The “Radioastron” space mission is the unique project of Russian Space Agency (Roscosmos) and Russian Academy of Sciences to investigate the Universe by means VLBI principles implementation with “Spektr-R” space satellite. “Spektr-R” onboard 10-m radio telescope has been operating since 15 November, 2011 as the Space element of the space-ground interferometer at the orbit with its apogee up to 350000 km. The first and the basic step in VLBI observations data processing is correlation. Space-VLBI brings new requirements in correlation process due to significant uncertainties in delay model for space telescope. Radioastron mission correlator is a part of ASL (Astro Space Locator) software package for Windows environment developed in Astro Space Center (ASC) of Lebedev Physical Institute. In this report the main features and operational procedures of the ASC Correlator are described with the emphasis on the Space-VLBI data-processing differences compared to the ground VLBI. Also, a description of time delay and its derivatives calculation algorithm is presented in this report, as well as the procedure of correction for these parameters. This approach is critical for the correlation of space-ground interferometer data. In this report we also show the importance of the orbit accuracy and correlator requirements for the future Space-VLBI missions, such as the “Millimetron” project.