Complex sentence: The two stage Tsyklon-2 was first launched October 27,1967, while the Tsyklon-3, which features a restartable third stage, first launched June 24 1977.
Split into simpler sentences: The two stage Tsyklon-2 was first launched October 27,1967. The Tsyklon-3 features a restartable third stage, and first launched June 24 1977.