ESA gives £6m to Brit spaceplane project
Just another $9,993m needed to get it flying
The European Space Agency (ESA) has inked a deal with British firm Reaction Engines Ltd to work on a paradigm-punishing new type of spacecraft engine. The tech could lead to fully reusable runway-launched space shuttles "within ten years".
According to Alan Bond, MD of Reaction Engines:
“Traditional throw-away rockets costing more than a $100 million per launch are a drag on the growth of this market. The Holy Grail to transform the economics of getting into space is to use a truly reusable spaceplane capable of taking off from an airport and climbing directly into space, delivering its satellite payload and automatically returning safely to Earth.
“We have an inside track on realising this goal. SKYLON could reduce the cost of getting into space by a factor of ten.”
Many Reg readers will be familiar with Reaction Engines and its longstanding plans for proper spaceplanes. The ideas being funded by the ESA centre around the firm's nifty "Skylon" design. Here's a concept vid:
Skylon is in essence a 270-foot-long unmanned, winged liquid-hydrogen tank with a payload bay and oxygen tanks at the middle. At each wingtip it has a unique "Sabre" engine - the keys to the whole plan.
From takeoff up to Mach 5, the Skylon's Sabres operate by burning liquid hydrogen fuel with air from their intakes. They aren't ram or scram jets, however: the incoming air is compressed and almost instantly chilled to the point where it is about to liquefy, using a turbocompressor and tremendously powerful freezer kit running on a closed liquid-helium loop. Then the air is fed into the combustion chamber and burned. The heat arising from the super air chilling process is dumped into the liquid hydrogen fuel prior to burning it.
As the Skylon accelerates through Mach 5.5, it will have climbed to such heights that the air is no longer worth scooping. The intakes are shut off and liquid oxygen from the ship's tanks used instead, as the Sabres become relatively normal liquid fuelled rocket engines.
Once in orbit, the Skylon carries out its mission. It has an auxiliary orbital-manoeuvring system which also runs on liquid hydrogen and oxygen, though in special tanks able to hold their contents safely for longer. Reaction Engines says that the Skylon could carry 12 tonnes to an orbit 300km up, good for many satellite applications: alternatively it could deliver 10.5 tonnes to 460km (these figures are for equatorial orbits).
Passengers if you like: Pilots largely pointless
The spaceplane would initially be unmanned, but Reaction Engines say the payload bay could easily carry a pressurised module holding thirty passengers. (One or more of these could be "pilots", though there wouldn't be any genuine need for such and they certainly couldn't be provided with normal windows.)
The whole Skylon is designed with cost and commercial operation in mind. It can be moved about on the ground by a standard aircraft tractor (Skylon weighs 275 tonnes fully fuelled and loaded, as opposed to 300+ for a jumbo jet). Fuelling is intended to be easier than is normally the case with cryogenic liquid rocket juice, too:
For safety and operational simplicity the cryogenic propellants are loaded subcooled without venting of vapour. Cryogen loading is automatic through services connecting in the undercarriage wells whilst the vehicle is stood on the fuelling apron.
One snag for potential Skylon owners is that it needs a "heavily reinforced" runway. In order to lighten the undercarriage system to where a decent payload could be carried, the designers had to put more weight on each wheel than is normal. But compared to all the manifold hassles involved in vertical launch, this is no big deal.
Skylon comes down and re-enters the atmosphere in the same general fashion as the space shuttle. The airframe is a carbon-fibre and plastic structure attached to a ceramic/fibre aeroshell (just 0.5mm thick and "corrugated for stiffness") at "flexible suspension points", which let it expand under the huge heating of hypersonic ascent and re-entry. The suspension points are also "low conductivity", so as to keep the inside of the craft safe from the sizzling-hot aeroshell. Any heat which gets past the aeroshell is warded off by "layers of reflecting foil".
No need to worry about environmental issues, either - Skylon's only exhaust product is steam. The use of hydrogen fuel offers the potential for it to be a zero-carbon-burden ship, if the hydrogen were made using electricity from nuclear plants, wind farms or other such sources. (At the moment it's normally made from natural gas, emitting loads of carbon in the process.)
It's all very cool indeed, but Reaction Engines estimate the total development cost to produce a working Skylon at around US$10bn. The ESA contract announced today will yield just £6m over time, less than 1 per cent of the requirement. (Reaction Engines say that the ESA funds have been awarded as a result of UK taxpayers' money paid into ESA programmes via the British National Space Centre, an alliance of British government bodies.)
So while the Skylon "could" be flying in ten years, it seems sadly unlikely that it actually will be. ®