Complex sentence: The two stage Tsyklon-2 was first launched August 6,1969, from the Baikonur Cosmodrome in Kazakhstan, while the Tsyklon-3, which featured a restartable third stage, first launched on June 24,1977 from the Plesetsk Cosmodrome.
Split into simpler sentences: The two stage Tsyklon-2 was first launched August 6,1969, from the Baikonur Cosmodrome in Kazakhstan. The Tsyklon-3, which featured a restartable third stage, first launched on June 24,1977 from the Plesetsk Cosmodrome.