American rocket and missile propulsion manufacturer Aerojet Rocketdyne has announced the successful completion of a series of hot-fire tests on a Bantam demonstration engine built entirely using additive manufacturing.

According to the company, the tests were an important step in developing cost-effective engines for booster, upper-stage and in-space propulsion.

Aerojet Rocketdyne advanced launch propulsion programmes director Jay Littles said: "We are not just making a standalone chamber or injector derived from traditional design approaches. Rather, we are integrating the full capability of additive manufacturing processes to evolve a proven, reliable, affordable design.

"The tests were an important step in developing cost-effective engines for booster, upper-stage and in-space propulsion."

"We are doing so with technical depth and rigor to meet our unparalleled quality and safety requirements."

The engine generally comprises dozens of components, and is made from only three additive-manufactured parts, the entire injector and dome assembly; the combustion chamber; and a throat and nozzle section.

Tested liquid oxygen/kerosene engine dubbed ‘Baby Bantam’ has a thrust of 5,000lb.

Bantam engine family extends up to 200,000lb of thrust, and can be operated using various fuels, including kerosene, ethanol, methane and storable propellants.

Adapted from the design of the Atlas Sustainer engine, the Bantam engine family could reduce total design and manufacturing time from more than one year to two months, while cutting the costs by around 65%.

This engine test was part of a multi-year Aerojet Rocketdyne additive manufacturing development process that has already demonstrated successfull process development, design tool evolution, component fabrication and component hot-fire tests.

Defence Technology