Radhakrishna Rao / Bangalore
Tests continue on new cryogenic engine to allow replacement of underperforming Russian upper stage
The Indian Space Research Organisation (ISRO) aims to replace the Russian upper stage of its geosynchronous satellite launch vehicle (GSLV) with a new indigenous cryogenic engine as early as the fourth flight of the launcher.
"In the next one and a half years we will go through a series of tests on the engine. Our plan is that by the fourth or fifth flight of the GSLV we could use the Indian cryogenic engine," says Dr Kasturirangan, ISRO chairman.
The 401t three-stage GSLV made its inaugural flight in April. However, because the Russian cryogenic upper stage of the rocket underperformed, it left a 1,450kg (3,200lb) G-SAT-1 experimental communication satellite in an orbit lower than the one planned.
The satellite could not be moved to its final location in geosynchronous orbit, which means it cannot be used for the range of communication experiments it was originally intended for.
ISRO's Cryogenic Upper Stage Project was launched in 1994 to design and develop an Indian cryogenic engine. The engine will carry 12.5t of liquid oxygen and liquid hydrogen. The first firing of the engine was carried out in February 2000 and tests are continuing.
The first two stages of the GSLV are derived from India's Polar Satellite Launch Vehicle and both feature a combination of liquid and solid fuel systems. The first stage of the GSLV employs a 129t solid propellant core motor with four liquid propellant strap-on motors. The second stage is a liquid propulsion system.
The Russian upper cryogenic stage of the rocket, which will be replaced, carries 12t of liquid oxygen and liquid hydrogen fuel.
The GSLV is designed to allow India to launch its Insat domestic spacecraft series into geosynchronous transfer orbit. Insat satellites are currently launched by Ariane boosters.
Source: Flight International
