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#240
by
Dalhousie
on 15 Jan, 2021 00:34
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Efforts to robotically drill or dig into planetary surfaces have not been very successful. Somebody could compile a list of examples.
Most have been successful.
DRILLING
Curiosity has drilled 29 successful holes on Mars, each about 6 cm. I have not been able to find a list of failures, but there have only been two or three. Rotary percussion method
Luna 16 partial success. Drill reached 35 cm. Hollow stem auger method.
Luna 20 partial success, reaching a depth of 25 cm. Hollow stem auger method.
Luna 24 success. Drill reached 2.25 m. Hollow stem auger method.
Chang'e 5 success. Drill reach depth of ~1m. Hollow stem auger method.
Venera 13 success. Drill depth 3 cm. Method rotary percussion?
Vega 14 success. Drill depth 3 cm. Method rotary percussion?
Vega 2 success. Drill depth 3 cm. Method rotary percussion?
EXCAVATION (by robot arm)
Surveyor 3 success
Surveyor 5 success
Surveyor 6 success
Surveyor 7 success
Viking 1 success
Viking 2 success
Phoenix success
Chang'e 5 success
Missions where drilling not achieved because of spacecraft issues (e.g. Surveyor 4, Luna 23, Vega 2, Beagle 2, Philae) not included
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#241
by
Phil Stooke
on 15 Jan, 2021 03:37
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(wrote this before I saw Dalhousie's post) (Dalhousie - only Surveyors 3 and 7 had arms to dig with, Chang'e 3 didn't drill, must be a typo for CE5)
Drill - yes, clearly it's tricky. Dig - not really a poblem. Surveyors 3 and 7 dug multiple trenches without any real problems. Several Apollo trenches were dug, most or all were OK. Vikings 1 and 2 did lots of scooping and digging. Phoenix - lots of digging and all goals accomplished. Chang'e 5 scooped just fine as far as we can tell.
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#242
by
plutogno
on 15 Jan, 2021 05:39
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Phoenix, while eventually successful, had lots of trouble scratching under the surface of Mars and I seem to remember that some of its objectives were eventually accomplished in quite a hurry.
from Phoenix and Insight, it seems to me that the behavior of Martian "loose" soil (soil, not rocks) is poorly understood. I wonder what this might mean for ExoMars' deep drill
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#243
by
Blackstar
on 15 Jan, 2021 12:03
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Look at Chang'e 5. It had drilling problems.
I don't think that drilling to 3 cm really counts. That's not even the length of a finger. How many robotic missions got below a few centimeters without problems?
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#244
by
eeergo
on 15 Jan, 2021 12:48
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How widespread are autonomous "mole" penetrometers on Earth, and which heritage do they have?
This review paper online:
https://www.lpl.arizona.edu/~rlorenz/penetrators_asr.pdf seems to suggest similar devices to HP3 have only been recently developed and were only validated in laboratory (or limited field campaigns) settings. Those which have been longer, and more reliably utilized on Earth (although with little success in planetary exploration thus far) have been impact penetrators derived from military applications:
https://www.lpl.arizona.edu/~rlorenz/penetrators_asr.pdf .
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#245
by
Dalhousie
on 23 Jan, 2021 21:03
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Look at Chang'e 5. It had drilling problems.
I don't think that drilling to 3 cm really counts. That's not even the length of a finger. How many robotic missions got below a few centimeters without problems?
Two so far, from four attempts. I have used small diamond drills in the field, they often block and have to be tried in a different location
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#246
by
leovinus
on 01 Feb, 2021 18:22
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#247
by
eeergo
on 04 Feb, 2021 09:35
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Roundup of HP3's efforts, which appears to have largely been driven in the recent past by power AND budgetary issues rather than just having exhausted all options - which they nevertheless have, in practice, and the 'mole' will be used as a thermal probe for the first 40 cm or so of terrain, in conjunction with the radiometer.
One can only wonder whether, if power levels should increase due to some major wind cleaning for the panels, and some funding coughed up to make it possible, further efforts might be made after analysis is consolidated.
https://www.dlr.de/blogs/en/desktopdefault.aspx/tabid-5893/9577_read-1158/
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#248
by
redliox
on 04 Feb, 2021 11:01
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One can only wonder whether, if power levels should increase due to some major wind cleaning for the panels, and some funding coughed up to make it possible, further efforts might be made after analysis is consolidated.
Could be possible, although funding is the bigger X factor. What'll probably happen is a cleaning event occurs, the scientists get excited, and if the engineering shows there's enough power they request firing up the mole one more time.
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#249
by
Blackstar
on 15 Feb, 2021 13:48
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New image from Sol 789 contrasted to earlier photo from Sol 10. Spacecraft solar panels and deck devices are quite dusty. InSight landed on November 26, 2018. Image Credits: NASA/JPL-Caltech
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#250
by
litton4
on 18 Feb, 2021 13:58
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Has there been no thought to develop cleaning mechanisms for the panels in future landers?
Either by tilting and shaking the panel or some sort of brush to remove dust?
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#251
by
whitelancer64
on 18 Feb, 2021 14:31
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Has there been no thought to develop cleaning mechanisms for the panels in future landers?
