ISRO could not accomplish the launch of a key Earth observation satellite on Sunday after the rocket carrying it, the workhorse PSLV-C61, failed mid-air, less than seven minutes after it took off. Determined to find the root cause of the failure, the space agency has set up a National Failure Analysis Committee and a complete audit of the rocket is underway, with all systems being reviewed thoroughly.
The committee, more than half of whose members are from premier institutions like the Indian Institute of Science (IISc) and Indian Institutes of Technology (IITs), is expected to submit its report around the middle of next month. A set of voluminous data has already been shared with the panel.
ISRO has also set up several internal committees to scrutinise every aspect of the Polar Satellite Launch Vehicle (PSLV), which is a highly dependable rocket, with a reliability of over 94% and just four failures in 63 launches - an enviable track record.
Sources in the space agency said only the PSLV, and no other rocket, has been put on hold since its third stage uses a solid fuel motor, which is unique to it. The final call, they indicated, will be taken on future launches only after the National Failure Analysis Committee submits its report and ISRO fixes the problem.
Giving an analogy, an expert said each rocket is like a child. "If one child falls down, can you ask the entire village to stop walking?" he quipped.
A notice to airmen (or NOTAM), has, meanwhile, already been issued for the launch of the Geosynchronous Satellite Launch Vehicle Mark-2 or GSLV F-16 to fly between June 18 and July 17. The rocket, initially dubbed 'ISRO's naughty boy' and eventually tamed, is all set to fly the world's most expensive civilian Earth imaging satellite, named the NASA-ISRO Synthetic Aperture Radar Satellite or NISAR. It has been built by India and the US at a cost of $1.5 billion.
Third-Stage Issue
NDTV had earlier reported that a 'misbehaviour' of the third stage rocket motor may have contributed to the failure of the PSLV-C61, which was launching the EOS-9 surveillance satellite. The PSLV-C61 was travelling at 20,160 km per hour - about 28 times the speed of an airplane - when, some 888 km downrange from Sriharikota over the Indian Ocean, it tumbled down 6.26 minutes into its nearly 18-minute flight.
Experts say the third stage did not explode, as speculated. In fact, as the rocket coasted along while losing altitude and thrust, even the fourth stage was probably ignited. It is still being analysed why the rocket motor "misbehaved" 100 seconds after it ignited the third stage. ISRO Chairman V Narayanan said there was a "fall in the chamber pressure of the motor case".
Dr G Madhavan Nair, former Chairman of ISRO, a rocket specialist who played a key role as project director in mastering the PSLV rocket, estimates that a "possible rupture in the fibre casing of the nearly 8-tonne rocket motor could have been the cause of the failure". This remains the main suspect, but all angles are being investigated.
The PSLV is a much-sought-after vehicle globally and India's launch site offers a unique location to maximally use its potential.
