Chennai: Development of GSLV Mk II, the next version of India's prestigious Geo-synchronous Satellite Launch Vehicle (GSLV) has made substantial progress with its engine having already undergone full flight duration ground test, according to Indian Space Research Organisation (ISRO).

GSLV Mk II, which will have a Cryogenic third stage developed by ISRO indigenously instead of the imported Russian cryogenic stage used in the two successful developmental flights of GSLV Mk I, will have a capability to launch up to 2.5 tonnes of satellites into Geo-synchronous Transfer Orbit (GTO), the latest edition of "Space India", the official journal of ISRO says.

The initial version GSLV Mk I is already operational after its two successful developmental flights in a span of two years (the latest one on May 8, 2003) is now available for launching satellites of up to two tonnes into GTO.

GSLV Mk II will enter into service after just one developmental flight, the schedule for which is yet to be finalised.

PTI