JANNAF Lessons Learned Panel Discussion

The difference between the AS-510 observed and predicted separation distance is attributed to a greater F-1 engine "tail off" impulse than that used in the separation distance prediction. . The F-1 thrust decay was normal and not appreciably different from previous (AS-505 through 509) flights. . Analysis indicates that with an S-IC stage having only four retro motors, failure of one retro motor to ignite would result in marginal separation distances and, in the 3-sigma case, re-contact of the two stages. . S-IC-11 and subsequent flight stages were equipped with eight retro motors rather than the planned four.