Rolls-Royce and Boeing HorizonX Ventures have invested £26.5m in British aerospace manufacturer Reaction Engines to develop a hybrid aerospace engine that features both rocket and jet technology.

The project is part of the SABRE (Synergetic Air-Breathing Rocket Engine) programme, which aims to test a SABRE core in 2020. The engine will be capable of reaching Mach 5 in air-breathing mode, and Mach 25 in rocket mode for space flight.

“This is a significant milestone for Reaction Engines and I am delighted to welcome our new strategic and financial shareholders,” said Reaction Engines chief executive Mark Thomas.

“In addition to providing our largest round of private investment, these new partners bring invaluable expertise in both hypersonics and engine technologies with significant access to target markets. This is not only a vote of confidence in our technology but also underlines belief in our ability to develop a thriving commercial business which will provide strong financial returns for our shareholders.”

The investment follows a £20.6m contribution by global defence company BAE Systems. Reaction Engines has also signed a contract with the US Defense Advanced Research Projects Agency to conduct high-temperature airflow testing of a Reaction Engines precooler heat exchanger.

Having raised over £100m from backers including the British government, Reaction Engines anticipates further investments in the form of subscriptions for new shares. The company has begun construction of a new facility in Westcott, Buckinghamshire for SABRE testing.

“These investments are a real vote of confidence in Reaction Engines and its revolutionary SABRE engine, which has benefited from £60m in UK Government support,” said US Minister of State for Universities, Science, Research and Innovation Sam Gyimah.

“Boeing and Rolls-Royce will bring world-class expertise to the project ahead of its testing at Westcott, alongside the new National Space Propulsion Facility. This is an exciting time as the UK’s commercial space industry goes from strength to strength, boosting the economy and creating high-skilled jobs across the country.

“Through our ambitious industrial strategy, we are working with the sector to pursue new opportunities, develop technologies and infrastructure, and enable small satellite launch and sub-orbital flight from UK spaceports for the first time,” Gyimah concluded.