# Alternate uses for rail gun technology

1. May 28, 2016

### 1oldman2

2. May 28, 2016

### Staff: Mentor

I don't like the article. The author doesn't know how conventional guns work, has never heard of rounding numbers, mistakes gravitational acceleration for the acceleration in the gun, does not understand the difference between density and hardness, and so on.
Based on the Mach cone of the object behind the projectile, the video shows a projectile with just Mach 3-4, which is below the quoted one mile per second.

If the system could be scaled up to several km/s, launches to orbit would be interesting, but maglev-like systems should work better at those speeds.

3. May 30, 2016

### Hoophy

So some companies (such as Planetary Resources) have ambitious plans to mine asteroids for water ice to manufacture rocket fuel IN space. From what I understand Planetary Resources wants to provide a refueling service to probes in space. According to them rocket fuel situated in space is pound for pound more valuable than gold to companies and organizations with probes in earth orbit. I was wondering if using rail guns or mass relays on the asteroids being mined would be a good way to move packets of rocket fuel from asteroid to earth orbit. I would imagine it would be easier than using rocket propelled transport vessels because fuel would not need to be burned to move the extra weight of 'transit' fuel. This I think would increase efficiency. Also the rail gun could use solar energy -> electric energy instead of (in the case of rocket propelled fuel transport vessel) solar energy -> electric energy -> electrolysis -> rocket fuel -> combustion to move transport vessel. Converting to rocket fuel being an extra conversion. So using an electromagnetic rail gun would have less energy conversions so maybe less energy would be lost to thermal form. I would imagine that escaping an asteroids gravity well would be relatively easy to escape from. Overall I would love to see what uses rail guns and mass relays will be put to in space industry and exploration in the near and far future.

4. May 31, 2016

### Staff: Mentor

5. May 31, 2016

### Hoophy

6. May 31, 2016

### Hoophy

I sure hope that this kind of thing happens in our lifetimes, with the current space exploration pace it is not going to happen, but if private companies are really motivated with the hope of extreme profit I think we will get there. Once you mine one, you can mine others much easier because now you have the funds. Asteroid mining gets me so excited. After all, there are trillion dollar checks up there just waiting to be cashed! :D

7. May 31, 2016

### Staff: Mentor

An average cubic kilometer of soil on Earth has gold with a market value of about 1 billion US-dollar. How much do you have to pay to get 1 cubic kilometer of random soil in a desert? Basically nothing. Because extracting the gold costs more than 1 billion. And getting to a random spot in a desert is much easier than getting to an asteroid and back. The asteroid has higher concentrations of gold and other precious metals, but you still have to process cubic kilometers of its material. That is expensive on Earth, and it will certainly not be easier in space.

8. May 31, 2016

### OmCheeto

I'm still looking for an investor.......

re: suspected amount of a liquid gold layer, somewhere between here and the Earth's core.

I think that's 53.96876 sextillion dollars.

ps. I still haven't figured out why gold is so valuable. hmmmm......

9. May 31, 2016

### 1oldman2

http://www.bbc.com/news/magazine-25255957

I loved "court and spark" what a vocalist.

10. May 31, 2016

### Hoophy

I don't think they even compare.

http://m.phys.org/news/2012-05-profitable-asteroid.html
"Most Cost Effective: 2000 BM19, a very small O-type asteroid (less than 1 km wide) that makes several close approaches to Earth. Its estimated value is $18.50 trillion and an estimated profit of$3.55 trillion."

That margin is not amazing but maybe it will get smaller, perhaps the 'estimates' are exaggerated or completely wrong. Either way I will keep my hopes up.

I understand where you are coming from but I do disagree. I THINK it would be be easier (and If not at least more interesting) to profit (especially on a small scale) from mining an asteroid rather than "said sand" Maybe not so viable now, but who's to say about the future? (Although the same may go for the sand) I don't know, maybe I disagree for the sole reason that your strategy is more lame. :D

Last edited: May 31, 2016
11. May 31, 2016

### 1oldman2

Please reconsider this, I'm relatively new here but mfb isn't known for "lameness". He has much to teach you as you will see.

12. May 31, 2016

### Hoophy

I am much newer than you and I am also MUCH less experienced with, well life in general! :D I am sure that mfb is an immensely interesting person and I did not think his post was 'lame' at all. I should have been more clear and that was my mistake, I was just of the opinion (opinion mind you that mining desert sand was less interesting and neat (by using the word 'lame') than mining asteroids. I am sorry if it can off sounding like I was saying mfb was a lame person or that his post was lame. I promise that was NOT what I meant! Once again, sorry for my lack of clarity.

13. May 31, 2016

### 1oldman2

I like to read the general discussion thread "Today I learned" for perspective. We have a lot of learning that needs done.

14. Jun 1, 2016

### Staff: Mentor

A 4-digit precision for the estimated costs to disassemble and bring back a kilometer-sized asteroid, while we didn't even drill deeper than 3 meters into any object outside Earth? Forget it. Anyone quoting numbers like that has no idea what they are talking about or deliberately makes up random numbers.
Why do you think so?

Edit: fixed formatting bug.

Last edited: Jun 1, 2016
15. Jun 1, 2016

### Hoophy

Perhaps I only think this way because I take the bait the media feeds me. Naturally the media wants to get me excited about it so that they can make money off of stories, in any rate they sure got me.
Edit* Also if you are suggesting that I have no idea what I am talking about, you would be exactly right. Please enlighten me. :)
Edit** Are you mad? I think you are but I can not tell.

Last edited: Jun 1, 2016
16. Jun 1, 2016

### Staff: Mentor

I think in terms of asteroid mining, no one has an accurate idea. It is something that has never been done. We had a few robotic probes (Luna xx) drilling two meters into moon and returning a few hundred grams of samples, and one spacecraft (Hayabusa) grabbing less than a milligram of material from an asteroid to return it to Earth. That is the closest to asteroid mining we ever came: not even a milligram. The concepts ask for processing cubic kilometers of rock.
I hope not?

17. Jun 1, 2016

### Hoophy

Ok good, it just seemed like you were.
Also, do you even think that commercial asteroid mining would have a CHANCE at all say 60 years from now? Assuming private company's and national/international agency's continue to develop new technology?

18. Jun 1, 2016

### Staff: Mentor

Mining asteroids for bringing materials back to Earth: Well, at some point I can certainly imagine that. In a timeframe where companies would have to care about that now? Would surprise me.
Mining asteroids or the moon for bringing materials to space stations or other destinations: I can certainly imagine that.

19. Jun 1, 2016

### Hoophy

Perhaps LOX/LH2 refueling like earlier mentioned. In fact now that I think about it that's all that was originally mentioned. Do you think bringing small asteroids (or chunks) back to Earth and processing on the surface is more likely, or is that completely unreasonable as well?

20. Jun 1, 2016

### 1oldman2

Rail guns are cool but so is the subject of mining asteroids, I have created a thread devoted to that subject in Astronomy.