A team of rocket engineers could propel the UK to the forefront of commercial space flight.

In the quiet suburbs of Oxfordshire, a small team of engineers may be on the way to achieving what NASA scientists couldn’t – the development of a spaceplane that could reach far into the solar system.
Abingdon-based Reaction Engines has designed the Skylon plane to take payloads – or even passengers – into space from a conventional airport and return them back down to the same runway. The design can carry a 12-tonne payload and could, according to the company, fundamentally change the way we view space travel.
But a spaceplane that can break away from the Earth’s gravitational clutches and return in one piece remains, for many, a near-impossible dream. The European Space Agency (ESA), the Russian Federal Space Agency (RKA) and NASA have poured billions of pounds into single-stage-to-orbit (SSTO) projects and so far none have been successful.
The problem is that the technology to build an SSTO vehicle is extremely challenging, given the huge fuel and power requirements. Rocket-powered vehicles need to achieve a high enough mass ratio to enter orbit and currently the best way to do this is to use the thrust of throwaway rockets, such as the Shuttle’s solid-fuel boosters. However, at around $150m (£96m) per flight in a Shuttle compared with $100,000 in a jumbo jet, the cost of sending even modest numbers of people to space is huge.
Richard Varvill, technical director and one of the founders of Reaction Engines, is adamant that SSTO vehicles could change all that. ’Access to space is extraordinarily expensive, yet there’s no law of physics that says it has to be that way,’ he said. ’We just need to prove it’s viable.’
It is this entrepreneurial attitude that has driven Varvill, along with chief executive Alan Bond and chief engineer John Scott-Scott, to spend 30 years of their lives and more than £20m doing just that.
Their concept for the Skylon is based around a synergistic air-breathing rocket engine (SABRE) that uses jet propulsion to reach the edge of the Earth’s atmosphere before switching to rocket power to get into orbit. The first phase of SABRE requires air from the atmosphere to be cooled before being compressed into the engine and burned with hydrogen, while the second phase draws on liquid hydrogen and a small supply of liquid oxygen to propel the plane into space at speeds of Mach 25.
No one has ever made these heat exchangers at the size, scale and weight that we need to achieve
Richard Varvill, Reaction Engines
The breakthrough for Reaction Engines has been in the development of its pre-cooler system. At Mach 5, SABRE will need to cope with gases entering at temperatures reaching 1,000 degrees celcius. The pre-cooler uses thousands of small-bore thin-wall tubes, each around the width of a human hair, to drop the air temperature to -150degrees celcius in just 30ms. Back when Skylon was still a concept, the required heat exchangers for this type of pre-cooled jet engine were impossible to make, but with improvements in materials and manufacturing techniques, Varvill believes the technology has turned a corner.
’No one has ever made these heat exchangers at the size, scale and weight that we need to achieve,’ said Varvill. ’We’re attempting do that at the moment and it’s technically very demanding…; If all goes well, we’re hoping to run tests by the middle of next year in front of a Viper jet engine.’ The pre-cooler demonstration technology will be boosted by 1m euros (£817,000) provided by the ESA in February last year to help fund the development programme. Using this money alongside private backing, the team has made huge leaps forward, most notably with its frost-control system.

’A number of years ago, we made a wind tunnel to test the frost-control system, one of the world’s slowest and smallest, and spent four years trying to get it to work,’ he said. ’The problem is that if you don’t do anything about frost, during low altitude atmospheric moisture clogs the matrix and blocks it in about three seconds flat. In the end, we succeeded and now we have a new technology for which there is no precedent.’
Varvill believes the Skylon project is now reaching its final stages. After decades of withdrawn government support and huge technical hurdles, the tide has turned in favour of high-tech manufacturing and, more importantly, human space travel. A recent study into the Skylon’s ability to carry passengers suggests that a trip to orbit in an upright seat, for stays of up to 14 days, would cost around $500,000. Compared with the plans of some groups, Skylon’s space tourism ambitions are still relatively modest. However, the team is also looking to include an upper stage that would move out of low Earth orbit and, if successful, the project could have far wider significance.
You can imagine a situation when some of our industrially important but polluting processes are done in space and the finished products are brought back down to Earth
Richard Varvill, Reaction Engines
’The simple truth is that the Earth is part of a much bigger system,’ said Varvill. ’The mineral resources of the solar system exceed that of the Earth by many orders of magnitude. We’re talking a bit of science fiction now, but in theory there’s nothing that stops you going out and enjoying some of that… You can imagine a situation when some of our industrially important but polluting processes are done in space and the finished products are brought back down to Earth.’
After the departure of science minister Lord Drayson, a strong advocate of Skylon, new science minister David Willets looks set to continue supporting the project.’The UK government has changed its attitude to the project enormously in recent years,’ said Varvill. ’That has helped us a lot and lifted our credibility. The financial crash has also helped our case… People are talking about rebalancing the economy and bringing back innovation and manufacturing. And what we’re talking about is the creation of an industry with long-term job opportunities and good export potential.’
Skylon is thought to cost about $10m per flight once development costs have been paid. If all goes to plan, within 10 years the UK could become the first country in the world to launch a single-stage spaceplane in orbit.

