Complex sentence: On 21 February 1979, "Ranger" deployed for her 14th WestPac cruise, tentatively scheduled to cross the Indian Ocean to present a show of force during the strife between North and South Yemen, a mission she would not complete.
Split into simpler sentences: On 21 February 1979, the "Ranger" deployed for her 14th WestPac cruise. Tentatively scheduled to cross the Indian Ocean to present a show of force during the strife between North and South Yemen, a mission she would not complete.