Search the Internet          Tips

Countdown for GSLV's re-launch commences

A SHAR spokesman said the countdown was progressing 'smoothly with all systems working perfectly', adding that if everything goes well, GSLV-D1, using a cryogenic engine for the first time, will soar into the skies at 1543 hours on Wednesday. The launch will be telecast live by Doordarshan.

However, the launch window extends up to 1930 hours so as to facilitate any last minute adjustments in the exact launch time.

The lift-off of the newly developed GSLV, carrying an experimental communication satellite GSAT-1, got automatically aborted on the original test launch attempt on March 28 last when one of the four liquid strap on engines could not develop the required thrust on ignition.

A detailed analysis revealed that a defective plumbing in the oxidiser flow line of the strap-on engine caused the mission to be aborted. The launch was re-scheduled after successfully replacing the defective strap-on engine with a standby one, he said.

GSLV-D1, the first developmental flight of GSLV, is primarily intended to validate the vehicle design and its performance parameters as well as the associated ground infrastructure.

The experimental communication satellite on board GSLV-D1 carries three C-band transponders and two S-band transponders.

The launch sequence begins with ignition of the four liquid strap-on engines. The core solid propellant stage will be ignited 4.6 seconds later after the strap-ons are declared normal.

This stage will burn for 100 seconds while the strap-on stage will last for 160 seconds by the end of which the vehicle would have attained an altitude of about 73 km from the earth.

The second stage ignites 1.6 seconds before separation of the first stage and burns for about 150 seconds and falls off at about 127 km above the earth.

The most critical cryogenic stage, which is the third and final one, containing liquid oxygen and hydrogen burns for about 710 seconds generating the required injection velocity of 10.2 km per second to place the satellite into the Geo-synchronous Transfer Orbit (GTO) exactly 1040 seconds after lift off.

At least 150 critical events have to be gone through during the entire launch sequence ending with the placing of the satellite in the GTO.

A Successful launch of the 410 ton vehicle, the biggest ever developed by ISRO, would mark India's entry into an elite club comprising - United States, European Union, China, Japan and Russia - nations which have already managed to place satellites in the geostationary orbit.

It would also open up tremendous commercial opportunities for India in the highly lucrative multi-billion global satellite launch business.

According to ISRO sources, GSLV is the most technologically challenging space mission so far undertaken by ISRO, especially as it involved experimenting with a cryogenic engine in the third and final stage.

The Rs 14 billion GSLV project dates back to 1991 when India signed an agreement with Russia for supply of cryogenic technology. The project later ran into rough weather with the US imposing certain sanctions against India.

Though the initial flights of GSLV would be using imported cryogenic engines from Russia, ISRO is engaged in developing cryogenic technology for use in future missions.

GSLV will be declared operational after two successful developmental flights. Efforts are already on to increase the payload of GSLV up to 2000 kg and above in about two to three years.

RELATED SPECIALS
'It is technically a good vehicle'
ISRO looks beyond GSLV failure
Reaching for the Skies

Tell us what you think of this report