Some near earth asteroids are worth a staggering £20 trillion in precious metals, that would go a long way to reduce this planets massive debt!
Unfortunately, if the project to mine the precious metals succeeded, they would not be scarce any more, and the price would crash (remember the 1980s Ostrich scheme?).
It is very hard to believe doing things in space could ever be cheaper than doing things sustainably in the wonderfully benign environment provided by the earth. Certaily, the evidence so far points very much in that direction
HOTOL and then Skylon has been many years in development and deserves to be a success. It is a fundamentally right principle.
Travel to the stars is a necessity, I think. If human kind contents itself with living on earth and has no greater ambitions then we shall turn in on ourselves and probably wipe ourselves out. People need a vision of possibiities and a better life. It has always been that way – there has always been exploration and discovery. Better to mine the solar system responsibly and preserve Earth in an enjoyably habitable state.
The UK should exploit its technology in thi area and put some money into establishing an industry around commercial SSTO space flight.
Skylon may well be the first. It depends whether Burt Rutan and his team are able to develop their TSTO (two-stage to orbit) technology for LEO capability before Reaction Engine’s project is flight-ready. I think they will.
Eventually, though, like airborne aircraft, there will be different designs for different tasks. An SSTO design like Skylon is only one general configuration.
Which ever project (preferably non military funded) is first to orbit, this is an exciting and pivotal time for the space launcher industry.
From a military POV.
If we must have nukes, could this not be a cheaper delivery mechanism for nuclear weapons than Trident?
20m Vs 20bn
Sad to think that one of the drivers of this project is to export our polluting processes to yet another environment. Surely if we can meet the space flight challenge, we can redesign the processes we use to be non-polluting?
The aerospace plane can be justified first for point-to-point terrestrial “air” travel. A huge market exists already.
After a fleet of aerospace planes are plying the airways, it can then be used (upgraded) to fly to LEO.
When the Skylon project reaches the point of cutting metal, I sincerely hope that BAE Systems are not involved. Ditto the MoD. If either participate, Skylon will be years late, many times over budget, and will have been beaten to LEO by the US.
Not bad, 12 Tonne payload is over half the current space shuttles max payload, and greater than the current Ariane 5 7 tonne! If it could go to LEO, then it could end up being the craft for resupplying the International Space Station!
What a staggering example of tenacity in the face of myopia.
Estimated probability of success for space projects is inversely proportional to money spent.
Actual probability of success is roughly proportional to amount spent.
Based on these, it isn’t surprising that these guys think that their chances are good and I think that it is harder than they think.
Space travel need not be expensive nor difficult.
One of the greatest problems we face is the mistaken belief that ‘rocket science’ can only be funded by governments with large expensive teams. The team at Scaled Composites was the first to disprove that misconception.
There are many more who, over the coming decades, will prove that flying to orbit can be as routine as flying to Australia. Skylon, and Lapcat, must be a part of that new thinking and new approach.
The chaps at Reaction Engines are designing systems that should have been developed years ago.
Consider if aviation had been developed in the same manner as spaceflight has been: after the outward journey a completely new vehicle would be needed for the return journey.
Bits would fall off the aircraft as it flew through the air to its destination: Fuel tank empty? Get rid of it; we don’t need its dead weight.
Whether future launchers are SSTO or TSTO, the Bond et al approach, using the Sabre engine, is a viable, desirable future of reliable, routine, affordable spaceflight.
With this research mankind on earth will be grateful to the engineers for the scope of interplanetary travel this device can unfold.
Couldn’t agree more about BAE keep them well away from it. As for space industry being too expensive is there any proof of that?
Skylon is the future of space exploration don’t give up Team we are counting on you. Good luck and outstanding work
Burt Rutan’s two stage launch project is similar in concept to Orbital’s air launches, which has already launched over 40 missions. It is completely different to Skylon.
To Robert Kleinsmann: When you burn Hydrogen the result is pure water hardly a polutant. 2H2+ O2 —–> 2H2O
It’s always exciting to see British innovation in the news, especially when it has been constantly set back by our own governments lack of funding.
Even more so when you’re related to the Chief Enginner 🙂
I hope this project achieves full success and the UK retains all patents, IP rights and manufacturing.
What many non-engineers may not realize is that the fuel in a normal sized cars fuel tank has enough energy to propel that car into orbit. It just requires 100% utilization of the energy contained in the fuel. Probably not going to happen any time soon, but it highlights just how inefficient current LEO launcher vehicles are.
Space is empty and full of possible riches.
The things this vehicle may make possible are limited mainly by imagination