Page 23 - Apollo Moonships

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3 LUNAR EXCURSION MODULE (LEM)
The Lunar Module was used by two crew members to descent over the lunar surface and served to them as support base during their stay on the moon. The top portion of lunar module lifted the astronauts from the lunar surface to rendezvous with the Command–Service Module (CSM) that waited for them in lunar orbit (see page 4).
4 LUNAR MODULE ADAPTER (SLA)
This adapter protected the LEM during the launch. The LEM remained into the SLA, until the CSM was separated from the S–IVB third stage in space. Then, the CSM docked and extracted the LEM to go to the moon.
5 INSTRUMENT UNIT (IU)
The ring shaped structure was the “brain” of Saturn V and carried all systems to guide and fly the rocket.
6 S–IVB THIRD STAGE
This stage burned twice before being discarded. First, 9 minutes after launch to positioned the Apollo spaceships into the Earth parking orbit at 115 miles of altitude, and a few hours later to put the vessels in translunar trajectory.
7 INTERSTAGE SKIRT When the S-II second stage
turned off and the S-IVB third stage ignited, the interstage ring that joined both sections was dropped into space.
8 S–II SECOND STAGE
Propelled by five rocket engines, the S-II second stage ignited 3 minutes and 12 seconds after launch, when the S-IC first stage turned off. The second stage burned for approximately 7 minutes and drove the Saturn V’s payload at an altitude of 114.5 miles.
MULTISTAGE ROCKET
The Saturn V rocket used three driving sections or stages mounted in tandem (one above the other) to propel the Apollo spaceships to the moon. This configuration allows the rocket to discard stages that have run out of fuel. As a result, the launch vehicle lost mass, which allowed the active stage to impart more acceleration to the payload. During the flight, the stages of Saturn V were separated using explosive charges to break their joints with the rest of the rocket, while retrorockets were fired
to pull them backwards. The separation of the driving sections began when their thrust decayed at 10% or less of its rated value. At the end of launch, every part of the Saturn V was discarded, leaving behind only the Apollo moonships (the CSM and the LEM). The initial blast-off impulse was provided by the mighty five-engine cluster of the S-IC first stage, while the S-II second section carried the Apollo spacecraft near the Earth parking orbit, a circular region around the planet where the astronauts stayed a few hours, waiting for permission to continue the trip
to the moon. The final push to leave the Earth parking orbit and the subsequent translunar injection boost were provided by the S-IVB third stage.
STAGE SEPARATION
A camera mounted aboard a reconnaissance EC–135 N U.S. Air Force airplane photographed the separation of Saturn V first stage (S–IC) in the early moments of the Apollo 11 launch. The image shows the mated Apollo spacecraft and the Saturn V second and third stages pulled away from the expended first driving section.
9 INTERSTAGE RING This interstage ring was discarded when the S–II
stage ignited.
10 S–IC FIRST STAGE
The five F-1 rocket engines of the
S-IC first stage burned at liftoff and blasted the Saturn V up to 38 miles in altitude. The stage operated for 150.7 seconds and consumed its propellant at a rate of 2100 gallons per second.