The Indian Space Research Organization has managed a successful test of its home-developed Cryogenic upper stage for the The Geosynchronous Satellite Launch Vehicle Mark III. GSLV MkIII is launch vehicle developed by the ISRO for use in its missions.

The tests took place at the ISRO propulsion complex situated at Mahendragiri, Tamil Nadu. The tests were quite comprehensive and saw the C25 cryogenic stage put through its paces for a total duration of 640 seconds, or in excess of 10 minutes. This is the second test of the C25, with the first one — that saw the cryogenic stage in action for 50 seconds — taking place in January.

With this test, ISRO has gotten itself even nearer to the first development flight of the GSLV MkIII. Before stage development hot tests, three CE20 engines were realized and two were tested in sea level conditions. While these tests included an 800 second hot test, the third engine was tested in high altitude conditions for a total of 25 seconds.

Hot test, in case you are unaware of the term, is a type of test that is typically performed to determine factors like efficiency and drivability, and for the evaluation of the  quality of production. Meanwhile, this latest test is specially significant as it is the last one to be performed before the GSLV MkIII is sent on its first development flight. The vehicle is capable of launching four ton class of satellites into the Geosynchronous Transfer Orbit.

In case you are unaware of it, a geosynchronous transfer orbit (GTO) is an elliptical orbit that has a high point of 35,784 km as compared to a low point of a few hundred km. These orbits have an inclination roughly equal to the latitude of the launch site itself.


Meanwhile, using liquid Oxygen and Hydrogen as its fuel, the C25 stage is the most powerful upper stage to be developed by ISRO. It was not easy developing the stage — considering that merely the propellants weighed over 35 tonnes and needed to be stored at temperatures as low as -353 degree Celsius. However, the research organization managed the feat and the upper stage is now ready for deployment with the GSLV MkIII

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