Original sentence: Construction began in 1959 and the site was accepted by NASA to support the Saturn IB program in 1963.LC-37A has never been used, but LC-37B saw unmanned Saturn I and IB flights in the mid sixties, including the first (unmanned) test of the Apollo Lunar Module in space
Edited sentence: Construction began in 1959 and the site was accepted by NASA to support the Saturn I program in 1963.LC-37A has never been used, but LC-37B launched unmanned Saturn I flights and was modified and launched Saturn IB flights in the mid sixties, including the first (unmanned) test of the Apollo Lunar Module in space