Complex sentence: The Bussard ramjet method of spacecraft propulsion was proposed in 1960 by the physicist Robert W. Bussard and popularized by Carl Sagan in the television series and subsequent book' as a variant of a fusion rocket capable of fast interstellar spaceflight.
Split into simpler sentences: The Bussard ramjet method of spacecraft propulsion was proposed in 1960 by the physicist Robert W. Bussard. Bussard proposed a ramjetvariant of a fusion rocket capable of fast interstellar spaceflight.