Author Topic: Mars HSF landing sites?  (Read 17134 times)

Offline KelvinZero

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Mars HSF landing sites?
« on: 05/25/2015 07:36 am »
This forum often has generic discussions about where we should land, ie near a glacier, near the equator or so on. We know quite a bit about mars by now. I was thinking it would be good to discuss more specific candidate sites.

I think this would also form a very good introduction to specific mars places of interest to a layman like me.

The HEM-SAG report ( http://mepag.jpl.nasa.gov/reports/HEM-SAG_final_draft_4_v2-2.doc )  suggested landing at the foot of Arsia Mons, at Jezero crater, Mangala Vellis and Centauri Montes, all amazing science sites.   Check out their reasons and strategy.  Prefer settlement over exploration?  Then aim for resources even if ISRU is not feasible in the near to mid term.




The idea for this thread came from another where it was a bit off topic:

This seems to show a spot with more water around the equator. Does anyone know what it is called and why it is higher in water? (The caption says something about hydrogen measured in the top meter of soil)

water in lower latitudes?

I also thought it would be interesting to start a thread purely on landing sites for HSF.

It's a bit east of Opportinuty's area.  The giant crater closest to the center was Schiaparelli Crater: http://en.wikipedia.org/wiki/Schiaparelli_%28Martian_crater%29.  I actually looked over that same map while gaguing what regions of Mars would have decent hydrogen (i.e. water) rich regolith.  That crater has some layered terrain and is one of the larger craters outside of Argye and Hellas.  I'd be tempted to suggest that for a base site but aside from the layering and hydrogen-richness I'm honestly unsure how it ranks.  Anything that would be green or better should be targeted for resources, and fortunately that looks like about half the planet, even excluding the poles.

(edit) and here is a link on google mars:
http://www.google.com/mars/#lon=-27.860546&q=Schiaparelli
« Last Edit: 05/27/2015 10:42 pm by KelvinZero »

Offline redliox

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Re: Mars HSF landing sites?
« Reply #1 on: 05/25/2015 08:43 am »
Good to see to you took my advice about a fresh thread.  8)

I'll put in my two cents...

I think there'll be a convergence of points a future committee will argue about when picking a site for human exploration:
1) Accessibility from orbit
2) Accessibility to local resources
3) Photogenic science (at least half for P.R. and half for actual research)
4) Minimizing contamination

For example, the resource people would point straight at the glaciers and poles (and would get some support from the science folks) and say "that's what we need!"  However, the engineers designing approach and EDL would hate wasting fuel just to crank inclination up high and the anti-contamination folk would want to avoid 'special areas' (which I think translates to areas where there could be active water and a hypothetical active Martian biosphere).  Both have some good points in their arguments, but it might end in a stalemate that results in a de facto "no landing at icy sites".

As far where specifically they should send humans (and likely a base), I would have to say ultimately it would be someplace photogenic.  As to why that, out of the 4 factors I previously mentioned, might end up becoming precedent is simple: PR.  If they want the public to stay interested and their congressmen (and President even) to shell out funds, seeing something wondrous like jagged craters, a mysterious riverbed, a vast canyon...something to look at as opposed to a blank slate of a flat plain.  The general public will, frankly, care little if a buried ice patch could provide eons of living means for a future city in the middle of a peaceful flat planum.

Landing in the heart of Valles Marineris would be a prime example I'd suggest.  There's science and even a sense of romance in exploring a new not just grand, but titanic canyon.  Only climbing to Olympus Mons' summit would top interest ratings, but that would be a feat even riskier with current means.

I'm pretty confident there is a huge number of inspiring places to land, and even revisiting Gusev or Gale Craters may make the list.  But if we're talking the future and a desire to keep enduring interest, they'll need to take some risk; there will be some kind of autonomous preparation sent ahead anyway, at the least in the form of a crate of oxygen tanks and freeze-dried tang.
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Offline redliox

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Re: Mars HSF landing sites?
« Reply #2 on: 05/25/2015 09:15 am »
Here's a run-down on why an older site like Gusev Crater may be worthwhile to revisit and establish a base at...

Within the same region of Mars as Gusev, there are three notable channel formations (one being Ma'adim that feeds directly into Gusev [but wasn't directly visited by Spirit itself mind you]), three volcanic formations with the largest, Apollinaris Mons, being essentially a mini-Tharis-style volcano in more accessible terrain; in addiiton, there are dozens of other craters with Gusev's large westerly neighbor, de Vaucouleurs, being essentially a larger version of Gusev itself.

If there's to be a long-term strategy, a region where the same rover expedition with a range of ~200 kilometers from base can encounter volcanoes, craters, lakebeds, and riverbeds at once makes for a geologist's grand road trip.
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Offline sanman

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Re: Mars HSF landing sites?
« Reply #3 on: 05/26/2015 01:18 am »
Good to see to you took my advice about a fresh thread.  8)

I'll put in my two cents...

I think there'll be a convergence of points a future committee will argue about when picking a site for human exploration:
1) Accessibility from orbit
2) Accessibility to local resources
3) Photogenic science (at least half for P.R. and half for actual research)
4) Minimizing contamination


What about
5) Best place to find life

For example, the deepest parts of Hellas Basin have been speculated to possibly be able to support triple-point of water. Although personally I feel that the deepest underground caves are the best possible candidates to support life, since the Martian crust is very thick, varying from 31km to 125km in thickness. Imagine the ambient pressure when you get down that deep!

Another thing to consider is the Martian Dichotomy:

http://en.wikipedia.org/wiki/Martian_dichotomy
« Last Edit: 05/26/2015 01:41 am by sanman »

Offline scienceguy

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Re: Mars HSF landing sites?
« Reply #4 on: 05/26/2015 04:23 am »
Pavonis mons is on the equator and a good place to eventually put a space elevator (eventually? We have the materials to build a space elevator on Mars now!).
e^(pi*i) = -1

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #5 on: 05/26/2015 01:32 pm »
Pursuing my own radical agenda: Korolev crater.

(This is not a location I would seriously push, It just makes a pet idea of mine straightforward to implement)

(1) http://www.google.com/mars/#lat=71.784418&lon=-166.262885&q=Korolev
(2) http://en.wikipedia.org/wiki/Korolev_(Martian_crater)
(3) http://www.hou.usra.edu/meetings/lpsc2014/pdf/2536.pdf
(4) http://www.planetary.brown.edu/planetary/documents/Micro_36/Abstracts/031_Head_etal.pdf

quote from 3:
Korolev crater is a water ice-filled, ~80 km diameter, impact crater located at 73o N, 163o E on Mars. Given its location over 600 km south of the modern ice cap's edge (Fig. 1), this crater is unusual because of the domal deposit of H2O ice [1]. Mapping efforts using SHAllow RADar (SHARAD) on Mars Reconnaissance Orbiter revealed the deposit's thickness to be at least 2 km

Because the latitude is 73 degrees, and mars has an axial tilt around 25 degrees I guess it would get solar power for much of the year. The crater rim facing the equator could be a good location for solar panels due to it facing the sun, and by placing panels on a slope they should mostly keep themselves free of buildup.

Initially my pet plan is robotic landers with nuclear power plants, similar but easier than the europa ocean probe schemes. You only need to melt down 30 meters and then let the reactor sit there melting more ice with its waste heat. A list of other advantages:
http://forum.nasaspaceflight.com/index.php?topic=33069.msg1109011#msg1109011

Despite the dome shape, I imagine we could find a flat 'shore' of ice at the edge nearest the equator. This would be well placed for future solar power on the crater rim. Another possibility is the edge furthest from the equator. This probably has a bit less access to sun year round but the sun-facing crater slope would be nearer the ice.

---
Alternatively there is Louth Crater, at a slightly better latitude.

The ice patch is smaller but that is hardly an issue in the short term. The shape might make it easier to find a spot with reasonable solar power and ice of around 30m depth over useful ore.
http://apod.nasa.gov/apod/ap050720.html
The ice pocket was found in a 35-kilometer wide crater that resides 70 degrees north of the Martian equator. There, sunlight is blocked by the 300-meter tall crater wall from vaporizing the water-ice on the crater floor into the thin Martian atmosphere. The ice pocket may be as deep as 200 meters thick. Frost can be seen around the inner edge on the upper right part of the crater, while part of the lower left crater wall is bathed in sunlight.

http://abrown.seti.org/publications/papers/Brown_et_al_2008_Louth_crater-Icarus.pdf
Taking the ice mound to be a section of a sphere that is 12 km across and 200 m deep, the water ice mound deposit is roughly 11 km3 in volume
« Last Edit: 05/27/2015 11:42 am by KelvinZero »

Offline sghill

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Re: Mars HSF landing sites?
« Reply #6 on: 05/27/2015 06:13 pm »
Good to see to you took my advice about a fresh thread.  8)

I'll put in my two cents...

