“Nothing Succeeds like Success” said the French writer Alexandre Dumas, and scientists from the Indian Space Research Organization (ISRO) couldn’t agree more.
Scripting another success story, “The Indian Space Research Organization (ISRO) successfully tested its indigenously developed Cryogenic Upper Stage (CUS) for GSLV MkIII on February 17, 2017. The cryogenic stage designated as C25 was tested for a flight duration of 640 seconds at ISRO’s Propulsion Complex (IPRC) in Mahendragiri. The C25 Stage had earlier been tested successfully for 50 seconds on January 25, 2017 to validate all the systems,” said an official release from ISRO.
In what is slated to be ISRO’s biggest satellite launch in its history, the Indian space agency is looking to launch a 3.2 ton satellite – the GSAT 19E – soon, from its spaceport the Satish Dhawan Space Center (SDSC) at Sriharikota.
The GSAT satellites are India’s indigenously developed technologies of communications satellites, used for digital audio, data and video broadcasting.
Hence, the recent successful C25 test is a significant milestone in the annals of ISRO, as it is the last in the series of engine and stage development hot tests before the first development flight of the GSLV MkIII.
The Salient Features of ISRO’s Cryogenic Upper Stage (CUS) – The C25 (source ISRO)
• The C25 stage uses Liquid Oxygen (LOX) and Liquid Hydrogen (LH2) propellant combination.
• The stage carries 27.8 tons of propellants loaded in two independent tanks.
• Development of a cryogenic stage has unique design challenges, with liquid Hydrogen stored at -253 deg C and liquid Oxygen stored at -195 deg C in its tanks. To store these cryogenic fluids, special multi-layer insulation is provided for the tanks and other structures.
• The C25 has a length of 13.5 m (44 ft), diameter 4.0 m (13.1 ft); propellant mass of 27,000 kg (60,000 lbs); one Engine: the C20; thrust developed 200 kN; specific impulse: 443 secs; burn time: 586 secs.
• A large team of ISRO scientists have worked on the design, development and testing of the C25 CUS, they were led by the Liquid Propulsion Systems Centre (LPSC), Mahendragiri, with support from various system development agencies from other ISRO centres like Vikram Sarabhai Space Centre, Trivandrum, ISRO Propulsion Complex, Mahendragiri and Sathish Dhawan Space Centre (SDSC), Sriharikota.
ISRO says that, “the flight cryogenic stage is in advanced stage of realization, and forms the upper stage of GSLV MkIII the next generation launch vehicle of ISRO, capable of launching 4 ton class satellites into Geosynchronous Transfer Orbit. The vehicle consists of two solid strap-ons (S200), motors, one earth storable liquid core stage (L110) and the Cryogenic Upper Stage (C25).” It also adds that, “The GSLV MkIII vehicle-integration activities are in progress at SDSC, SHAR for its first development flight (GSLV MkIII-D1) targeted for April 2017”.