question: What is the greatest CCBs with Launches to date of 4, and a Payload to GTO of 8,900kg?
answer: SELECT MAX(ccbs) FROM table_name_52 WHERE launches_to_date = 4 AND payload_to_gto = "8,900kg"
context: CREATE TABLE table_name_52 (ccbs INTEGER, launches_to_date VARCHAR, payload_to_gto VARCHAR)