by Dan Richards
This week has seen a UK company announcing the successful testing of an innovative new propulsion system, designed to propel a single vehicle into space almost as easily as a conventional airliner.
The company behind the project, Reaction Engines Ltd  (REL) of Oxfordshire, herald the technology as “the greatest advance in propulsion since the jet engine.” On Twitter this looked exciting, but it wasn’t trending and there wasn’t the media hype befitting such a great invention. After a bit more reading I came across Jonathon Amos’s BBC Online  article on the story and quickly realised that unfortunately it’s not a fully-fledged prototype taking to the skies, but no less than a historic aviation milestone.
High-performance cooling, the first hurdle
REL’s engine, aptly named Sabre, represents a much earlier stage in what could be a revolution in our skies. This week’s test demonstrated the viability of the engine’s unique pre-cooler. This light-weight, high-performance heat exchanger is a vital component that manages the very hot air entering the engine at high speeds, before being mixed with hydrogen to produce a great deal of thrust.
Led by visionary engineer Alan Bond, their idea is for an 84m space plane, called Skylon, with one engine type that would take off and land from a normal runway to carry satellites into space. Skylon’s Sabre engine would burn a mixture of hydrogen and oxygen, working in the same way as a conventional jet engine in the lower atmosphere where the oxygen is taken directly from the air. Once it reaches sufficient speed at higher, oxygen-thin altitudes, the engine would utilise on board oxygen supplies and switch to rocket mode to propel itself into space.
Up until now, space access has required vast amounts of thrust and a two-stage engine. This is costly since part of the engine gets dumped en-route. With the Sabre engine on its wings, Skylon would slash the cost of accessing space, with a single reusable vehicle that just requires refuelling.
So are we likely to see this taking to the skies anytime soon? According to REL, this largely privately funded proof-of-concept opens the door for further commercial and potentially public funding. REL need to raise £250m for the next phase of development and testing before final designs can be produced and handed to a manufacturer. The UK Government is assessing its future involvement, with the Science Minister David Willets stating this week that “it would be a fantastic achievement if we could one day use this home-grown technology for our own commercial space launches.” To me that sounds like it could really give the UK space industry a massive boost, perhaps one that the public will get behind as well.
New invention, or evolution?
At this point let’s not forget the humble beginnings of the jet engine in Lutterworth, Leicestershire by a chap called Frank Whittle and his visionary engine. He too, like Alan Bond’s REL, sought private investment when he set up Power Jets Ltd in 1936. His small team developed the Power Jets WU prototype engine, which fired up and ran for the first time in 1937. The engine was quickly incorporated into the Gloster E28/39 and then introduced into the RAF’s Gloster Meteor, seeing its first active service during World War II by 1944. The reasons for such innovation were very different to todays, and after the war ended Power Jets was nationalised and the engines mass produced by Rolls Royce in the UK, and General Electric in the USA.
The rest is history, a jet age that started in the Midlands from the vision of one man – no less than a revolution. I have a personal affinity to Power Jets, since it’s an important part of my own family’s history with my Great Grandfather working as one of Whittle’s engineers, and his son as an apprentice with the company. So while I don’t admit it, I’m a bit of an aviation enthusiast.
This can inspire the engineers of tomorrow
Britain has since been central to developments in aviation, the Concord and the Harrier jump jet to name just two more of my favourite examples. Alan Bond and REL’s offering could be the next big thing and with the right backing and public appreciation could propel our nation into space. It’s a disruptive technology, if Sable delivers. What is almost as important, however, is the shining example this presents to inspire a new generation of budding mechanical engineers, and Britain’s next biggest invention.
National Science & Engineering Week runs 15-24 March 2013 with the theme invention and discovery…