Dr John Williams is an engineer at Lumentum where he works on the extreme challenges of sub-millimetre scale photonic circuits. For the purpose of this conversation, however, we will be discussing John’s former role as a design engineer at Reaction Engines, a UK company that is developing the Synergetic Air-Breathing Rocket Engine, also known as SABRE.

The vision of SABRE is to build a new hypersonic engine that can operate both as an air-breathing jet engine and as a traditional rocket. This versatility means SABRE can be used as a propulsive platform for future hypersonic aircraft or to propel space planes into orbit. Furthermore, SABRE combines the unique fuel efficiency of a jet engine with the power and high-speed ability of a rocket. Having started at Reaction Engines early on when there were only two people in the design office, and later founding his own design and manufacturing company, John has many years of high-tech experience in the aerospace sector.

In this episode of the Aerospace Engineering podcast, John and I talk about:

• his background as an aerospace engineer


• the benefits of an air-breathing rocket engine


• the particular design challenges in realising this type of engine


• and his lessons learned from high-tech development

This episode of the Aerospace Engineering Podcast is brought to you by my patrons on Patreon. Patreon is a way for me to receive regular donations from listeners whenever I release a new episode, and with the help of these generous donors I have been able to pay for much of the expenses, hosting and travels costs that accrue in the production of this podcast. If you would like to support the podcast as a patron, then head over to my Patreon page. There are multiple levels of support, but anything from $1 an episode is highly appreciated. Thank you for your support!

Selected Links from the Episode

• Reaction Engines webpage


• The SABRE engine: REL, WIRED, Wikipedia


• Precooler test at Mach 5


• The Three Rocketeers BBC documentary


• Lecture by Alan Bond, co-founder of Reaction Engines


• Carbon nanotube composites