I think there'll be a convergence of points a future committee will argue about when picking a site for human exploration:
1) Accessibility from orbit
2) Accessibility to local resources
3) Photogenic science (at least half for P.R. and half for actual research)
4) Minimizing contamination

Good two cents!  The only considerations I'd add are  5) Possibility of life (Sanman posted this first) and 6) Diversity of resources.

i.e., land someplace with lots of interesting things to see and study.  I happen to think the wash out area near the exit from Valles Marineris would be an amazing place for exploration and mining.  Nature has dug deep here starting at the feet of volcanoes, and there may literally be gold and other metals laying about the surface if the area interacted with water over time.  Also, from a geologist's and exo-biologist's standpoint, the area, while rough, will have a treasure trove of different types of rocks from different points in Mar's history all in one confined space to sift through...

« Last Edit: 05/27/2015 06:15 pm by sghill »
Bring the thunder!

Offline Russel

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Re: Mars HSF landing sites?
« Reply #7 on: 05/27/2015 10:06 pm »
Now, why does that beautiful picture of Olympus Mons make me feel like I want to pick at a scab/pimple? :)

The other thing about Olympus Mons is that from the point of view of landing propulsively its a great choice. There's less distance to fall basically. I'm not sure what the science case is for being up there. And if you've got a decent lander/ascent vehicle you've also got a mountain hopper.

One thing I would like to add to this conversation is that we're simply going to have to get better at long distance manned rovers. There are too many sites worth looking at and a lot of the ones worth looking at are just too rough to risk a landing on. I don't care how pinpoint the technology is, I'd still aim for a bit of flat ground.

I think we also have to come to terms with a manned landing working hand in hand with a simultaneous robotic exploration at a number of sites.

Online Phil Stooke

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Re: Mars HSF landing sites?
« Reply #8 on: 05/27/2015 10:21 pm »
Unfortunately, the science case for being on top of Olympus Mons is pretty much zero.  And since so many other, more interesting, sites would be passed over, it's probably negative rather than zero.

The HEM-SAG report ( http://mepag.jpl.nasa.gov/reports/HEM-SAG_final_draft_4_v2-2.doc )  suggested landing at the foot of Arsia Mons, at Jezero crater, Mangala Vellis and Centauri Montes, all amazing science sites.   Check out their reasons and strategy.  Prefer settlement over exploration?  Then aim for resources even if ISRU is not feasible in the near to mid term.

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #9 on: 05/27/2015 10:45 pm »
@Phil Stooke: I edited that into the OP since it is clearly an excellent starting point.

(I wish forum threads created a 'references' page of external links and posts that referenced them. After a thread grows to any size you can never find anything in it.)
« Last Edit: 05/27/2015 10:53 pm by KelvinZero »

Offline Seer

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Re: Mars HSF landing sites?
« Reply #10 on: 05/27/2015 11:50 pm »
Given the immense difficulty and cost of an expedition to mars, the prime consideration for a lancing site is: does it help in making such a mission become possible in the first place? A low altitude landing site is very helpful from that point of view.
In the DRM 5.0 document there is a cost constrained mission that only has 4 astronauts and more limited surface capabilities. The big advantage of that approach is that you only need 7 heavy lift launch vehicles - 170 tonnes leo payload class - and don't have nuclear thermal engines. Still SLS won't have that capacity, its only 130 tonnes, but upgrade paths to 150 tonnes aren't that difficult, you can use liquid boosters for instance. And a 150 tonne HLV will be sufficient if you land at low altitude due to the longer deceleration phase during entry into the atmosphere. So you've already reduced the time and expense in developing the required HLV if you go down that route.

Once you on mars a low altitude means less radiation and less micrometeoroid flux. This is important since you have an fairly fragile mars ascent vehicle on the surface of mars for over two years after the astronauts launch from Earth.

By low altitude I mean really as low as possible so only two choices really: bottom of Hellas basin or Valles Marineris. I think the latter site is good enough from a scientific point of view anyway and it would certainly be the most spectacular site from an aesthetic perspective.


Offline Russel

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Re: Mars HSF landing sites?
« Reply #11 on: 05/28/2015 07:26 am »
If I may interject. A fully propulsive crew landing isn't constrained to a low altitude. Of course a low altitude would be an advantage to heavy cargo landings. That's maybe an opportunity.

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #12 on: 05/28/2015 09:31 am »
Ice Domes on Mars? :o
Don't skate near the edge ;)

btw what crater was that?
« Last Edit: 05/28/2015 09:32 am by KelvinZero »

Online guckyfan

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Re: Mars HSF landing sites?
« Reply #13 on: 05/28/2015 10:03 am »
If I may interject. A fully propulsive crew landing isn't constrained to a low altitude. Of course a low altitude would be an advantage to heavy cargo landings. That's maybe an opportunity.

There won't be fully propulsive landing until there is some direct fusion drive.

Online guckyfan

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Re: Mars HSF landing sites?
« Reply #14 on: 05/28/2015 01:36 pm »
There won't be fully propulsive landing until there is some direct fusion drive.

You'd better tell Elon that.

He is not planning full propulsive landing. He is planning to shed about 90% of the speed by aerobraking. And with that a landing in a low lying area is very helpful. Full propulsive would be braking all speed with propulsion. In that case the altitude would not matter.

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #15 on: 05/28/2015 04:46 pm »
KelvinZero, as an advocate if colonization, I try to think like SpaceX. IMHO this means an initial base for the exploration of Mars that will grow into a base for colonization, which will then grow into one of a series of towns around the planet. The choice of initial HSF landing site should help achieve the long-range goals. I like your opening paragraph but I might rearrange priorities as follows:

(1)   A good landing site that can be easily developed into a landing and launch site.
    (a) We are exploring the requirements for such a site in the thread “A Mars Launchpad for MCT.” Apparently the initial landings will require a vehicle with canted engines like Dragon 2, but a large vehicle like MCT will require a prepared landing pad.
    (b) Low altitude with a denser atmosphere to facilitate aero-entry plus propulsive landings.
    (c) Low latitude to facilitate landings, i.e. better orbital mechanics.
    (d) Good local terrain feature (a small crater) to be exploited for landing and launching. The crater will contain the L/L pads and will constrain flying FOD. The crater rim will provide natural protection for equipment.
    (d) Relatively flat area around the landing zone.
(2) A large source of water:
    (a) a glacier that is largely  above the local elevation, or
    (b) a buried source that is close enough to the surface to be exploited.
(3) A denser atmosphere will also facilitate the production of O2, CH4 and other atmosphere-derived products.

The site will initially be established to ensure the survival of humans and to accumulate the equipment required for their continued survival.  At first, proximity to features of scientific interest would not be a primary motive. But once the necessities of survival are assured, then the site can be the base for scientific forays using rovers. Later, it can be the base for planet-wide forays using hoppers.

A moderate latitude will facilitate the use of solar arrays.

As far as habitats are concerned, there are a large variety of proposals for habitats that can utilize local ISRU, so I now believe that presence or lack of local ISRU resources is not a limiting factor.

The site will not be a public relations stunt. This idea is repugnant to serious backers of exploration or colonization. Keep our motives pure and sponsorship will fall into place.

I am not an expert on the geology of Mars, but the site near Valles Marineras recommended by sghill in Reply #9 above seems to meet these requirements rather well.
« Last Edit: 05/28/2015 08:51 pm by Ionmars »
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Offline Alexsander

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Re: Mars HSF landing sites?
« Reply #16 on: 05/28/2015 06:18 pm »
What about lava tubes?

Offline philw1776

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Re: Mars HSF landing sites?
« Reply #17 on: 05/28/2015 06:54 pm »
I missed where we tried colonization.  When & where was this?
"It'll bang right out!"

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #18 on: 05/28/2015 08:49 pm »
...
...
...
On closer inspection, it turns out that spot I pointed out- Eos Chasma- was considered as a MSL landing site for the same reasons I mentioned!

The close-up photo of Eos Chasma that you provided to us actually caused me concern rather than encouragement. I had no idea that the area was so rugged - the opposite of a good landing site. Is there not a nearby location that is relatively flat with a small crater?  This picture is scientifically interesting but not a good site for a base.

