Has NASA's Mars Insight lander hit rock bottom? Heat probe struggles to penetrate Red Planet NASA engineers are trying to fix an instrument on the Mars Insight lander that was supposed to burrow five metres (16 feet) into the Red Planet's surface – and has instead tapped out at just 30 centimetres (one foot.) The device, known as the Heat Flow and Physical Properties Package (HP3), is essentially a very fancy hammer. …
This article is very light on details, so if you actually want to read about the problems, and the great work NASA and DLR scientists are doing to rescue the mission, have a look here:
https://www.dlr.de/blogs/en/desktopdefault.aspx/tabid-5893/9577_read-1090/
Basically, the soil in this location is an extremely fine soft powder, which has formed a hole around the mole. The Mole requires friciton on it's side walls to operate, so sitting in a hole means it cant grib and cant penetrate beyond the 20 or so cm it already has. There are ways to dig into such soil (as similar soils do exist here on earth) and the team will be pushing forward with those.
There is still a possibility that the mole has encountered a second rock under the surface (it encountered one in the first 10cm but was able to deflect past it), but the more likely problem is this super fine soil. Once through this top layer, the Mole should be able to operate without problems. Of course that's a big "should", as it's impossible to know how deep the fine soil goes, and what lays beneath. Still now that the Mole is free from its support structure, and engineers can see directly what the mole is doing when it tries to penetrate, chances of a successful mission are greatly increased.
Good work by the whole team, and good luck for getting the mole down deep! (from an ex-HP3 team member)... :)
My favorite phrase of the week, but unlikely to work as an excuse for being in the pub, not work. A fascinating blog though, and I'm happily geeked out after reading it. Also science vs bureaucracy-
(BTW: It takes 2 entire weeks to clear customs over here for such a shipment. Add to that some time for customs clearing in the US)
I'm guessing there was a lot of export paperwork to get the Mole to Mars as well. I'm also guessing it's providing a lot of useful data, even if it's not hit the desired depth. I'd been curious about the surface, ie the result of all the large dust storms leading to either fine sands, or scoured rock. Presumably those effects were part of the site selection, but has a lot of implications if we plan to use robo-dozers to start digging for burying manned structures for radiation and storm protection.
And I've also been having fun playing "Surviving Mars", which makes it all seem easy :)
Check the 11th April log/blog entry. For Science!
But geologists have also seen that the topmost centimeters on Mars is formed by what is called a "duricrust". Here, chemical reactions between grains of sand have made them stick together, providing cohesion in that layer.
And theories about whether the surface has cohesion, or not. Either way, the Mole is providing data to test those theories. And I still find it awesome that we can see the surface in hi-res colour, and footprints left in the dust/duricrust.. Which I guess can also be used to test assumptions regarding the surface. I guess one plan could have been to include a slim probe to pathfind for the Mole, but that'd add mass/volume to the experiments & AFAIK has been done with previous missions, leading to the initial assumptions about the soil structure.
(And being a comms wonk, having to wait for the stars (ok, satellites) to be in alignment is an interesting insight into the challenges of remote controlling Marsbots.)
For info, the data from other Mars landers and rovers (Curiousity, Spirit, Opportunity, etc) showed the Duricrust to be a relatively thin layer. Thats what the Mole was designed for, based on the best available evidence. It turns out in InSight's location, it seems to be quite a thick layer.
But remember, even if you have excellent Soil data from lets say Australia, whats the likelihood of the Soil in northern France being similar? Planets are big, and their geology changes significantly. You design for the best info you have, but you're still throwing a dart from a continent away and hoping you get a bullseye (you're also hoping the dartboard is still there and is actually made from the material you thought it was, and which your dart is designed for). Exploration is a gamble, but hopefully this one pays off in the near future! :)
It turns out in InSight's location, it seems to be quite a thick layer.
So.. a literal case of Sod's Law. Sort of. But as an engineer, any problem can be resolved with the application of the right hammer!
(So while eagerly awaiting the next log update, been pondering terraforming and SF-style approaches like worms to create soil, add bacteria etc etc. Which presumably gets more challenging if there's a thick crust. And like you say, on a planetary scale, would require an extensive worm farming operation to get going.)
Actually Andy it has already hit one stone and gone around it. Stone's arent that big a danger, unless you happen to hit dead on on a flat surface, but even then with enough time it can usually crack its way through most things. You should have seen some of the nice scars we left on solid blocks of concrete we embedded in the soil for testing just that scenario.
Of course, there is the chance it hit something dead on and super hard. but based on the surface scatter of rocks, the likelihood of hitting two rocks in close proximity and just the right configuration to block the mole is considered low. It's considered to be only a couple of percent likely.
If you look at the link I posted above, and check out the latest pics, you will see the giant hole around the Mole. That definitely will stop the mole running. Fill that in, and apply pressure on the correct spot to prevent hole reemergence, and we should be back up and running.
So no, not 50/50 and you can put away your told you so voice.
"...the likelihood of hitting two rocks in close proximity and just the right configuration to block the mole is considered low...."
I have hammer augured probably well over a thousand soil samples, typically 0.5, 1.0 or even occasionally 2.0 meters deep in my career and I would say that I hit rocks that required relocating the augur about 1/3 the time. Occasionally several relocations were required. So, how low was the likelihood estimate? Evem with a large truck-mounted geotechnical riig, I've seen them stopped dead.
A friend of mine has a beautiful swimming pool with a car-sized boulder in the center. When they were excavating for the pool and they encountered this beast they had to make a decision - dynamite it, fill the hole back in and forget the whole thing, or build the pool around it. They chose the latter, and now have a very unique design with a nice centerpiece from which to dive.
NASA didnt design it DLR did, but anyway the reason can be put simply as Budget, Complexity, Weight and Space Constraints. Adding a winch or some other mechanism for repositioning would have seriously added to all of them.
Also keep in mind, the mole is designed to go 5 m down and then take measurements for the next 2 years. Assuming it got down, there's no point to pull it back up, so the winch would be dead weight, you've carried for nothing. There was always a risk that it wouldnt get all the way down, but it was a risk worth taking ot keep with in the above requirements.
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