albino boo said:
Lets look at the figures. Nasa has just spent $671 million on getting a 65 kg satellite into orbit around Mars. The cost of gold per kg is $34000. So 65x 34000 = 2210000, the cost of the mission is roughly 3 times its weight in gold. Bear in mind that the large asteroids are further away and are not made of solid gold and you have to price in a return trip and atmospheric shielding, you don't make money.
your calculations are running under flawed assumption.
1. Mining equipment may be cheaper than a space sattelite.
2. For examples sake lets say we use a 65 KG Mining equipment droid. This only means that 65 KG had to go up into space. this is not the mass that is going to go down. the asteroid part being brought down will likely be measured in tons, not kilograms. Landing something may also be cheaper than lifting off, because you only need to counter the gravity enough not to burn the craft up instead of not only countering the gravity completely but also propeling it above that force. you are also allowed to use things like parachutes which are relatively very cheap compared to slowing down using rockets. you can even use the friction of asteroid itself as part of the stopping power.
3. there are quite a lot of asteroids between us and Mars. they just arent all that interesting, or discovered. we actually havent discovered half of asteroids around us. Aiming for smaller asteroids also means you need less energy to mine/propell it.
4. It may be possible to refine the material in space so you would only have to land pure product. Alternatively, moon could be used as a rest stop for a refinery. due to its low gravity and no atmosphere, it is much more easier to land and lift off there.
5. expenses of space operation are currently highly increased due to pretty much every craft being unique and designed as a new project. reusable craft that can be mass produced will be much cheaper and thats whats going to happen if we are going to be mining space.
id be much more worried not about profitability but about mass added to earth. if we add too much mass we may affect the gravity enough to kick earth into spiral orbit towards sun. of course, thats going to take decades if not centuries to do.