This image of East Eos Chasma is more what I had in mind:

« Last Edit: 05/29/2015 12:21 pm by Ionmars »
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Offline Alexsander

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Re: Mars HSF landing sites?
« Reply #19 on: 05/28/2015 09:27 pm »
« Last Edit: 05/28/2015 09:28 pm by Alexsander »

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #20 on: 05/29/2015 12:01 am »
http://www.marstravel.org/2011/12/mars-photo-of-day-dec-20-2011.html
Today's Image of Mars is a closeup of a pit on the Eastern flank of Pavonis Mons, a large volcano located in the Tharsis region of Mars. The pit is 180m at its widest diameter.
Even though the Western half of the pit is shrouded in shadow, HiRISE was able to peer into the shadows and determine what lies within. The boulders visible within the pit range from less than 1m to 5m in diameter. The HiRISE team reports that the boulders are covered in sediments.
Pits like the one below are called skylights and often form when the roof of an inactive lava tube collapses.


That is a tempting looking hole in the ground. Anyone have opinions on how the region around this crater rates? Im mainly interested in viability for settlement (water, power, convenience from orbit) but all criteria of interest to someone are valid.


Ice Domes on Mars? :o
btw what crater was that?
You have to go to Google Earth, and select Mars mode.  Then toggle HIRISE imagery under "Spacecraft Imagery" and search for PSP_007230_2170.
Found this info: (oops, it was also in your screen shot. I think it didn't load first time or something. Anyway here is same thing with text and you can click on the link)

This image was taken by the High Resolution Imaging Science Experiment (HiRISE) camera on board NASA's Mars Reconnaissance Orbiter (MRO) spacecraft.

See this image’s observation information page.

Observation ID: PSP_007230_2170
Image of: Crater with textured mound in central Acidalia Planitia
Location: 36.59°N 332.52°E
Acquired on: February 10, 2008


That is about half the distance to the equator as the ice craters I mentioned. I don't really know how to read the images though so I can't guess the scale or true color.


« Last Edit: 05/29/2015 12:20 am by KelvinZero »

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #21 on: 05/29/2015 01:22 am »
From the thread, "A Launchpad for MCT," an ideal small crater for landing and launching might have some additional desirable characteristics:

(a) About 0.5 to 2 km in diam. Just large enough to capture flying FOD during L/L activity.

(b) Moderate slope, maybe 1:3 to allow rovers and mobile equipment to easily traverse from a landing pad inside the crater to a protected equipment area just over the rim.

(c) A relatively hard surface near one sidewall of the crater to serve as an initial pad. Later, it will be further hardened by techniques already suggested by forum participants.

(d) Modest crater height, maybe 100-200 m from bottom to rim. This will allow equipment, especially O2 and CH4 tanks, to be located just over the rim from the pad. Thus a relatively short pipeline from the tanks to the fuel-loading equipment at the launchpad.

(e) Moderate winds that do not affect L/L activity.

 If an optimum crater cannot be found , a hillock could be employed for most of the same purposes.
« Last Edit: 05/29/2015 11:59 am by Ionmars »
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Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #22 on: 05/29/2015 03:11 am »
Mr. Scott, there are TV watchers and there are colonizers. Time to choose sides.
Could a Mars pole-vaulter set a new record? Not in a space suit. (smiley)

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #23 on: 05/29/2015 08:15 am »
KelvinZero, as an advocate if colonization, I try to think like SpaceX. IMHO this means an initial base for the exploration of Mars that will grow into a base for colonization, which will then grow into one of a series of towns around the planet. The choice of initial HSF landing site should help achieve the long-range goals. I like your opening paragraph but I might rearrange priorities as follows:

...

I am not an expert on the geology of Mars, but the site near Valles Marineras recommended by sghill in Reply #9 above seems to meet these requirements rather well.
I can't remember if I mentioned any priorities. I might have deleted that bit. Anyway Im not trying to sell any agenda of my own. I welcome anyone to suggest any site for any criteria that appeal to them.

Here it is:
...I happen to think the wash out area near the exit from Valles Marineris would be an amazing place for exploration and mining...

If this spot is popular maybe people can dig up more info about it. Im hazy about which places on mars we have extreme detail on. I will probably know more soon. ;)


Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #24 on: 05/29/2015 11:41 am »

I can't remember if I mentioned any priorities. I might have deleted that bit. Anyway Im not trying to sell any agenda of my own. I welcome anyone to suggest any site for any criteria that appeal to them.
...I happen to think the wash out area near the exit from Valles Marineris would be an amazing place for exploration and mining...

If this spot is popular maybe people can dig up more info about it. Im hazy about which places on mars we have extreme detail on. I will probably know more soon. ;)

I dug up this statement from a NASA article about Eos Chasma as a landing site for rovers:

"Wind is a chief reason why mission planners have passed up otherwise tempting landing sites here and elsewhere in Valles Marineris. Yes, the valley is home to places with fantastic exploration possibilities — but not at the price of a crash landing".

http://themis.asu.edu/feature/54

They go on to say the valley exhibits very high contrasts in temperatures, which lead to very high winds, so that it is called the "whistling straits." Looks like another criterion to add to our list.

I wonder if this problem could be overcome by landing at a quiet time of day?
 
« Last Edit: 05/29/2015 12:05 pm by Ionmars »
Could a Mars pole-vaulter set a new record? Not in a space suit. (smiley)

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #25 on: 05/29/2015 12:17 pm »
"The Second Landing Site Workshop for the Mars 2020 Rover will be held August 4-6, 2015 at the DoubleTree by Hilton in Monrovia, CA."

http://marsnext.jpl.nasa.gov

"The goal of the second workshop will be to narrow the original list of sites as well as new candidate sites to approximately 8 sites based on existing mission engineering constraints and available atmosphere and terrain data products."
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Offline kdhilliard

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Re: Mars HSF landing sites?
« Reply #26 on: 05/29/2015 12:31 pm »
... someplace photogenic.  ...

Landing in the heart of Valles Marineris would be a prime example I'd suggest.  There's science and even a sense of romance in exploring a new not just grand, but titanic canyon.  Only climbing to Olympus Mons' summit would top interest ratings, but that would be a feat even riskier with current means.

SpaceX's recent travel poster builds on the common misconception that this tallest of volcanoes must be steep and craggy, while the shield volcano actually has a gentle profile with an average slope of only 5°.  But what about Valles Marineris?  Does it live up to it's Grand Canyon comparison?  Does this rift valley have sheer cliff faces into which tunnels could be bored?

~Kirk

Offline Russel

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Re: Mars HSF landing sites?
« Reply #27 on: 05/29/2015 01:16 pm »
Speaking about denser air making a difference to the efficiency of gas processing. What sites if any are near the equator and at least 5Km below MOLA? You'd have to go that far to make a realistic difference and not just a fractional difference.

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #28 on: 05/29/2015 06:13 pm »

SpaceX's recent travel poster builds on the common misconception that this tallest of volcanoes must be steep and craggy, while the shield volcano actually has a gentle profile with an average slope of only 5°.  But what about Valles Marineris?  Does it live up to it's Grand Canyon comparison?  Does this rift valley have sheer cliff faces into which tunnels could be bored?

~Kirk

By viewing the photos, we would have to say yes. It does have cliff faces that could be bored into. So we could build habitats.

Our concern on this thread is whether it has a nearby site that could be readily adapted for landings and launches. (Not sure.)
« Last Edit: 05/29/2015 06:20 pm by Ionmars »
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Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #29 on: 05/29/2015 06:20 pm »
Speaking about denser air making a difference to the efficiency of gas processing. What sites if any are near the equator and at least 5Km below MOLA? You'd have to go that far to make a realistic difference and not just a fractional difference.
IIRC Eos Chasma has the second lowest elevation after Hellas Basin. Don't recall exact elevation.
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Offline Alexsander

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Re: Mars HSF landing sites?
« Reply #30 on: 05/29/2015 06:31 pm »
We could devise a spreadsheet: each row is a candidate site, each column a feature.
Some possible columns:
- Distance (km) from nearest known surface ice
- Atmosphere pressure (pascals)
- Temperature range (degrees C)
- etc

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #31 on: 05/29/2015 06:54 pm »
We could devise a spreadsheet: each row is a candidate site, each column a feature.
Some possible columns:
- Distance (km) from nearest known surface ice
- Atmosphere pressure (pascals)
- Temperature range (degrees C)
- etc
Good idea. Maybe add the list of criteria in Reply #20?
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Re: Mars HSF landing sites?
« Reply #32 on: 05/29/2015 07:25 pm »
In Reply #33 I referenced the upcoming workshop on landing sites for the 2020 rover mission. The connection to HSF is that some of these locations could also be good landing sites for larger craft. And some of these scientific sites were chosen to search for water.

