Steam could do serious work not only in the 19th century, but also in the 21st century.
The first artificial Earth satellite, launched into orbit on October 4, 1957, by the USSR, weighed only 83.6 kg. It was he who opened the space age for humanity. At the same time, the space race began between the two powers - the Soviet Union and the United States. Less than a month later, the USSR amazed the world again by launching a second satellite weighing 508 kg with the dog Laika on board. The United States was able to answer the call only in the next year, 1958, by launching the Explorer-1 satellite on January 31. Moreover, its mass was ten times less than the first Soviet satellite - 8, 3 kg … American engineers, of course, could imagine putting a heavier satellite into orbit, but at the very thought of how much fuel the launch vehicle should carry, they did not by oneself. One of the popular American magazines wrote: “In order to launch a satellite into low-earth orbit, the mass of the rocket must exceed the mass of the payload by several thousand times. But scientists believe that advances in technology will allow them to reduce this ratio to one hundred. But even that figure implied that launching a satellite large enough to be useful would require burning huge amounts of expensive fuel.
To reduce the cost of the first stage, a variety of options have been proposed: from building a reusable spacecraft to completely fantastic ideas. Among them was the idea of Arthur Graham, head of advanced development at Babcock & Wilcox (B&W), which has been making steam boilers since 1867. Together with another B&W engineer, Charles Smith, Graham tried to figure out if the spacecraft could be put into orbit using … steam.
Steam and hydrogen
Graham at this time was engaged in the development of supercritical high-temperature boilers operating at temperatures above 3740C and pressures above 220 atm. (above this critical point, water is no longer a liquid or a gas, but a so-called supercritical fluid, combining the properties of both). Can steam be used as a "pusher" to reduce the amount of fuel in the first stage of a launch vehicle? The first estimates were not overly optimistic. The fact is that the rate of expansion of any gas is limited by the speed of sound in this gas. At a temperature of 5500C, the speed of sound propagation in water vapor is about 720 m / s, at 11000C - 860 m / s, at 16500C - 1030 m / s. These speeds may seem high, but one should not forget that even the first cosmic speed (required to put a satellite into orbit) is 7, 9 km / s. So a launch vehicle, though large enough, will still be needed.
However, Graham and Smith found another way. They did not limit themselves to just the ferry. In March 1961, on the instructions of B&W management, they prepared a secret document entitled "Steam Hydrogen Booster for Spacecraft Launch", which was brought to the attention of NASA. (However, the secrecy did not last long, until 1964, when Graham and Smith were granted US patent No. 3131597 - "Method and apparatus for launching rockets"). In the document, the developers described a system capable of accelerating a spacecraft weighing up to 120 tons to a speed of almost 2.5 km / s, while the accelerations, according to calculations, did not exceed 100g. Further acceleration to the first space velocity was to be carried out with the help of rocket boosters.
Since steam is not capable of accelerating a space projectile to this speed, B&W engineers decided to use a two-stage scheme. At the first stage, the steam compressed and thus heated hydrogen, the speed of sound in which is much higher (at 5500C - 2150 m / s, at 11000C - 2760 m / s, at 16500C - more than 3 km / s). It was hydrogen that was supposed to directly accelerate the spacecraft. In addition, the friction costs when using hydrogen were significantly lower.
Super gun
The launcher itself was supposed to be a grandiose structure - a gigantic supergun, equal to which no one had ever built. The barrel with a diameter of 7 m was 3 km (!) High and had to be located vertically inside a mountain of appropriate dimensions. To access the "breech" of the giant cannon, tunnels were made at the base of the mountain. There was also a plant for producing hydrogen from natural gas and a giant steam generator.
From there, the steam through pipelines entered the accumulator - a steel sphere of 100 meters in diameter, located half a kilometer under the base of the barrel and rigidly “mounted” into the rock mass to provide the necessary wall strength: the vapor in the accumulator had a temperature of about 5500C and a pressure of more than 500 atm.
The steam accumulator was connected to a container with hydrogen located above it, a cylinder with a diameter of 25 m and a length of about 400 m with rounded bases, using a system of pipes and 70 high-speed valves, each about 1 m in diameter. In turn, a hydrogen cylinder with a system of 70 slightly larger valves (1.2 m in diameter) was connected to the base of the barrel. It all worked like this: steam was pumped from the accumulator into the cylinder and, due to its higher density, occupied its lower part, compressing hydrogen in the upper part to 320 atm. and warming it up to 17000C.
The spacecraft was installed on a special platform that served as a pallet during acceleration in the barrel. It simultaneously centered the apparatus and reduced the breakthrough of accelerating hydrogen (this is how modern sub-caliber projectiles are arranged). To reduce the resistance to acceleration, air was pumped out of the barrel, and the muzzle was sealed with a special diaphragm.
The cost of building the space cannon was estimated by B&W at about $ 270 million. But then the cannon could "fire" every four days, reducing the cost of the first stage of the Saturn rocket from $ 5 million to some measly $ 100 thousand. At the same time, the cost of putting 1 kg of payload into orbit fell from $ 2500 to $ 400.
To prove the efficiency of the system, the developers proposed to build a scale model of 1:10 in one of the abandoned mines. NASA hesitated: having invested huge amounts of money in the development of traditional rockets, the agency could not afford to spend $ 270 million on competing technology, and even with an unknown result. Moreover, an overload of 100g, albeit for two seconds, clearly made it impossible to use the supergun in a manned space program.
Jules Verne's dream
Graham and Smith were not the first or the last engineers to be captured by the concept of cannon launching of spacecraft. In the early 1960s, Canadian Gerald Bull was developing the High Altitude Research Project (HARP), firing high-altitude atmospheric probes to an altitude of almost 100 km. At the Livermore National Laboratory. Lawrence in California until 1995, as part of the SHARP (Super High Altitude Research Project) project under the leadership of John Hunter, a two-stage gun was developed, in which hydrogen was compressed by burning methane, and a five-kilogram projectile accelerated to 3 km / s. There were also many projects of railguns - electromagnetic accelerators for launching spacecraft.
But all these projects faded before the B&W supergun. “There was a terrible, unheard-of, incredible explosion! It is impossible to convey its power - it would cover the most deafening thunder and even the roar of a volcanic eruption. From the bowels of the earth a gigantic sheaf of fire rose, as if from the crater of a volcano. The earth shook, and hardly any of the spectators at that moment managed to see the projectile triumphantly cutting through the air in a whirlwind of smoke and fire "… - this is how Jules Verne described the shot of the giant Columbiade in his famous novel.
The Graham-Smith cannon should have made an even stronger impression. According to calculations, each launch required about 100 tons of hydrogen, which, following the projectile, was thrown into the atmosphere. Heated to a temperature of 17000C, it ignited when it came into contact with atmospheric oxygen, turning the mountain into a giant torch, a pillar of fire stretching several kilometers upward. When such an amount of hydrogen burns, 900 tons of water are formed, which would dissipate in the form of steam and rain down (in the immediate vicinity, possibly boiling). However, the show did not end there. Following the burning hydrogen, 25,000 tons of superheated steam were thrown upward, forming a giant geyser. Steam also partially dispersed, partially condensed and fell out in the form of heavy rainfall (in general, drought did not threaten the immediate vicinity). All this, of course, had to be accompanied by phenomena such as tornadoes, thunderstorms and lightning.
Jules Verne would have loved it. However, the plan was still too fantastic, therefore, despite all the special effects, NASA preferred a more traditional way of space launches - rocket launches. Too bad: a more steampunk method is hard to imagine.
