IPB

Welcome Guest ( Log In | Register )

35 Pages V  « < 6 7 8 9 10 > »   
Reply to this topicStart new topic
Spring at Cape York, Sol 2947 (after Greeley Haven) - sol 3040
Stu
post Jun 7 2012, 03:37 PM
Post #106


The Poet Dude
****

Group: Moderator
Posts: 5551
Joined: 15-March 04
From: Kendal, Cumbria, UK
Member No.: 60



"Monte Cristo" in all its glory...

Attached Image


--------------------
Go to the top of the page
 
+Quote Post
Phil Stooke
post Jun 7 2012, 04:06 PM
Post #107


Solar System Cartographer
****

Group: Members
Posts: 10128
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)
Go to the top of the page
 
+Quote Post
walfy
post Jun 8 2012, 06:33 PM
Post #108


Member
***

Group: Members
Posts: 404
Joined: 5-January 10
Member No.: 5161



A micro from sol 2974, "Monte Cristo":

Attached Image
Go to the top of the page
 
+Quote Post
RoverDriver
post Jun 8 2012, 07:48 PM
Post #109


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! mad.gif 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.
Go to the top of the page
 
+Quote Post
Phil Stooke
post Jun 9 2012, 11:01 AM
Post #110


Solar System Cartographer
****

Group: Members
Posts: 10128
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)
Go to the top of the page
 
+Quote Post
Stu
post Jun 9 2012, 12:31 PM
Post #111


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...

Attached Image


Attached Image


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 smile.gif


--------------------
Go to the top of the page
 
+Quote Post
Floyd
post Jun 9 2012, 01:59 PM
Post #112


Member
***

Group: Members
Posts: 909
Joined: 4-September 06
From: Boston
Member No.: 1102



QUOTE (Phil Stooke @ Jun 9 2012, 07:01 AM) *
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.


--------------------
Go to the top of the page
 
+Quote Post
Phil Stooke
post Jun 9 2012, 02:02 PM
Post #113


Solar System Cartographer
****

Group: Members
Posts: 10128
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)
Go to the top of the page
 
+Quote Post
mhoward
post Jun 9 2012, 02:13 PM
Post #114


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 rolleyes.gif
Go to the top of the page
 
+Quote Post
Matt Lenda
post Jun 10 2012, 04:09 PM
Post #115


Junior Member
**

Group: Members
Posts: 98
Joined: 17-July 11
From: Pasadena, CA
Member No.: 6066



QUOTE (Floyd @ Jun 9 2012, 06:59 AM) *
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
Go to the top of the page
 
+Quote Post
elakdawalla
post Jun 11 2012, 08:34 PM
Post #116


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.
Go to the top of the page
 
+Quote Post
Floyd
post Jun 11 2012, 11:17 PM
Post #117


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?


--------------------
Go to the top of the page
 
+Quote Post
Matt Lenda
post Jun 12 2012, 04:51 AM
Post #118


Junior Member
**

Group: Members
Posts: 98
Joined: 17-July 11
From: Pasadena, CA
Member No.: 6066



QUOTE (Floyd @ Jun 11 2012, 03:17 PM) *
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
Go to the top of the page
 
+Quote Post
Tesheiner
post Jun 14 2012, 06:24 AM
Post #119


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.
Attached Image

Original: http://qt.exploratorium.edu/mars/opportuni...P9P1312L0M1.JPG

Attached Image
Go to the top of the page
 
+Quote Post
RoverDriver
post Jun 14 2012, 06:03 PM
Post #120


Member
***

Group: Admin
Posts: 976
Joined: 29-September 06
From: Pasadena, CA - USA
Member No.: 1200



QUOTE (Floyd @ Jun 11 2012, 04:17 PM) *
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.
Go to the top of the page
 
+Quote Post

35 Pages V  « < 6 7 8 9 10 > » 
Reply to this topicStart new topic

 



RSS Lo-Fi Version Time is now: 29th March 2024 - 10:29 AM
RULES AND GUIDELINES
Please read the Forum Rules and Guidelines before posting.

IMAGE COPYRIGHT
Images posted on UnmannedSpaceflight.com may be copyrighted. Do not reproduce without permission. Read here for further information on space images and copyright.

OPINIONS AND MODERATION
Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators.
SUPPORT THE FORUM
Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member.