Here are the proposed sites to be discussed:

Day 2, 8:30 am session: Mawrth Vallis; Oxia Planum; Nili Fossae; N.E. Syrtis Major; Nili Padera; and Circum-Helles region.

Day 2, 11:00 am session: Vallis Marineris; S.W. Melas Basin; and Coprates Chasma.

Day 2, 1:10 pm session: Hypansis Delta; Eberswalde Delta; Jazero Crater Delta; Ladon Vallis; Terminus of Sabrina Vallis; Kashira Crater; Eastern Margaritafer Terra; Hadriacus Palus; and Firsoff Crater

Day 3, 8:30 am session: Gusav Crater and Columbia hills.

I'm ging to look into the first one, Mawrth Vallis, about which i know nothing.
« Last Edit: 05/29/2015 07:43 pm by Ionmars »
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Re: Mars HSF landing sites?
« Reply #33 on: 05/29/2015 10:43 pm »
water in lower latitudes?

I thought that Valles Marineris was supposed to be dry, but this 2014 Geomorphology article suggests otherwise: One million cubic kilometers of fossil ice in Valles Marineris: Relicts of a 3.5 Gy old glacial landsystem along the Martian equator.

The Water Equivalent Hydrogen Abundance map which KelvinZero linked was generated from data collected by Mars Odyssey's Neutron Spectrometer (part of the Gamma Ray Spectrometer instrument suite) which was sensitive to concentrations of hydrogen in the upper meter of the surface and would not have detected the buried glacier remnants Marine Gourronc and her coauthors are describing.

~Kirk

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Re: Mars HSF landing sites?
« Reply #34 on: 05/30/2015 08:09 am »
water in lower latitudes?

I thought that Valles Marineris was supposed to be dry, but this 2014 Geomorphology article suggests otherwise: One million cubic kilometers of fossil ice in Valles Marineris: Relicts of a 3.5 Gy old glacial landsystem along the Martian equator.

The Water Equivalent Hydrogen Abundance map which KelvinZero linked was generated from data collected by Mars Odyssey's Neutron Spectrometer (part of the Gamma Ray Spectrometer instrument suite) which was sensitive to concentrations of hydrogen in the upper meter of the surface and would not have detected the buried glacier remnants Marine Gourronc and her coauthors are describing.

~Kirk
There is a picture titled "Platy terrain (central depression)" on page 13 (labelled page 247) that seems to suggest current day ice about a kilometer thick under a layer that is very thin, at least at that scale.. perhaps ten or tens of meters? I couldn't tell from the diagram. It was really just a thick line.

Am I reading that right and is there any more information about how thin the cover is expected to get if we hunt around a bit? The only thing I found about this quote mentions tens of centimeters:
However, field observations in ice disintegration landscapes on Earth and theoretical calculations demonstrate that mantling of relict ice bodies by debris layers as thin as a few decimeters is enough to significantly inhibit rates of ice disintegration by melting (Ostrem, 1959; Mattson et al., 1993) or by sublimation (Marchant et al., 2002; Kowalewski et al., 2006, 2011).

Also, what sort of robotic mission would give us maximum confidence short of actually digging down tens of meters?

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Re: Mars HSF landing sites?
« Reply #35 on: 05/30/2015 10:17 am »
From a short scan I understand that the cover is not less than a meter. If it were less, it would have been detected by radar like many other locations.

But even 10m or more is good, considered you will find pure fresh water ice below.

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Re: Mars HSF landing sites?
« Reply #36 on: 05/30/2015 10:41 am »
10m of cover and you have a herculean task of removing the overburden and you're back to drilling/heating.

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Re: Mars HSF landing sites?
« Reply #37 on: 05/30/2015 10:44 am »
I thought that Valles Marineris was supposed to be dry, but this 2014 Geomorphology article suggests otherwise: One million cubic kilometers of fossil ice in Valles Marineris: Relicts of a 3.5 Gy old glacial landsystem along the Martian equator.

The Water Equivalent Hydrogen Abundance map which KelvinZero linked was generated from data collected by Mars Odyssey's Neutron Spectrometer (part of the Gamma Ray Spectrometer instrument suite) which was sensitive to concentrations of hydrogen in the upper meter of the surface and would not have detected the buried glacier remnants Marine Gourronc and her coauthors are describing.

~Kirk
Your reference is ground zero for anyone to understand one of the major features of Mars and to appreciate the huge extent of this 2600 km long buried glacier. Please read - it is filled with photos and diagrams.

The following annotated composite photo of Vallis Marineris includes the  names "Melas" and "Coprates, " which are two potential landing sites to be addressed in the upcoming workshop.
« Last Edit: 05/30/2015 11:05 am by Ionmars »
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Re: Mars HSF landing sites?
« Reply #38 on: 05/30/2015 10:56 am »
10m of cover and you have a herculean task of removing the overburden and you're back to drilling/heating.
Yes, but once you have a drilled well and can lower a heat generator into it to melt the ice, you have a source of water that could serve a growing colony for many years.
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Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #39 on: 05/30/2015 11:10 am »
10m of cover and you have a herculean task of removing the overburden and you're back to drilling/heating.
Yes, but once you have a drilled well and can lower a heat generator into it to melt the ice, you have a source of water that could serve a growing colony for many years.
Before you guys go any further, remember that '10 or 10s of meters' was me guessing from the thickness of a line from a diagram I may not have read right. Go and look at it and you will see what I mean. I was really asking if anyone had real info about it.

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Re: Mars HSF landing sites?
« Reply #40 on: 05/30/2015 11:37 am »
...
...
...
Also, what sort of robotic mission would give us maximum confidence short of actually digging down tens of meters?
Good question. I don'y know the answer, but it seems reasonable that if we can detect water from orbit we should be able to detect it with more confidence from the ground surface.
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Offline Russel

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Re: Mars HSF landing sites?
« Reply #41 on: 05/30/2015 11:44 am »
Who has that map of inferred water percentage?

Edit: Oh never mind, I Googled this..

http://www.astrobio.net/articles/images/mars_water_mosaic.jpg

Anyhow, what that map says to me is that first of all we don't know about anything deeper than a metre. But that in that top metre there plenty of soils with over 3% water equivalent (measured by hydrogen content). I'm tempted to be a bit more favorable towards processing soil. But, only where there is loose soil. the kind you can brush, sweep or vacuum up.

Also, the patches on this map that are of interest (near the equator) seem to lie in a spot close to 180 East/180 West and around 20 degrees East.

Now how much of those areas intersects with at least 1Km below MOLA? Sorry about the scale on that map.
« Last Edit: 05/30/2015 12:02 pm by Russel »

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Re: Mars HSF landing sites?
« Reply #42 on: 05/30/2015 03:16 pm »
..
...
Before you guys go any further, remember that '10 or 10s of meters' was me guessing from the thickness of a line from a diagram I may not have read right. Go and look at it and you will see what I mean. I was really asking if anyone had real info about it.
Done and done, but I have nothing to add. We need a specialist!
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Re: Mars HSF landing sites?
« Reply #43 on: 05/30/2015 03:24 pm »
OK first we would need to establish, how deep the ice really is. A sonar can do that easily. The reflective properties of ice is extremely different to regolith.

Digging down there? A small bulldozer can dig a trench in a few weeks, not a problem at all. And then there is pure water ice. A glacier will in all likelihood contain pure drinking water. Maybe not a task for a 4 man 4 week mission. But a very minor thing for anything larger than that.

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Re: Mars HSF landing sites?
« Reply #44 on: 05/30/2015 05:08 pm »
OK first we would need to establish, how deep the ice really is. A sonar can do that easily. The reflective properties of ice is extremely different to regolith.

Digging down there? A small bulldozer can dig a trench in a few weeks, not a problem at all. And then there is pure water ice. A glacier will in all likelihood contain pure drinking water. Maybe not a task for a 4 man 4 week mission. But a very minor thing for anything larger than that.

Rather than strip mining the water and allowing quite a bit (more and more after time) to sublime away, I would suggest drilling down to it initially, tunnelling down later and probably making use of space in the ice, I think habitats could be more easily built in that space than regolith.  Also I don't see that ice that built up over time in a glacier would not be as much as 10% suspended particles. If this is glacier, the surface that isolates it from the atmosphere it would sublime into is probably the sediment from the top layers subliming away.
It is all well and good to quote those things that made it past your confirmation bias that other people wrote, but this is a discussion board damnit! Let us know what you think! And why!

