[X] My Assistant

[Phil Stooke]

According to this tweet from the recent MEPAG meeting:

https://twitter.com/genejm29/status/1489325707067023367

There will be a new cleaning attempt on Feb. 12th.

Phil

[abalone]

Just out of interest what kind of power production could be expected if instead of horizontal panels it had them facing east west at say a 70deg tilt to the horizontal. That is almost vertical. I assume that dust accumulation would then not be an issue.

[rlorenz]

Just out of interest what kind of power production could be expected if instead of horizontal panels it had them facing east west at say a 70deg tilt to the horizontal. That is almost vertical. I assume that dust accumulation would then not be an issue.

That's a pretty big geometric loss. I suspect the energy impact for the nominal mission duration would far outweigh the (uncertain) retention of capacity due to lower dust accumulation. It is known after all that at least some dust can be deposited even on vertical surfaces (including camera windows) on Mars.

I could well believe that some combination of modest tilt, and mounting arrays closer to the ground (so that sand can more easily get onto them to scrub the dust off) could help mitigate power loss, but that it's also a very site-dependent issue.

More practically, InSight was sold somewhat as a 'build to print' Phoenix rebuild, so even though the arrays were slightly larger, the deployment mechanism was the same. You'd need to expensively redesign those mechanisms to have inclined arrays. Arrays as steeply tilted as you suggest would also raise concerns about the effect of wind loads, not least on the seismic noise background.

[Deimos]

I question the accumulation assumption as well. Dust accumulation would be a different issue, but not a non-issue. Dust accumulates freely on vertical surfaces--see any pictures of posts on cal targets from MER. It sticks to camera windows, as Ralph said. Dust does not only 'fall' onto the surface--it is frequently far too windy for that. While there is a major advantage in dust being cleaned from vertical surfaces, that is different from avoiding accumulation. See this article.

In addition to the geometric loss (and seismic noise!) Ralph mentions, consider what happens in a dust storm, when you need every photon you can get: the arrays are aimed at the low Sun and have poor incidence angles when the Sun is high; but those low-Sun photons are the ones least able to get through the dust.

[djellison]

If dust didn't stick to vertical surfaces....we would never need to clean office windows.

[Explorer1]

Vertical/tilted panels work fine on the Moon (see concept art of the various lunar south pole rovers being planned/built, which have panels on the sides or sticking up like sails to benefit from the low sun angle at those latitudes). The trouble is once an atmosphere is introduced, dust can settle in almost any direction.
Such a design might be of benefit for a mission at the Martian poles, but as Phoenix taught, those regions have a much bigger long-term limit on lander lifetime than dust on the panels!

[Deimos]

So, I ran the numbers. For the tilted panel case with no atmosphere at all, and no surface reflection, 2x70deg tilt is 67% as good as 2x0deg tilt. Adding in idealized reflected light from the surface gets to a bit above 80% (as long as I can use red albedo, which may not be appropriate for the triple-junction cells). Adding in a small dust storm--with surface and sky light--gets back to 2/3, which is better than I would have guessed. Of course, that is 2/3 of a much smaller number and that eats into margins. If one were not worried about things like SEIS or using parts out of a warehouse, a mixed tilt approach might be worth it.

The math changes quite a bit at the poles; note that Mars Polar Lander had both level and tilted panels.

[Phil Stooke]

Another arm contact west of the SEIS, purpose still not understood (by me), on sol 1171.

Phil

[Phil Stooke]

Sol 1183... the arm camera images an area in the workspace west of the SEIS. This is probably completing the stereoscopic coverage of the full panorama. I was told recently that there were two small gaps in the full stereo pan and this looks like being the second sequence filling the gaps. We had monoscopic coverage of the full scene but not stereo. I hope the project will release a full mission panorama (combined horizon and workspace) soon. If there's no change in power generation we only have about 3 months left in the mission.

Phil

[Phil Stooke]

Sol 1184 - a new trench is dug, pushing soil into a pile. That probably signals soil pickup and sprinkling on the lander deck in the near future to boost power again.

Phil

[Quetzalcoatl]

Greetings to you all

Interpretation of 47 seismic events previously undetected in the data provided by SEIS :

https://www.nature.com/articles/s41467-022-29329-x#Sec1

[Phil Stooke]

"Another arm contact west of the SEIS, purpose still not understood (by me), on sol 1171."

OK, now the analyst's notebook explains the soil contacts west of the SEIS. They are part of an 'elastic properties' experiment - soil mechanics basically, testing the soil properties by pressing down on the surface.

Phil

[Phil Stooke]

Just in case this might be useful to anyone, I have compiled the full set of Mission Manager reports from the InSight Analysts Notebook from sol 1 to sol 1100. It is a c. 5000 line text file.

Phil

 insight_mission_manager_reports.txt ( 307.36K ) Number of downloads: 289

[Quetzalcoatl]

Remarkable receipting !

Thank you very much mister Stooke.

[vikingmars]

Just in case this might be useful to anyone, I have compiled the full set of Mission Manager reports from the InSight Analysts Notebook from sol 1 to sol 1100. It is a c. 5000 line text file.
Phil

What a stunning work Phil ! Thanks a lot