Either by tilting and shaking the panel or some sort of brush to remove dust?
Yes, that was thought of even for the MER rovers (Spirit and Opportunity). Concepts using a brush or compressed air were studied. It was decided that they were too heavy or mechanically complicated to be worth it.
However, there is (was?) an interesting concept of periodically running an electrostatic charge across the solar array itself to repel dust, which would require no moving parts. I don't know what the current state of development is on that.
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#252
by
the_other_Doug
on 18 Feb, 2021 14:32
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Has there been no thought to develop cleaning mechanisms for the panels in future landers?
Either by tilting and shaking the panel or some sort of brush to remove dust?
Might be simpler than that. Put in a small, low-power pump and "air" tank. Compress Martian air in this tank. You don't need a big, powerful motor, just do it gradually. You only need to clean your panels every few months. Then put little blower-heads in strategic locations around the panels and some lightweight tubing back to the compressed air tank. When the panels get too dirty, blow down the tank. Et voila, a natural-looking cleaning event that does little to disturb the environment you're investigating. No shaking to disrupt delicate seismometers, no odd chemicals (or pre-stored gasses that could be contaminated somewhere along the line) that could interfere with chemical analyses of the rocks and soils. Just, very slowly, take in a really big breath and then use it to blow the dust off.
It can't be that challenging to the people who designed and actually flew the current American Mars landing system...
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#253
by
whitelancer64
on 18 Feb, 2021 15:14
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#254
by
Jeff Lerner
on 18 Feb, 2021 15:20
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Has there been no thought to develop cleaning mechanisms for the panels in future landers?
Either by tilting and shaking the panel or some sort of brush to remove dust?
Already being attempted ...
https://mars.nasa.gov/news/8858/insight-is-meeting-the-challenge-of-winter-on-dusty-mars/?site=insight“.....Later this week, InSight will be commanded to extend its robotic arm over the panels so a camera can take close-up images of the dust coating. Then the team will pulse the motors that unfurled each panel after landing to try to can disturb the dust and see if the wind blows it away. The team considers this to be a long shot but worth the effort....”
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#255
by
Phil Stooke
on 18 Feb, 2021 20:38
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Brushing is a bad idea because the abrasive dust will damage the panel surface and permanently reduce power generation. A vibrating system could be good, and in a way that is what the motor pulsing is intended to do. An electrostatic system might work, special coatings might work, but Spirit and Opportunity had success with natural wind gust cleaning and that was anticipated here as well. There are dust devil tracks but not yet one right over the lander.
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#256
by
litton4
on 19 Feb, 2021 08:33
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Yes, I would have thought combining the deployment and tracking motors (ok, not on current landers), so that they can tilt the panels and allow vibration and gravity to remove the dust would have the least weight penalty.
Assumes the dust isn't particularly "sticky" - the physical properties have surprised people (eg the mole) on more than one occasion.
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#257
by
Blackstar
on 19 Feb, 2021 12:48
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Brushing is a bad idea because the abrasive dust will damage the panel surface and permanently reduce power generation. A vibrating system could be good, and in a way that is what the motor pulsing is intended to do. An electrostatic system might work, special coatings might work, but Spirit and Opportunity had success with natural wind gust cleaning and that was anticipated here as well. There are dust devil tracks but not yet one right over the lander.
When I was working with Steve Squyres I asked him about his rovers' solar panels and dust. He said that they did a number of trade studies during the design phase to figure out ways to clean off the dust. In the end the best option was to make the panels bigger to increase the power even when dusty. I can imagine that this evaluation had many different variables, and increasing the size might not have been the best option in terms of mass, but other options such as brushes or shakers posed other risks (like they would break, or they might damage the panels).
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#258
by
Star One
on 20 Feb, 2021 11:04
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While Perseverance’s Feb. 18 landing attempt marks the first opportunity for a heavily instrumented Mars lander to record the acoustic and seismic impacts of another spacecraft’s entry, descent and landing (EDL) sequence, there’s a second such opportunity later this year when China’s recently arrived Tianwen-1 orbiter sends it rover down to the surface.
However, longstanding U.S. restrictions on working with China — and China’s limited release of mission specifics —could see an opportunity to collect unique data on Mars’ atmosphere and interior go begging.
https://spacenews.com/nasas-china-exclusion-could-spell-a-missed-opportunity-for-mars-insight/
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#259
by
Dalhousie
on 22 Feb, 2021 04:25
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While Perseverance’s Feb. 18 landing attempt marks the first opportunity for a heavily instrumented Mars lander to record the acoustic and seismic impacts of another spacecraft’s entry, descent and landing (EDL) sequence, there’s a second such opportunity later this year when China’s recently arrived Tianwen-1 orbiter sends it rover down to the surface.
However, longstanding U.S. restrictions on working with China — and China’s limited release of mission specifics —could see an opportunity to collect unique data on Mars’ atmosphere and interior go begging.
https://spacenews.com/nasas-china-exclusion-could-spell-a-missed-opportunity-for-mars-insight/
China generally releases enough information ahead of time to make this data gathering possible. We knew when Chang'e 3 4, and 5 were going to land to within minutes, with accurate timing later which will enable useful comparisons. But yes, the US registrations are silly.