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Re: Mars HSF landing sites?
« Reply #45 on: 05/30/2015 10:38 pm »
OK first we would need to establish, how deep the ice really is. A sonar can do that easily. The reflective properties of ice is extremely different to regolith.

Digging down there? A small bulldozer can dig a trench in a few weeks, not a problem at all. And then there is pure water ice. A glacier will in all likelihood contain pure drinking water. Maybe not a task for a 4 man 4 week mission. But a very minor thing for anything larger than that.
A small correction: I think you meant indifferent to regolith, which is very informative.

I actually have experience in operating construction equipment. In theory a  bulldozer might work to dig a trench, but in practice you frequently run into boulders or hard ground that requires a narrow bucket with teeth. I mostly used a loader/backhoe to dig a trench. The depth was limited by the length of the backhoe arm, about 2-1/2 to 3 m.

If we need to reach down 5 to100 meters I would trade in this equipment for a well driller of the same mass. On Earth we routinely drill water wells down to 400 m or so and IMO it could work on Mars. When we decide to use the water ice we would insert a well casing down into the zone of ice. Then we would drop down a heat source to melt the ice, a well pump and a flexible pipe to bring water to the surface, We would have to continuously warm the water to maintain its liquid state.

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Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #46 on: 05/31/2015 02:34 am »
A small correction: I think you meant indifferent to regolith, which is very informative.
Im confused whether you are saying sonar will not work, or it will work even if the ice is mixed with regolith. Remember Poe's Law! I can't detect satire without smilies... like this: ;)

Offline Russel

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Re: Mars HSF landing sites?
« Reply #47 on: 05/31/2015 03:23 am »
I hate to be no-fun but so far we have absolutely zero direct evidence of there being something-like-ice close to the surface anywhere on Mars anywhere within 30 degrees of the equator. We have some theories and suppositions that there almost certainly is some shallow ice in some circumstances but so far we don't have any actual locations. And my suggestion is that such deposits of something-like-ice anywhere near the equator have to be actually found and characterized.

Added to your misery is that when you do actually discover subsurface ice on Mars (I'm certain we will) then you'll run into practical issues. You may find the layer of ice is thin (even just a few inches) and when you do try to drill/extract it the overlying strata subsides and you lose flow. You may find that the heat you try to use is ineffective because melt water may find other paths or the veiny nature of the ice means you have to heat a prohibitively large volume of soil/rock.

In short what you really need is a thick deposit of ice, many meters deep. You'll need to accurately characterise the "ore" body just as they do on Earth, which involves landing instrumentation and doing a field survey at many points at once. Space based instruments probably aren't going to see far enough below the surface.

And I'd bet you lunch and dinner that such easy to mine deposits will show up but they will be fairly rare at any useful latitude. Meaning you could send a robotic mission to do this kind of detailed geological survey but it will be hit and miss.

Also, if you mine a hole inside a large deposit of ice and try to call it a shelter, please count me out. that would be so unstable. I'd rather just blow a hole in a cliff face.

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Re: Mars HSF landing sites?
« Reply #48 on: 05/31/2015 07:20 am »
In short what you really need is a thick deposit of ice, many meters deep. You'll need to accurately characterise the "ore" body just as they do on Earth, which involves landing instrumentation and doing a field survey at many points at once. Space based instruments probably aren't going to see far enough below the surface.

I see a deposit of 100 1 million km³ qualifying as "a thick deposit of ice, many meters deep".

Corrected wrong number but the argument is still true. ;)

I am also surprised that you are so much better informed than the University of Nantes and the Institute of Planetary Research of DLR  in Berlin, Germany. They do not give 100% certainty but a very high confidence of their finding. That is why I suggested that sonar probes at the surface would be needed before a mission relies on that water.

And I mean different reaction of regolith vs. ice to sonar to find the depth of that ice.
« Last Edit: 05/31/2015 05:35 pm by guckyfan »

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Re: Mars HSF landing sites?
« Reply #49 on: 05/31/2015 07:29 am »
It has been argued that those radar readings are ambiguous and may not point to water, because they identify hydrogen, not water. That may be a valid concern. Maybe it is oil deposits rather than water? But I don't really think so. ;)

About that glacier study. There is vast experience on plastic flow of ice and the geologic traces it gives. It is a very valid assessment that there is water in the identified area Vallis Marineris.

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Re: Mars HSF landing sites?
« Reply #50 on: 05/31/2015 08:45 am »
A small correction: I think you meant indifferent to regolith, which is very informative.
Im confused whether you are saying sonar will not work, or it will work even if the ice is mixed with regolith. Remember Poe's Law! I can't detect satire without smilies... like this: ;)I
It is very possible that I misunderstood. I thought you meant that sonar could reflect off ice effectively despite the presence of regolith overburden, therefore being indifferent to its presence. I am open to correction. (??)

If sonar is effective then sonar needs to be aboard the 2020 rover that is being planned. From info on this thread, we may agree that we need to employ it to verify the presence of glacial ice beneath Vallis Marineris.

I hope someone on this thread can attend the workshop. I cannot.
« Last Edit: 05/31/2015 09:09 am by Ionmars »
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Re: Mars HSF landing sites?
« Reply #51 on: 05/31/2015 09:11 am »
It is very possible that I misunderstood. I thought you meant that sonar could reflect off ice effectively despite the presence of regolith overburden, therefore being indifferent to its presence. I am open to correction. (??)

Sonar can find boundaries within the underground. Propagation of sound is different in different materials and there will be reflection on a boundary of different materials. So they can determine how deep the ice is. That is what I was trying to say.

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Re: Mars HSF landing sites?
« Reply #52 on: 05/31/2015 09:20 am »
Btw I started a thread on excavation with impactors in advanced topics here..
Found this page that can allow a much more easily quantifiable discussion:
..and concluded that you could dig a 17 meter deep hole (and about 5m wide at bottom) with two impacts. It seemed to be easily within ARRM scales.

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Re: Mars HSF landing sites?
« Reply #53 on: 05/31/2015 09:34 am »



Sonar can find boundaries within the underground. Propagation of sound is different in different materials and there will be reflection on a boundary of different materials. So they can determine how deep the ice is. That is what I was trying to say.

Info received and appreciated. Now let's get sonar aboard the 2020 rover.
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Re: Mars HSF landing sites?
« Reply #54 on: 05/31/2015 10:06 am »
Btw I started a thread on excavation with impactors in advanced topics here..
Found this page that can allow a much more easily quantifiable discussion:
..and concluded that you could dig a 17 meter deep hole (and about 5m wide at bottom) with two impacts. It seemed to be easily within ARRM scales.
Nice thread. I'm going there to respond so I won't go OT here.
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Re: Mars HSF landing sites?
« Reply #55 on: 05/31/2015 12:06 pm »
OK, here’s my report on the subject assigned to me by me in Reply #40:  “Mawrth Vallis as a Landing Site for HSF.”

Mawrth Vallis is a valley on Mars at 22.3°N, 343.5°E with an elevation approximately two kilometers below datum. It is an ancient water outflow channel and one of the oldest valleys on Mars (1).

Mawrth Vallis is located in the middle of a mysterious region on the boundary between the southern highlands and northern lowlands of Mars. At this line the entire planet suddenly drops in elevation. It is also conveniently near a hazard-free landing zone. The Mars Science Laboratory science team would use the 2020 rover to piece together the history of this puzzling site (2).

This region also holds special interest to science because of the presence of clay minerals (phyllosilicates) that form only if water is available. Some of the clays are montmorillonite, kaolinite and nontronite. On Earth such clays occur in weathered volcanic rocks or in hydrothermal systems where volcanic activity and water interact. Such clay minerals preserve microscopic life, so traces of ancient life might be found at Mawrth (1).

[Image 1 below]


Evaluation as a HSF landing site:

(a) Proximity to nearest surface ice:    unknown (poor)   
(b) Atmospheric pressure/elevation:   -2000 km (good)
(c) Temperature range:          unknown
(d) Latitude:         22.3 degrees N (Fair for L/L)
(e) Small crater or hillock available: Yes, the tiny crater just north of the 24-mile wide crater may be about the right size.

[Image 2 below]

(f) Flat hard area within the crater: unknown

Conclusion: Among the sites being studied for the 2020 rover mission there is no doubt that some are outstanding candidates for an HSF landing site. This is not one of them.

References
(1)   http://en.wikipedia.org/wiki/Mawrth_Vallis
(2)   http://mars.nasa.gov/msl/mission/timeline/prelaunch/landingsiteselection/mawrthvallis2/
« Last Edit: 05/31/2015 12:22 pm by Ionmars »
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Re: Mars HSF landing sites?
« Reply #56 on: 05/31/2015 12:07 pm »
In short what you really need is a thick deposit of ice, many meters deep. You'll need to accurately characterise the "ore" body just as they do on Earth, which involves landing instrumentation and doing a field survey at many points at once. Space based instruments probably aren't going to see far enough below the surface.

