ISRO Conducts Ground Test of SSLV Third Stage at Sriharikota

Source: Deccan Chronicle

Relevance:
GS Paper III: Science & Technology – Space Technology, Indigenous technology development
Role of ISRO in strategic and commercial space sector

Important Key Concepts for Prelims and Mains:

For Prelims:

ISRO, Small Satellite Launch Vehicle (SSLV), SS3 (SSLV Third Stage), Satish Dhawan Space Centre (SDSC), Vikram Sarabhai Space Centre (VSSC)

For Mains:

Indigenous launch vehicle development, Solid rocket motor technology, Private sector participation in space, Launch-on-demand capability

Why in News?

Indian Space Research Organisation (ISRO) successfully conducted a static ground test of an improved version of the third stage (SS3) of the Small Satellite Launch Vehicle (SSLV) at the Satish Dhawan Space Centre, Sriharikota.

The test marks a key milestone in enhancing payload capacity, reliability, and industrial readiness of SSLV.

Location: Satish Dhawan Space Centre (SDSC), Sriharikota, Andhra Pradesh

About Small Satellite Launch Vehicle (SSLV)

A three-stage, all-solid launch vehicle developed by ISRO.
Designed to:
- Launch small satellites (up to ~500 kg) into Low Earth Orbit (LEO).
- Enable launch-on-demand with quick turnaround time.
- Be amenable to industrial production, supporting private sector participation.
Intended to complement PSLV for the growing small-satellite market.

Key Technical Details of the SS3 Static Test

Third Stage (SS3) Characteristics

Delivers velocity of up to 4 km/s to the launch vehicle.
Employs:
- Monolithic composite motor case
- Free-standing nozzle divergent, reducing inert mass.

Major Improvements Validated

Carbon-epoxy motor case:
- High-strength, filament-wound structure.
- Significantly reduced stage mass.
- Improved payload performance by ~90 kg.
Improved igniter and nozzle system:
- Enhanced efficiency and robustness.
Fault-tolerant electro-mechanical nozzle control system:
- Low-power control electronics.
- Higher reliability during flight.

Manufacturing & Indigenous Capability

Motor case realised at:
- Vikram Sarabhai Space Centre (VSSC) – Composites Entity.
Solid motor casting and testing:
- Satish Dhawan Space Centre (SDSC).
Test duration: 108 seconds.
Outcome:
- All parameters matched predictions.
- Improved SS3 motor qualified for induction into flight missions.

Infrastructure Expansion for Solid Motors (2025)

Solid Motor production facilities commissioned (July 2025) at Sriharikota to augment capacity.
Second production line for Ammonium Perchlorate commissioned (September 2025) at Alwaye:
- Doubled production of the key oxidiser for solid propellants.
Indigenous 10-tonne vertical mixer commissioned at SDSC:
- World’s largest solid propellant mixing equipment.
SMPST facilities at SDSC:
- Successfully realised and tested solid motor for the first orbital launch vehicle developed by an Indian space start-up.

Significance

Technological Self-Reliance:
Strengthens indigenous capability in solid rocket propulsion and advanced composites.
Commercial Space Readiness:
Enhances SSLV’s competitiveness in the global small-satellite launch market.
Private Sector Enablement:
Industrial-friendly design supports ISRO–industry collaboration under the Indian Space Policy.
Strategic Capability:
Reliable solid motor technology is critical for both civilian and strategic launch systems.
Launch-on-Demand Vision:
Reduced turnaround time aligns with responsive space launch requirements.

Conclusion

The successful static test of the improved SSLV third stage (SS3) marks a major step in ISRO’s efforts to modernise India’s small satellite launch capability. By combining advanced materials, indigenous manufacturing, and expanded infrastructure, ISRO is strengthening India’s position as a reliable, self-reliant, and competitive space-faring nation.

CARE MCQ

Q. With reference to the Small Satellite Launch Vehicle (SSLV), consider the following statements:

SSLV is a three-stage all-solid launch vehicle designed for launch-on-demand missions.
The third stage of SSLV delivers approximately 4 km/s velocity to the launch vehicle.
The improved SS3 motor uses a carbon-epoxy motor case to enhance payload capacity.

Which of the statements given above are correct?

A. 1 and 2 only
B. 2 and 3 only
C. 1 and 3 only
D. 1, 2 and 3

Answer: D

Explanation

Statement 1 is correct.
The Small Satellite Launch Vehicle (SSLV) is a three-stage, all-solid launch vehicle developed by ISRO. It is specifically designed to support launch-on-demand missions with a quick turnaround time and is suitable for industrial production, catering to the growing small-satellite market.
Statement 2 is correct.
The third stage (SS3) of SSLV provides a velocity of up to about 4 km/s to the launch vehicle. This high velocity contribution is critical for inserting small satellites into their intended Low Earth Orbits.
Statement 3 is correct.
The improved version of the SS3 motor uses a carbon-epoxy composite motor case, which significantly reduces the inert mass of the stage. This weight reduction has resulted in an increase of about 90 kg in payload capacity, thereby enhancing the overall performance of SSLV.