Apollo Expeditions to the Moon



About eighty percent of the people on these teams worked for the contractors; the rest were NASA employees. All of them had to go through examinations. We'd call a man in - say a swing-arm console operator - before a board of three or four examiners and we'd have his part of the mission simulated on a console. He would have five minutes to get set, before making split-second decisions. We'd say, "Okay, here's your console, and here's your condition." The examiners would move a red-green slide, or put a yellow light on. The operator would look at the simulation on his console, and say, "Okay, that's green, and it means the pressure is okay; that's red and it means the pressure is too low." Dozens of other simulators would test his proficiency. We had to make sure. We had to be able to say "We understand the problems, we've done the detective work; we've found the solution and we've tested it, and we have confidence everything will work".

Photo of Apollo 17 lunar module and Lunar Roving Vehicle Checkout and assembly of the Apollo 17 lunar module in a clean room of the Manned Spacecraft Operations Building. In the foreground, the Lunar Roving Vehicle is undergoing its final checkout (with Astronauts Schmitt and Cernan aboard) prior to being packaged and stowed into the descent stage of the lunar module.

In our testing we had a building block approach, very logical, very methodical; you built each test on the last test, and the whole sequence expanded in the process. Everything culminated in the two main tests, Flight Readiness and Countdown Demonstration. Flight Readiness would take us through the total flight, including an abbreviated trip to the Moon, with all the valves working, all the sequences following according to the logic we had worked out for them. It was a total test of the electrical system and the software.

Photo of Petrone,President Lyndon Johnson, and Chancellor Ludwig Erhard
The newly completed Launch Complex 39 attracted many VIPS. Here Petrone briefs President Johnson and Chancellor Ludwig Erhard of the Federal Republic of Germany in 1966 on the characteristics of the Mobile Launcher.

The Flight Readiness Test was dry (that is, without propellants) but the Countdown Demonstration Test (93 hours) was loaded with propellants, including several thousand tons of cryogenics in the three stages and tons of RP-1 fuel in the first stage. This one we took right up to the point of 14 seconds before ignition. We had four or five different ways to stop the countdown sequence at 14 seconds, and I would customarily look at Ike Rigell and say "How many stops have we got?". The test had to be stopped at T minus 14 seconds because if it went down to 9 we would activate the ignition sequence. So everybody wore a sort of tense smile when it came to 14 seconds. We never had an accidental ignition, which would have meant chaos. (We did not have the astronauts in the CM during this part of the CDDT.)

Then we would unload the cryogenic propellants and dry out the tanks, which took five or six hours, a little longer than it took to load. Next day we would pick up the count at about three hours and run through the schedule up to simulated lift-off, now with the astronauts on board. It was important for the flight crew to go through this final exercise: to suit up in the Manned Spacecraft Operations Building, get in the vans, ride out to the pad, load into the CM, and check the flight systems.

Photo of Launch Control Center
TV screens and display panels ablaze, Firing Room 2 of the Launch Control Center, adjacent to the VAB, is the hub of activity for the start of Apollo 6's unmanned Earth-orbit mission. Large wall screens show the Saturn V in readiness.

I have often been asked why it took hundreds of men to launch the astronauts to the Moon, whereas just two of them on the Moon can launch themselves back to Moon orbit. Well, the two of them were there on the Moon in the LM's ascent stage. They had everything they needed: their fuel was loaded; they had water; their cooling system was working and so was their oxygen supply. Their radar was tracking and their communications to Earth were functioning, and long before launch we had checked to see that they had no electrical interference. These systems were working because of the preparations and check-out efforts of hundreds of people on the ground before the spacecraft was committed to launch.

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