The Command Module

The words

1. Apex Cover

   The apex cover was the forward heat shield over the command module’s parachute compartment. It was discarded during descent so the landing parachutes could deploy.

   NASA news reference: the command module (opens a new tab) · NASA: Apollo’s apex cover and landing (opens a new tab)

2. Avcoat

   Avcoat was the material packed into Apollo’s heat-shield cells. It absorbed reentry heat while being consumed, helping protect the crew compartment inside the command module.

   NASA: Apollo heat-shield construction (opens a new tab) · Smithsonian: Apollo heat-shield fragment (opens a new tab)

3. Block II

   Block II included equipment for docking with the lunar module. After the Apollo 1 ground-test fire killed three astronauts, NASA made further changes before crews flew this version.

   NASA: Apollo 1 and spacecraft changes (opens a new tab)

4. Blunt Body

   Apollo entered the atmosphere broad end first. Its blunt shape pushed the shock wave away from the capsule, keeping much of the heated air from reaching its surface.

   NASA Ames: Apollo’s blunt-body shape (opens a new tab)

5. Boilerplate

   Boilerplate command modules were engineering test capsules. Dropping them from aircraft let engineers examine the parachute landing system before astronauts relied on it during a return from space.

   Did you know?

   The first parachute drop of an Apollo boilerplate from a modified Air Force C-133 took place on May 3, 1963.

   NASA: qualifying Apollo’s parachutes (opens a new tab)

6. Caulking Gun

   Workers used a tool like a caulking gun to put heat-protective material into Apollo’s honeycomb cells. Each cell was filled by hand, making construction laborious.

   p. 72 (PDF p. 85) · NASA: Apollo heat-shield construction (opens a new tab)

7. Docking Tunnel

   A short passage led from the command module’s cabin to the docking hatch in its nose. After docking, astronauts could move through it to the lunar module.

   NASA: Apollo 11 command module (opens a new tab)

8. Downey

   Downey, California, was home to North American Aviation’s Apollo spacecraft plant. The company built the command and service modules there for NASA’s lunar program.

   NASA: building Apollo’s command module (opens a new tab) · NASA: qualifying Apollo’s parachutes (opens a new tab)

9. El Centro

   Northrop Ventura dropped test capsules at El Centro, California, to qualify Apollo’s landing system. The trials included conditions in which only some parachutes opened.

   NASA: qualifying Apollo’s parachutes (opens a new tab)

10. Equipment Bay

    Equipment bays lined the command module’s cabin walls. The lower bay served as the navigation station, while other bays held life-support equipment, clothing, food and medical supplies.

    p. 48 (PDF p. 10) · NASA news reference: the command module (opens a new tab)

11. Faget

    Maxime Faget helped shape the Apollo command module after his work on Mercury’s capsule. From 1962, he led engineering and development at NASA’s Manned Spacecraft Center in Houston.

    NASA Langley: Maxime Faget (opens a new tab)

12. Fiberglass

    Fiberglass formed the honeycomb that held resin in Apollo’s outer heat shield. This layer was designed to wear away during reentry, protecting the crew compartment from heat.

    Did you know?

    The Smithsonian’s fragment came from command module 011, flown on the uncrewed AS-202 test in 1966. The shield was cut into smaller museum pieces in 1972.

    Smithsonian: Apollo heat-shield fragment (opens a new tab)

13. Honeycomb

    Apollo’s inner shell sandwiched aluminum honeycomb between metal sheets. Fiberglass honeycomb served a different purpose outside, holding the material that protected the capsule during reentry.

    NASA news reference: the command module (opens a new tab) · Smithsonian: Apollo heat-shield fragment (opens a new tab)

14. Main Parachute

    Three main parachutes were stored near the command module’s nose. They opened during the final descent to slow the capsule for its landing in the ocean.

    NASA: Apollo 11 command module (opens a new tab) · NASA: Apollo’s apex cover and landing (opens a new tab)

15. Storms

    Harrison A. Storms led North American Aviation’s Space and Information Systems Division. The division in Downey was responsible for building Apollo’s command and service modules.

    NASA: building Apollo’s command module (opens a new tab)