I see a deposit of 100 million km³ qualifying as "a thick deposit of ice, many meters deep".

I am also surprised that you are so much better informed than the University of Nantes and the Institute of Planetary Research of DLR  in Berlin, Germany. They do not give 100% certainty but a very high confidence of their finding. That is why I suggested that sonar probes at the surface would be needed before a mission relies on that water.

And I mean different reaction of regolith vs. ice to sonar to find the depth of that ice.

That thick deposit of ice is near the equator?

Offline Russel

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Re: Mars HSF landing sites?
« Reply #57 on: 05/31/2015 12:13 pm »
It has been argued that those radar readings are ambiguous and may not point to water, because they identify hydrogen, not water. That may be a valid concern. Maybe it is oil deposits rather than water? But I don't really think so. ;)

About that glacier study. There is vast experience on plastic flow of ice and the geologic traces it gives. It is a very valid assessment that there is water in the identified area Vallis Marineris.

I'm quite happy to believe that hydrogen signature is hydrated minerals. But if you're basing a landing site on mining water from soil then you're going to be steered towards area with a lot of loose surface soil and areas that have higher concentrations of water.

The questions I keep groping at are these.

In the areas where you have easily mined soils (deep and loose) is there a correlation or an anti-correlation between that desirable property and water content.

In the areas of the planet that have shown up as having higher concentrations of water in the top metre of soil (again we're talking about the equatorial zone) is there any correlation between these areas and areas of scientific interest and areas that are below "sea level". From the maps I linked earlier I think there's only a few small areas that are both high in water and below "sea level".

Also I might add that deep loose soil isn't necessarily a good thing for a landing site.

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Re: Mars HSF landing sites?
« Reply #58 on: 05/31/2015 12:22 pm »
That thick deposit of ice is near the equator?

http://www.dmzone.org/papers/Gourroncetal2014_VM.pdf

Yes the Vallis Marineris according to that paper.

Offline Russel

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Re: Mars HSF landing sites?
« Reply #59 on: 05/31/2015 12:47 pm »
That thick deposit of ice is near the equator?

http://www.dmzone.org/papers/Gourroncetal2014_VM.pdf

Yes the Vallis Marineris according to that paper.

Ok, I'm not a geologist but my reading of that paper is that its worth looking for. Here are the most important paragraphs..

Quote
6.2. Ice preservation
Surface ice is currently not stable at the Martian equator (Fanale
et al., 1986; Baker, 2001). However, field observations in ice disintegration
landscapes on Earth and theoretical calculations demonstrate that
mantling of relict ice bodies by debris layers as thin as a few decimeters
is enough to significantly inhibit rates of ice disintegration by melting
(Ostrem, 1959; Mattson et al., 1993) or by sublimation (Marchant
et al., 2002; Kowalewski et al., 2006, 2011). The development of
protecting ablation tills during the first stages of glacial disintegration
can thus explain the preservation until the present day of huge volumes
of ancient ice on Valles Marineris chasma floors, as it does at higher
latitudes on Mars (Squyres, 1978, 1979; Shean et al., 2005; Milkovich
et al., 2006; Holt et al., 2008). In addition, rock debris produced by
periglacial weathering at high elevations along valley walls and around
basement massifs can have accumulated on the ice surface during
the glaciation and favored later preservation of stratified benches and
lateral banks. Paraglacial mass movements also are able to provide a
large amount of debris during deglaciation and thus contribute to ice
preservation.]

and

Quote
7. Conclusion
Self-consistent landform assemblages indicate that Valles Marineris,
the giant valley system that stretches along the Martian equator, was
entirely glaciated during late Noachian to early Hesperian times and
still contains huge volumes of fossil ice inherited from this ancient
glaciation. Alternative nonglacial interpretations may be tentatively
proposed for the individual significance of each landform described
here. However, a glacial interpretation is supported by the fact that
these individual landforms collectively compose an elegant and selfconsistent
assemblage typical of a relict glaciated valley landsystem.
Fig. 13 shows our favored scenario for the history of this glacial fill.
The Valles Marineris glacial system comprised wet-based glaciers
that were able to flow and slide over their beds at some time of their
history at least. It was most probably fed by ice accumulating at low
elevations directly from the atmosphere onto chasma floors and valley
walls, with only minor contributions from tributary glaciers flowing
down from higher elevations. Similar fossil glacial landsystems dating
back from the early Martian history are to be expected in many other
low-latitude troughs such as chasmata, chaos, valleys, impact craters,
and other basins.

They're not exactly making a claim about how much fossil ice exists although they are making a strong claim that it can be preserved and probably does exist in some places. They're also saying at one point that ice can survive a long time under relatively think layers of cover.

So the bottom line for me is you can't expect to strike it lucky the first go you drill. Its still a huge area. What I need more convincing of (and again I'm not a geologist) is whether the sort of ice that is preserved in this sort of situation is likely to be found in deep layers. Its a real possibility I guess, but you'd need to both find it (robotic mission) and then characterise it (another mission).

That being said it would be a real cool place to have a first human landing.

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #60 on: 05/31/2015 08:19 pm »
...
...
So the bottom line for me is you can't expect to strike it lucky the first go you drill. Its still a huge area. What I need more convincing of (and again I'm not a geologist) is whether the sort of ice that is preserved in this sort of situation is likely to be found in deep layers. Its a real possibility I guess, but you'd need to both find it (robotic mission) and then characterise it (another mission).

That being said it would be a real cool place to have a first human landing.

Welcome to the Club.
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Offline the_other_Doug

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Re: Mars HSF landing sites?
« Reply #61 on: 05/31/2015 09:00 pm »



Sonar can find boundaries within the underground. Propagation of sound is different in different materials and there will be reflection on a boundary of different materials. So they can determine how deep the ice is. That is what I was trying to say.

Info received and appreciated. Now let's get sonar aboard the 2020 rover.

SONAR isn't exactly the right term for what we're discussing -- that primarily applies to sound detection in water, and is often done passively.

What you're talking about is more on the order of active seismology.  Oil companies do this a lot, using geophone and seismometer emplacements and then generating their own seismic waves using things ranging in energy from mechanical thumpers to TNT explosions.

To evaluate subsurface structure from the ground, a rover might best be designed to emplace a variety of geophones, seismometers and explosive charges during its traverse.  Once everything is set up and you're getting good signals from your sensors, you start setting off your charges.

This might sound like an odd thing to do on another planet, but Apollo did active seismology three times, including a strategy of placing explosives along the traverse performed during Apollo 17.  It's not only do-able, it's a great idea.
-Doug  (With my shield, not yet upon it)

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Re: Mars HSF landing sites?
« Reply #62 on: 06/01/2015 06:54 am »
I am quite willing to give up the term sonar.

However seismic with explosives will be good for deep sensing. I believe other methods might be more useful if you want to sense 10 or 100m deep. Something like a vibrator, I would imagine. Something that can be used many times to make a map, not with a very limited supply of explosives.

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #63 on: 06/01/2015 12:21 pm »
I was thinking the same thing. I suppose once you have a fleet of sensors on the ground you can mix several methods of creating impacts, all the way from crashing a stage to a mechanical thumper for detailed investigation of a promising location where ice is near the surface. It is the same principle as Apollo but I guess to accept a location for HSF ISRU we will want neurotic amounts of detail.

http://en.wikipedia.org/wiki/Apollo_Lunar_Surface_Experiments_Package
This mentions a depth of "several hundred feet" for the active seismic experiment, which I guess is probably more than a hundred meters, but we probably can't go that much smaller initially.
« Last Edit: 06/01/2015 12:22 pm by KelvinZero »

