This paper tackles the problem of time synchronization for the mobile extension of DVB-S2/RCS air interfaces. To increase robustness against other system interference, Direct Sequence Spread Spectrum (DS-SS) is selected, which calls for efficient code acquisition. Designed to operate jointly with frame synchronization, a novel high level control logic is proposed for code acquisition, along with robust detectors to cope with the large frequency uncertainty experienced at terminal start-up. The results show that the mean acquisition time is always limited to a few milliseconds, allowing fast acquisition even in the most challenging railway scenario.