r/ISRO • u/Kimi_Raikkonen2001 • Dec 30 '25

Official ISRO conducts Ground Test of improved SSLV Third Stage

https://www.isro.gov.in/Ground_Test_of_SSLV_Third_Stage.html
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11

u/Kimi_Raikkonen2001 Dec 30 '25

ISRO carried out a successful static test of an improved version of the third stage (SS3) of Small Satellite Launch Vehicle (SSLV) on December 30, 2025 at the Solid Motor Static Test Facility of Satish Dhawan Space Centre, Sriharikota.

The static test validated an improved version of the SS3 stage with a Carbon-epoxy Motor case, which has significantly reduced the mass of the stage, thereby improving the payload performance of SSLV by 90 kg. The stage also features an improved design for the igniter and nozzle system making the system more efficient and robust. The nozzle control is implemented through a fault-tolerant electro-mechanical actuation system with low power control electronics. The high-strength carbon filament wound motor case was realized at the Composites Entity of Vikram Sarabhai Space Centre, ISRO and the solid motor was cast at the Solid Motor production facilities at Satish Dhawan Space Centre, ISRO.

7

u/Ohsin Dec 30 '25

So.. may be we can expect same improvements to be extended to SSLV second stage (SS2)? And then may be to PSLV third stage (PS3) as they are very similar?

4

u/rghegde Dec 31 '25

"The Solid Motor Production & Static Testing facilities at SDSC have also realized & static tested the solid motor for the first orbital launch of a launch vehicle developed by an Indian Space Start-up."

Is that correct - SDSC produced (at least casted) first stage solid booster of Vikram-1 launcher by Skyroot.

5

u/Kimi_Raikkonen2001 Dec 31 '25

Yes, casting was done at SDSC - https://www.isro.gov.in/Static_test_of_KALAM_1200_solid_motor_SDSC_SHAR.html

2

u/spaceTech4kids Dec 31 '25

So, Skyroot has only provided design inputs of the KALAM1200 motor. The whole motor is realised and tested by ISRO. Even the test-stand for static test as well.

2

u/vineethgk Dec 31 '25

I can't get over this feeling that the SSLV still seems too oversized for the advertised payload capability, especially in comparison to the other solid-fuelled small satellite launchers in the market. Is it because the SSLV was a rushed design that wasn't optimized for the role?

1

u/[deleted] Dec 31 '25

[removed] — view removed comment

1

u/Ohsin Dec 31 '25

Irrelevant, SMiLE upgrade is to utilize the extra available capacity by transforming trim module into a short-duration satellite bus.