Kilometer-High Waves Flow In Saturn's Rings 31
An anonymous reader sends along a Cosmos Magazine piece on the discovery by NASA's Cassini probe of vertical structures in Saturn's rings, 150 times as high as the rings are thick. The structures were seen because a once-every-15-years orientation of the rings caused vertical features to cast visible shadows. "NASA's Cassini probe has uncovered for the first time towering vertical structures in Saturn's otherwise flat rings that are attributable to the gravitational effects of a small moon. 'We thought that this vertical structure was pretty neat when we first saw it in our simulations,' said John Weiss, the paper's lead author at the Cassini Imaging Central Laboratory for Operations in the US city of Boulder, Colorado. 'But it's a million times cooler to have your theory supported by such gorgeous images. It makes you suspect you might be doing something right,' he added." Update: 06/17 19:29 GMT by KD : The CICLOPS team sent a note correcting the attribution of the quote; the linked article also had it wrong, and has since been corrected.
Resolve the rings (Score:1, Interesting)
Anyone in this audience with actual knowledge of the policies and planning for Cassini missions? If so I some questions.
The primary mission of Cassini ended recently and the extended mission has just begun. Yet only now are we beginning to receive imagery of detailed ring structure. Since the primary mission has ended it is apparent that obtaining detailed images of ring structure was never a priority. All of the time has been spent on the moons, Saturn and relatively wide shots of the rings.
Is resolving the ring constituents even feasible for Cassini? I can see from the flight schedule that close up passes of some sheppard moons will occur in 2010. Will attempts be made to image the detailed structure of the rings at this time?
I know the rings are largely particulate; a fog of ice particles. However there are larger constituents and some regions where large, dense matter is suspected. Obviously there is high risk to Cassini attempting directly image such objects. Yet this mission is finite and perhaps, primary goals having been fulfilled, some riskier goals should be considered.
budgets for long lasting missions.... (Score:4, Interesting)
What I notice is that the primary mission has finished and I just bet that the men in suits are circling the project with their budget cutting shears - but then we get new data, stunning imagary and confirmation of old predicitons.
This just goes to show that given the cost of assembling and launching this missions it makes absolute sense to supply funding until the mission carks it. What would of happened if the budgets for the two Mars rovers was removed after the (very short) planned life cycle was finished?
So, does anybody know how long term budgets are assigned, reviewed and extended to cover missions that exceed their predicted life span? I'm kinds interested.
Re:budgets for long lasting missions.... (Score:5, Interesting)
Are the conservative estimates an example of the Scotty factor. In other words if the team is 90% confident that the mission will last 5 months do they then quote 3 to management - that way if they mission carks it after 4 then they are still covered? I would imagine even the scientists and engineers are very concerned about managerial aspect like project tracking and meeting specification now.
More to the point, how do they estimate such a difficult and unpredictable mission parameter anyhow? I mean somethings like battery life, wear and tear and so on must be quite well understood, but others like the stress of launch, damage, and the great "other" option must be much harder to predict.
Re:budgets for long lasting missions.... (Score:5, Interesting)
It's not so much the Scotty factor as standard engineering procedure for years. If you're told to design an elevator to life 5 people, you make sure it can hold 10 just to be safe. If the design requirements from NASA say "Four years", you design for 6 or 8. You don't want to be penalized for early failure, after all.
And I don't know how the engineers estimate life expectancies, but most components aren't mission-enders. You worry mostly about things like fuel/reaction mass and power sources, first. These are relatively predictable. Other parts that fail generally seem to do so gradually. (Electronics degradation, the reaction wheels on Cassini, etc.) So while you wouldn't necessarily have predicted that a priori, you can track it once it starts to happen.
Weiss is borderline crazy (Score:2, Interesting)
One thing I never understood about him was his compulsion to call 'derivatives'...'potatoes'. Take the potato here. Reverse potato here. The solution is the potato. Coupled with his thick european (swiss maybe?) accent, it made for one of the bigger WTF moments in my college career.
Re:Weiss is borderline crazy (Score:4, Interesting)
Except I've never taught Physics 2 to you or to anyone else.
Although I do love me my potatoes. Maybe you're from the future? Did you bring back stock tips? Or future-potatoes?