Under four billion

kunkmiester · Post by **kunkmiester** » Mon Dec 10, 2012 6:33 am

How do you get it above ten?
https://docs.google.com/spreadsheet/ccc ... FBKOEJFWGc

I can give people access to edit this, so it can be tweaked by others, let me know if you're interested, I'll need a google account to do that.

hanelyp · Post by **hanelyp** » Tue Dec 11, 2012 3:06 am

SpaceX lists a baseline Falcon9 launch at $54M. I suppose they charge NASA more to cover umpteen extra requirements.

kunkmiester · Post by **kunkmiester** » Tue Dec 11, 2012 4:03 am

I was guessing 54M was for a rocket with nothing on top of it, maybe for the service of putting your satellite on top, so I was going with the NASA numbers so as not to underestimate. Note the "moon Dragon" which would basically be a lunar orbit ferry, is less. What I'm really looking for is where people think this stuff would cost more than I figured, to get it closer to the 100B mark and higher that people throw around.

Blankbeard · Post by **Blankbeard** » Thu Dec 13, 2012 2:39 am

Regarding the rocket formula, I think the form you're looking for is

Total mass = Wet Mass * e^(Delta V *9.8 / Isp)

Assuming wikipedia is right, total delta V for a one way trip to mars is about 21 km/s If you're using effective exhaust velocity, Delta V /Veff is what you need. Make sure your units for delta V and exhaust velocity match and you should be ok.

I think dividing by wet mass gives you a more interesting form - essentially the fraction of non-fuel mass. Hope this helps some.

kunkmiester · Post by **kunkmiester** » Thu Dec 13, 2012 2:53 am

I already have the dry mass though(though it is a bit arbitrary), what I needed is the fuel mass needed to make the trip(to the moon for this case, though you can do a Mars trip by changing the delta V, engine mass, and ISP accordingly).

My big concern was with ISP being pounds of thrust and propellant per second. Since there's a m/s measurement directly, I think I'll be okay with that.

Blankbeard · Post by **Blankbeard** » Thu Dec 13, 2012 3:47 am

Propellant mass is wet mass or total mass - dry mass where dry mass includes the rocket and the payload.

ISP/standard gravity has units of m/s so you should be just fine there. If you have Imperial units, you can just drop them, replace them with seconds and treat the same way.

Aero · Post by **Aero** » Thu Dec 13, 2012 3:43 pm

kunkmiester wrote:I already have the dry mass though(though it is a bit arbitrary), what I needed is the fuel mass needed to make the trip(to the moon for this case, though you can do a Mars trip by changing the delta V, engine mass, and ISP accordingly).

My big concern was with ISP being pounds of thrust and propellant per second. Since there's a m/s measurement directly, I think I'll be okay with that.

You might find this web page helpful. Use the delta V listed for any leg of the trip, or add legs together as you wish, along with the rocket equation to calculate your free parameters.

http://en.wikipedia.org/wiki/Delta-v_budget

GIThruster · Post by **GIThruster** » Thu Dec 13, 2012 9:17 pm

Are you calculating to build a base or a colony? You are familiar with the calcs done by CSIS stating a small base would cost $35B+7.5B/year? That was in 2005 dollars.

These figures don't include developing a lunar lander, which NASA estimates at $2B, but obviously they would not spend less than 4X that. Just look at what they've spent on Orion.

Many tens of billions for a very small base that is nothing like a colony. Not self-sustaining. Doesn't pay for itself. For a real colony it's a multi-trillion dollar investment with no clear path to any return on investment.

Musk's Mars project makes more sense.

Blankbeard · Post by **Blankbeard** » Thu Dec 13, 2012 10:03 pm

I think you need a lot more solar panel weight. Solar panels weight about 13 kg m^-2 and (on earth) make about 1 kw per 9.5 m^-2. You've got enough for about 308 square meters and 32 kw of power. Is that per trip? Also, I'm not sure if you're considering the long periods of darkness.

