Prerequisites:

Description:

    This is the technology of using a controlled fusion reaction to propel a spacecraft, usually by the emission of high-energy reaction products backward from the vessel.  Depending on whether extra reaction mass is used, this technology may be highly efficient (several percent as efficient as antimatter rocketry) or not very efficient at all in terms of mass expelled per unit thrust.
    The reaction products of a fusion reaction, while relatively "clean" in the radioactive sense when compared with fission byproducts, are still quite lethal when organic tissue is exposed to them.  Thus, while fusion launch device use does not make a planet radioactive, it will pose substantial danger to nearby inhabitants due to the high energy output.