posted 07-19-2019 10:54 PM               

What do I see? I see two human beings encased in a spacesuit with the most sophisticated, the most complex and the most technologically advanced life support devices designed in the 1960s to keep human beings alive on the surface of a place where no man had ever been before, a place where there is no breathable air, a place where temperatures can range from approximately +250 degrees in sunlight to -250 degrees.

The devices on the backs of Apollo 11 astronauts Armstrong and Aldrin can be seen without their protective covers in the below photo. You have to be totally amazed at what you are looking at! These devices that we call the Portable Life Support System (PLSS) and the Oxygen Purge System (OPS) accomplished their intended purpose of keeping our two Apollo 11 astronauts alive on the surface of the moon while they successfully carried out their historic mission.

I am proud to say that I was the engineer responsible for the final testing of these incredible devices before they were accepted for their intended mission to the moon.

posted 07-20-2019 11:54 PM               

Fifty (50) years ago on July 20th, 1969, I was both extremely nervous and proud to be an American as Neil Armstrong slowly and carefully crawled through the open Lunar Module (LM) hatch on to the LM porch and then step by step down the LM ladder to the lunar surface below.

Would the technologically complex Portable Life Support System (PLSS) perform as expected operating to design specifications. As Apollo 11 PLSS/OPS Mission Manager, I was responsible for conducting the PLSS final testing before the historic Apollo 11 flight for both Armstrong's and Aldrin's PLSS. Testing began on June 23, 1969 and was completed July 10th, 1969 just six days prior to Apollo 11 launch.

During testing of both Armstrong's and Aldrin's PLSSs, there were previously undiagnosed issues and out of specification issues that had to be resolved by either procedural changes and/or component repairs or replacement. I have to admit that all of us involved in the final PLSS testing before flight considered PLSS failure scenarios that no one talked about but that we all thought about.

Knowing the complexity of the PLSS and possible failure scenarios, how could we not be extremely nervous. After all, the PLSS had to pressurize the spacesuit, provide pressure regulated breathable oxygen, circulate cool water through the suit, re-cool the water, remove exhaled carbon dioxide, remove body odors, control suit humidity, provide voice transmission between the earth and moon, provide telemetry transmission of bio-medical data to earth, provide telemetry transmission of PLSS functional performance data to earth, provide suit pressure and oxygen pressure readouts (transducers), ventilation oxygen flow sensor readout, oxygen temperature readout, oxygen pump and water pump functional capability. pressure relief valve capability, out of specification warning alarms and many other detailed functional capabilities.

After PLSS testing was complete and all problems addressed, I was the engineer that signed my name to the test document declaring that both Armstrong's and Aldrin's PLSSs were "acceptable" for their intended purpose, i.e. keeping both Apollo 11 astronauts alive while they performed their assigned tasks on the moon.

As we now, of course, know, both Armstrong and Aldrin's Portable Life Support System (PLSS) backpacks performed perfectly. I was both thrilled and relieved and thanked everyone involved that contributed to the operational success of the astronaut Portable Life Support Systems!