Ex-chairman of the Indian Space Research Organisation(ISRO) Dr.K. Radhakrishnan offered prayers in the temple of Lord Venkateswara on Thursday morning. At the entrance of the Srivari temple he was accorded warm welcome by Tirumala JEO Sri KS Sreenivasa Raju. Later he offered prayers to the presiding deity of Lord Venkateswara in the Sanctum Sanctorum.