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 |
Jun 13 2018, 04:31 PM
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#46
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Member Group: Members Posts: 279 Joined: 19-August 07 Member No.: 3299 |
Are the solar panels able to raise up? I say this when MER traveled thru the space, the solar panels was inside in compact mode before it landed.
During the process of closing (raising) and opening (lowering) solar panels might shake due to the motor vibration or also due to the slope, some dust will slip down. |
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Jun 13 2018, 04:35 PM
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#47
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Senior Member Group: Members Posts: 2090 Joined: 13-February 10 From: Ontario Member No.: 5221 |
No, those were a one-time use, though good thinking outside the box!
Telecon starting now.... |
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Jun 13 2018, 05:52 PM
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#48
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Founder Group: Chairman Posts: 14433 Joined: 8-February 04 Member No.: 1 |
People should think of their TV screen. It has dust on it. It's vertical. The dust just sits there.
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Jun 13 2018, 06:22 PM
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#49
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Member Group: Members Posts: 122 Joined: 19-June 07 Member No.: 2455 |
The news conference was upbeat. They expect the rover to survive based on observations so far. Good news is this is happening during the summer so battery temps aren't as much of a concern. (I was unaware there were warming plutonium sources inside the battery compartments). Very little power is required to run the onboard clock and even if it stops, the rover can awake again from new solar input and go into a search mode to contact Earth. Fascinating. Such amazing engineering and staff.
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Jun 13 2018, 10:48 PM
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#50
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Forum Contributor Group: Members Posts: 1372 Joined: 8-February 04 From: North East Florida, USA. Member No.: 11 |
Are the solar panels able to raise up? I say this when MER traveled thru the space, the solar panels was inside in compact mode before it landed. During the process of closing (raising) and opening (lowering) solar panels might shake due to the motor vibration or also due to the slope, some dust will slip down. The wind blows the panels clean from time to time. |
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Jun 13 2018, 11:24 PM
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#51
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Senior Member Group: Members Posts: 2517 Joined: 13-September 05 Member No.: 497 |
The good news from the press conference is that the low-power fault state is basically the same thing as deep sleep, which they use all the time.
I don't know two things: first, how long it has until it loses its mission clock, which complicates the situation, and second, how the stuck-on IDD heater that deep sleep was added to get around will affect the recovery -- since that's a 0.5A load that will start as soon as the battery controller comes up. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Jun 14 2018, 12:35 AM
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#52
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Senior Member Group: Members Posts: 2430 Joined: 30-January 13 From: Penang, Malaysia. Member No.: 6853 |
ICYMI : Here is a link to the YouTube recording of the 'Dust Storm' teleconference: https://youtube.com/watch?v=fIKxdRFx2Wo#
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Jun 14 2018, 02:13 AM
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#53
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Senior Member Group: Members Posts: 1045 Joined: 17-February 09 Member No.: 4605 |
The extent of this dust storm seems to be emulating the 1971 Mariner global dust storm. That storm lasted over three months so we could be in for a long wait as the atmospheric transfer between poles slows down and the dust settles.
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Jun 14 2018, 02:55 AM
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#54
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Member Group: Members Posts: 306 Joined: 4-October 14 Member No.: 7273 |
Another potential alternative is the 1977 dust storms observed by Viking. There was an early season storm that followed the Acidalia storm track (started in Mare Acidalium, crossed south across Chryse and Thaumasia, and exploded in the southern hemisphere) that cleared by mid-summer, followed by an even more intense storm in late summer originating from the Hellas Basin.
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Jun 14 2018, 03:17 AM
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#55
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Member Group: Members Posts: 507 Joined: 10-September 08 Member No.: 4338 |
...how long it has until it loses its mission clock, ... If it gets no power from the solar panels, is there a ball-park figure on how long the pre-existing battery charge could keep the clock going? Days or weeks? [EDIT: Based on figures here: https://trs.jpl.nasa.gov/bitstream/handle/2...400/05-3884.pdf and some assumptions, my own rough estimate is 8 days if zero power from the solar panels.] |
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Jun 14 2018, 03:27 AM
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#56
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
Because a lot of questions being asked here were answered in the press briefing, I'm going to break my usual practice and link to my own writing, in this case a single-page version of all my live tweets of the press briefing.
-------------------- My website - My Patreon - @elakdawalla on Twitter - Please support unmannedspaceflight.com by donating here.
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Jun 14 2018, 04:09 AM
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#57
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Senior Member Group: Members Posts: 2517 Joined: 13-September 05 Member No.: 497 |
Because a lot of questions being asked here were answered in the press briefing, I'm going to break my usual practice and link to my own writing... John Callas said "If rover is generating less than 22Wh, then it won't have enough power to maintain clock". I'm not sure how to parse this. AFAIK, the mission clock is powered directly from the batteries during sleep and will presumably drain them down to some minimum voltage cutoff. 22Wh per sol would be a little under 1 watt of power, which is a heck of a high power draw for a simple clock. At any rate, I think it's safe to assume that over the next few days there will be essentially no power generated. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Jun 14 2018, 04:33 AM
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#58
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Senior Member Group: Members Posts: 2090 Joined: 13-February 10 From: Ontario Member No.: 5221 |
The main thought I keeping coming back to is that Oppy has been out of contact for much longer stretches of time during conjunctions (though obviously this is a very different circumstance in other respects!) We know the rover won't suffer some cold-related issue as Spirit did; it's just a matter of crossing our fingers and waiting it out...
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Jun 14 2018, 03:05 PM
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#59
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Senior Member Group: Members Posts: 2517 Joined: 13-September 05 Member No.: 497 |
https://trs.jpl.nasa.gov/handle/2014/43244 "The effects of clock drift on the Mars Exploration Rovers" is an interesting paper about the MER clock architecture. It didn't really have anything germane to the issue of losing time reference but it has a lot of detail about how the mission clock works.
-------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Jun 14 2018, 03:11 PM
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#60
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Senior Member Group: Members Posts: 2517 Joined: 13-September 05 Member No.: 497 |
The main thought I keeping coming back to is that Oppy has been out of contact for much longer stretches of time during conjunctions... During conjunction the rover has still been powered, of course. The most worrisome thing about this is whether there's some issue associated with losing the mission clock (go back through all the Spirit status reports after loss of comm for lots of discussion about various permutations there). We can assume that Spirit just got too cold, but there's no proof of that I'm aware of. And then there's the possibility that the panels will be so dusty after the storm clears that they won't produce a useful amount of power (although I think that's probably unlikely.) -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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