February 21 marks the 50th anniversary of a landmark development in the history of the Indian space programme.
It was on this day in 1969 that the first composite solid rocket propellant developed by the fledgling Indian space establishment was flight-tested from Thumba, near here. An interesting element in what was otherwise a purely scientific enterprise was this: The propellant was christened ‘Mrinal’, reportedly after Mrinalini Sarabhai, the noted classical dancer and wife of Vikram Sarabhai, the father of the Indian space programme.
Mrinal was developed by a team at the Propellant Engineering Division (PED) of the Space Science and Technology Centre (SSTC), a precursor to the Vikram Sarabhai Space Centre (VSSC). At the time, the PED was headed by Vasant Gowarikar.
The VSSC plans to felicitate the surviving members of the PED team at a function on February 27.
Mrinal was significant in that it marked the space agency’s first major step in developing solid propellants, which are still used today in ISRO launch vehicles.
On February 21, 1969 the propellant was used to fly a Rohini series RH-75 sounding rocket, which was the designated Dynamic Test Vehicle (DTV), from Thumba.
Former members of the PED team which developed Mrinal such as K.N. Ninan and V.N. Krishnamoorthi remember that the February 21, 1969 test was a huge success.
“'It's significance is that composite propellants form a class of propellants that are ideal for space launch vehicles. Mrinal was the first totally indigenous composite propellant manufactured using locally available raw materials,” Mr. Ninan, who retired as Deputy Director, VSSC, said. What was till then available were mostly double-base propellants suitable for missiles, Mr. Krishnamoorthi said.
Altogether, the DTV was test-flown thrice, but no records are available as to whether subsequent tests were carried out. Anyhow, the propellant itself was short-lived.
Mrinal did not find extensive use with the Indian Space Research Organisation (ISRO) in later years due to scaling-up issues.
ISRO chairman K. Sivan is also scheduled to attend the February 27 function.
