Thor-Delta C, also called Standard Delta, upgraded the three-stage Delta with an AJ10-118D second stage and a higher-thrust Altair A-258 third stage. Ten vehicles flew for NASA from November 1963 through March 1967: eight completed nominal ascents, TIROS 9 reached an unintended elliptical orbit after a launch-vehicle malfunction, and the OSO-C flight failed during third-stage operation.