Digging Holes on the Moon
Dirt: the bleeding obvious radiation barrier:
The best way to protect astronauts living and working on the Moon from harmful solar radiation is being debated by lunar scientists.Burying a habitat module under lunar dirt is one option currently being discussed by scientists on a lunar discussion group. Another option, to protect astronauts from solar flares when working away from their base, might be to set off explosives to create an emergency trench as a shield.
Well, I guess when your alternative is getting irradiated by a solar flare and possibly dying a nasty death, the risks from being sandblasted by flying regolith and pelted by falling debris might seem at least a little bit appealing.
Using a bulldozer or other robot to push soil over a habitat module would not be easy. If the bulldozer’s weight is reduced to one-sixth its Earth weight on the Moon, the force it is able to push with is also reduced by one-sixth.“That means it gets stuck much easier,” explains Edward McCullough, principal scientist in advanced aero analysis at Boeing Phantom Works in Huntington Beach, California, US.
One hopes that the Boeing guys considered the obvious fix for that: piling regolith or rocks on the bulldozer itself to add weight.
May 31st, 2006 at 10:50 pm
“That means it gets stuck much easier,” explains Edward McCullough, principal scientist in advanced aero analysis at Boeing Phantom Works in Huntington Beach, California, US.
One hopes that Boeing is engaging a few guys with experience in actually building ‘stuff’ using real bulldozers.
June 1st, 2006 at 6:26 am
Ed is a former mining engineer.
June 1st, 2006 at 6:45 am
Call me crazy, but doesn’t the soil ALSO weigh 1/6th of what it would on earth? While the pushing force of the dozer may be reduced, the VOLUME of material it could push would remain unchanged. (Actually, I’m guessing it would increase, since I imagine lunar soil is less dense than earth soil.)
There are a number of problems with getting a bulldozer to work in the lunar environment, but I’m not convinced that pushing capacity is one of them.
June 2nd, 2006 at 12:33 pm
“Ed is a former mining engineer.”
And knowing is half the battle. But I was thinking more ‘heavy equipment operator’ and less ‘engineer’.
June 9th, 2006 at 6:41 pm
The problem with moving lunar regolith around is not its mass, but its cohesion. A few megayears of pounding by micrometeorites packs it down very solidly, so a bulldozer would have to first drag a narrow pick through the material to break it up.
Getting the traction to move that pick would be difficult, because piling up six times the dozer’s mass in loose regolith (a chicken and egg problem right there) would be *bulky*.
Dragline systems may work better, but are not as portable as a self-contained vehicle. Moving lunar regolith is not a straightforward problem.
June 12th, 2006 at 8:04 am
“The problem with moving lunar regolith around is not its mass, but its cohesion. A few megayears of pounding by micrometeorites packs it down very solidly, so a bulldozer would have to first drag a narrow pick through the material to break it up.”
As far as I know regolith cohesion should be like dry sand if you dig the first half meter, and like wet sand if you go deeper.
This because meteroids ipacts pack down regolith, but also spreads all around a lot of it. This one will be very easy to dig when it falls down again.