Polar Satellite Launch Vehicle (PSLV)
Polar Satellite Launch Vehicle (PSLV) can carry 1 ton class spacecraft in 900 Km sun synchronous orbit. The PSLV is a four stage vehicle adopting solid and liquid propulsion systems.
The first stage motor has 2.8 m diameter. The first stage propellant casing is made of maraging steel. 139 tons of HTPB solid propellant is used in first stage of PSLV vehicle. This stage also has six numbers of strapon motors derived from SLV programme. The control of first stage is done by adopting multi-port SITVC system.
The second stage is a liquid stage. It uses N2O4 as the oxidiser and UDMH as the propellant. The fuel and propellant are stored in 2.8 m dia tankages. It has a Vikas engine generating a thrust of 75 tons.
The third stage of PSLV is also a solid motor. It is carrying 7 tons of propellant. The third stage motor case is made out of Kevlar composite materials and it uses a flex nozzle control system.
The fourth stage is a liquid stage using N2O4 as oxidizer and MMH as propellant . It have two engines of 7 kN thrust. The tankages are made of titanium alloy.
The vehicle equipment Bay is housed around the 4th stage which consists of vehicle onboard navigation, guidance and control system, Power system etc.
The spacecraft is interfaced with the payload adaptor with merman band separation system.
The first successful launch of PSLV took place on October 15, 1994 carrying Indian Remote Sensing Satellite of 900 kg mass. This was followed by number of successful launches of PSLV for IRS missions including that of carrying multiple spacecraft in the same launch. PSLV is an operational system which can carry LEO/ SSPO/ GTO missions in a cost effective manner.
The overall lift-off mass of the vehicle - 297 tons
Payload capacity of PSLV :
Low Earth Orbit (LEO) - 3.5 tons
Sun Synchronous Polar Orbit (SSPO) - 1.6 tons
Geo Transfer orbit (GTO) - 1 ton.