Photo: NASA
Some stories are almost forgotten about Apollo 11’s launch from Pad LC-39A — seemingly small stories that actually had a huge effect on the mission happening as it did. One of those stories concerns a hydrogen leak late in the countdown on the third stage of the Saturn V that was poised to launch on July 16, 1969 – if it had not been remediated, Apollo 11 would not have launched on the day that it did.
Stephen Coester, an engineer on the console that day, has an excellent recollection of the events that morning, and Florida Media Now would like to thank Mr. Coester for allowing us to share them here. Presented in his own words with only light editing for continuity, here is “Apollo 11 Final Countdown LH2 Leak That Could Have Changed History“
Launch Control Staff Member Stephen Coester’s Recollections
“My favorite Apollo memory was performing my final walk down of the LUT just before launching Apollo 11. We were so aware of the enormity of what we were about to do. The MSS (mobile service structure) had been rolled back, revealing the enormous Saturn V in full view. It was after dark and the spotlights were casting their cones of illumination on the stack.
“I was virtually alone on the tower as I examined every component of the LH2 system to be as sure as I could that “my” system would do its job. It was just me and the Saturn V with a bright moon overhead. I would look at the moon, then at the rocket and think, ” I don’t want to be anywhere but right where I am right now.”
Photo credit: Stephen Coester
“Long forgotten is the fact that the Apollo 11 launch was almost scrubbed on July 16. I was assigned to the launch console (C4HU) that maintained a 100% liquid hydrogen level in the Saturn third stage, which was used to propel the astronauts from Earth orbit to the moon. Late in the propellant loading, as we were beginning the S-IVB replenish operation, a large liquid hydrogen leak at -423 degrees occurred on the third stage replenish valve on the 200-foot level of the launch umbilical tower.
“Loading was terminated, and the lines drained to prevent a fire or explosion, and a Red Crew went to the Pad to fix the problem. Using troubleshooting I developed the Red Crew torqued packing and flange bolts and cycled the valve. then we resumed liquid hydrogen flow but were unsuccessful in stopping the leak, which prevented maintaining the 100% fuel level in the Saturn third stage. Without a full tank of liquid hydrogen, there would be no launch.
“Here is the location of the leaking valve (at left.)
“Finally the leak was isolated by freezing the valve by pouring water over it, but that made the critical valve inoperable. We then developed a way to use the large main fill valve which was not intended for that purpose to maintain the level and the launch countdown could finally continue. For several hours another engineer (CPH1) manually cycled the valve from his console as I reported the tank level as it fell below or exceeded 100%.
“See the PCR (procedure change request) that I wrote:
“If we hadn’t controlled the leak and maintained proper LH2 level the moon launch would have been scrubbed for at least July 16 and probably for several days.
Photo: NASA
“I was twenty-eight years old when we landed on the moon, responsible for loading 600000 gallons of LH2 on the “moon rocket.” The managers were in their early thirties, and someone over forty was ‘talk the old man.’ Exciting times!”
In Summary
Exciting times indeed. Mr. Coester and the launch crew of Apollo 11 made indelible world history, and it was their work that made it possible for Neil Armstrong and Edwin “Buzz” Aldrin to take humanity’s first steps on another celestial body some four days later on July 20, 1969. History will always remember Armstrong, Aldrin and Command Module pilot Mike Collins, of course, but it should always remember the names Coester and so many other as well. It truly was a national effort.
Florida Media Now would like to salute Mr. Coester and every person still living who helped the US launch the most important mission in space exploration thus far.
Video of Inside the Launch
Fran Blanche, a noted film historian, assembled this video of what it looked behind the scenes that day. This is well worth watching.
Note: this story was originally published in Talk of Titusville by the author.
