HYDERABAD: ISRO is in the process of further improving the capability of its GSLV-Mk III so that it can use this heaviest rocket for human space flight mission once government approval comes, a top scientist said here.GSLV-Mk III is really the vehicle that will be the workhorse in the coming years for primarily launching geo-synchronous missions and also very heavy spacecraft in near-earth missions, K Kasturirangan , former chief of ISRO, told PTI.The Indian Space Research Organisation (ISRO) earlier this week successfully launched from the Sriharikota spaceport, the first developmental flight of GSLV-MK III, capable of launching four-ton class satellites."ISRO is in the process of further improving the capability of this vehicle. It could go up to a ten-ton kind of capability," said Kasturirangan.It was during his tenure as ISRO Chairman the GSLV-Mk III was configured and the programme secured approval by the Space Commission in the early part of the previous decade."So, this will be a level of vehicle which India will use for most of the requirements of geo-synchronous missions. It can take to up to four tons and, hopefully with improvements in some of the areas, one can go even beyond four tons," he said."With this we want to build our communication satellites. So, it's very tailored for future communication satellites to be launched by India. We will not have to depend on any other foreign launch agency," according to him.Kasturirangan said ISRO is trying to do a "man-rating sort of thing" (or human rating), which is a certification of a spacecraft or launch vehicle as worthy of transporting humans.So as and when there is a need and the country takes a decision on going for human space flight, it would have an "autonomous ability" to access the space through this vehicle in those missions, he said"Certainly, it's a very elegantly-configured system (GSLV-Mk III). I am sure this will certainly serve us for a long time to come in the context of a variety of missions and also make us much more self-reliant in respect to accessing space," he said.On opportunities for ISRO to tap into the market of launching four-ton class satellites from foreign customers, Kasturirangan said: "I am sure India will be one of the important contenders for taking some share of the market. India can provide a competitive market for that kind of launches with GSLV Mk III".But he was quick to add that New Delhi would have competitors from (launch vehicle providers in) France, (some other parts of) Europe, the United States, China and Russia."There are contenders...many of them are established over the years. At this stage, we have to explore the market and slowly get into it," Kasturirangan said.He, however, added that foreign customers find working with Indians for launch services a "very good experience" given their culture and attitude, which are appreciated by many countries.