“Remind me not to let that thing take my temperature with a rectal thermometer.”
Yeah, it would take the undertaker a week to get the smile off of your face.
I believe the… ahem, polite word is “rictus.”
“Yeah, it would take the undertaker a week to get the smile off of your face.”
Because it would mean he was on Mars, I assume.
I looked at the video of how this thing works on wikipedia. I am surprised that the mission planners just assumed that this thing would simply hammer its way 15 feet down. Fifteen feet is a long way in dead, dessicated “soil”. Living soil has microbes and air and water in it. Once you remove the microbes, air and water; it gets dense and hard really quick. It is probably something like caliche just a few inches below the surface. A drilling device is likely what was needed.
” It is probably something like caliche just a few inches below the surface. A drilling device is likely what was needed.”
While true, that is *not* any simple solution. Our team hosted a test of a drilling rig development device with a rotating drill bit, from Rockwell, for use on the Moon, out at our lava tube cave site in the early 1990s. It seemed well designed, however, it never was able to go any deeper than 30 centimeters, IIRC. It simply seemed that the torque loads on the rotating drill became *much* higher than planned. Rotating drills in soils, especially when you cannot easily test sample the soil before designing the device, are far from simple engineering with *any* lightweight drill kit that a robot would take on a Mars science excursion. Impossible? No. Easy? Hell No!
Uhhh… Needs Astroglide?
Sorry. Couldn’t resist.
If it is stupid, but it works…
If you’ve ever watched a caisson rig, they work by rotating the auger into the dirt for a ways, then withdraw it vertically to bring the excavated earth to the surface, then repeat. If they try to go too far at once, it bogs down like Tom said. Then the depth of the hole is limited to between 10 and 20 times the diameter depending on the soil. Very dry sand would be on the lower end unless you could fill the hole with water to keep it from caving in.
On the other hand, drilling a 1-1/2″ hole for a good many feet through solid rock is fairly routine, using air or occasionally water to eject the cuttings.
I’ve seen 5/8″ ground rods driven into fairly hard ground for more than 20 feet with a jack hammer.
I assume they tried it out here and it worked. It’s hard to imagine any of the above approaches being feasible on the rover.
If you don’t have a drill handy, NASA can probably get you one in 7 to 10 years.
Sounds like the way to do the job is a rotary drill bit, driven at the bit by small expansion nozzles with compressed CO2, using the CO2 flow to eject the cuttings. Compress the CO2 to liquid for a few days, then use whatever amount you can store to drill, till it gives out. Then go back to compressing more CO2. Rinse, Repeat.
The core of it is that drilling into any ground is civil engineering in this extent: Civil Engineering is *site*specific*. To get many drilled samples, you need a drill rig that can be adapted to many different sites successfully.
Regarding ice, and cold ice in particular (Frozen CO2), wouldn’t it be possible to make a tripropellant rocket with liquid or slurry CO2?
There should be lots of CO2 on the Martian atmosphere.
There is. From Wikipedia:
“It is primarily composed of carbon dioxide (95.32%), molecular nitrogen (2.6%) and argon (1.9%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen and other noble gases.”
“Remind me not to let that thing take my temperature with a rectal thermometer.”
Yeah, it would take the undertaker a week to get the smile off of your face.
I believe the… ahem, polite word is “rictus.”
“Yeah, it would take the undertaker a week to get the smile off of your face.”
Because it would mean he was on Mars, I assume.
I looked at the video of how this thing works on wikipedia. I am surprised that the mission planners just assumed that this thing would simply hammer its way 15 feet down. Fifteen feet is a long way in dead, dessicated “soil”. Living soil has microbes and air and water in it. Once you remove the microbes, air and water; it gets dense and hard really quick. It is probably something like caliche just a few inches below the surface. A drilling device is likely what was needed.
” It is probably something like caliche just a few inches below the surface. A drilling device is likely what was needed.”
While true, that is *not* any simple solution. Our team hosted a test of a drilling rig development device with a rotating drill bit, from Rockwell, for use on the Moon, out at our lava tube cave site in the early 1990s. It seemed well designed, however, it never was able to go any deeper than 30 centimeters, IIRC. It simply seemed that the torque loads on the rotating drill became *much* higher than planned. Rotating drills in soils, especially when you cannot easily test sample the soil before designing the device, are far from simple engineering with *any* lightweight drill kit that a robot would take on a Mars science excursion. Impossible? No. Easy? Hell No!
Uhhh… Needs Astroglide?
Sorry. Couldn’t resist.
If it is stupid, but it works…
If you’ve ever watched a caisson rig, they work by rotating the auger into the dirt for a ways, then withdraw it vertically to bring the excavated earth to the surface, then repeat. If they try to go too far at once, it bogs down like Tom said. Then the depth of the hole is limited to between 10 and 20 times the diameter depending on the soil. Very dry sand would be on the lower end unless you could fill the hole with water to keep it from caving in.
On the other hand, drilling a 1-1/2″ hole for a good many feet through solid rock is fairly routine, using air or occasionally water to eject the cuttings.
I’ve seen 5/8″ ground rods driven into fairly hard ground for more than 20 feet with a jack hammer.
I assume they tried it out here and it worked. It’s hard to imagine any of the above approaches being feasible on the rover.
If you don’t have a drill handy, NASA can probably get you one in 7 to 10 years.
Sounds like the way to do the job is a rotary drill bit, driven at the bit by small expansion nozzles with compressed CO2, using the CO2 flow to eject the cuttings. Compress the CO2 to liquid for a few days, then use whatever amount you can store to drill, till it gives out. Then go back to compressing more CO2. Rinse, Repeat.
The core of it is that drilling into any ground is civil engineering in this extent: Civil Engineering is *site*specific*. To get many drilled samples, you need a drill rig that can be adapted to many different sites successfully.
Regarding ice, and cold ice in particular (Frozen CO2), wouldn’t it be possible to make a tripropellant rocket with liquid or slurry CO2?
There should be lots of CO2 on the Martian atmosphere.
There is. From Wikipedia:
“It is primarily composed of carbon dioxide (95.32%), molecular nitrogen (2.6%) and argon (1.9%). It also contains trace levels of water vapor, oxygen, carbon monoxide, hydrogen and other noble gases.”
s/cold ice/dry ice/