Dust Storm- Opportunity EOM, the end of the beginning of a new era in robotic spaceflight |
Dust Storm- Opportunity EOM, the end of the beginning of a new era in robotic spaceflight |
Oct 7 2018, 12:17 AM
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#301
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Member Group: Members Posts: 507 Joined: 10-September 08 Member No.: 4338 |
Although there was an excellent detailed description of the recovery efforts in the MER report, there are a few things that are unclear to me.
What is the "checkmate" condition, exactly? Can someone explain this a little more? Also, hypothetically, if the solar panels were clean but the battery was impaired, could Opportunity communicate on solar power alone, without current from the battery? I realize that might mean a continuing clock fault, which would probably make timing too awkward to continue the mission very long, but it would still be worthwhile to learn the state of the rover following the dust storm. |
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Oct 7 2018, 12:37 AM
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#302
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
Checkmate scenarios are where the vehicles is getting 1.2A on the arrays - so it's 'solar groovy' - but for a duration that means - combined with the fault protection timing - it never actually opens up a fault window. It's pretty likely for short solar groovy periods- and then increasingly unlikely as the solar groovy duration gets longer with cleaning.
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Oct 7 2018, 03:57 PM
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#303
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Member Group: Members Posts: 923 Joined: 10-November 15 Member No.: 7837 |
I'm using 'solar groovy' in every Oppy discussion from now on.
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Oct 8 2018, 12:40 AM
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#304
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Member Group: Members Posts: 507 Joined: 10-September 08 Member No.: 4338 |
If it's time for some levity, maybe in the future Mars helicopters can fly over ground rovers, and blow off the dust!
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Oct 8 2018, 02:39 AM
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#305
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Member Group: Members Posts: 691 Joined: 21-December 07 From: Clatskanie, Oregon Member No.: 3988 |
The Columbia Hills (Spirits location) is one of the landing site candidates for Mars2020 and the Helicopter.
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Oct 8 2018, 03:43 AM
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#306
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Senior Member Group: Members Posts: 2073 Joined: 13-February 10 From: Ontario Member No.: 5221 |
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Oct 8 2018, 05:18 PM
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#307
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Newbie Group: Members Posts: 13 Joined: 19-December 04 Member No.: 125 |
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Oct 8 2018, 06:12 PM
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#308
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Senior Member Group: Members Posts: 4246 Joined: 17-January 05 Member No.: 152 |
The fact of the matter is that not much can be determined from the HiRISE image, but clearly people want to believe that the rover is very dusty, since that's an explanation for why it hasn't woken up yet. At least there is a bit more that can be done. From the September report: QUOTE In coming weeks, MRO will be gathering more data with CRISM, HiRiSE and the CTX. “We’re planning on making observations over next several months to monitor the surface changes over Endeavour as the storm subsides,” said Arvidson.
With CRISM, which is a little better calibrated and a little more sensitive to dust cover, they may be able to get a better idea of how much dust there might be on the ground. “It would be a way of trying to estimate whether the dust on the arrays is high, medium or low,” said Zurek. “We’re trying things. We’re going to try with CRISM. We don’t know if we can get something out of that, but it’s worth a try and we’re going to give it a try.” “Obviously we’re not going to be able to resolve the rover in CRISM data, but it could give us a better handle on what’s going on with the dust environment,” Squyres agreed. |
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Oct 10 2018, 02:20 AM
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#309
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Member Group: Members Posts: 507 Joined: 10-September 08 Member No.: 4338 |
QUOTE “It has been suggested that we are commanding just a little too late in the day, that we should be commanding earlier in the sol,” said Nelson. “And there is some rationale for that.” Therefore, the mission is now trying to move some of their dish time earlier and/or negotiate their timeslot to pick up the Martian mornings at Endeavour. “We’re trying to widen our pattern,” Lever said. “We figure that we’re on a nice easterly tilt and when the Sun comes up, chances are we could get a solar array wake up in the morning instead of at noon. Indeed, if the rover is tilted 30 eastward, then a morning sun elevation of 60 degrees might optimally match that tilt. I think that might occur at around 10 am local time. Perhaps that is the most "solar groovy" time. |
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Oct 10 2018, 02:19 PM
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#310
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Member Group: Admin Posts: 976 Joined: 29-September 06 From: Pasadena, CA - USA Member No.: 1200 |
Indeed, if the rover is tilted 30 eastward, ... Not sure if this is a typo, but it could be I misled someone in thinking so with a post made some time ago. When I said the attitude *difference* between two positions was 30 degrees it was due to the fact the rover in the first position was at about 10 deg Westerly tilt, and now it is at 20 deg Easterly. So the current rover Easterly is (only) 20 deg. Still the point being made about the SAW is correct. 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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Oct 10 2018, 10:04 PM
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#311
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
At least there is a bit more that can be done.... Would additional HiRISE images reveal tracks of dust devils or gusts, maybe on the basis of appropriately adjusted difference images? If so, this should return a hint of when the dust load on the arrays should have changed, i.e. cleaning events may have taken place. These gusts are probably larger than the rover, and their tracks would be easier to resolve. Another approach would be the inference of an SR image from several HiRISE images, provided the size of the pixels is the limiting factor for the resolution. Alternatively, S/N could be improved by averaging a sequence of well-registered HiRISE images. |
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Oct 11 2018, 02:31 AM
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#312
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Senior Member Group: Members Posts: 1043 Joined: 17-February 09 Member No.: 4605 |
Perhaps the best indication of dust clearing, or a dust cleaning event will be communication from Opportunity.
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Oct 18 2018, 03:31 AM
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#313
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Member Group: Members Posts: 507 Joined: 10-September 08 Member No.: 4338 |
At least there is a bit more that can be done. From the September report: QUOTE In coming weeks, MRO will be gathering more data with CRISM, HiRiSE and the CTX. “We’re planning on making observations over next several months to monitor the surface changes over Endeavour as the storm subsides,” said Arvidson. Perhaps observations of the very bright Winnemucca plateau area might provide a good estimate of the dust cover by comparing the current albedo with the previous one. (I seem to recall mention of plans to do a CRISM orbital study of Winnemucca.) |
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Oct 18 2018, 07:41 AM
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#314
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Member Group: Admin Posts: 976 Joined: 29-September 06 From: Pasadena, CA - USA Member No.: 1200 |
Perhaps observations of the very bright Winnemucca plateau area might provide a good estimate of the dust cover by comparing the current albedo with the previous one. (I seem to recall mention of plans to do a CRISM orbital study of Winnemucca.) I would be surprised if CRISM could resolve that feature. CRISM pixels are about 25-30 meter GSD, depending on the observation geometry. Even with oversampling, a pixel is never better than 6x27 meters. 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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Oct 18 2018, 02:56 PM
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#315
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
In my many winters' experience with snow, and three recent experiences with forest fire ash, the deposition of a windborne, granular substance does not cover all surfaces equally. Maybe Oppy's solar panels accumulate half as much as nearby surface units, maybe twice as much. I don't know how we could know – unless and until Opportunity wakes up and sends us pictures.
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