Editing Fusion rocket (section)

=== Magnetic ===
To sustain a fusion reaction, the plasma must be confined. The most widely studied configuration for terrestrial fusion is the [[tokamak]], a form of [[magnetic confinement fusion]]. Currently tokamaks weigh a great deal, so the thrust to weight ratio would seem unacceptable.<ref name=":0">"The large mass and the need for a high power removal of a terrestrial fusion reactor make the MCF [Magnetic Confinement Fusion] and the ICF [Inertial Confinement Fusion] hardly implementable for space propulsion applications. Rocket mass is indeed a hard constraint in space propulsion, and power exhaust is a critical issue in space due to the absence of an efficient thermal sink." {{Cite journal |last1=Meschini |first1=Samuele |last2=Laviano |first2=Francesco |last3=Ledda |first3=Federico |last4=Pettinari |first4=Davide |last5=Testoni |first5=Raffella |last6=Torsello |first6=Daniele |last7=Panella |first7=Bruno |date=2023-06-07 |title=Review of commercial nuclear fusion projects |journal=Frontiers in Energy Research |volume=11 |doi=10.3389/fenrg.2023.1157394 |doi-access=free |issn=2296-598X }}</ref> [[NASA]]'s [[Glenn Research Center]] proposed in 2001 a small aspect ratio spherical torus reactor for its "Discovery II" conceptual vehicle design. "Discovery II" could deliver a crewed 172 metric tons payload to [[Jupiter]] in 118 days (or 212 days to [[Saturn]]) using 861 metric tons of [[hydrogen]] propellant, plus 11 metric tons of [[Helium-3]]-[[Deuterium]] (D-He3) fusion fuel.<ref name="realizing2001">{{cite conference |title=Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion |id=NASA/TM—2005-213559 |conference=37th Joint Propulsion Conference and Exhibit |publication-date=March 2005 |date=July 2001 |publisher=[[Glenn Research Center]] |url=https://ntrs.nasa.gov/api/citations/20050160960/downloads/20050160960.pdf |archive-url=https://web.archive.org/web/20230704080840/https://ntrs.nasa.gov/api/citations/20050160960/downloads/20050160960.pdf |archive-date=4 July 2023 |url-status=live |last1=Williams |first1=Craig H. |last2=Dudzinski |first2=Leonard A. |last3=Borowski |first3=Stanley K. |last4=Juhasz |first4=Albert J. }}</ref> The hydrogen is heated by the fusion plasma debris to increase thrust, at a cost of reduced [[exhaust velocity]] (348–463&nbsp;km/s)  and hence increased propellant mass.