SABRE engine passes milestone tests

British engineers have successfully tested new engine technology that could pave the way for a high-speed orbital spaceplane.

The team from UK firm Reaction Engines announced this morning that the SABRE engine technology, which could power a reusable spaceplane known as Skylon capable of entering orbit without additional rockets, had been proven in tests evaluated by the European Space Agency (ESA).

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Reaction Engines has been testing the SABRE heat exchanger and anti-frost system using a standard jet turbine engine

The company called the technology, which could also lead to supersonic flights from Europe to Australia in four hours, ‘the biggest breakthrough in aerospace propulsion since the invention of the jet engine’.

Reaction Engines’ CEO Tim Hayter said the SABRE engine, which utilises both jet turbine and rocket technology, would be made possible by the company’s innovative pre-cooler heat exchanger.

‘The heat exchanger is the thing that cools the air from 1000ºC to -150ºC in 1/100th of a second,’ he told a press conference. ‘This means that we can build a hybrid air-breathing rocket engine. This is going to permit orbital and high-speed propulsion.’

He added that as well creating the possibility for six to 15 times more space launches than are currently performed, the technology could improve the fuel burn of existing gas turbine technology by five to 10 per cent, leading to savings of an estimated $10bn to $20bn for the airline industry.

Other applications may also be possible, he said, including a 15 per cent efficiency improvement in multi-stage flash (MSF) desalination, which is typically used to create drinking water in many Middle Eastern countries.

The heat exchanger, which rapidly cools air so it can be compressed and fed into the rocket combustion chamber, is made possible by secret technology that prevents frost from forming and blocking the exchanger’s pipes.

With this in place, the exchanger can displace 400MW of heat energy with a weight of around 1.5 tonnes, less than one per cent of the weight of current technology.

Reaction Engines has also developed a way to manufacture the exchanger, which is formed from hundreds of millimetre-thick pipes arranged in a spiral formation, that involves checking it for sub-microscopic holes.

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The Sabre engine, with its heat exchanger system in place

After successfully completing 141 tests with the engine and pre-cooler installation, the team plans to design the full SABRE engine and build a demonstration model, largely from existing gas turbine technology, as well as flight-testing the installation.

This is the latest development in the technology’s long history, which dates back to a Rolls-Royce/British Aerospace project in the 1980s that was shut down when the government withdrew funding but rescued by the engine’s designer Alan Bond, who founded Reaction Engines.

Bond said the company will also look at setting up a consortium to manufacture the engine and eventually develop Skylon. ‘Reaction Engines has never had ambitions to build all of that itself,’ he told the press conference, adding that the firm would look to work with the likes of Rolls-Royce, BAE Systems or Astrium.

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The Skylon spaceplane is a single-stage-to-orbit design

Nigel McNair Scott, the company’s chairman and a major shareholder, said Reaction Engines would inevitably have to take a partner and were talking to a lot of people but that it was too early to consider takeover offers.

For more in-depth information on SABRE and Skylon, take a look at our recent Q&A with the Reaction Engines team.