India’s first Gee-Synchronous Satellite Launch Vehicle (GSLV – Dl) was launched from Sriharekota on April 18,2001. With this launch of GSLV India has become one of the six countries of the world (other being USA, Russia, Japan, China and European Space Agency) that now have the capacity to do this.
The 49-metre three stage GSLV injected the 1540 kg experimental satellite GSAT-1 in Geo Transfer Orbit (GTO) after 1040 second flight. The launch took place exactly three weeks after the March 28 last-second abort reflects not just the mastery of the Indian Space Research Organisation (ISRO) over launch vehicle techniques, it is also a testimony in space to the ability of the organisation that it can quickly and accurately identify its mistakes and correct them.
The launch of GSLV means access to the launch vehicle market that is estimated at $ 5 billion per annum currently. It also means the ability to put up Indian satellite of the INSAT class at a much cheaper cost currently, such satellites that provide transponders for communications and TV channels, are launched by Asian space, the European consortium, or the Russians. India needs tan autonomous space launch capability mostly for military reasons, not for offensive purposes which are banned but for surveillance and communications. So far, India has been laggard in using outer space for military uses.
Beyond surveillance and communications the GSLV-D1 and its predecessor the PSLV, also signal India’s ability to build long-range intercontinental missiles.
These launch of GSLV capped the decade long efforts on ISRO’s Rs. 1,400 crore project. This launch marked a major milestone in Indian space research. These programmes, demonstrating the capability to launch communication satellites into GTO with a perigee of 180 km and an apogee of about 36,000 km. “This paves the way for end-to-end capability of application spacecraft launching in communication area also,” ISRO Chairman Dr. Kasturangan said the GSLV can carry satellites weighing more than a ton and place them in a geosynchronous orbit, which means it goes round earth at the same rate as the planet turns, so the satellite is always over the same point on earth’s surface. To do so, the satellite needs to reach a very high orbit of 36,000 km from earth, which will literally and meta-phorically, be the high point of this launch.
The satellite GSAT-1, carrying three C-band transponders and one S-band transponder, will be used for conducting communication experiments like digital audio broadcasts, Internet services and compressed digital TV transmission. Several new spacecraft elements like improved reaction control thrusters, fast recovery star sensors and heat pipe radiation panels are also being tested on this satellite.
While there is no doubt that Indian space capability has gained a remarkable boost with the GLSV, it would also be necessary to place the latest achievement in perspective. The most important factor to the weighed while evaluating the significance of the launch is that the very crucial cryogenic stage of the launch vehicle is imported. The ability of the GSLV to launch heavier communication satellites presently in vogue would also come under question, especially given the rapid advances made by other agencies. Nonetheless, the success should give the Indian space establishment the confidence to proceed with its own developments in cryogenic technology.