes which shared instruments between them to reduce the chance of complete loss.
experience has shown that this doesn't help. they either all work, or all fail. the only thing multiple probes get you is a more diverse data set, not increased reliability.
the galileo atmospheric probe parachute problem is new to me though, do you have any references?
http://news.bbc.co.uk/1/hi/sci/tech/423414.stm It looks like Cassini is powered by nuclear, which is opposite of your argument above. Or were you trying to restrict ion engines to this type of technology http://news.bbc.co.uk/1/hi/sci/tech/4015227.stm Happy holidays slashdotters