i.e.: https://en.wikipedia.org/wiki/Antimatter-catalyzed_nuclear_pulse_propulsion https://en.wikipedia.org/wiki/Antimatter-catalyzed_nuclear_p..., although it d

i.e.: https://en.wikipedia.org/wiki/Antimatter-catalyzed_nuclear_pulse_propulsion https://en.wikipedia.org/wiki/Antimatter-catalyzed_nuclear_p..., although it doesn't really replace the primary, just decreases the required quantity.