2 years ago

The Motor that moves us! – Part 1

From Thiruvananthapuram, Nagpur, Bangalore and finally to Sivakasi, India’s first solid fuel powered model rocket motor has shown us highs and lows and it is a journey that we are still on.

If you asked them if they knew all along that they would be heralding the Indian new space movement, you wouldn’t get a definitive answer. But Divyanshu Poddar and Akash Ekka knew that if they were to go ahead with realizing their dream, they had to get the heart of the matter just right.

It all started back in their alma mater, The Indian Institute of Space Science and Technology, Kerala. Divyanshu and Akash were classmates who shared a common passion for all things space. Divyanshu was a model rocketry enthusiast and it was not long before he had a group of friends who would experiment with model rockets. Akash, who was more into space science, would observe their experiments and took on the active role of recording test launches with great interest and helped the team with lab test and calculations.

Akash had always liked propulsion systems as a subject at college. Fate had it this way that as an intern, he got an opportunity to work at Cryogenic Engines, specifically analyzing the material properties of Superalloy Inconel which was heavily used in CE-20 engines. Under the guidance of Dr. Ninan who pioneered propulsion at VSSC, it was in the chemistry lab of IIST where they use to prepare the BP mix. It involved grinding the mix for long hours, trying a variety of compositions and then curing it in the lab oven. Later, they would test the mix in unearthly hours to avoid attention (they never knew how big the explosion would be) at the basketball court as the college didn’t have many open spaces around them. All these activities, for the first time, ignited the thrill in them of working with explosives, taming the explosive power for propulsion, not for mere academic interest and which then in the future became the mainstay R&D frontier of Rocketeers. Thus, when Divyanshu and Akash set off to start rocketeers, they both know that they had to get the heart of the operation just right.

While Divyanshu was focusing on the manufacturing and production of the model rocket kits, Akash has tasked the job to find means to make the engines. This meant, developing, designing and sourcing the engines from scratch. So, in 2016 Akash set off to find a manufacturer in the city of Nagpur. He went in search of explosive manufacturers who would be willing to help. Since, it was all experimental at this stage, finding a vendor was proving to be difficult.

The first step was understanding the critical component: Black powder.

Black powder = Fuel(Charcoal) + Oxidizer (Pot. Nitrate) + Binder (Dextrin) + Sulphur

These components also make up the fuel for a firecracker rocket, however it is the composition and proportion that makes the difference. Source and quality of the raw material is also important as charcoal of different varieties are available. The idea was to get consistent results every time the motor was fired. Firecrackers tend to explode and their success rates are not a matter of concern. Model rockets couldn’t be taken so lightly.

It was during this time of exhaustive researching and searching did Akash and Divyanshu find Ameen Explosives. Ameen explosives supplied black powder to firecracker factories and was situated 20km outside Nagpur in a town called Katol. Mr. Pimple from Ameen Explosives turned out to be very helpful considering that the engines were still experimental at this point. He helped Akash understand explosives and black powder better and also study its manufacturing. It was here Akash realized the importance of safety. Mr. Pimple used to paraphrase Murphy’s law and say “If anything can go bad, it will go bad”. Being in the fireworks industry he had a first hand account of how crucial safety is.This was quite a learning experience to work in an explosive factory as fatal accidents always reminded importance of alertness and safety as first priority.

Under Mr. Pimple’s mentorship, Akash began designing and testing the solid fuel mixture. They tested out various proportions of the black powder to see what works. They conducted rudimentary weekly tests to see progress. Slowly, but surely they achieved the perfect blend.

Mixture Composition Percentage%(Weight) Physical State
Potassium Nitrate(KNO3) 75-78 Solid powder granules
Charcoal(C7H4O) 15-19 Solid powder granules
Sulphur(S) 4-5    Solid powder granules
Dextrin(C6H10O5)n 1-2 Solid powder granules

Over the course of many weeks, Akash realized that the density of the mixture was affecting the outcome. They realized that the mixture needed to be compressed and that simple hand pressing just wasn’t cutting it. Hence, they developed a jig that would pack in more black powder.

Although, conceptually the motor was taking shape, practically there were no results. The motor collapsed even after trying out different samples. To add to that, Ameen Explosives had to be dissolved. The owners had to sell it off  and the new owners were not as cooperative. This meant that all the stock that was tested couldn’t be recovered. Although, they did have the test results, they were empty handed. After inhaling black powder fumes for these many months, beating the grind of this unregulated and informal industry, getting down and dirty with the materials and dealing with hundreds of people, this felt like a major setback

The hunt was on for another vendor. But, lessons were learnt from past experiences. The need of the hour was an expert in the industry who would understand model rockets and guide. Backyard manufacturing was out of questions and dealing with amateurs was not in the cards. Safety and quality, as Akash knew so very well, was not to be compromised.

Owing to the unregulated nature of the fireworks industry, the next logical conclusion was to go to the largest firework manufacturers in the country. Only one name popped up: Sivakasi. Sivakasi produces 80% of the county’s fireworks and hence finding a vendor here wouldn’t be too difficult.

Sivakasi turned out be a whole other game. Sivakasi, as Akash found out, was just a small village in Tamil Nadu. Yes, every other person was into firework manufacturing, but there was another barrier. Language. It’s not people didn’t want to understand Akash, they couldn’t. With very little cosmopolitan influence, no one knew even broken english/hindi. It was thus difficult to first make them understand model rockets and second, seek their help. For 2 months, Akash went one factory to another, searching for a suitable vendor. The local crowd nor the weather provided any hope. It would take for a non Tamil speaker, a whole 2 mins just to put together “I have an offer for you” into an understandable language.

Just when things looked the bleakest, there was a ray of hope. Enter Somnath Babu.

To be continued…

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