Quote from: Hop_David on 06/22/2010 07:18 amWhat do the boys at ULA say? They endorse your plan to buy Caterpillar heavy equipment off the shelf and slapping them under Atlas fairings?Caterpillar and NASA have been talking.https://www.cat.com/cda/layout?x=7&m=8703&id=976621
What do the boys at ULA say? They endorse your plan to buy Caterpillar heavy equipment off the shelf and slapping them under Atlas fairings?
I wrote, "The next logical stop towards mining lunar ice is a surface reconnaissance and evaluation mission."Quote from: Warren Platts on 06/23/2010 01:22 amForget it. It's not worth it. [...] the $2 billion that it would take [...] is better off just folded into the manned program. We're going there anyway. Better to let the trained geologists figure it out once they get there.Wouldn't it be great if a crewed mission to the lunar ice fields were reintroduced as something NASA (or an international partnership) might do anytime soon? Dream on.... Realistically, robotic precursors are an integral element in both the plan of record and the FY11 proposal. Is there a proposal gaining any traction whatsoever that doesn't include them?
Forget it. It's not worth it. [...] the $2 billion that it would take [...] is better off just folded into the manned program. We're going there anyway. Better to let the trained geologists figure it out once they get there.
Those of you interested in this subject should view this paper: http://www.springerlink.com/content/2765nxu162056462/Google searches on the paper's authors' names along with ice melting should show other results, though to my knowledge no one has examined the questions under realistic Lunar polar or Europan conditions.
Quote from: jimgagnon on 06/23/2010 02:06 amThose of you interested in this subject should view this paper: http://www.springerlink.com/content/2765nxu162056462/Google searches on the paper's authors' names along with ice melting should show other results, though to my knowledge no one has examined the questions under realistic Lunar polar or Europan conditions.That's very interesting. Thanks for the link Jim! It would seem that the ice will not suck the lifeblood out of our equipment as fast as people were fearing. . . .
Integral element in the PoR and FY2011??? [...] What robot precursors are you referring to? They aren't on the drawing board.
Quote from: Warren Platts on 06/23/2010 02:04 amIntegral element in the PoR and FY2011??? [...] What robot precursors are you referring to? They aren't on the drawing board. (This response is not directed at Warren Platts, who already knows about the information provided below. The intent of this response it to make sure other forum readers are not mislead.)Some robotic precursors are long off the drawing board, constructed, launched and at or on the Moon. http://moon.msfc.nasa.gov/ Those missions were conducted under the aegis of the Constellation program, which is the plan of record.Regarding FY11, quoting from the statement General Bolden made on Feb 1, "In addition to the trailblazing technology programs, the President’s budget provides $3 billion over five years for robotic exploration precursor missions that will pave the way for later human exploration of the moon, Mars and nearby asteroids."http://www.nasa.gov/pdf/420994main_2011_Budget_Administrator_Remarks.pdf
With what is known today based on orbital reconnaissance it is a wee bit premature to design extraction equipment. The next logical stop towards mining lunar ice is a surface reconnaissance and evaluation mission. If you had a rover on the surface near the edge of what was believed to be an ice sheet, what sensors would you want on that rover? If the rover included an arm that could reach out and touch the ice, what instruments would you want on the tip of that arm?
In other words, you have no idea if they'd work or not.
So it follows that lunar ice is sure to be friable?
Wasn't Halliburton one of British Petroleum's subcontractors?
...the catastrophe will be the cause of the end of the world...
...you apparently have no problem with sticking the taxpayers for $12,000/kg for rocket propellant...
Assuming that cold steel is harder than cold ice . . .
Trying to find Moh's hardness of ice at close to absolute zero has been beyond my Google Fu so far. I have found there are several forms of ice. Lunar ice might be ice 6 so far as I know. A few have speculated the ice would be Moh's hardness of 6 or more. Would diamond saws be needed to cut it? Would pikes, saws or other cutting devices be brittle and vulnerable to breaking?
QuoteIn other words, you have no idea if they'd work or not.Nope, he doesn't. Do you? I just typed "cryogenic steel" for starters. Most of its about treating steel cyrogenically. Not so much about what it's like at those low temps.
One of the most important breakthroughs in the field of cryogenics occurred in 1945, when scientists discovered that materials frozen to very low temperatures showed more resistance to long term wear....Metal parts, castings, forging, plastica, and composite materials all respond well to cryogenic processing. It is a non-destructive process, which does not affect the carbon content of steel, and leaves any surfaces clean and free of oxides. Unlike heat stress relief, there is no discoloration. The process essentially deadens the stress in welded or machined components, and can make a big difference to the durability of parts requiring intricate machine processing.Aluminum can benefit from cryogenic stress relief, as can non-ferrous metals. They become stronger and tougher as a result of the densification of their molecular structure, making them as close to stress-dead as possible.
Quote from: JohnFornaro on 06/25/2010 04:10 pmQuoteIn other words, you have no idea if they'd work or not.Nope, he doesn't. Do you? I just typed "cryogenic steel" for starters. Most of its about treating steel cyrogenically. Not so much about what it's like at those low temps.Since cryogenic temperatures are regularly used in the steel industry to increase the strength of steel, then it stands to reason that such steel would be able to be used at such temperatures to dig up ice, does it not? And why expect steel to become brittle at 33K, but not water ice? Indeed, the very link you provide is to contest for people to have their guns cryogenically treated. It appears that far from being dangerous to steels, cryogenic temperatures apparently tend to improve the mechanical properties of steel. As for your "clean" sheet designs, why do you think they would do a better job than this one?: ET-400 Electric Backhoe
No, it does not strengthen steel. Using cryogenics during the tempering period will strengthen steel when brought back to room temperature. If kept cryogenic, steel becomes brittle, weaker than glass.
Quote from: downixNo, it does not strengthen steel. Using cryogenics during the tempering period will strengthen steel when brought back to room temperature. If kept cryogenic, steel becomes brittle, weaker than glass.Is a reference too much to ask for?
The effects of temperature on metal toughness can be critical in many applications. For instance, it is hypothesized that the sinking of the Titanic ocean liner might have been averted if the steel in the hull had had greater low-temperature ductility. Tests on hull samples from the Titanic retrieved in recent years indicate that the steel had a high sulfur content,which caused it to become brittle at temperatures as high as -1 deg C, which is substantially above the freezing point of salt water. As a result, when the Titanic struck the iceberg, the steel in its hull fractured rather than deformed, causing the fatal gash. If the metal had just buckled, it is possible the ship would not have sunk. These properties were not well-understood or appreciated until the 1940's.