Apollo command and service module Facts for Kids

The Apollo command and service module (CSM) was a very important spacecraft used by NASA for the Apollo program. This program aimed to land astronauts on the Moon. The CSM was one of two main parts of the Apollo spacecraft, working together with the Lunar Module. It was built by a company called North American Aviation.

The CSM was launched into space many times. It flew on its own for three test missions, using the smaller Saturn I rocket. It also flew twelve times on the much larger Saturn V rocket. Sometimes it flew alone, and sometimes it flew with the Lunar Module. In total, the CSM made nine successful trips to the Moon with astronauts on board, all boosted by the powerful Saturn V rocket.

What was the Apollo CSM?
- The Command Module
  - Inside the Command Module
- The Service Module
  - What the Service Module Carried
Apollo Missions with the CSM
Images for kids
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What was the Apollo CSM?

The Apollo Command and Service Module (CSM) was like the main spaceship for the Apollo missions. It had two main parts that worked together:

The Command Module (CM)
The Service Module (SM)

The CSM's job was to carry the astronauts from Earth to the Moon, keep them safe during the journey, and then bring them back home. It was the only part of the Apollo spacecraft that returned to Earth.

The Command Module

The Command Module (CM) was the part of the spacecraft where the three astronauts lived and worked during their mission. It was shaped like a cone, which helped it re-enter Earth's atmosphere safely.

Inside the Command Module

Inside the Command Module, there were many important things:

Crew Cabin: This was where the astronauts sat during launch, landing, and much of the journey. It was quite small, but it had everything they needed to control the spacecraft.
Control Panels: The CM had thousands of switches, buttons, and dials. These allowed the astronauts to control the spacecraft's systems, navigation, and communication.
Life Support: This system provided fresh air, regulated temperature, and removed waste. It kept the astronauts alive and comfortable in space.
Heat Shield: The bottom of the CM had a thick heat shield. This shield protected the astronauts from the extreme heat generated when the module re-entered Earth's atmosphere.
Parachutes: After re-entry, large parachutes deployed from the top of the CM. These slowed the spacecraft down for a gentle splashdown in the ocean.

The Command Module was the only part of the Apollo spacecraft that returned to Earth. After splashing down, it was recovered by a ship.

The Service Module

The Service Module (SM) was attached to the back of the Command Module. It was a cylinder shape and carried many things needed for the long trip to the Moon. The Service Module did not return to Earth. It was separated from the Command Module just before the CM re-entered the atmosphere.

What the Service Module Carried

The Service Module was packed with essential equipment:

Main Engine: The Service Propulsion System (SPS) engine was the SM's most important part. It was used to push the spacecraft into orbit around the Moon and then to push it out of lunar orbit for the journey back to Earth.
Fuel Tanks: Large tanks held the fuel and oxidizer for the main engine.
Power Supply: Fuel cells in the SM generated electricity for the entire spacecraft. These cells combined hydrogen and oxygen to create power and also produced water for the crew.
Oxygen Tanks: These tanks held oxygen for the astronauts to breathe and for the fuel cells.
Antennas: Various antennas were used for communication with Earth and for navigation.
Small Thrusters: These were part of the Reaction Control System (RCS). They were smaller engines used for making small adjustments to the spacecraft's direction and position.

The Service Module was crucial for the mission's success. It provided the power, propulsion, and supplies needed for the journey to and from the Moon.

Apollo Missions with the CSM

The Apollo CSM was a key part of all Apollo missions that went to the Moon.

It first flew on its own for test flights in low Earth orbit.
Later, it carried astronauts on missions that orbited the Moon, like Apollo 8.
For the Moon landing missions, the CSM stayed in orbit around the Moon while the Lunar Module took two astronauts down to the surface.
After the Lunar Module returned from the Moon, it docked with the CSM. The astronauts then transferred back into the CSM for the journey home.

The Apollo CSM was a marvel of engineering. It successfully carried astronauts to the Moon and back, making history for the United States.

Images for kids

Command module interior arrangement
Command module reentering the atmosphere at a non-zero angle of attack in order to establish a lifting entry and control the landing site (artistic rendition)
Scale model of the Apollo command and service module at the Euro Space Center in Belgium
The Apollo 15 Command Module splashes down in the Pacific Ocean, 1971.
Main control panel
Guidance and navigation equipment
Apollo 14 command module Kitty Hawk at Kennedy Space Center, Florida.
Apollo 15 command module Endeavour at the National Museum of the United States Air Force, Dayton, Ohio
Block II service module interior components
Apollo Service Module Propulsion System
RCS quad containing four R-4D thrusters, as used on the Apollo Service Module
Three of these fuel cells supplied electric power to the spacecraft on lunar flights.
VHF scimitar antennas mounted on the Service Module.
Apollo CSM in white for a Skylab mission, docked to the Skylab space station
Block I command module exterior
Block I service module interior components
World map showing locations of Apollo command and service modules (along with other hardware).