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m WP:CHECKWIKI error fixes + general fixes using AWB (7661)
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The '''radioisotope rocket''' is a type of [[rocket engine]] that uses the heat generated by the decay of [[radioactive]] elements to heat a [[working fluid]], which is then exhausted through a rocket nozzle to produce [[thrust]]. They are similar in nature to the [[nuclear thermal rocket]]s such as [[NERVA]], but are considerably simpler and often have no moving parts.
The basic idea is a development of existing [[radioisotope thermoelectric generator]], or RTG, systems, in which the heat generated by decaying nuclear fuel is used to generate power. In the rocket application the generator is removed, and the working fluid is instead used to produce thrust directly. Temperatures of about 1500 to 2000°C are possible in this system, allowing for [[specific impulse]]s of about 700 to 800 seconds (7 to 8 kN·s/kg), about double that of the best chemical engines such as the [[LH2]]-[[LOX]] [[
However the amount of power generated by such systems is typically fairly low. Whereas the full "active" reactor system in a nuclear thermal rocket can be expected to generate over a gigawatt, a radioisotope generator might get 5 kW. This means that the design, while highly efficient, can produce thrust levels of perhaps 1.3 to 1.5 N, making them useful only for thrusters. In order to increase the power for medium-duration missions, engines would typically use fuels with a short [[half-life]] such as [[polonium|Po 210]], as opposed to the typical RTG which would use a long half-life fuel such as [[plutonium]] in order to produce more constant power over longer periods of time. The even shorter half-life element [[fermium]] has also been suggested<ref>[http://pdf.aiaa.org/preview/CDReadyMSPACE06_1393/PV2006_7272.pdf AIAA meeting paper comparing fermium, polonium and plutonium as power sources]</ref>
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