ISRO looks to get it right on GSLV this time

Even as ISRO successfully launched the Mars Orbiter Mission (MOM), preparations are in full swing for flighttesting of GSLV with indigenous cryogenic engine, a key step to boost the country's confidence in terms of its self-reliance in launch capability, on December 15.

"We have put all our efforts for the development of GSLV," ISRO Chairman K Radhakrishnan said.

"The assembly of GSLV is going on at Sriharikota. It started on October 18. Now, the launch is scheduled for December 15," he added.

The maiden flight testing of the indigenous cryogenic engine and stage conducted in GSLV-D3 on April 15, 2010, failed.

ISRO made another attempt on August 19 this year but the the launch was called off as a leak was observed in the UH25 fuel system of the liquid second stage during the pre-launch pressurisation phase on the vehicle just two hours before the scheduled lift-off.

GSLV is a three stage vehicle. GSLV is 49-metre tall, with 414 tonne lift off weight.

First stage comprises S125 solid booster with four liquid (L40) strap-ons. Second stage (GS2) is liquid engine and the third stage (GS3) is a cryostage.

The cryostage is more efficient compared to the liquid stage in PSLV.

This means that the thrust developed by burning each kg of propellant is higher in cryo engine, hence can place larger payloads with higher weight into orbit.

"Cryo stage as final stage is hence essential for a launcher with higher payload capacity," an ISRO official said.

PSLV is capable of launching 1,600 kg satellites in 620-km sun-synchronous polar orbit and 1,050 kg satellite in geo-synchronous transfer orbit (GTO).

"This poses a serious limitation on launching communication satellites which are heavier. The GSLV will be capable of launching satellites which are 2000 kg - 2500 kg which matches with the GSAT class of Communication satellites," it was noted.

Presently, India is forced to outsource the heavy launch services from abroad which is not a cost-effective solution.

The establishment of a proven GSLV launcher is the need of the hour. The successful development of indigenous cryostage will boost India's confidence in terms of its self-reliance in the launch capability, ISRO officials said.