Five F-1 engines were clustered at the base of the first stage of a Saturn 5. Together, the five engines developed 3,450,000 kilograms (7,610,000 pounds) of thrust at lift off, and burned 2,021,000 liters (534,000 gallons) of liquid propellants in the 2 ½ minutes before first stage burnout. By then the big rocket had reached 9660 kilometers per hour (6000 miles per hour) and an altitude of 61 kilometers (38 miles).