Skylon is the name of a promising project presented by Reaction Engines Limited. Within the framework of this project, in the near future, an unmanned reusable spacecraft can be created, which, according to the developers, can be used to carry out inexpensive and reliable flights into space. The preliminary examination of this project has shown that there are no design and technical errors in it. According to some experts, the Skylon spacecraft will be able to reduce the cost of launching cargo into orbit by about 15-20 times. In recent years, the company has been actively looking for the necessary financing for the development of the project, and it seems that it has found it.
On July 17, 2013, the UK government announced plans to invest money in the development of the new SABER air-breathing rocket engine. For these purposes, it is planned to allocate nearly 60 million pounds (about 91 million dollars). Thanks to this, the most daring and ambitious space project of the last 10 years received money for further work and recognition. In case of successful work on the creation of an innovative power plant SABER, which is a hypersonic combined air-jet engine and is, in fact, the heart of the spacecraft, flight tests of the Skylon could begin as early as the end of this decade.
It is planned that the creation of Skylon will help to make cheap launch of cargoes weighing up to 12-15 tons into orbit. At the same time, the design of this spacecraft is such that it does not have any detachable stages, and takeoff and landing take place in an airplane mode, which significantly simplifies the operation of the spacecraft.
After lifting into the air from the runway, the SABER power plant installed on the spacecraft operates as a hypersonic ramjet engine. During this time, very high pressure outside air is delivered to a combustion chamber that uses hydrogen as fuel. In this mode, the engine works until the spacecraft accelerates to a speed of 5M, and the flight altitude reaches 25 km. After that, the power plant switches to rocket mode using an oxidizer in the form of liquid oxygen.
The principle described above can significantly reduce the amount of oxidizer on board; this also saves the spacecraft from the need to discharge the spent stages. But at the same time, one more problem remains: when the engine is operating in the scramjet mode, the air that is supplied to the combustion chamber must be compressed to 140 atmospheres. Which, in turn, is fraught with such an increase in the temperature of the process that any of the known earthly materials will not be able to cope with this temperature and will simply melt.
It is this fact that until recently put an end to the creation of a combined engine. However, at the end of 2012, Reaction Engines representatives were able to present a solution to this problem to the general public. The engineers of the British company managed to create a key element of the new SABER engine - an air cooler that enters the air intake. It was this detailing of the new combined engine that raised the greatest questions.
The innovative development of the Reaction Engines company allows in the shortest possible time (in just 0.01 seconds) to drop the temperature of the incoming atmospheric air from 1000 ˚C to -150 ˚C. It seems incredible, but engineers were able to demonstrate a similar installation on a prototype. In the pre-cooling chamber, British engineers used a two-stage scheme "gaseous helium - liquid nitrogen". A special heat exchanger with high efficiency is actually able to cool the incoming air flow to the required temperature in a split second (below the freezing point of water). Of course, we have to admit that such heat exchangers existed before, but they were huge in size as a real factory, while the British managed to reduce them to a size suitable for use on the Skylon spacecraft, which has a maximum length of 84 meters.
About one year ago, Reaction Engines reported successful ground tests of a preliminary version of its cooler. Therefore, most likely, the "bottleneck" of the hybrid engine has been overcome. This is evidenced by the strong financial support from the British government. With this financial support, the British company can start creating a prototype of the SABER hybrid engine, which should be ready by 2017.
Revolutionary, in its essence, the spacecraft will be able to take off from ordinary runways, which are in any major airport. And installed on it 2 oxygen-hydrogen engines will be able to deliver it to an altitude of more than 29 kilometers, as well as launch satellites into low earth orbit. According to preliminary information, the passenger version of Skylon will be able to take on board at least 24 passengers, while the spacecraft will not have pilots - the engines, altitude and thrust will be controlled using a modern computer system. This computer system will also be responsible for the transition to the rocket mode of operation of the engines when the spacecraft leaves the earth's atmosphere.
With the most ideal development of the situation, Reaction Engines expects to begin testing the first built Skylon spacecraft already in the 2020s, which theoretically will have every chance of becoming a revolution in the entire space industry. In the future, British engineers expect to use the Skylon as a transport ship that could deliver astronauts and cargo to the ISS. “Access to space today is incredibly expensive, but there are no laws of physics that say that it should be so in the future. We are well aware that now all this is a bit like science fiction, but at the same time we firmly believe that Skylon will be able to prove the opposite to the world, making space travel affordable enough for everyone,”- said Richard Warwill, Technical Director of Reaction Engines.
