Spring at Cape York, Sol 2947 (after Greeley Haven) - sol 3040 |
Spring at Cape York, Sol 2947 (after Greeley Haven) - sol 3040 |
Jun 7 2012, 03:37 PM
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#106
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
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Jun 7 2012, 04:06 PM
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#107
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Solar System Cartographer Group: Members Posts: 10129 Joined: 5-April 05 From: Canada Member No.: 227 |
Nice one, Stu!
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Jun 8 2012, 06:33 PM
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#108
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Member Group: Members Posts: 404 Joined: 5-January 10 Member No.: 5161 |
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Jun 8 2012, 07:48 PM
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#109
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Member Group: Admin Posts: 976 Joined: 29-September 06 From: Pasadena, CA - USA Member No.: 1200 |
Darn! Nowadays I get one shift every two weeks or so. Today I was on shift and no driving due to ODY being in safe mode! My next shift is in three weeks!
Paolo -------------------- Disclaimer: all opinions, ideas and information included here are my own,and should not be intended to represent opinion or policy of my employer.
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Jun 9 2012, 11:01 AM
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#110
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Solar System Cartographer Group: Members Posts: 10129 Joined: 5-April 05 From: Canada Member No.: 227 |
That safe mode could last until August, they say now. Ready in time for Curiosity's landing, but not good news for Opportunity.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Jun 9 2012, 12:31 PM
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#111
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The Poet Dude Group: Moderator Posts: 5551 Joined: 15-March 04 From: Kendal, Cumbria, UK Member No.: 60 |
The latest PDS release covers Sols 2701-2790, which includs the time Oppy spent approaching, studying and then destroying "Homestake"... A couple of pics made using the PDS images, shown here in advance of Oppy spotting a bigger, fatter "Homestake" to use her instruments on...
Very pleased with the second one - first time I've been able to see and bring out the "sparkly bits" referred to by the rover team -------------------- |
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Jun 9 2012, 01:59 PM
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#112
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Member Group: Members Posts: 909 Joined: 4-September 06 From: Boston Member No.: 1102 |
That safe mode could last until August, they say now. Ready in time for Curiosity's landing, but not good news for Opportunity. Phil The report on the Odyssey site doesn't seem that dire: "NASA's Mars Odyssey orbiter put itself into a precautionary standby status early Friday, June 8, Universal Time (Thursday evening, Pacific Time), when the spacecraft detected unexpected characteristics in movement of one of its reaction wheels. The spacecraft uses three of these wheels as the primary method for adjusting and maintaining its orientation. It carries a spare reaction wheel.""The spacecraft is safe, and information we've received from it indicates the problem is limited to a single reaction wheel," said Odyssey Mission Manager Chris Potts of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The path forward is evaluating the health of the reaction wheel and our options for proceeding." Hopefully that means a week or so unless you have more specific information Phil. -------------------- |
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Jun 9 2012, 02:02 PM
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#113
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Solar System Cartographer Group: Members Posts: 10129 Joined: 5-April 05 From: Canada Member No.: 227 |
I was going by this, maybe a bit alarmist...
http://news.yahoo.com/nasa-troubleshoots-p...-232759130.html Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Jun 9 2012, 02:13 PM
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#114
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Senior Member Group: Moderator Posts: 3431 Joined: 11-August 04 From: USA Member No.: 98 |
Perhaps to journalists, publicists and the general public, the main point is that it should be operating normally when Curiosity gets there. Of course the rest of us would like to see it operating normally considerably before then
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Jun 10 2012, 04:09 PM
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#115
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Junior Member Group: Members Posts: 98 Joined: 17-July 11 From: Pasadena, CA Member No.: 6066 |
The report on the Odyssey site doesn't seem that dire: "NASA's Mars Odyssey orbiter put itself into a precautionary standby status early Friday, June 8, Universal Time (Thursday evening, Pacific Time), when the spacecraft detected unexpected characteristics in movement of one of its reaction wheels. The spacecraft uses three of these wheels as the primary method for adjusting and maintaining its orientation. It carries a spare reaction wheel.""The spacecraft is safe, and information we've received from it indicates the problem is limited to a single reaction wheel," said Odyssey Mission Manager Chris Potts of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The path forward is evaluating the health of the reaction wheel and our options for proceeding." Hopefully that means a week or so unless you have more specific information Phil. That's the feeling I'm getting around the office. Chris isn't hiding anything in his oh-so-very-PR statement! It was just a bit of funny data that the spacecraft didn't like. She's an old bird, the one... Needless to say the MSL folks are a little rattled. -m |
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Jun 11 2012, 08:34 PM
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#116
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
It's kind of amazing to me that with all the electronic complexity of spacecraft, one of the things that most reliably fails is....THE WHEEL. Hayabusa, FUSE, Cassini....Seriously, you'd think humans would've got the hang of The Wheel by now.
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Jun 11 2012, 11:17 PM
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#117
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Member Group: Members Posts: 909 Joined: 4-September 06 From: Boston Member No.: 1102 |
Does anyone know if the WHEELS have magnetic or ball bearings? Is it the bearings that usually fail, or some other component?
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Jun 12 2012, 04:51 AM
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#118
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Junior Member Group: Members Posts: 98 Joined: 17-July 11 From: Pasadena, CA Member No.: 6066 |
Does anyone know if the WHEELS have magnetic or ball bearings? Is it the bearings that usually fail, or some other component? Usually magnetic, to reduce all friction that you can. There's even the concept of "stiction" across the 0-rpm boundary, when the wheel is spinning very slowly but then crosses 0-rpm and goes the other direction -- even great reaction wheels can get a little "stuck" at that point. Some missions can have attitude control systems that will explicitly avoid 0-crossings, but it often cannot be avoided, depending on your pointing profile. Wheels are indeed tricky -- just ask Oppy! -m |
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Jun 14 2012, 06:24 AM
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#119
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Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
Just a pair of F/RHAZ pics came down on the last batch, but confirming that Opportunity is now located quite close to the edge.
Original: http://qt.exploratorium.edu/mars/opportuni...P9P1312L0M1.JPG |
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Jun 14 2012, 06:03 PM
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#120
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Member Group: Admin Posts: 976 Joined: 29-September 06 From: Pasadena, CA - USA Member No.: 1200 |
Does anyone know if the WHEELS have magnetic or ball bearings? Is it the bearings that usually fail, or some other component? If you are asking about the reaction wheels on ODY, I have no idea, on MER drive/steer actuators they have bearings and magnetic detents. In Oppy's RF steering actuator it is believed that the magnetic detent came loose and prevents motion, while in Oppy's IDD Az actuator we have reasons to believe it is one of the windings that is no longer operational. In Spirit's RF and RR drive actuator it is less clear but the best explanation I have heard is that there is some kind of deposit on the commutators which prevent current to flow through the windings. Paolo -------------------- Disclaimer: all opinions, ideas and information included here are my own,and should not be intended to represent opinion or policy of my employer.
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