Why in news?
ISRO has successfully placed a GSAT-6 communication satellite on board GSLV D6 in the intended orbit which will be eventually manoeuvred into the final geostationary orbit.Details:
Source: The Hindu |
About GSLV D6:
- GSLV, or Geosynchronous Satellite Launch Vehicle, is an advanced launch vehicle that can be used to carry satellites heavier than 2000-kg, even those weighing up to 5000-kg, into space.
- ISRO has been banking on this to realise its future projects to explore deep space, far beyond even Mars where it has already reached.
- Technical details:
- 3-stage heavy weight rocket:
- First stage : fired with solid fuel while the four strap-on motors by liquid fuel.
- Second stage: liquid fuel
- Third stage: cryogenic engine -
- indigenous cryogenic upper stage (CUS)
- Cryogenics:
- GSLV’s higher capabilities, as compared to the PSLV or Polar Satellite Launch Vehicle that has made 28 successful launches in a row, is made possible by a the cryogenic part of the three-stage engine.
- Cryogenics is the science of extremely low temperatures.
- The cryogenic engine uses liquid oxygen and liquid hydrogen as propellants.
- Oxygen liquifies at -183 degree centigrade while hydrogen exists in liquid stage below -253 degree centigrade.
- The cryogenic engine is extremely efficient, providing greater thrust for every kilogram of propellant used as compared to solid or “earth-storable” liquid propellants.
- But it is also a highly complex system owing to the extremely low temperatures that need to be maintained.
- Success:
- The first successful flights of GSLV used Russian-made cryogenic engines, including the GSLF-F04 that carried the heaviest-ever satellite launched from the Indian shores, the INSAT-4CR that weighed 2130 kg, 13 kg more than GSAT-6.
- This launch is the 9 time ISRO was using GSLV rocket, this is the third time the rocket was being launched with indigenous cryogenic upper stage.
- ISRO’s initial attempts to use its own cryogenic engine in the GSLV resulted in failure.
- It was only in January last year that the first GSLV with an indigenous cryogenic-stage engine made a successful flight.
About GSAT-6:
- The GSAT-6 satellite that will beam communication signals from
- 5 slots in the S-band and
- 1 in the C-band
- for “strategic purposes” will be placed in the geostationary orbit.
- GSAT-6 will provide S-band communication services in the country.
- This system also includes a first-of-its-kind S-Band unfurlable antenna with a diameter of six metre. This is the largest antenna ISRO has ever made for a satellite.
- In this orbit, 36000 km above the earth’s surface, a satellite appears stationary from any point in the earth because the time it takes to go around the orbit is the same as earth’s rotational period.
- Ground stations can remain permanently pointed to the satellites in this case and do not need to move to track them.
- The launch vehicle will carry the GSAT-6 satellite till the geostationary transfer orbit (GTO) from where the satellite will use its own propellants to make its way to the geostationary orbit.
- GSAT-6 is the 25th communication satellite that India will put in the geostationary orbit and the 12th in the GSAT series.
Significance:
- GSLV-D6 flight is significant since it intends to continue the testing of CUS
- Foreign exchange can be saved by launching communication satellites on its own
- Currently done by European space agency Ariane.
- More indigenisation --> more industries --> more jobs --> more employment --> more growth
A l s o , t h i s i s t h e f i r s t t i m e a G S L V r o c k e t w i t h a n i n d i g e n o u s C U S h a s c r o s s e d t h e t w o - t o n n e p a y l o a d m a r k - ISRO has not had a single launch failure in four and a half years, a fact that boosts the confidence level and morale of the scientific fraternity in the country.
- The record also buttresses the image ISRO commands in the realm of space launches, especially given that other global players are not very generous with technology transfers.
Critical Analysis:
- However, earning the ‘operational rocket’ tag for the GSLV-Mk-II following the two consecutive successful launches will not immediately mean much, as most of the communication satellites ISRO currently makes are beyond the GSLV-Mk-II’s two-tonne capability.
- India’s dependence on foreign space agencies to launch those heavier satellites will continue till the GSLV-Mk-III is tested and declared operational.
- The GSLV-Mk-II, at most, can save money on our own launches but it is not a revenue-earner yet.
- The INSAT-4A weighing over 3 tonnes was designed way back in 2005 by ISRO, and the GSLV-Mk-II has cleared 2 tonnes only a decade later.
- As global trends reflect an increase in the size of communication satellites and a reduction in the size of earth observation satellites, rocket-making should aim to match future requirements besides being cost-effective.
- For India, a developing country, every rupee spent has to be worth it.
- ISRO will require more flawless Mk-II launches to understand GSLV behaviour adequately and develop the requisite confidence and expertise.
- But the paucity of launch pads might still limit the process.
- While the Mars mission and the experimental crew capsule mission are feathers in ISRO’s cap, making rockets for satellites should be the priority.
- Even as ISRO expands its capabilities, how soon it would achieve true self-reliance will be a crucial factor.
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