Relevance: GS III (Science & Technology – Space); Source: The Hindu / ISRO

Context

ISRO’s reliable “workhorse,” the PSLV-C62, failed to place its satellites into orbit. A technical anomaly occurred in the third stage, resulting in the loss of the primary satellite (EOS-N1) and 15 smaller co-passengers.

Why did it fail?

To understand this, you must know the PSLV (Polar Satellite Launch Vehicle) structure. It has 4 Stages that alternate fuels:

• Stages 1 & 3: Solid Fuel
• Stages 2 & 4: Liquid Fuel

The Glitch: The failure happened in Stage 3 (Solid Fuel).

• Analogy: Solid fuel rockets are like firecrackers—once lit, they burn at full power and cannot be steered or stopped. Liquid engines are like car engines—you can throttle or turn them off.
• The Result: Because the issue occurred in a solid stage, engineers couldn’t “correct” the path, leading to the mission’s end.

What was lost?

1. EOS-N1: A strategic Earth Observation Satellite for the DRDO (Military use). Since it was a government strategic asset, it was likely uninsured (loss to the Exchequer).
2. Commercial Satellites: 15 small satellites from startups/foreign clients. These were managed by NSIL and are typically insured.

Why is this Significant?

• Reliability: This is a rare stumble for the PSLV, which usually has a near-perfect track record.
• Commercial Risk: It highlights the role of NewSpace India Limited (NSIL), ISRO’s commercial arm, which manages risks and contracts for private clients.

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

1. It is a four-stage launch vehicle.
2. It uses solid propulsion in the first and third stages, and liquid propulsion in the second and fourth stages.
3. It is primarily used to launch satellites into Geostationary Orbit only.

Which of the statements given above is/are correct?

(a) 1 only

(b) 1 and 2 only

(c) 2 and 3 only

(d) 1, 2 and 3

Correct Answer: (b)