UK government excited by 'disruptive' Sabre engine

George Osborne George Osborne sees the proof-of-principle Sabre test rig at the Culham science park

The UK government is putting £60m into the revolutionary Sabre engine, but its inventors will need about four times this sum to produce the final design.

Discussions with private investors are now under way to secure the additional funding, says project leader Alan Bond.

Sabre is a jet-cum-rocket that could, say its supporters, propel a fully re-usable space plane into orbit.

Chancellor George Osborne has witnessed a display of its enabling technology, and is excited by the innovation.

He intends to release £35m in 2014-15 and a further £25m in 2015-16 to help Mr Bond conclude the power unit's development phase.

This would see the construction of a demonstration engine and a blueprint for manufacture.

Alan Bond: "The investment will be tied to achievement"

Mr Bond, the chief engineer at Reaction Engines Ltd (REL), said the next nine months should see the extra financing come together.

"The value of the next phase of development is of the order of £200m-plus, and the government's investment represents about 25% of the total.

"I cannot go into detail at this time because it's commercially confidential, but I have every belief that the other investment will come along to support the programme," he told BBC News.

Our science editor David Shukman watches a pre-cooler test run

The Sabre (Synergistic Air-Breathing Rocket Engine) concept is for a power unit that can operate like a jet turbine at low speed and then transition to a rocket mode at high speed.

It would burn hydrogen and oxygen to provide thrust, but at low altitudes this oxygen would be taken straight from the atmosphere.

The approach should save weight and allow Sabre to impel a space vehicle straight to orbit without the need for the multiple propellant stages seen in today's throw-away rockets.

Crucial to the engine's performance, however, is a compact pre-cooler heat-exchanger that can take an incoming airstream from over 1,000C to -150C in less than 1/100th of a second.

This pre-cooler module contains arrays of extremely fine piping that dump energy very efficiently but also avoid the frost build-up that might otherwise compromise their operation.

A series of "proof of principle" experiments has passed an independent audit from European Space Agency (Esa) experts, and Mr Osborne himself has inspected the test rig on the Culham science park in Oxfordshire.

Sabre Engine (Reaction Engines) A concept drawing of the Sabre engine with a series of pre-cooler modules

The UK government's science minister, David Willetts, said he and Mr Osborne had been very impressed.

"It is because of the clear evidence that Reaction Engines has passed crucial technical tests - that the principles have been established; that the technology has been proven - that the British government has taken this very significant decision to invest £60m in REL.

"The technologies that particularly interest us are disruptive technologies that can have a wide effect.

"The experts have convinced me that this heat exchanger is not simply for use in the space industry - it has many other applications as well. I've been told, for example, that for desalination plants it could be of great significance."

It is conceivable this technology might also be used within the atmosphere to shorten journey times from one side of the globe to the other. Brussels to Sydney could be done in four and a half hours by a Sabre-equipped airliner.

Air flow over pipes Sabre's trick: Hot air passes over the piping, plunging to -150C in just 1/100th of a second

This final phase of engine development should get under way in earnest at the start of next year, and, once again, it will be supported by Esa.

The agency's propulsion experts will offer their insights on many technical aspects of the programme, but they plan also to provide due diligence to ensure REL delivers against milestones.

The desire is to have a full set of engineering drawings completed by the end of 2017 that would enable a real flight model of Sabre to be manufactured.

Before then, REL hopes also to have produced a ground demonstrator.

"I always liken the demonstrator to a dissected rabbit, with all its organs spread out," explained Mr Bond.

"It would not resemble a flight engine, but it will have all the correct features of a real engine, and it will show that it's controllable, that it's self-sustaining and indeed that it can simulate operation from take-off conditions."

The head of Esa's mechanical engineering department, Constantinos Stavrinidis, said the agency took the view that Sabre was a realisable technology, but that it might be some years yet before the engine got into the skies.

"It took a while before steamships took over from clippers; it took a while before jet engines took over from propellers. But I'm convinced this is the last frontier: utilising oxygen from the atmosphere. This technology - the heat exchanger - has demonstrated that it can work," he told BBC News.

Sabre engine: How the recent "proof of principle" experiments were conducted

Illustation of how the skylon engine works Groundbreaking pre-cooler
  • 1. Pre-cooler

    During flight air enters the pre-cooler. In 1/100th of a second a network of fine piping inside the pre-cooler drops the air's temperature by well over 100C. Very cold helium in the piping makes this possible.
  • 2. Jet engine

    Oxygen chilled in the pre-cooler by the helium is compressed and burnt with fuel to provide thrust. In the test run, a jet engine is used to draw air into the pre-cooler, so the technology can be demonstrated.
  • 3. The silencer

    The helium must be kept chilled. So, it is pumped through a nitrogen boiler. For the test, water is used to dampen the noise from the exhaust gases. Clouds of steam are produced as the water is vapourised.

Sabre briefing Alan Bond (C-L) shows off a model of Sabre to David Willetts (F-L), Constantinos Stavrinidis (F-R), and David Parker (C-R), the CEO of the UK Space Agency
Jonathan Amos Article written by Jonathan Amos Jonathan Amos Science correspondent

Lisa Pathfinder: 'Exquisite' gravity probe leaves UK

UK industry completes construction of the modules that make up the Lisa Pathfinder satellite - a remarkable probe that will test the key technologies needed to detect gravitational waves in space.

Read full article

More on This Story

Related Stories

The BBC is not responsible for the content of external Internet sites


This entry is now closed for comments

Jump to comments pagination
  • rate this

    Comment number 231.

    Robert Lucien, Curtains2012

    The real problem with the Space Shuttle was Senator William Proxmire.

  • rate this

    Comment number 230.

    The article states that the air comes in at 1000C and leaves the precooler at -150C. The 1.2.3. explanation with diagram at the bottom states it comes in at 20C cooling down to -140C with the caption stating it cools the air by over 100 degrees. Both mention the same time frame of 1/100 of a second. Its quite a discrepancy without explanation. Is that at different stages? An extra 0 was used?

  • rate this

    Comment number 229.

    @224 lucas north - Piffle.

    The "Free Market" is all too often looking for a quick return and (as the sad history of Great GB Inventions being developed abroad shows) UK firms are reluctant to take risks on technology. By investing about 25% of the necessary funds, the Govt. is keeping the momentum of this fantastic project, while its backing should reassure private investors. A good balance.

  • rate this

    Comment number 228.

    These ideas are fantastic, others include Hypersonic aircraft with a rocket boost function for sub orbital flight, the only fear I have is that such craft could be used a bombers, having all the speed of a ICBM but with out those pesky anti-proliferation treaties standing in there way, if such craft a is built, successfully flow etc. an international UN treaty must force them out of military hands

  • rate this

    Comment number 227.

    222.Robert Lucien
    The real problem with the Shuttle was that it was first gen reuseable tech, the direction they needed to go was bigger and cheaper not smaller.


    And not so likely to fail.


Comments 5 of 231


Features & Analysis

  • BeefaloBeefalo hunt

    The hybrid animal causing havoc in the Grand Canyon

  • This Chinese character has taken China's internet by stormDuang duang duang

    How a new word 'broke the Chinese internet'

  • Sound of Music PosterFar from a flop

    Even Sound of Music film crew surprised by success

  • Don Roberto Placa Quiet Don

    The world's worst interview - with one of the loneliest men on Earth

BBC Future


Space like you've never heard it

Listen to out-of-this-world music


  • 3D model of Christ the Redeemer statueClick Watch

    Using drones to 3D map the famous Brazilian landmark Christ the Redeemer

Copyright © 2015 BBC. The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.