III, additional facilities were set up at SDSC. A new plant (SPP) is set up to process heavier class boosters with 200 tonnes of Solid propellant. The static test complex is being augmented for qualifying the S-200 booster. Other new facilities include a Solid Stage Assembly Building, Satellite Preparation and Filling Facility and Hardware Storage buildings. The existing liquid propellant and cryogenic propellant storage and filling systems, Propellant Servicing Facilities will also be augmented. The range instrumentation system will be enhanced further. SDSC also has a S band Doppler weather radar that contributes to India Meteorological Department radar network and serves as a stand-in for Doppler weather radar in Chennai. ISRO opened a viewing gallery at the Satish Dhawan Space Centre in March 2019. The gallery faces the two launchpads and can accommodate 5,000 people giving the general public the opportunity to witness rocket launches. The launch of PSLV-C45 on 1 April 2019 was the first launch that allowed spectators into the gallery. Launch pads SLV3 Launch Pad The SLV3 Launch Pad began operation in 1979 and was decommissioned in 1994. It was used by two launch vehicles of the ISRO: the Satellite Launch Vehicle (SLV) and the Augmented Satellite Launch Vehicle (ASLV). Initially it was built for launching SLV-3s but was later also used as an ASLV launch complex. The first launch from this pad occurred on 10 August 1979, and was that of the first experimental flight of SLV-3 carrying the Rohini Technology Payload satellite. The last flight was of ASLV on 4 May 1994 carrying SROSS-C2. First Launch Pad The First Launch Pad began operation in 1993. It is currently used to launch the Polar Satellite Launch Vehicle, and formerly used by the Geosynchronous Satellite Launch Vehicle. It is one of two operational orbital launch pads at the site, the other being the Second Launch Pad, which opened in 2005. The first launch from this pad occurred on 20 September 1993, and was the maiden flight of the Polar Satellite Launch Vehicle carrying the IRS-1E satellite. The maiden flight of the Small Satellite Launch Vehicle also occurred from this pad on 7 August 2022. The First Launch Pad is undergoing major expansion with PIF (PSLV Integration Facilities) project worth . Once complete, the first launch pad is expected to cater to around 15 launches per year. Second Launch Pad The Second Launch Pad was designed, supplied, erected