 Apollo lunar missions would begin with a nominal 100-nautical-mile (185 km) circular Earth parking orbit. Apollo 8 was launched into an initial orbit with an apogee of 99.99 nautical miles (185.18 km) and a perigee of 99.57 nautical miles (184.40 km), with an inclination of 32.51°to the Equator, and an orbital period of 88.19 minutes. Propellant venting increased the apogee by 6.4 nautical miles (11.9 km) over the 2 hours, 44 minutes and 30 seconds spent in the parking orbit.