The first thing you might do is to figure out an energy budget and how you're going to store that energy until it is needed. You can melt water or heat rock to store heat without needing to bring mass with you, but you'll need batteries for electricity, obviously.

kunkmiester · Post by **kunkmiester** » Fri Dec 14, 2012 4:47 am

Initial business plan: Haliburton of the Moon. Lunar Exploration and Technologies Inc. would not be the end user of this stuff, it's customers would be. Surely you'd find plenty of customers among other countries and various schools and universities that would be willing to pay for this? I need to redo the transfer vehicle, I'd like to get that weight to the point where it only needs one refueling for a trip, which will put the tag below $500 million--for a seven man mission. At least for now. Increasing the solar panels will bump the price up some, but I can't see some of the CSIS numbers making sense; well, maybe for a government project.

SpaceX developed the Falcon family for about a third of a billion, and they're saying about a billion more for certifying it for crew--part of which is just launches others will be paying for anyway. They're development costs are an order of magnitude below NASA's, and operations are at least a couple of factors. Why would this trend not continue in a commercial moon base?

Most of this stuff is dual use too though, so the Moon isn't your only source of revenue. I'm sure a ship with 2200+ m/s of delta V would find a lot of uses in earth orbit when it costs 130M or so to get a crew there, and not much more to get propellant. Plus almost everything can be designed for Martian resilience too.

Throwing more zeros on those numbers, someone want access to edit so they can see what they can see?

GIThruster · Post by **GIThruster** » Fri Dec 14, 2012 6:25 am

kunkmiester wrote:Why would this trend not continue in a commercial moon base?

SpaceX is a business providing the highest value for its service of any company on the planet. What high value service are you going to use to drive base development? Unless you have one, you have no comparison with SpaceX.

First rule of business is to make money. How does your moon base make money in ways that no competitor can match?

krenshala · Post by **krenshala** » Fri Dec 14, 2012 7:20 pm

The ones that come to mind for me are (in no particular order):

Astronomy sans atmospheric distortion and always away from the lights of Earth (though, obviously, not always away from the light of the nearest star)
Tourists wanting a (short) stay on the moon; cost would scale inversely with difficulty/cost in getting there, of course.
Providing (raw) materials collected from the lunar surface for off-Earth use (assuming manufacturing); the advantage here is the lower gravity well for Luna, which means much lower energy requirements to get stuff to space, meaning lower launch cost (possibly offset far too much due to additional costs from working in vacuum on the Lunar surface)
Possible communications point for off-earth-to-earth comms traffic (this is probably much more practical to do via earth orbiting satellite networks or dedicated station at one of the Lagrange Points, however).

hanelyp · Post by **hanelyp** » Sat Dec 15, 2012 12:21 am

krenshala wrote:The ones that come to mind for me are (in no particular order):
[*] Astronomy sans atmospheric distortion and always away from the lights of Earth

For optical this works well in freefall. Radio astronomy may benefit from the massive backside block.

[*] Providing (raw) materials collected from the lunar surface for off-Earth use (assuming manufacturing); the advantage here is the lower gravity well for Luna, which means much lower energy requirements to get stuff to space, meaning lower launch cost (possibly offset far too much due to additional costs from working in vacuum on the Lunar surface)

Asteroids have much less gravity, though longer trip times.

[*] Possible communications point for off-earth-to-earth comms traffic (this is probably much more practical to do via earth orbiting satellite networks or dedicated station at one of the Lagrange Points, however).

Works well in freefall, even better when your com station can see in all directions without that big chunk of rock behind it.

kcdodd · Post by **kcdodd** » Sat Dec 15, 2012 1:46 am

I find the question of economics and space colonization weird the way it is usually discussed. People usually leave to another place because the new place is better to live than the place they left. Not because they could make a bunch of money by trading with the place they came from. If that happens at all, it seems only incidental. A colony in space would have to have something intrinsic that gives a better standard of living to those that live there.

kunkmiester · Post by **kunkmiester** » Sat Dec 15, 2012 4:34 am

Most of my interest in this is just that I really fail to see how people get such huge budgets to do this stuff. Finding people to actually pay for it is indeed another matter, but does depend on your budget. Doing something like this for less than ten billion is a different animal than even 35 billion.

The main reason I could see for leaving would be politics--move out to the frontier where there is less ability for the powers that be to try to govern how you live and work. Libertarians, the ones most likely to want to do this, are however one of the poorest suited to it, we're mostly poor, and getting us to do something is like herding cats, it will be very difficult to get a return on investment besides charging simple rent, which comes back to how much it actually costs to get something up there.