None of the invention does not disappear into oblivion. Researchers at NASA, realizing that new is well forgotten old, draw inspiration from the inventions of the last century. Recently they have experienced miniature nuclear reactor, which can be used when creating space ships-scouts. But it is based on two inventions of the nineteenth century.

Yes, indeed, the basis of this experimental miniature design - a long-forgotten Stirling engine, which was invented in the nineteenth century. The principle of operation of the engine is simple: it is based on periodic heating and cooling of gas, due to changes in volume, and energy is released. The space Agency engineers also used the technology of thermal handsets, invented at Los Alamos national laboratory in 1963 as part of the engine. Actually both of these inventions were made earlier. However, let us all the more.

The Stirling engine is actually bears the name of two people - one who has patented the invention, and the one who first tested it. Do not be surprised that these two people have the same last name - we are talking about two brothers. Moreover, the inventor was a Scottish priest of life kirk Robert Stirling. But if to be objective, the monk Stirling had not invented the engine, and one very important detail, which is called "economy of heat" (now such a device would call regenerator or heat exchanger).

Life Creek is located close to industrial centre Methven, so the arrival of Stirling often visited workers, workers in factories nearby. Every day the priest had to listen to their stories about what steam engines, with whom they had to deal with, often explode because of the low quality of iron, which went to their production. These explosions killed and maimed people, however, business owners couldn't help it - more durable materials did not exist. And so impressionable priest, who since childhood, fond of design of different machines, decided to help their parishioners.

Stirling decided to use the experience of the designers of the end of XVII century and studied the drawings of the so-called air engines, which by that time was virtually replaced the traditional steam machine. These engines were a camera, through which moved gas. Going one way, he gave heat, and the other took it. Himself Stirling just invented a kind of facing, which increases heat transfer properties of the engine, which allowed him to work at lower pressure steam. Thus, the mechanism could not explode - it just would not have enough pressure circulating gas.

Robert Stirling received a patent for his invention in 1816, and in 1840 his brother, engineer James Stirling built the first such engine. Secure mechanism to quickly became interested in many Industrialists, and the popularity of the engine has increased rapidly. It was used until 1876, when the invention Henry Bessemer made sufficiently safe traditional steam machine. From this time on air engines have forgotten, however, as it turns out, not forever. In our days remembered experts from NASA, which, incidentally, is very symbolic - the fact that among the Hobbies of the Reverend Robert Stirling (and his brother James, too), was listed astronomy.

As for thermal handsets, the first time these devices also appeared in the XIX century. In fact, they represent an element of the cooling system, the principle of which is based on the fact that in closed tubes of heat-conductive metal (for example, copper) is boiling liquid. Heat transfer in them is due to the fact that the liquid evaporates at the hot end of the tube, absorbing heat of vaporization, and condenses on the cold, where moved back to the hot end.

The first heat pipes used for cooling steam engines from the middle of the last century, but in the twentieth century George GROOVER from Los Alamos National Laboratory proposed the use in these tubes, the principle of capillary effect (that is the effect, for example, allows kerosene up the wick of the lamp). These tubes were used in electronics - in particular, they are still used for cooling the processors and chipsets.

But back to modern developments - research team of NASA and the Department of energy showed that a nuclear reactor on the basis of old technologies can be installed on the spacecraft. The engine will run on 23 kg of uranium batteries, and it produces heat will go to eight Stirling engines, which will produce about 500 watts of power. Test samples produced so far, only 24 watt, while space probes typically requires eh 600 to 700 watts.

Heat pipes and Stirling engines will be able to provide energy to a single module of the ship, just to ensure a flight will take several modules, which together will produce about one kilowatt of energy. The main advantages of the new development, said in Los Alamos, is the simplicity of the mechanism and use in his work of resources, which the United States possesses in abundance. In addition, because a nuclear reactor will only work in space, the likelihood of accidents on the ground or during startup practically reduced to zero.

In the last few years, NASA has used as a source of energy for space probes plutonium-238 - on it, in particular, was flying ships Voyager series. Cassini, who is now in orbit of Saturn, also uses plutonium-238. However, in the early 1980s, the States began to curtail production of plutonium, and by 1991 to create it was simply nowhere. One of the latest projects NASA, which used plutonium-238, was the Curiosity Rover, which is now sweeping the surface of the red planet.

In 2011, NASA and the Department of energy has received about $ 10 million to restart plutonium production, and in the near future the United States will be able every year to issue on a few pounds of this energy source. Nuclear Stirling engine, generating electricity and running on uranium, will lead to reduction of demand for plutonium.

Meanwhile, experts say, it seems that the era of space exploration by man over. The robot can do the same thing as Homo sapiens, the only cost is cheaper and risking the health and lives do not have anyone. The traces left on the moon, already 40 years were executed, and the following will leave not the sole, and wheels.

All the latest studies of the planets of the Solar system worked robotic probes, lowered and orbital spacecraft landed on the moon, asteroids, comets, each planet of the Solar system and the majority of their satellites. On the other hand, and in manned research has a very good track record. Over the last four decades have been published more than two thousand works, based on the data collected during the Apollo manned missions, and the number of new reports continues to grow.

Compared with robots, the man has a lot of advantages. He responds more quickly to changing circumstances and takes decisions independently, without waiting for instructions from Earth. People are significantly more mobile: astronauts of Apollo 17 in three days covered a distance of 35 kilometers, while the Rover that would take eight years. In the end, people can get samples of rocks at a greater depth and to use a whole Arsenal of geological instruments.

Chief researcher of the Center of space flight center at NASA says that as such the battle between man and robot - rather, it's comparing apples and oranges. "We send robots as Rangers and scouts, so they opened new frontiers and we would decide when and where to send people", - the expert concludes.