A high-tech spacecraft that can take off and land from an ordinary runway, and will slash the cost of flying to space, could be just 10 years away, according to its developers.
Being developed by the Oxfordshire-based Reaction Engines, the Skylon plane – which received one million euros in support from the European Space Agency this week – is designed to carry cargo into orbit and return to land on the same runway.
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.
The unmanned, 82-metre plane is totally reusable, unlike most current launch technology. NASA's Space Shuttle is partly reusable and can carry 24.4 tonnes of cargo to low earth orbit, but has to be launched like a conventional rocket at phenomenal expense.
Skylon's designers estimate that the shuttle could slash the cost of launching into orbit, from up to $700 million per launch to just $10 million. "Traditional throw-away rockets costing more than a $100 million per launch are a drag on the growth of this market," said Alan Bond, managing director of Reaction Engines.
"The Holy Grail to transform the economics of getting into space is a truly re-usable space plane capable of taking off from an airport and climbing directly into space, delivering its satellite payload and automatically returning safely to earth," he said.
The plane could later be adapted to carry a pilot and 30 passengers and used for space tourism, said Bond – and, if all goes to plan, would be ready to take tourists by 2030.
The latest bundle of ESA funding will go towards the development of the craft's hybrid 'Sabre' engine, which works like a a jet engine while in the earth's atmosphere, but converts to liquid oxygen in space.
Reaction Engines said that a key part of the technology is the 'precooler' they have developed.
At very high speeds, air entering the engines can reach 1000 ºC, and must be cooled before it can be compressed and pumped into the combustion chamber. Working somewhat like a car radiator, the precooler contains a fine network of cooling tubes that almost instantly chills the searing hot gas to minus 130 ºC.
The small size and jet engine technology would mean that the Skylon doesn't suffer from many if the safety risks and noise pollution issues of conventional rockets, so it could even be launched in populated areas. "I would say that we could have a Skylon plane leaving [London's] Heathrow airport sometime during this century," said Bond.
As a further benefit, the spaceplane is relatively eco-friendly in that its main exhaust product is water, he added.
The spaceplane technology under development at Reaction Engines is "the most advanced in the world," said Duncan Law-Green, a space and computer scientist at Leicester University in England, who is not involved in the project. What's more, the reusable nature of the plane means it can be tested extensively "until it's potentially as reliable as a car engine," he said.
Though he believes it has great prospects, Law-Green was quick to stress that the project is still at a fairly early stage "There are still many technological and engineering hurdles, and we are a long way from getting something that actually flies," he said.
The biggest roadblock could be funding - Reaction Engines estimates the total development cost of Skylon to be in the range of $10 billion, and the ESA funding is just a drop in the ocean of what will be required.