Tuesday, December 22, 2009
Ground-firing of S200
ISRO is supposed to take the first step towards the launch of GSLV-Mk III by ground-firing the S200 booster in January, 2010. S200 is a major component of the Mk-III, providing the thrust at lift-off of the launch vehicle.
The S200 is the third biggest solid booster of any launch vehicle in active service, after the space Shuttle's SRBs and Ariane-5's EAP. This in a way shows that India is going beyond what was historically thought to be a Soviet-based space program. It's a matter of fact that Soviet and soviet based programs like the Chinese, never use solid propellent on their heavy-launch vehicles. Whereas, it's the western space programs that are famous for their extensive use of solids in heavy-lift vehiclea and crew-launch vehicles.
The S200 is a expendable stage carrying 200 tons of propellant with a lenght of 25 m and diameter of 3.2 m. The thrust at liftoff should be around 7000 kN. But, the average thrust output should be around 4500 kN to go with the stated burn-time of 103-104 seconds.
The ground-firing of the S200 will mark the successful development of 2 stages of the Mk-III, viz the L110 and the S200. The C25 is the final stage that remains. According to reports, ISRO has already finalized the design of CE-20 and that the process of fabrication also seems to have started. Once the engine is completed, its will be tested extensively following which there will be full-stage firing of the C25 stage.
Althought ISRO has quoted a launch of 2011 for the Mk-III, it would be an almost improbable task given the status of the upper stage. Fabrication to certication normally takes around 2-3 years. So, it would be safe to assume that the probable launch date of Mk-III would more-likely be 2012-13.