Why it is not fair to compare GSLV-Mk-3 and Ariane-5?
New Delhi, Feb 21: ISRO's GSLV MK-3 and Arianespace' Ariane-5 are both good launch vehicles in their own right. While India GSLV Mk-3 is a medium-lift launch vehicle, Ariane-5 is a heavy lift launch vehicle which has been operating for many years now.
Most of the Ariane-5s launches are for commercial purposes and in fact it was designed to provide satellite launching services to customers across the globe. Arianespace has carved out a sizeable chunk of the satellite-launching market. Especially when it comes to heavier satellite launch contracts, Arianespace almost commands almost 45-50% of the market share.
ISRO, on the other hand, is a state-backed space agency. It has a mandate from the Department of Space to be India's primary launch-services provider and fulfil the needs of both private entities as well as the government, but government first.
Coming to the launch vehicles, GSLV-MK-3 is fairly new and is designed to carry 4 ton class of satellites into Geosynchronous Transfer Orbit (GTO) or about 10 tons to Low Earth Orbit (LEO). Ariane-5 has been in operation for many years now and can carry payloads weighing more than 10 metric tons to geostationary transfer orbit (GTO) and over 20 metric tons into low-Earth orbit (LEO).
ISRO successfully conducted the first orbital test launch of GSLV-III on 5 June 2017 from the Satish Dhawan Space Centre. Ariane 5 rockets have accumulated 103 launches since 1996, 98 of which were successful, yielding a 95.1% success rate. Between April 2003 and December 2017, Ariane 5 flew 82 consecutive missions without failure, but the rocket suffered a partial failure in January 2018.
So, it would be quite unfair to compare GSLV with Ariane. Also, before comparing anything one should consider where the starting line was. The funding that went into Ariane's development, the R&D budget and technical expertise are all together in a different league when compared to ISRO developing GSLV.
If India has GSLV then why was GSAT-31 launched on Ariane-5?
The probable reason could be this. Launch contracts are often done a couple of years ahead of the launch for such large satellites. Since GSLV Mark III was then technically still in the developmental phase, ISRO might have taken a decision to go with Ariane-5, in case GSLV Mk III development gets delayed. GSLV Mk III is designed to carry 4 ton class of satellites into Geosynchronous Transfer Orbit (GTO) or about 10 tons to Low Earth Orbit (LEO), which is about twice the capability of GSLV Mk II.
GSLV MkIII-D2, the second developmental flight of GSLV MkIII, successfully launched GSAT-29, a high throughput communication satellite on November 14, 2018, from Satish Dhawan Space Centre SHAR, Sriharikota. GSAT-29 satellite weighed 3423 kg, far heavier than GSAT-31.
So, GSLV-MK-3 will be fully operational to carry commercial satellites soon, a crucial step that will enable India's space agency to compete globally in the 3-4 tonne category of satellites.