Complex sentence: Their prior launch pad Space Launch Complex 40 at Cape Canaveral Air Force Station was damaged in the Amos-6 accident in September 2016, repair work is still ongoing as of September 2017.
Split into simpler sentences: Their prior launch pad, Space Launch Complex 40 at Cape Canaveral Air Force Station, was damaged in the Amos-6 accident on September 2016. Repair work is still ongoing as of September 2017.