POGO STIX

A major developmental problem of the Saturn V's first stage was the so-called "pogo effect." This resulted from inconsistent ignition of the fuels when mixing in the F1 engine combustion chambers. On Apollo 10, the vibration became so pronounced that the astronauts could not focus on their instruments, and considered aborting the flight!

Here we see a memo regarding the pogo effect and the potential damage to the descent stage of the Lunar Module. Penned by Sam Phillips, the Apollo Program Director, it came just eight days before the launch of Apollo 11, the first critical use of the LM.

The last few days have found me increasingly busy doing publicity for "Missions to the Moon" and Apollo 11. Saturday, July 18, I'll be doing two talks at Griffith Observatory in Los Angeles. Stay tuned.