Complex sentence: A plastic liner was added to the LOX turbopump to prevent friction rubbing, in addition Atlas 113D, the booster used for Wally Schirra's flight, was given a PFRT (Pre-Flight Readiness Test) to verify proper functionality of the propulsion system.
Split into simpler sentences: A plastic liner was added to the LOX turbopump to prevent friction rubbing. In addition Atlas 113D, the booster used for Wally Schirra's flight, was given a PFRT (Pre-Flight Readiness Test) to verify proper functionality of the propulsion system.