WHY Return to the Moon? - Page 3
Explore new potential energies.
Todays nuclear power generation plants produce electricity by fission. This process results in a lot of radioactive and unmanageable long-term waste dangerous to the environment. Fossil fuel energy plants damage the environment by extraction and burning. I am not at all in favor of using nuclear (fission) propulsion in space. Nuclear refueling would be a daunting task. Nuclear containment would degrade protective housings forcing replacement and scrapping driving up expense. Fusion reactors would have far less radioactive waste and much safer to an environment.
In Return to the Moon Harrison talks extensively about Helium-3 and fusing it with Deuterium as an energy source producing more power than a comparable fission reactor. He goes on to describe quantities required, lunar mining, and potential profits to transport Helium-3 to Earth. The patents in developing the technology to accomplish any part of this task would be a financial benefit. If he is correct about Helium-3 on the Moon then Helium-3 must also be on asteroids.
Wikipedia states " Much speculation has been made over the possibility of helium-3 as a future energy source. Unlike most other nuclear fusion reactions, the fusion of helium-3 atoms releases large amount of energy without causing the surrounding material to become radioactive. However, the temperatures required to achieve helium-3 fusion reactions are much higher than in traditional fusion reactions (superscript note 3) and the process may unavoidably create other reactions that themselves would cause the surrounding material to become radioactive (superscript note 4). Superscript 4 is an article by Dr. Frank Close, a theoretical physicist that was published in Physicsworld.com August 2007. The article is titled Fears over Factoids, subject: Helium errors. He relates that using Helium-3 with Deuterium would take higher temperatures and longer time than using Tritium to fuse with Deuterium. Dr. Close's article mentions that the Joint European Torus in the UK is a tokomak using deuterium and tritium fusion.
Currently there are no fusion reactors using Helium-3.
The International Thermonuclear Experimental Reactor (ITER) is projected to have construction completed in 2025. Tokamak Energy in the UK is targeting 2030. Ran Mandelbaum wrote on March 9, 2018 that MIT has received millions to build a fusion power plant within 15 years.
Use of Helium-3 for fusion is currently educated probability. Empirical evidence won't be gained until it's explored.
FUSION for electrical requirements in space can be converted to terrestrial use.
Terrestrial methods won't work due to: radiation; electrostatic charging/discharging, regolith "dust"; and a minimum amount of gravity. Each of those will have a direct impact on human life and equipment usage.
It makes little economic sense to mine something from space for the return to the Earth's surface. I will make one exception to this statement and that is for materials that are scarce on Earth such as Helium-3 (for exploratory energy production). Mining for things such as diamonds and precious gems for return to the Earths surface for consumers should be considered very expensive novelties.
The biggest issue is going to be the international community objecting to an entity claiming a space asset for personal/organizational financial gain (space treaties). Once you get around that you will have expenditures that would be moved to the consumers. Those costs will include the costs to launch from the Earth's surface to the target, safe harvesting, and Earth surface return. Drilling into these costs include: salary of the miners and equipment costs; the cost of launch; how much fuel is required; human miners life support needs; time required to mine; time and method to package the material for transport back to Earth; safely returning the miners and cargo back to Earth's surface; further refinement of the product. A lot of mining costs can be reduced by mining material to be used only in the space environment.
Collecting water-ice on the Moon is likely to be the first "product" to be mined and will likely be a manual effort. A storage method will need to include some process to melt and remove all traces of "dust", test it, and use it simply as water. A refining method would need to be developed and tested for breaking water down to its components of Hydrogen and Oxygen and storage for use.