What's Up With Ulysses?, alive? dead? cancelled soon? |
What's Up With Ulysses?, alive? dead? cancelled soon? |
Jan 29 2007, 04:38 PM
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#16
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Rover Driver Group: Members Posts: 1015 Joined: 4-March 04 Member No.: 47 |
ah I see now.
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Feb 7 2007, 01:47 PM
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#17
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
There goes Ulysses...again...
I really enjoy Dr. Marsden' updates: "It's amazing to think that a satellite that was designed in the mid-1970's and built in the early 1980's is still operating perfectly in 2007!" -------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Guest_AlexBlackwell_* |
Feb 7 2007, 05:34 PM
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#18
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Guests |
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Feb 11 2007, 08:17 PM
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#19
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Merciless Robot Group: Admin Posts: 8785 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
I agree with ustrax; the longevity of this spacecraft (and others) is astounding. These are arguably among the most complex devices ever built, yet without hands-on maintenance, periodic overhauls, etc., they just keep going. Wonder if the space agencies might be interested in building a few cars on the side...
All that aside, how much longer can Ulysses keep going given this new power conservation strategy? Also, is there any possibility that it will re-encounter Jupiter at some point? -------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
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Feb 11 2007, 08:44 PM
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#20
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Senior Member Group: Members Posts: 1729 Joined: 3-August 06 From: 43° 35' 53" N 1° 26' 35" E Member No.: 1004 |
Also, is there any possibility that it will re-encounter Jupiter at some point? Back when I was in university, a dozen of years ago I played with simulating Ulysses' orbit. In that occasion I "discovered" the second flyby of 2003. Ulysses crosses Jupiter's orbit every 6.5 years, and approaches it every 13 years, but IIRC, the encounter distance is increasing and there will be no more flybys during all of the 21st century. |
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Feb 13 2007, 03:36 AM
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#21
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Member Group: Members Posts: 477 Joined: 2-March 05 Member No.: 180 |
I agree with ustrax; the longevity of this spacecraft (and others) is astounding. These are arguably among the most complex devices ever built, yet without hands-on maintenance, periodic overhauls, etc., they just keep going. Wonder if the space agencies might be interested in building a few cars on the side... All that aside, how much longer can Ulysses keep going given this new power conservation strategy? Also, is there any possibility that it will re-encounter Jupiter at some point? I figure that they've probably got some pretty tight tolerances on these components. What I'm learning in my engineering classes is that tight tolerances are expensive. According to my Product Design professor, a Professional Engineer, they probably could design cars that would come with lifetime warranties. But they might cost $500,000 each, or more. Parts would need to be made out of more corrosion-resistant materials (more expensive), more parts wouldn't pass inspection because they'd be out of tolerance (higher manufacturing costs, and more time required to manufacture, which also = higher costs), and you might need more highly skilled engineers and machinists to properly design and construct this super-accurate car. If they manufactured the MER's to the tolerances you probably find in the consumer auto industry, the rovers might never have left their landers. Something else to consider - car manufacturers want you to buy a new car every so often. A car that might fail eventually increases your chance of buying again. NASA and JPL don't expect a lot of that sort of return business for most of their designs. |
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Feb 13 2007, 03:56 AM
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#22
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Senior Member Group: Members Posts: 2173 Joined: 28-December 04 From: Florida, USA Member No.: 132 |
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Feb 20 2007, 02:54 PM
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#23
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Member Group: Members Posts: 153 Joined: 14-August 06 Member No.: 1041 |
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Feb 21 2007, 04:06 AM
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#24
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Member Group: Members Posts: 477 Joined: 2-March 05 Member No.: 180 |
But not from that manufacturer. I think car failure is due mostly to keeping costs down, not planned shoddy workmanship. How much would a car built to NASA specifications cost? It depends how long it lasted, and it depends on the person. I doesn't have to last long. Just long enough. If it was long enough, the person may rather stay with a brand whose quirks and issues they know, rather than risk venturing into the unknown, buying something different that might be much worse. And maybe it's not planned, but the engineers making it have to know what's going to happen. Heck, one of the equations I've learned has "reliability factor" built into it. What reliability do you want? 50%? 90%? 99.9%? Different percentages have different numbers (1 for 50%, .75 for 99.9%) that go into determining endurance strengths and allowable stresses to give the certain reliability rating. I guess it's not planned so much as it is a side effect. How much would a car built to NASA spec cost? See the post you quoted me out of. It'll be interesting to see how much longer it'll last. They seem to have a fair level of confidence in it: "The definitive proof will come when Ulysses measures the temperature of the north polar coronal during the next 15 months." |
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Feb 21 2007, 03:43 PM
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#25
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Senior Member Group: Members Posts: 3419 Joined: 9-February 04 From: Minneapolis, MN, USA Member No.: 15 |
This is the old argument they went through when they were designing the Apollo system. They asked themselves, how much would it cost to develop a system that would have a 100% reliability rating, that could never fail and never, ever endanger the lives of any of the crews.
They decided it would cost more than the entire American gross national product from then to their deadline (the "end of the decade") to accomplish that, and it would likely result in a first manned lunar landing sometime around 1980. They also figured they could develop Apollo for about five billion dollars if they were willing to lose about half of the crews they launched. They settled on having a 90% chance of completing any given mission, and a 99% chance of getting any given crew back alive. That determination *alone* set the cost of the program at about $25 billion in 1960s dollars. So, yes, you can pursue perfection. Just understand that, first, you'll never achieve it, and second, that you'll spend an *awful* lot of time and money trying to get there. The better is the mortal enemy of the good enough... -the other Doug -------------------- “The trouble ain't that there is too many fools, but that the lightning ain't distributed right.” -Mark Twain
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Feb 22 2007, 02:19 AM
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#26
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Member Group: Members Posts: 809 Joined: 11-March 04 Member No.: 56 |
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Feb 22 2008, 02:56 PM
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#27
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Special Cookie Group: Members Posts: 2168 Joined: 6-April 05 From: Sintra | Portugal Member No.: 228 |
We'll miss you...
-------------------- "Ride, boldly ride," The shade replied, "If you seek for Eldorado!"
Edgar Alan Poe |
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Feb 22 2008, 03:37 PM
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#28
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
Well - there's a lot of science to be had from the archives, and while it's always sad to see a spacecraft go, it's always a bonus to get some DSN time back.
Doug |
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Feb 22 2008, 04:23 PM
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#29
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Member Group: Members Posts: 753 Joined: 23-October 04 From: Greensboro, NC USA Member No.: 103 |
...and a 99% chance of getting any given crew back alive. I can't remember who said it, but someone once commented that all the safety features of modern cars - multiple airbags, seatbelts, etc. - actually cause more crashes, with people driving less safely because they assume they'll survive an impact. The person said, "Imagine how much more safely we would drive if our cars had foot-long spikes extending from the steering column and ending just in front of our chests. You wouldn't DARE make a stupid move or tailgate someone!" Think how much cheaper that would make our cars - a spike is a lot cheaper than an airbag! -------------------- Jonathan Ward
Manning the LCC at http://www.apollolaunchcontrol.com |
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Feb 22 2008, 06:07 PM
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#30
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Senior Member Group: Members Posts: 1591 Joined: 14-October 05 From: Vermont Member No.: 530 |
You know, for all the flack that ESA's press folks get, I have to say that their framing of this story is pretty apt. Usually this sort of thing ends up reported in the press as "BILLION EURO SPACECRAFT MALFUNCTION" not http://news.google.com/news?hl=en&ned=...tnG=Search+News
"End of the odyssey for brave space probe Ulysses" "Ulysses mission coming to a natural end" |
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