Prakash Chandra
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| GSLV MK-III |
To paraphrase a famous quote, it may have been one small step in launching rockets, but a giant leap for a country’s space ambitions. The debut experimental flight of India’s Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk III) on Thursday must have dispelled whatever doubts that lingered in the minds of India’s space scientists about their flagship launcher’s capabilities. For, India’s most powerful rocket was yet to prove its reliability, having failed in four of its previous seven flights.
The Mk III did not launch any satellite. Instead, the 630-tonne rocket carried aloft the hopes of Indian Space Research Organisation (Isro) scientists as they validated its flight parameters and stability during its suborbital hop of the planet at a height of around 126 km.
The success of this launch is crucial for two reasons. One, Isro plans to send two astronauts into space at some point as part of its human space flight programme, an ambition that hinges on an effective Mk III lifting a manned spacecraft to low Earth orbit (LEO). A prototype of the 3.65-tonne crew module to be used for India’s first manned mission rode on the Mk III on its maiden experimental flight on Thursday.
Manned space flight capability will enable India to enter an advanced field where there are few competitors, especially given Isro’s credentials as a unique organisation where the return on investment is very high. Even on a modest budget, the space agency has achieved so much. At some point, privatisation of India’s space sector could lead to a further lowering of costs, which would enable Isro to even compete in space tourism.
The second reason is that only a reliable Mk III booster, which can deliver four-tonne payloads to geosynchronous transfer orbit (GTO), will help India capture a sizeable chunk of the global satellite launch market. The GSLV now needs just one more test flight to become commercially operational and enter the niche market for four-tonne satellites, currently the exclusive preserve of American space boosters and the European Space Agency’s Ariane rockets. The biggest challenge before Isro in operationalising the Mk III and achieving these two goals is the development of an indigenous cryogenic engine, which is crucial for the Mk III.
Cryogenic engines use fuels like oxygen and hydrogen in liquid form — stored at extremely low temperatures —to produce enormous amounts of thrust per unit mass (engineering parlance for the mass of fuel the engine requires to provide maximum thrust for a specific period such as, say, pounds of fuel per hour per pound of thrust). Rockets powered by cryogenic motors, therefore, need to carry much less fuel than would otherwise be required.
But developing a cryogenic engine from such propellants is a huge challenge, and India’s indigenously developed cryo engine is still some way off. For Thursday’s launch, the Mark III carried a dummy cryo engine with inert nitrogen to simulate the characteristics of the actual flight version. The launch otherwise tested the performance of the rocket —avionics, stage separation, etc — and the re-entry characteristics of the crew module. No engine was fired at the third stage.
India’s space engineers can be justifiably proud of standing up to the exaggerated jitters of the world’s most advanced space-faring nation in the early 1990s — that India might use its space launch capabilities for military purposes. (At that time, under US pressure, Russia reneged on its original deal to transfer cryogenic technology to India, forcing India to buy off-the-shelf cryo engines from Russia.)
But now that Isro has developed its own cryo engine that will be testflown on the GSLV’s next flight, it can put the unpleasant past firmly behind it and literally aim for the stars. There is a long way to go, though, before Mark IIIs routinely hoist fourtonne and heavier payloads to GTO.
Rockets belonging to the Mk III class are the workhorse launchers for US, Russian, European and Chinese space agencies. The future of the global satellite launch market is all about communication satellites, and it is imperative for Isro to augment its launch capability constantly to compete with powerful rockets like the European Ariane and America’s Delta and Atlas that dominate the business of heavy-lift launchers.
An operational Mk III will even give Isro the capability to build an orbiting space station. The space agency, however, cannot afford to ignore the fact that by then, other players would probably have saturated the market and pushed the bar still higher.
Courtesy : Economic Times
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