To the Cape!, Quackmire and arm troubles |
  |
To the Cape!, Quackmire and arm troubles |
 May 14 2008, 08:06 AM
Post
#196
|
|
|
Senior Member  Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253  |
The same report says:
After completing a battery of diagnostic tests, engineers planned to attempt to move Opportunity's shoulder azimuth joint, also known as Joint 1, during the coming week. That would be this week. I've seen some sequences, which are probably related with this attempt, planned for sols 1528, 1529, and 1530. However, after checking the pictures downlinked and available at the exploratorium no movement at all is visible. Pictures from sol 1530 (today) are not yet available. Let's see what happens... |
 |
 
|
|
May 15 2008, 12:20 PM
Post
#197
|
|
 Member Group: Members Posts: 568 Joined: 20-April 05 From: Silesia Member No.: 299 |
Before
http://qt.exploratorium.edu/mars/opportuni...AHP1157L0M1.JPG After http://qt.exploratorium.edu/mars/opportuni...AHP1157L0M1.JPG 
-------------------- Free software for planetary science (including Cassini Image Viewer).
http://members.tripod.com/petermasek/marinerall.html |
|
|
|
|
May 15 2008, 12:28 PM
Post
#198
|
|
|
Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
You beat me, Peter.
Arm deployed!! 
|
|
|
|
|
May 15 2008, 01:50 PM
Post
#199
|
|
 Senior Member Group: Members Posts: 2920 Joined: 14-February 06 From: Very close to the Pyrénées Mountains (France) Member No.: 682 |
QUOTE (Tesheiner @ May 15 2008, 02:28 PM)  Arm deployed!! How the troublesome joint is involved there? Isn't it commending side movement? By any mean, there's progress there. Probably somebody informed Oppy to stay on the news instead of waiting for Phoenix landing unoccuped. -------------------- |
|
|
|
|
May 15 2008, 02:01 PM
Post
#200
|
|
|
Founder Group: Chairman Posts: 14432 Joined: 8-February 04 Member No.: 1 |
The only motor needed to move from where it was to where it is - is the one that's had the trouble.
If you look at the image sequence, not only did is succesfully drive the arm out, they also then moved it a tiny bit back, and then out again. Doug |
|
|
|
|
May 15 2008, 02:27 PM
Post
#201
|
|
|
Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
In the latest status report we could find this:
QUOTE Tests during the past week included electrical resistance tests at the warmest and coldest times of day to determine if a persistent stall in the joint was dependent on temperature. Test results indicated that electrical resistance in the shoulder motor at the warmest time of day approached normal levels. Curiously, today's successful move was executed at 09:20am local time (aprox.). I wouldn't call that the "warmest time of day", would you? 
|
|
|
|
|
May 15 2008, 03:32 PM
Post
#202
|
|
|
Member Group: Admin Posts: 468 Joined: 11-February 04 From: USA Member No.: 21 |
QUOTE (Tesheiner @ May 15 2008, 07:27 AM) Curiously, today's successful move was executed at 09:20am local time (aprox.). I wouldn't call that the "warmest time of day", would you? Good point Tesheiner, but if they know from testing that it is a temperature problem, the solution might be as simple as waking up from deep sleep a little early, and letting the stuck heater do its thing. |
|
|
|
|
May 15 2008, 04:02 PM
Post
#203
|
|
|
Member Group: Members Posts: 470 Joined: 24-March 04 From: Finland Member No.: 63 |
I wonder if the heater can still be manually turned on. 9:20 sounds awfully early for a rover to be up though.
