Edinburgh manufacturer Skyrora, which aims to launch its rockets from Scottish sites such as the recently confirmed Sutherland spaceport, revealed the engine parts to Professional Engineering before end-of-year ground testing. The same design, which should offer 30kN of thrust at sea level, will be used on the company’s Skyrora One launcher.
The released photograph shows the engine nozzle, chamber and injector head – each 3D-printed out of nickel alloy Inconel in a powder bed machine.
With many companies targeting the small-payload launch niche – including competitor Orbex, which secured the first contract to launch from Sutherland – Skyrora is using 3D printing as a differentiator, said lead engineer Robin Hague.
“We feel our opportunity for cost competitiveness is in the way we make the vehicle,” he told Professional Engineering. “What we are looking to do is step back a little bit from the bleeding edge.”
3D printing – also known as additive manufacturing – was therefore a perfect fit, said Hague, helping the company focus on the “holistics” of satellite launch instead of pure performance.
“The ability to print the complex shape of the engine and also reduce the part count… means we can make our engine quickly and cost effectively,” said Hague.
The technology not only offers process and cost reductions, said Hague, it also allows engineers to envisage and create more geometrically complex structures – and therefore, possibly, better engines.
“Engines typically have double walls, and one propellant is pumped through that double wall to keep the chamber cool. With additive manufacturing, you can make that wall in one piece – printing the double wall and printing the gap for the propellant in one go.”
He added: “In the same way that [3D printing] is helping aeroplane design, it means we can produce fewer parts, less material, and at the same time create geometries that are better at the job.”
The company, which also has a base in Dnipro, Ukraine, has taken inspiration from the British Skylark and Black Arrow rockets of the 1950-70s. Like Black Arrow, the 150kg maximum payload Skyrora One will use the propellants kerosene and hydrogen peroxide, which does not require cryogenic chilling and is therefore suitable for responsive launches during windows of good weather.
Professional Engineering magazine will feature Skyrora in an upcoming story on the UK space sector in Issue 7, 2018.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.