Under four billion

Blankbeard · Post by **Blankbeard** » Thu Dec 20, 2012 3:49 am

kunkmiester wrote:So far no one has asked for access to revise the spreadsheet. Is no one interested in that?

As of yet, I haven't seen the need to.

kunkmiester wrote: Quick search finds a website suggesting at least one meter of regolith for shielding, NASA would probably demand 5. What are the chances of collapse of piling 5 meters of regolith on top of a habitat, versus cutting a tunnel five meters down? Collapse is probably marginal risk, if you make your tunnel right, but the opportunity to kill a few thousand kilos of needed mass is a good point. I'm of the opinion though that if you want more than a few hundred square feet of space--such as a large colony--you'll want to tunnel, but a tunnel digger can probably be made in situ at that point.

I'd be mostly concerned about the lack of reinforcement across the ceiling as compared to a poured or molded ceiling.

kunkmiester wrote: The point here is to be able to send 7+ person trips to the moon to spend two weeks on the moon at a time, in comfort. Everything sent needs to be long term use--you buy something like a tractor or scraper on earth, it tends to hang around for decades in use, it's a very durable good. This is because after people start going to the moon, people will be interested in going longer, and eventually colonizing. If my fleet of robots can also prepare colony sites, that's that much less you have to spend on a colony effort. Frankly, aside from technologies like hydroponics and fabbing that a temporary base wouldn't deal with, the difference between a colony and a base is a matter of scale--a colony is bigger and uses more of the various materials than a base.

Issues of heat loss, atmosphere retention, and power distribution are going to keep your habitable areas close together. This is probably an area where you want to overplan.

Make sure you take a look at the pdf I linked. Lots of good stuff there.

palladin9479 · Post by **palladin9479** » Fri Dec 21, 2012 6:34 am

Interesting idea, how much work would it take to intercept an asteroid (or a couple) and realign / modify their orbits to make the more economical to mine?

For the "moon base", the only economical benefit it would provide is a low-G waystation / construction yard for space vehicles. Space vehicles that do long range transportation and or missions would be designed differently then anything needing atmospheric launch / reentry capabilities. You need a place to build those vehicles and that place must not have a high gravity well.

For power, you need something nuclear, nothing solar will provide anywhere remotely near enough useful power. It can't be anything overly large either, must be small enough to be transportable and have a low cost of maintenance. That's why I was so interested in the Polywell idea.

kunkmiester · Post by **kunkmiester** » Fri Dec 21, 2012 2:18 pm

Polywell would be a gamechanger for power, yes, but short of that, no one is going to allow you to build a fission reactor on earth and then shoot it into orbit. That's another reason for the moon--you get past the NIMBY's and envirowackos, and you can build just about anything you want. You have to do it on the moon though.

For the ultimate in ships, you want to build in orbit, no even on the moon. the big problem we have right now are the political and technical issues with building on and launching from earth. A resource asteroid would make a better shipyard than the moon's surface.

Blankbeard · Post by **Blankbeard** » Fri Dec 21, 2012 6:25 pm

palladin9479 wrote:Interesting idea, how much work would it take to intercept an asteroid (or a couple) and realign / modify their orbits to make the more economical to mine?

Here's a paper on just that.
http://kiss.caltech.edu/study/asteroid/ ... report.pdf

palladin9479 wrote: For the "moon base", the only economical benefit it would provide is a low-G waystation / construction yard for space vehicles. Space vehicles that do long range transportation and or missions would be designed differently then anything needing atmospheric launch / reentry capabilities. You need a place to build those vehicles and that place must not have a high gravity well.

We've had a couple threads recently detailing different people's ideas on what they thought such a base would be useful for.

palladin9479 wrote: For power, you need something nuclear, nothing solar will provide anywhere remotely near enough useful power. It can't be anything overly large either, must be small enough to be transportable and have a low cost of maintenance. That's why I was so interested in the Polywell idea.

I don't think anyone would turn down cheap reliable fusion power. Even some of the Gen IV/LFTR fission reactors may be light enough to send up and the right kind of asteroids are apparently just lousy with thorium and uranium. But don't forget the moon has spots that have solar radiation constantly. Getting enough panels there is still an issue but probably less of one than launching a nuclear reactor, unfortunately.

Blankbeard · Post by **Blankbeard** » Fri Dec 21, 2012 7:12 pm

Also

http://www.popularmechanics.com/science ... =pm_latest

3d printing using simulated regolith.

kunkmiester · Post by **kunkmiester** » Sat Dec 22, 2012 3:22 am

http://www.markuskayser.com/work/solarsinter/

How's that? Most of the machines I'd take with me exist as terrestrial machines, they'd just need shrinking, robotization, and replacement of diesel engines to work well.

Landing them isn't really that hard either. These are much harder machines than most planetary probes and rovers, and can take a bit more of a thump than say, Curiosity(in fact, they'd be designed to). You wouldn't use a rocket crane for them, they'd be palletized and dropped with a tethered rocket serving as a kind of parachute to hold velocity down to acceptable levels. We don't need to drop them on a dime either, as long as they're within a battery/capacitor charge of the main site.

Blankbeard · Post by **Blankbeard** » Sat Dec 22, 2012 4:38 pm

kunkmiester wrote:http://www.markuskayser.com/work/solarsinter/

How's that? Most of the machines I'd take with me exist as terrestrial machines, they'd just need shrinking, robotization, and replacement of diesel engines to work well.

Landing them isn't really that hard either. These are much harder machines than most planetary probes and rovers, and can take a bit more of a thump than say, Curiosity(in fact, they'd be designed to). You wouldn't use a rocket crane for them, they'd be palletized and dropped with a tethered rocket serving as a kind of parachute to hold velocity down to acceptable levels. We don't need to drop them on a dime either, as long as they're within a battery/capacitor charge of the main site.

If you're willing to trade speed for size, earth moving machines can be relatively small. Remember this guy?

http://carscoop.blogspot.com/2012/02/ca ... -only.html

I think that's a bit extreme but I suppose it shows what patience can accomplish.

kunkmiester · Post by **kunkmiester** » Sat Dec 22, 2012 6:01 pm

I think a cubic meter or so would be a decent target for a scraper. A big point is that a proper robot digger would not need a whole lot of interference once on the moon. Pay a guy or two to sit in a room with monitors in case something interesting happens, but once on the moon, they'd just go about their business. It wouldn't be a bit deal if you had to wait a year or two to send humans up, you'd probably be waiting that long or longer anyway.

RC construction has fascinated me, as well as RC tank paintball. Alas it'll be a bit longer before I have the money to spend on such things, and then I'll be spending money on having room for it, and probably have a wife and kids too. Slightly more interesting is doing something like automating the machines to run by themselves, like you'd have to do on the moon. Alas, I'm not much of a programmer. I can barely get my Arduino to do stuff, forget making GUIs and all that.