Indian Space Research Organisation (ISRO) suffered a setback when its first launch of 2026, the PSLV-C62 mission, failed to place 16 satellites into the intended orbit. The anomaly occurred during the critical third stage of the launch. The 44.4-metre tall, four-stage PSLV rocket lifted off as scheduled from Satish Dhawan Space Centre, but later deviated from its planned flight path.
Mission objective and launch profile
- Mission aim: Deployment of one primary Earth Observation satellite and multiple co-passenger satellites
- Intended orbit: 512 km Sun-Synchronous Orbit (SSO)
- Planned mission duration: ~17 minutes from lift-off to orbital insertion
- Launch sequence: Automatic launch sequence initiated after approval from the Mission Director
- Initial performance: First and second stages performed normally
What went wrong in PSLV-C62
- PSLV is a four-stage launch vehicle with two solid stages and two liquid stages
- During the third stage, scientists observed:
- Increased disturbances in vehicle behaviour
- Deviation in flight path close to the end of third-stage burn
- The anomaly occurred when strap-on motors and third-stage solid motor were providing thrust
- As a result, the vehicle failed to achieve the required velocity and trajectory for orbital insertion
- ISRO has initiated a detailed technical analysis to identify the exact cause
This is the second consecutive PSLV failure linked to the third stage.
Satellites lost in the mission
Among the 16 satellites that could not be placed in orbit were:
- Anvesha – A strategic satellite from Defence Research and Development Organisation (DRDO)
- Designed to detect military camouflage from ~500 km altitude
- AayulSAT – India’s first in-orbit fuelling satellite
- CGUSAT – A student-built Low Earth Orbit (LEO) satellite
- Intended for emergency communication and disaster management
- Earth Observation satellite – Jointly built by Thailand and the United Kingdom
- KID (Kestrel Initial Technology Demonstrator) – From a Spanish startup
- Prototype of a re-entry vehicle
Background: consecutive PSLV failures
- PSLV-C62 marks the second consecutive failure of ISRO’s workhorse launcher
- Earlier failure: PSLV-C61 (May 2025)
- Rocket performed well in first two stages
- Failure occurred in the third stage due to a motor pressure issue
- Caused by a manufacturing defect leading to leakage and drop in combustion chamber pressure
- The Failure Analysis Committee (FAC) report of PSLV-C61 was not made public
- The PSLV-C62 failure is suspected to be due to a similar pressure-related issue, though confirmation is awaited
PSLV: India’s workhorse launch vehicle
- PSLV has completed 63 missions so far
- Key missions include:
- Chandrayaan-1
- Mars Orbiter Mission (Mangalyaan)
- Aditya-L1
- Astrosat
- In 2017, PSLV set a world record by launching 104 satellites in a single mission
How PSLV reaches orbit (stage-wise)
First stage – Lift-off
- Solid propellant
- Near-vertical ascent to 50–60 km
- Overcomes gravity and atmospheric drag
Second stage – Velocity build-up
- Liquid propulsion with Vikas engine
- Takes vehicle to ~220–250 km altitude
- Accelerates to ~14,000 km/h
Third stage – Rapid acceleration (most critical)
- Solid motor
- Vehicle moves almost horizontally
- Accelerates rocket to 26,000–28,000 km/h
- Essential to achieve orbital velocity
Fourth stage – Precise orbital insertion
- Liquid propulsion
- Fine-tunes orbit between 250–2,000 km
- Payload deployment occurs here
Why third stage is critical
- Solid fuel burns to produce high-pressure gas
- Gas exits through nozzle to generate thrust
- Higher chamber pressure = higher thrust
- Any pressure drop (due to leakage or defects):
- Reduces thrust
- Prevents achievement of orbital speed
- Causes payload to fall back due to Earth’s gravity
Both PSLV-C61 and PSLV-C62 failures point to vulnerabilities in this stage.
Consequences of repeated PSLV failures
- Space missions allow very little margin for error
- With 3 failures in the last 6 missions, ISRO faces:
- Credibility concerns
- Commercial risks, as PSLV is a major revenue generator for foreign and private launches
- Reputational challenges for a launcher trusted for over three decades
- Questions raised on:
- Quality control
- Manufacturing processes
- Transparency in failure analysis and return-to-flight decisions
What Does It Mean
- By keeping the PSLV-C61 FAC report internal, ISRO limited external technical scrutiny
- Launching PSLV-C62 just eight months after a major failure, without public disclosure of corrective measures, has intensified concerns
- The focus now extends beyond technical fault-finding to:
- Institutional transparency
- Risk management
- Reliability assurance
Despite the setback, ISRO’s strong history of learning from failures and returning stronger provides cautious optimism that confidence in PSLV will be restored.