India's Skyroot Aerospace unveils upgraded liquid engine Raman-II ahead of test fire

Indian startup Skyroot Aerospace recently unveiled its brand new upgraded version of the Raman rocket engine. Named Raman-II, the new engine is the improved version of Raman, which was the first private homegrown liquid engine developed and tested in 2020. According to Skyroot, the newly developed engine has a higher thrust capacity and will soon be fired for testing. 

"We're pushing 3D-printing limits with even the plumbing printed along with the engine", the firm established by former ISRO scientists said in a statement.

What is 3D printing of rocket engines?

This revolutionary technology has become popular among rocket engineers as it allows them to develop rocket parts layer by layer and fix an anomaly within days. If anything goes wrong with the conventional methods, like an engine blowing up, the developers would have to start everything from scratch. 3D printing is also called additive manufacturing and involves a process called selective laser sintering. 

To develop rocket parts, first metal powder is exposed to lasers to melt them into desired shapes. The melted metal binds together and remains powder where it is untouched. Once cooled, the engineers add another layer and this process continues until the entire component is built. This method is highly preferred because even if something goes wrong, 3D modelling software can be used to fix the problem in a few days. 3D printing can even be used to develop engine nozzles with internal coolant channels, parts that are considered to be extremely complex. 

Skyroot Aerospace forges ahead

The newly unveiled engine aims to build on the success of the Raman engine which was successfully tested on 30 July 2020. Named after Indian physicist and Nobel Laureate, Sir CV Raman, the engine was also developed with 3D printing technology. According to Skyroot, these Raman class of engines are capable of multiple restarts which would enable the company's Vikram-1 launch vehicle to insert satellites into multiple orbits in a single mission.

Most recently, the firm conducted a successful full-duration static test-fire of its Vikram-1 rocket stage ‘Kalam-100’. The carbon fibre built stage produced a peak thrust of 10 tonnes in a burn time of 108 seconds. The Vikram-1 launch vehicle is designed to carry up to 480 kilograms to low-inclination orbits and it can be assembled and launched from any launch site within 24 hours.