Test-firing of Skyroot Aerospace's solid propulsion rocket motor – Kalam-5

by Anantha Krishnan M

Scripting a slice of history in the private space domain, Hyderabad-based Skyroot Aerospace successfully test-fired the technology demonstration version of their solid propulsion rocket motor – Kalam-5.

According to Skyroot Aerospace, the test was conducted at the facility of Solar Industries in Nagpur, India’s largest explosives manufacturer. With this latest test conducted on December 22 coupled with the Raman Engine test firing done in August this year, Skyroot has successfully demonstrated all propulsion technologies in Vikram-1 launch vehicle.

Pawan Kumar Chandana, co-founder and CEO, Skyroot said that this was for the first time in India a private company has successfully designed, developed and tested a full solid propulsion rocket stage.

“It’s a very significant milestone as we successfully demonstrated all propulsion technologies for Vikram-1. We all excited with the test results,” he said.

Currently under development, Vikram-1, is expected to be launched by end of next year in partnership with Indian Space Research Organisation (ISRO).

Carbon Composites


Skyroot says Kalam-5 is built with advanced carbon composite structure in a completely automated process. With this, the first of five Kalam series of solid rocket motors have been unveiled.

Each motor carries a thrust ranging from 5kN to 1000kN (approximately 100 ton).

“Carbon composite case is very challenging to design and manufacture and is five-times lighter than steel.

The remaining 4 motors are in various stages of manufacturing and will be tested in 2021,” a Skyroot statement said. Kalam-5 is a demonstrator solid rocket propulsion stage with exactly same propellant, materials and interfaces as the three solid propulsion stages of Vikram-1 launch vehicle.

It gives a peak sea-level thrust of 5.3kN and is designed to take 66 atmospheres and 30000C of combustion pressure and temperature respectively.

“This is also 1:4 scale in size of our Vikram-1 3rd stage. Solid motors are high thrust, low-cost rocket engines with propellant in solid form. They are highly reliable as they have very few moving parts,” Pawan said.

Major Milestone

Syroot co-founders Pawan (left) and Naga (right) soon after the successful Kalam-5 test-firing

He said Kalam-5 uses 15 different advanced materials, nine different manufacturing processes, and has zero moving parts.

“This is a major milestone for Skyroot and for the Indian private space sector. The test results closely matched our predictions and this success gives great confidence for our Vikram-I vehicle development,” Pawan added.

Naga Bharath Daka, Skyroot co-founder and COO said the company has named solid propulsion stages as a tribute to former President Dr A P J Abdul Kalam.

“The test-firing of Vikram-1 launch vehicle’s 3rd Stage (Kalam-100) is being planned in few months at ISRO facilities,” Naga said.

Earlier this month, Prime Minister Narendra Modi had a virtual interaction with both Pawan and Naga to capture their thoughts on the recent space reforms.

The duo promised the PM to that Skyroot would give their best to make India a global space superpower.

Skyroot also had recently won the national start-up award in the category of space/launch vehicles.

Fighting Pandemic

Backed by a bunch of young and experienced rocket engineers, Skyroot Aerospace has been actively developing Vikram series of launch vehicles for the past two years.

Despite the pandemic upsetting their plans in 2020, the team achieved several milestones this year.

“It’s been a big blow when the pandemic started. Everything halted almost for four months but picked up post that. However, I should say it put us back by four months which we are trying to compensate in all ways possible. The positive part is, it taught us crisis management. We quickly adapted to new remote ways of working to be more efficient but still be safe,” Pawan said.

Commenting on the success of Skyroot’s Kalam-5 motor, an ISRO official said that the private sector would now get ample opportunities to exploit the space sector.

“We are happy that players like Skyroot are growing in confidence. As the lead agency, ISRO is ever committed to support any space endeavours in the country. These are definitely exciting times with plenty of opportunities,” the official said.

In a soon-to-be-published comprehensive interview, Pawan and Naga shares their inspiring story of friendship as former scientists at ISRO, the idea that launched Skyroot and the thrills of chasing their space dream from Hyderabad, the city of nawabs and kebabs.