nuclear-fission engine
31Energy density — For energy density in the sense of energy per unit mass, see specific energy. For energy density of foods, see specific energy. Energy density is a term used for the amount of energy stored in a given system or region of space per unit volume.… …
32Electricity generation — is the process of converting non electrical energy to electricity. For electric utilities, it is the first process in the delivery of electricity to consumers. The other processes, electric power transmission and electricity distribution, are… …
33Gas core reactor rocket — Gas core reactor rockets are a conceptual type of rocket that is propelled by the exhausted coolant of a gaseous fission reactor. The nuclear fission reactor core may be either a gas or plasma. They may be capable of creating specific impulses of …
34international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
35Solar power satellite — A solar power satellite, or SPS or Powersat, as originally proposed would be a satellite built in high Earth orbit that uses microwave power transmission to beam solar power to a very large antenna on Earth. Advantages of placing the solar… …
36Radioisotope thermoelectric generator — A radioisotope thermoelectric generator (RTG, RITEG) is an electrical generator which obtains its power from radioactive decay. In such a device, the heat released by the decay of a suitable radioactive material is converted into electricity by… …
37Alternative fuel — Alternative fuels, also known as non conventional fuels, are any materials or substances that can be used as a fuel, other than conventional fuels. Conventional fuels include: fossil fuels (petroleum (oil), coal, propane, and natural gas), and… …
38Hydrogen — This article is about the chemistry of hydrogen. For the physics of atomic hydrogen, see Hydrogen atom. For other meanings, see Hydrogen (disambiguation). ← hydrogen → helium …
39Fuel — For other uses, see Fuel (disambiguation). Wood was one of the first fuels used by humans and is still the primary energy source in much of the world.[citation needed] Fuel is any material that stores …
40Colonization of the Moon — Lunar outpost redirects here. For NASA s plan to construct an outpost between 2012 and 2024, see Lunar outpost (NASA). Moonbase redirects here. For other uses, see Moonbase (disambiguation). 1986 artist concept The colonization of the Moon is the …
