An anxious Indian space establishment is keeping its fingers crossed over the launch of its new and most powerful rocket on June 5.
On that evening, the indigenous GSLV-Mark III makes a bid to breach a heavy-lift rocket club that can put four-tonne satellites into space. The U.S., Russia, Europe, China and Japan are already there.
The first development vehicle, called GSLV-MkIII D-1, is slated to fly from the Satish Dhawan Space Centre at Sriharikota at 5.28 p.m., says the Indian Space Research Organisation.
The success of the first full flight of Mk III will mean that soon, Indian communication satellites can be lofted into space from within the country. It will also improve ISRO’s ability to reach heavier satellites to both — the higher geostationary transfer orbit or GTO of 36,000 km; and to low-Earth orbit or LEO of up to 800 km.
ISRO Chairman and Secretary, Department of Space, A.S.Kiran Kumar, told The Hindu, “MkIII should enable us to launch communication satellites totally in India without going out. That is the primary aim.”
“We are improving our capacity to put higher payloads into GTO and LEO. What we now have with MkII is capability for lifting 2.2 tonnes to GTO. This rocket will give us a higher weight capability than what we now have, for both GTO and LEO. Since 1995, we launch all Earth observation satellites [which are smaller] ourselves on the [lighter lifting] PSLV rocket. Once we are through with GSLV MkIII, we will be able to launch all communication satellites ourselves.”
Independence apart, an indigenous launch vehicle also means lower cost of putting spacecraft to orbit, said K.Sivan, Director of the lead rocket development centre, Vikram Sarabhai Space Centre, Thiruvananthapuram.
Larger payload soon
The first payload, communication satellite GSAT-19, however, has been kept below 4 tonnes — at a safe 3,136 kg. “We will subsequently increase the payload,” Mr. Kiran Kumar said. Communication spacecraft are generally put into GTOs first (the orbit is adjusted over days.)
The need for a 4T launcher has become urgent in recent years. The first and second generation Indian communication spacecraft used until the late 1990s were around 2,000 kg (two tonnes) with about 24 transponders. Today they are over 3 tonnes and carry more transponders.