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Re: Mars HSF landing sites?
« Reply #64 on: 06/01/2015 12:41 pm »
Guckyfan and other Doug, who know me from UMSF, and can vouch for my background, are both right. Visualization of the subsurface over an area, without actually drilling, and/or coring, usually entails transmitting some kind of wave energy (acoustic in the case of seismic profiling, EM in the case of ground penetrating radar), and then recording the return times of reflections of those waves back to the surface, both at the source point and at other recievers in some kind of array. Through some fairly novel math and geometry, the depth (and orientation, to some extent) of surfaces in the subsurface materials over which the speed of these waves change (reflecting and refracting the wave fronts), can be determined. Inverting the impedance contrast at these changes in properties, which are primarily controlled by the rock and fluids they may contain, can allow one to estimate the wave speed of each zone, and assuming some realistic bounds, relate that back to rock and/or fluid type. Sources of seismic energy can range from a sledgehammer and a metal plate, to shotgun shells, to dynamite in shallow boreholes, for seismic surveys. Air guns are used in water. Oil and gas companies routinely use a truck-mounted vibrator in extensive land surveys. Ground penetrating radar sources are, of course, radio transmitters, and the resolution and depth of penetration depends on radar frequency and transmitting power, along with ground-EM coupling, and rock and fluid properties (complete absorption by brines or clays).
« Last Edit: 06/01/2015 12:54 pm by tdemko »
--
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Offline JasonAW3

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Re: Mars HSF landing sites?
« Reply #65 on: 06/01/2015 01:13 pm »
Guckyfan and other Doug, who know me from UMSF, and can vouch for my background, are both right. Visualization of the subsurface over an area, without actually drilling, and/or coring, usually entails transmitting some kind of wave energy (acoustic in the case of seismic profiling, EM in the case of ground penetrating radar), and then recording the return times of reflections of those waves back to the surface, both at the source point and at other recievers in some kind of array. Through some fairly novel math and geometry, the depth (and orientation, to some extent) of surfaces in the subsurface materials over which the speed of these waves change (reflecting and refracting the wave fronts), can be determined. Inverting the impedance contrast at these changes in properties, which are primarily controlled by the rock and fluids they may contain, can allow one to estimate the wave speed of each zone, and assuming some realistic bounds, relate that back to rock and/or fluid type. Sources of seismic energy can range from a sledgehammer and a metal plate, to shotgun shells, to dynamite in shallow boreholes, for seismic surveys. Air guns are used in water. Oil and gas companies routinely use a truck-mounted vibrator in extensive land surveys. Ground penetrating radar sources are, of course, radio transmitters, and the resolution and depth of penetration depends on radar frequency and transmitting power, along with ground-EM coupling, and rock and fluid properties (complete absorption by brines or clays).

     If memory serves, a certian amount of determination of what materials are un derground can also be determined by the frequency shifting of either the sonic or EM pulses reflected from those self same materials underground.  (However; obviously the frequency shifting of any material that the pulses are projected through must be accounted for when determining what materials lay below).
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Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #66 on: 06/01/2015 01:15 pm »
How much can be done with space based radar?

http://en.wikipedia.org/wiki/Space-based_radar#Planetary_radars
Sounding radars: these are low-frequency (normally, HF - 3 to 30 MHz - or lower) ground-penetrating Radars, used to acquire data about the planet sub-surface structure. Their low operating frequency allow them to penetrate hundreds of meters, or even kilometers, below the surface

Also apparently one already in orbit:
http://en.wikipedia.org/wiki/MARSIS

It would be useful to get a rough estimate of the depth of any ice, not to mention confirmation of ice itself, before designing instruments to land.

Offline sghill

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Re: Mars HSF landing sites?
« Reply #67 on: 06/01/2015 02:39 pm »
I was thinking the same thing. I suppose once you have a fleet of sensors on the ground you can mix several methods of creating impacts...

If time is on your side, then you don't need to create the impacts for active listening.  All you need are "ears" on the ground for passive listening, and build a map over time from small impacts that occur planet-wide each week which will create your "thumps".

This would be a pretty cool cube-sat idea.  Deploy hundreds or thousands of small listening cube-sats on parachutes from a carrier/coms relay probe during its aerobraking maneuver over your targeted region.
« Last Edit: 06/01/2015 02:40 pm by sghill »
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Re: Mars HSF landing sites?
« Reply #68 on: 06/01/2015 11:39 pm »
How much can be done with space based radar?

How much has already been done with space based radar?

Of the two, MARSIS on Mars Express is suppose to have greater penetration and SHARAD on MRO is supposed to have finer vertical resolution.  This paper says that MARSIS has detected echoes down to a depth of 3.7 km and SHARAD at least 1500 meters.  Shouldn't they have detected this relict glacial ice by now if it is there?

The Geomorphology paper has been out for nearly a year and a half now, and I find it strange that I can't find any other articles which either support or refute it.  I would have thought that news like this would have made even the mainstream press, much as ODU Professor Noffke's paper identifying possible fossilized biofilm structures in some Curiosity photos made a splash.

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Re: Mars HSF landing sites?
« Reply #69 on: 06/02/2015 02:02 am »
Guckyfan and other Doug, who know me from UMSF, and can vouch for my background, are both right...

Hi, Tim!  Yep, I definitely vouch for you -- you know what you're talking about, moreso than I do, usually.  Especially on this kind of subject.  (Though I like to think of myself as a pretty observant amateur, but still...)

The thing people need to remember, I think, is that this kind of profiling is not terribly high resolution.  As Tim pointed out, a lot of the information is inferred and based on models of how certain types of materials behave.  You get some subsurface structure information, but you don't get pretty pictures of layers of rock on top of layers of ice on top of aquifers, for example.  You get, in the best of imaging I've seen, some white blobs that look like they have a familiar or expected relationship.  And there's the occasional situation where a contact between layers is so striking that it shows up very clearly.  But, from the images I've seen, that's the exception, not the rule.

In other words, it's an art as well as a science, I think, particularly in the data reduction.  You get good information, but the analysis of it can only take you so far.  If it were truly high resolution, no oil company would ever sink a dry well... ;)

I will say, though, that I have seen one image -- of Earth -- that was labeled some type of tomography, and which seemed to show a huge slab of sea-floor crust after being subducted into the mantle, just accordion-ing its way down to the lower mantle.  That's the kind of thing I'd love to see for Mars.  But I doubt that we could get the kind of sensors needed to Mars, and besides, even though it would be cool to see, and would give us good information about the inner structure of Mars, I doubt that the same technique would shed much light on the location of exploitable resources.  Would be interesting to see if there were any remnants of crustal subduction in Mars' mantle, though.
-Doug  (With my shield, not yet upon it)

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #70 on: 06/02/2015 03:39 am »
The Geomorphology paper has been out for nearly a year and a half now, and I find it strange that I can't find any other articles which either support or refute it.  I would have thought that news like this would have made even the mainstream press, much as ODU Professor Noffke's paper identifying possible fossilized biofilm structures in some Curiosity photos made a splash.
So we don't really have a gauge on the scientific communities opinion on this? Hold off on those 500t impactors.. ;)

This is one of the reason I brought up those ice craters. Not because they are sensible locations, but just because we can see what we have got there so we can discuss detailed implementations now. In reality there are no doubt far better locations and the only correct action is to gather more information, but waiting for that is a bit dull.

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Re: Mars HSF landing sites?
« Reply #71 on: 06/02/2015 05:37 am »
Guckyfan and other Doug, who know me from UMSF, and can vouch for my background, are both right.

Seems I am not the only Guckyfan around. The one on UMSF is not me. ;)

Still I like your explanations a lot.

Offline redliox

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Re: Mars HSF landing sites?
« Reply #72 on: 06/02/2015 08:51 am »
In matters of water and ice, I think what would truly help decide where to land crews and establish bases would be the maps SHARD and MARSIS are generating.  We've seen the hydrogen maps from Odyssey's neutron spectrometer but, aside from profile strips of the poles, I honestly can't recall a map of Mars' subsurface displayed publicly.  Considering how long Mars Express has been orbiting alone, I would think enough data to create such a map exists with SHARD complementing.
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Offline zodiacchris

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Re: Mars HSF landing sites?
« Reply #73 on: 06/02/2015 11:08 am »
Well, I am a geologist and having just read the publication, it strikes me as well researched, with a solid foundation in previous work and publications, and logical conclusions.
The concept of geology in a natural setting, where no changes by humans have impacted soil or rock, is, that every feature, be it a hill or valley, cliff or sinkhole, rock or pebble, is there for a reason and in a location and shape that is defined by natural underlying processes. The underlying logic allows you to compare, reach conclusions and form a hypothesis that hopefully can be confirmed by on the ground observation and verification.

Specifically the comparatively consistent elevations and the apparent sinkholes and ablation related weathering features of the potential remnant glacier are intriguing. The ablation cliffs of the shrinking glaciers on top of Kilimanjaro are vertical and very impressive, and the sediment cover on the ice of the sink hole slopes/walls in the (potential) Valles Marineris remnant glaciers would likely be of limited thickness, and could allow tunnelling into a 1000m+ thick ice body to derive water and construct habitats. With the low temperature of the ice and the absence of flow of the glaciers, constructed cavities would be very stable and with suitable insulation would provide for well shielded and (comparatively easily constructed) habitats. During the First World War, both the Italians and the Austrians/Germans did build large cavities in glaciers in the high Alps, which housed whole garrisons of troops.

