Space Transportation system includes the satellite launch vehicles to place satellites like I NSAT and IRS Bnd scie ntific satellites in the requisite orbits as well as the sounding rockets for carrying out short duration scientific experiments. India made a modest beginning in this area with the launch of a 75 mm diameter sounding rocket in 1963 for investigation of ionosphere over the gee-magnetic equator over Thumba, near Thiruvananthapuram. Since then, India has established a s ubstantial capability in the design, development and operationalisation of a series of sounding rockets for scientific investigations, Polar Satellite Launch Vehicle, PSLV, for launching Indian remote sensing satellites and Geosynchronous Satellite Launch Vehicle, GSLV, for launching geo.stationary communication satellites.