On July 20, 1969, a whole nation tuned in to see astronaut Neil Armstrong take one small step on the surface of the Moon, ushering in a new era of space exploration. But how did Armstrong and the Apollo 11 astronauts get to the Moon in the first place?
The manned Apollo missions were each launched aboard a Saturn V launch vehicle. (The “V” comes from the five F-1 engines that powered the first stage of the rocket.) Almost five decades later, the Saturn V remains the United States’ largest and most powerful launch vehicle ever built. (Yes, even more than Space-X’s Falcon Heavy!)
The Saturn V launch vehicle had three stages:
The components of the Saturn V rocket. Credit: National Air and Space Museum
- First Stage: The five F-1 engines, producing nearly 7.7 million pounds of thrust. These powerful engines were required to lift the heavy rocket fast enough to escape Earth's gravity. The first stage engines were burned at liftoff and lasted for about 2.5 minutes, taking the vehicle and payload to an altitude of 38 miles. Then, the first stage separated and burned up in the Earth's atmosphere.
- Second Stage: The five J-2 engines. After the first stage was discarded, the second stage burned for approximately 6 minutes, taking the vehicle and payload to a 115 mile altitude. The second stage was then discarded.
- Third Stage: The one J-2 engine. This engine burned for 2.75 minutes, boosting the spacecraft to an orbital velocity of about 17,500 mph. The third stage was shut down with fuel remaining and remained attached the spacecraft while in Earth orbit. The J-2 engine reignited to propel the spacecraft into translunar trajectory, which brought the spacecraft to the Moon.
The Apollo spacecraft was made up of several components:
The Apollo Command and Service Module combination (CSM 105), was originally used for vibration and acoustic tests.
The Command Module Columbia: The living quarters for the crew during most of the first manned lunar landing mission. The Command Module is the only portion of the spacecraft to return to Earth.
The Service Module: Housed a liquid-fuel rocket engine propulsion system which astronauts used to steer the spacecraft toward the Moon, place it into lunar orbit, and propel it back toward Earth.
LM 2 was built for a second unmanned Earth-orbit test flight. Because the test flight of LM 1, named Apollo 5, was so successful, a second mission was deemed unnecessary.
The Lunar Module: A two-stage vehicle that brought Neil Armstrong and Buzz Aldrin from lunar orbit, to the Moon’s surface, and back.
All-together, the complete assembly (the Saturn V rocket, the Apollo spacecraft, and the emergency escape system at the top of the launch vehicle) stood over 360 feet tall, and weighed over 6 million pounds.