Anyway I am very glad about being wrong about my prediction that the motor was finished. Onwards to The Cape! -------------------- Antti Kuosmanen
|
|
|
|
|
May 15 2008, 04:17 PM
Post
#204
|
|
 Member Group: Members Posts: 213 Joined: 21-January 07 From: Wigan, England Member No.: 1638 |
QUOTE (akuo @ May 15 2008, 05:02 PM) I wonder if the heater can still be manually turned on. 9:20 sounds awfully early for a rover to be up though. I'm afraid the thermostat that brings the heater on cannot be overridden; you have to wait until the minimum setpoint is reached, and then the heater stays on, and on, and on... -------------------- "I got a call from NASA Headquarters wanting a color picture of Venus. I said, “What color would you like it?” - Laurance R. Doyle, former JPL image processing guy
|
|
|
|
|
May 15 2008, 04:23 PM
Post
#205
|
|
|
Senior Member Group: Members Posts: 2920 Joined: 14-February 06 From: Very close to the Pyrénées Mountains (France) Member No.: 682 |
QUOTE (Del Palmer @ May 15 2008, 06:17 PM) I'm afraid the thermostat that brings the heater on cannot be overridden; you have to wait until the minimum setpoint is reached, and then the heater stays on, and on, and on... I guess we're talking about the stucked heater that will be on as soon as deep sleep is over -------------------- |
|
|
|
|
May 15 2008, 05:47 PM
Post
#206
|
|
|
Junior Member Group: Members Posts: 63 Joined: 20-April 05 Member No.: 312 |
Do you think they will now leave the shoulder so it's pointing as it is now i.e with the upper arm at 90 degress out, surely
driving at such a low speed <1mph is extremely unlikely to cause any damage to the arm or the instruments. I'm very surprised that they risk stowing the arm before each move. |
|
|
|
|
May 15 2008, 11:53 PM
Post
#207
|
|
|
Member Group: Members Posts: 910 Joined: 4-September 06 From: Boston Member No.: 1102 |
Does anyone have an inside knowledge of the discussions or reasons that led to the policy of stowing the arm for drives, and unstowing it when the drives are completed. I know that they thought that night temperatures (or thermo cycling) might cause a wire to break in the motor, and so they wanted the arm unstowed. What specifically were the fears of leaving the arm permanently unstowed during drives. Can the joints creep--I think not--but what is the gearing--a worm gear? Worm gears can't creep. Doug or some of you engineers need to better explain the working of the arm joints and why it is (somewhat) dangerous to travel with the arm unstowed. Diagrams and pictures would help
 -Floyd -------------------- |
|
|
|
|
May 16 2008, 12:36 AM
Post
#208
|
|
 Senior Member Group: Members Posts: 4246 Joined: 17-January 05 Member No.: 152 |
Floyd, your question was addressed in this rover update:
QUOTE ... we're not going to be able to move the joint enough to actually fully stow the arm. So now the problem becomes a driving challenge, in terms of the clearance envelopes for the vehicle given the arm in this configuration, and the second has to do with what forces you put into the arm that might possibly move the arm from its current location. The danger there is not so much that the arm could wobble and return to its current position, but that you put in forces that might cause the actuators to backdrive a bit. When you do that, because we're not actually actuating the arm while we're trying to drive, you've created uncertainties in terms of what your knowledge is of the locations of the joints.
Another thing, which does not affect driving so much, but does affect any further operation of the IDD, is, Matijevic said, that there is "going to be increased difficulty and some uncertainty in the placement of instruments." That, in turn, will limit in some respects the kinds of targets the rover can work with and add additional uncertainty in terms of where the rover is actually taking measurements on the target." |
|
|
|
|
May 16 2008, 11:13 AM
Post
#209
|
|||
|
Senior Member Group: Moderator Posts: 4279 Joined: 19-April 05 From: .br at .es Member No.: 253 |
The last navcam pictures of a big panorama taken during sols 1508 and 1510 were finally downlinked.
01508::p1928::02::20::0::0::20::0::40::navcam_10x1_loco_custom_pri_95 01510::p1929::02::20::0::0::20::0::40::navcam_10x1_loco_custom_lower_tier_pri_95 This is not an usual 360º take because in this case the panorama is made of two rows, making for a bigger VFOV (81º instead of 45º), and the raw pictures have LOssless COmpression (LOCO) applied. Here's the result, although there are still some datadrops on the raw images.
The same in polar form.
BTW, I haven't seen a polar projection posted here since quite a long time! A Mars bar goes to the person who points to the latest before this one. |
||
|
|
|
||
|
May 16 2008, 12:50 PM
Post
#210
|
|
 Senior Member Group: Moderator Posts: 2262 Joined: 9-February 04 From: Melbourne - Oz Member No.: 16 |
QUOTE (Tesheiner @ May 16 2008, 12:13 PM) BTW, I haven't seen a polar projection posted here since quite a long time! A Mars bar goes to the person who points to the latest before this one. This one by Astro? (10th March) Not far from where we are now. -------------------- |
|
|
|
|
|
Lo-Fi Version | Time is now: 30th April 2024 - 07:59 AM |
|
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE 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. |
|
