Designing an Internal Combustion (IC) engine for an automotive itself is not that easy. For decades India was not able to develop its own successful and popularly used car engine, except in 1998 when the indigenous Indian car Tata Indica employed indigenously designed IC engine. The thermodynamics is not an easy science.
The cryogenic rocket engine developed and successfully tested on its real flight by ISRO, for which we all Indian need to be extremely proud of, is easily 1000x complicated compared to the car engine design. It is nothing less compared to Sachin's 100th ton in cricket, or any such off-science achievement India is proud of. Cryogenics is a science which is literally a rocket science and no other engineering task is as tough as this.
Mars-Mission success, though looks more tougher task, in reality GSLV success can enable India to achieve any space mission what others have achieved now. Now India becomes immediately powered with huge capability of sending a robot rover to Moon, Mars or any celestial body and also manned space missions. With GSLV, no need to do all that complicated multiple elliptical orbiting sling shots done with less powered PSLV to send Mangalyaan Mars Orbiter out of earth orbit.
Indigenous GSLV cryogenic achievement deserves etching it on a golden plate and ISRO deserves all the top awards.
We can do another comparison of this technology achievement with India's automotive and semiconductor industry. Tata Indica's success has now resulted into globally competitive Indian automotive industry. Bajaj pulsar bike is also highly successful indigenous two-wheeler. In space too, India sure to benefit economically from GSLV success.
Unfortunately in Indian electronics industry, an important enabler of space technology, we don't have an indigenously developed manufacturing technologies for fabricating semiconductor ICs or any such nanotech devices. India desperately needs an indigenously built advanced semiconductor fab to make electronics manufacturing successful in India. ISRO can help Indian electronics industry in this area which is also beneficial to ISRO's future growth and also to our defense sector.