It is hard to imagine a more suitable place to establish an early Martian colony, H2O in abundance and easily constucted habitats, provided you bring a suitable energy source. Exciting   8)

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #74 on: 06/05/2015 02:43 pm »
From info posted so far on this thread, it appears that a site somewhere in or near Vallis Marineris represents a top candidate for the HSF landing site. Yet there is a good reason why no site in this valley has ever been selected for the landing of exploration rovers. This is because of very high wind speeds that pose a danger during landing. (See Reply #29.). Is there anything we could do to ameliorate this problem? Here are some possibilities:

1) Locate the landing site downwind from a natural wind barrier, like a hillock or inside a crater.

(2) Restrict landing to a time of day that is least windy (early morning?).

(3) Locate a landing site at the mouth of Vallis Marineris, where the distance between sidewalls is much greater and wind speed (should) be lower. The explorers would organize forays on rovers to gather ice from the glacier within the valley.

4) Locate the landing site on one of the mesas above the valley, where wind speed and air pressure are much lower at much higher altitude. The explorers would organize forays down into the valley for ice.

[edit - added the following idea from KelvinZero]
(5) Use bigger landers.  A massive vehicle like MCT will be much less affected by wind than a small Mars Exploration Rover.
« Last Edit: 06/06/2015 09:04 am by Ionmars »
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Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #75 on: 06/05/2015 02:58 pm »
It just occurred to me that if wind speeds are so high (up to 100 mph) and air is more dense at this lower altitude, then wind could be an additional power source at Vallis Marineris.
Could a Mars pole-vaulter set a new record? Not in a space suit. (smiley)

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #76 on: 06/05/2015 09:02 pm »
Yeah I saw that as well. Something from whatever article I read implied to me it might be an issue that just sort of evaporates with more confidence. Strong winds compared to what?

We should land robotic probes before any manned landing in any case, and I expect large HSF-scale landers will have much less problem with wind, for the same reason that parachutes and airbags stop being useful at that scale.

There are probably also potential issues for wind near the poles by the way, at least at certain times of year. Not surprising if 20-30% of your atmosphere freezes at a pole during its winter!

Offline Ionmars

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Re: Mars HSF landing sites?
« Reply #77 on: 06/06/2015 08:53 am »
Yeah I saw that as well. Something from whatever article I read implied to me it might be an issue that just sort of evaporates with more confidence. Strong winds compared to what?

We should land robotic probes before any manned landing in any case, and I expect large HSF-scale landers will have much less problem with wind, for the same reason that parachutes and airbags stop being useful at that scale.

There are probably also potential issues for wind near the poles by the way, at least at certain times of year. Not surprising if 20-30% of your atmosphere freezes at a pole during its winter!
Yeah, and if NASA continues to let wind be an obstruction to choosing a landing site, how will we ever get that first robotic probe that lands there to check out the conditions??

Would it be too much to hope for that SpaceX would step in and land a Dragon with scientific instruments? Unlike NASA they could justify it on the grounds of HSF and not worry so much about the risk. Maybe this could be one of the differences between a private company in space and a government agency?
Could a Mars pole-vaulter set a new record? Not in a space suit. (smiley)

Offline Russel

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Re: Mars HSF landing sites?
« Reply #78 on: 06/21/2015 03:18 am »
I am not sure if the wind is an issue for reasons of landing accuracy (assuming parachutes etc) or if its an issue from the point of view of the actual settlement. Dust on solar panels etc. Anyone have a take on that?

I think landing accuracy is going to be less of an issue. For large payloads you're not going to be relying on parachutes or the like - they won't work. And for small payloads such as crew you can go to a fully propulsive landing anyhow.

And despite the horror scenes (did you guys see the trailer for "The Martian?") I don't know if the Martian wind is ever that brutal. It might be an issue for very light structures like solar farms. But I think its the dust that's the real problem.

Offline Bob Shaw

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Re: Mars HSF landing sites?
« Reply #79 on: 06/21/2015 03:39 am »

There are probably also potential issues for wind near the poles by the way, at least at certain times of year. Not surprising if 20-30% of your atmosphere freezes at a pole during its winter!

Interesting comment; there are certainly polar dunes, which are presumably related to winds, and there are the curious spiral dry valleys, which tend to support such a statement. On the other hand, why are the polar caps so dust-free?

The arctic regions of Mars need a great deal more in the way of study!

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Re: Mars HSF landing sites?
« Reply #80 on: 06/21/2015 06:36 am »
Dust on solar panels etc. Anyone have a take on that?

We do know that in certain locations, hills with an angle much less dust accumultes. I am sure we can draw conclusions from that.

Offline the_other_Doug

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Re: Mars HSF landing sites?
« Reply #81 on: 06/21/2015 03:39 pm »
Dust on solar panels etc. Anyone have a take on that?

We do know that in certain locations, hills with an angle much less dust accumultes. I am sure we can draw conclusions from that.

There are two things happening with that.  The first is that dust has an angle of repose, just as with any other particle on a slope.  It will "roll down" a slope.

The second, and more affective, aspect of it is that it tends to be windier on Mars when you are up on a topographic high point, especially one that causes turbulence in the winds.  The wind cleans surfaces of dust more effectively than a simple tilt does.

There are places on Mars where the dust situation is more depositional, where we see dust dumped into dune fields and such, and places where it is more deflational, where the winds are slowly stripping dust from the surface.  It all seems to be driven by wind patterns.  But note that this is a net depositional/deflational situation; at pretty much any location on Mars, you will get some of both processes.  The difference is in which process is more pronounced, and thus has the greater long-term effect.  A net deflational location, for example, will see some dust deposition, but will see it wind-cleaned more frequently than in a net depositional location.

Thus, a good understanding of wind patterns is essential in figuring out where to site equipment that you don't want to get covered by an ever-increasing layer of dust.

Note -- I put in the italic tags manually above; the text editor still doesn't let me use the text control buttons.  But if you recall the text of the tags, you can still, of course, insert them manually.  See my note in the NSF feedback thread for details of this issue.
-Doug  (With my shield, not yet upon it)

Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #82 on: 06/22/2015 01:16 am »
I like the idea of finding nice flat rocky slopes facing the right way (towards the equator) and free of dust.

Maybe someone can identify specific sites like that now, near the regions of interest we have been discussing.

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Re: Mars HSF landing sites?
« Reply #83 on: 06/22/2015 05:36 am »
I like the idea of finding nice flat rocky slopes facing the right way (towards the equator) and free of dust.

Maybe someone can identify specific sites like that now, near the regions of interest we have been discussing.

I wonder how the situation would be in the highlands. Landings will be in the low basins. Maybe not initially but later in the process of colonization they could build the really large panel farms several km higher. Dust should be a lot less with the thinner atmosphere. Both the dust settling on the panels and the attenuation of the sunlight during dust storms.

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Offline KelvinZero

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Re: Mars HSF landing sites?
« Reply #85 on: 12/22/2018 04:06 am »
Nice place for skiing anyway :)
I just replied to colbourne in another thread that I think this location is just low enough in latitude that you could at get some year-round solar power on the equator-facing rim. Any nearer to the poles and you would get months where the sun does not rise above the horizon at all.

I think you can guess the direction facing the equator from where the ice gathers on the rim. It looks like the edge that should get the best solar power is also right next to surface ice just over the lip at the same location.

(edit) I think you might also get wind power there. I recall something about seasonal winds on mars from a substantial fraction of the atmosphere freezing at the poles during their coldest seasons. It would be useful if this happened to coincide with when solar power was weakest.
« Last Edit: 12/27/2018 11:55 pm by KelvinZero »

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Re: Mars HSF landing sites?
« Reply #86 on: 12/22/2018 03:21 pm »
Nice place for skiing anyway :)
I just replied to colbourne in another thread that I think this location is just low enough in latitude that you could at get some year-round solar power on the equator-facing rim. Any nearer to the poles and you would get months where the sun does not rise above the horizon at all.

I think you can guess the direction facing the equator from where the ice gathers on the rim. It looks like the edge that should get the best solar power is also right next to surface ice just over the lip at the same location.
Agreed.

The Google Mars map link given in the previous post lets you confirm that. Just search for Korolev, change to visible, and zoom in.  As below:

https://www.google.com/mars/#lat=72.630708&lon=167.155652&zoom=7&map=visible&q=korolev
« Last Edit: 12/22/2018 03:21 pm by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

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