On the way to the moon
Apollo Command and Service Modules
We are now on the way to the moon, riding in the Command Module with the Service Module attached. The Service Module contains fuel tanks for the single engine, electrical power equipment and other supplies such as oxygen and water.
We started this process with a rocket of about 360 feet and are now down to a spacecraft that measures about 36 feet in length and only about 13 feet in diameter.
Attached to the CM & SM modules is the Lunar Module, so we are essentially flying two spacecraft toward the moon. The LM (or LEM) would be used to land on the moon, while the CM & SM remained in orbit around the moon. Two astronauts would leave the CM thru a tunnel connecting the two spacecraft, detach or undock from the CM and land on the lunar surface. A single astronaut would remain in orbit in the CM.
I mentioned the use of a tunnel between the spacecraft for crew transfers, this differs from the Soviet system of transferring from one craft to another. In the Soviet designs, the cosmonauts would put on spacesuits, open the hatches of the two craft and spacewalk to the nearby craft. Early versions of the Apollo capsule, called the Block 1 model, did not have the tunnel design incorporated into the craft.
While the Apollo craft was certainly roomier than the Gemini capsule, roomy enough for an astronaut to float down to an area behind or beneath the three seats. I’ve seen some of the capsules at the Air and Space Museum in Washington, D.C., it still looks a bit cramped for my liking. The Apollo capsule offered around 215 cubic feet of space. The upcoming Orion capsule, which should hold 4 astronauts, will have about 320 cubic feet. Roomier, yes, but Mars where it will one day journey to, is a long ways to travel.