Apollo Command and Service Module with Kuiper for scale (he’s 22.5″ at the shoulder.) Thank you Stafford Air & Space @staffordmuseum for letting Kuiper visit your beautiful, full-scale model in Weatherford, OK.
The shiny part of this CSM is the command module, which is the only part of an Apollo mission that comes back down to Earth (upon re-entry it is no longer shiny, alas. ?) It’s the only part with a heat shield (not visible; it’s on the bottom of the “gumdrop.”)
The cylinder portion (service module) contains supplies for power, life support (oxygen, water, cooling), communications antennas and an engine to propel the spacecraft. This part is ditched shortly before re-entry.
Why did we use a two part* spacecraft for Apollo? Physics! A lighter command module slams into the atmosphere with less force than a heavier command module, which means it generates less heat upon re-entry. Too much heat and re-entry simply wouldn’t be survivable with the heat shield technology we had at the time.
Because we started working on Apollo before we had committed to going direct ascent, earth orbit or lunar orbit rendezvous, we ended up with two versions of the CSM: Block I and Block II. Block I was designed solely for test missions in Earth orbit. There were some….problems…with the design, which we’ll explore soon… .
Next up: Apollo 2. Well, sort of. I’ll explain.
(* Lunar module sold separately. Literally, in fact. Not only is it physically separate from the CSM at launch, but the engineering contract was also awarded to a different company. ?)
Original post: https://www.instagram.com/p/BywomI-FYMY/