News story

Reaction Engines precooler test hits Mach 5

Reaction Engines has successfully tested its innovative precooler at airflow temperature conditions representing Mach 5, or five times the speed of sound.

This was published under the 2019 to 2022 Johnson Conservative government

This news article was withdrawn on

This news article has been withdrawn because it鈥檚 over 1 year old.

Reaction Engines test facility, Colorado

Reaction Engines test facility, Colorado

This marks a significant milestone in the development of the UK-designed SABRE鈩� engine and paves the way for a revolution in hypersonic flight and space access.

The precooler heat exchanger is a vital component of Reaction Engines鈥� revolutionary SABRE air-breathing rocket engine and is an enabling technology for other pre-cooled propulsion systems and a range of commercial applications.

The UK government committed 拢60 million through the UK Space Agency and European Space Agency to aid preparations for the design, manufacture and testing of SABRE demonstrator engines. This has led to further private investment from BAE Systems, Rolls-Royce and Boeing HorizonX.

Science Minister Chris Skidmore said:

The SABRE engine is one of the UK鈥檚 most exciting engineering projects which could change forever how we launch satellites into orbit and travel across the world.

It鈥檚 fantastic to see Reaction Engines passing this significant milestone, which demonstrates how its precooler technology can deal with the extreme temperatures associated with travelling at five times the speed of sound.

The government has invested 拢60 million in SABRE and is committed to taking a more strategic approach to space, developing our national capabilities to complement and expand on the UK鈥檚 leading role in the European Space Agency once we leave the EU.

This ground-based test achieved the highest temperature objective of the company鈥檚 HTX testing programme and took place at its specially constructed facility at the Colorado Air and Space Port, United States.

During the latest series of tests, Reaction Engines鈥� precooler successfully quenched airflow temperatures in excess of 1,000掳C in less than 1/20th of a second. The tests demonstrated the precooler鈥檚 ability to successfully cool airflow at speeds significantly in excess of the operational limit of any jet-engine powered aircraft in history.

Mach 5 is more than twice as fast as the cruising speed of Concorde and over 50% faster than the SR-71 Blackbird aircraft 鈥� the world鈥檚 fastest jet-engine powered aircraft.

Reaction Engines鈥� patented precooler heat exchanger has the potential to be used in a wide range of commercial thermal management applications. These include the development of precooled systems that would significantly enhance the performance of existing jet engine technology, along with applications in automotive, aerospace, energy and industrial processes.

For more information, visit

Updates to this page

Published 22 October 2019