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Decoding the Moon landing commentary

CAPCOM, Yaw, Slew ... Understand what those mission control communication loops really mean


Yaw – Side to side movement of the spacecraft in the horizontal plane

Slew – A particular setting for the spacecraft communications system. It enables the high gain antenna to be moved, in an attempt to get the best line of sight with Earth

PDI – Powered Descent Initiation

Go/no Go – A call from a flight controller to state whether their systems are functioning well enough for the mission to proceed

Delta-H – A critical measurement of the lunar module, Eagle’s, altitude for the landing attempt

MSFN – The Manned Space Flight Network


Neil Armstrong – Commander; Manoeuvres the space shuttle, and is responsible for the shuttle, crew, mission success and safety of the flight

Buzz Aldrin – Lunar Module Pilot; Monitors the spacecraft systems, keeps commander informed about systems status and navigational information

Michael Collins – Command Module Pilot; Runs systems checks, performs moon observations, and communicates with mission control


John Aaron (EECOM) – Electrical, Environmental and Communications Officer; Monitors cryogenic levels for fuel cells, and cabin cooling systems, electrical distribution systems, cabin pressure control systems and vehicle lighting systems

Steve Bales – Guidance Officer; monitors on-board navigational systems and on-board guidance computer software

Bob Carlton – Flight Controller; Control officers responsible for the guidance, navigation and control of the lunar module

Chuck Deiterich – Retrofire Officer; Responsible for abort procedures and Trans-Earth Injection, retrofire burns

Charlie Duke (CAPCOM) – Capsule Communicator; US astronaut or a member of the US astronaut corps who serves in the Mission Operations Control Center as liaison with the astronauts in space

Jay Greene (FIDO) – Flight Dynamics Officer; Monitors trajectory of the Apollo spacecraft, computing changes in orbit and plots course corrections and adjustments

Gene Kranz – Flight Director; Oversee and guide mission control

Don Puddy – Telecommunications Officer; Flight controller responsible for the electrical, life support and communications systems of the lunar module

Buck Willoughby (GNC, pronounced Gin-see) – Guidance, navigation, and controls systems engineer; monitors all vehicle guidance, navigation, and control systems

John Zieglschmid – Surgeon; Monitored both crew and controllers’ health

Mission control during the Apollo 11 mission