Fantasy and Reality —— The Rise and Fall of the Idea of "Sun Gun"
Wen _ Dianbingtang
It is said that at the end of World War II, the German Third Reich, which was violently attacked by the East and West lines of the Allies, came to an end in the rumble of guns.
Driven by madness and despair, German scientists put all their eggs in one basket and put forward a large number of new weapon designs, such as the "Giant Mouse" super heavy tank weighing more than 1,000 tons and the "Silver Bird" space plane with a range of 20,000 kilometers. These weapons, which are divorced from rationality and common sense, are jokingly called "Nazi black technology" by future military enthusiasts.
Among them, there is a "black technology" with the strongest power and the largest amount of work-and it is also the most impossible to achieve. This is the protagonist of this article: the solar cannon.
The fantasy of the solar cannon originated in 1929. In this year, hermann oberth, a famous German rocket scientist, accidentally opened a shocking brain hole in the process of daily research: launching a huge reflector with a diameter of 100 meters into space, which can reflect sunlight to the earth at night. In this way, ordinary crops can enjoy the sunshine 24 hours a day, and the growth rate can be greatly accelerated, thus rapidly increasing the grain output of the fields. In addition, large cities can also get enough light, thus saving a lot of electricity consumed in the lighting system.
Oberth recalled: "The sun mirror I imagined is like a naughty student reflecting on the ceiling of the classroom with a mirror. If this light shines across the teacher’s face, it will probably cause him unhappiness. And I am a school teacher who has collected enough data to make this mirror. "
With the outbreak of World War II, oberth and his favorite pupil, the famous German rocket scientist Werner wernher von braun, were recruited into the German rocket research and development department to develop the famous V-2 rocket for the army. In the process, oberth revealed the idea of this orbital solar reflector to the German army. After understanding the specific working principle, the German army organized a group of experts to improve oberth’s ideas. In the end, the orbital solar reflector originally conceived for peaceful use was transformed into the doomsday weapon plan of the German army: the solar cannon!
In fact, reflecting sunlight as a weapon is not a brand-new design. As early as more than two thousand years ago, there was a legend in Greece that Archimedes used a reflector to focus sunlight and burn the invading Roman fleet. However, the Nazis magnified the power of this concept to an unprecedented order of magnitude this time. According to the German vision, as long as a giant concave mirror is launched into space and enough sunlight is gathered, it can produce an ultra-high temperature that no defense facility can resist, burn enemy warships on the ground and even destroy enemy cities!
At that time, it seemed that the idea of solar cannon as an orbital weapon was undoubtedly very advanced. Once it is realized, it is definitely conan the destroyer’s big killer. However, the rocket technology of World War II is still in its infancy. Nazi Germany consumed a lot of resources and only developed a V-2 ballistic missile with a bomb load of 1 ton. It is undoubtedly an idiotic dream to use it to launch solar cannons that must be deployed in high-altitude space orbit. After the war, oberth and Braun were captured by American troops together. During the interrogation, oberth poured beans out of the bamboo tube and gave the details of the solar gun plan to the American interrogators in detail.
When the news reached Life magazine in the United States, the olfactory-sensitive editor was immediately attracted by the theme "The Nazis tried to scorch the earth with a sun mirror". They started at full speed at once. In July 1945, when the Second World War was not completely over, Life magazine made this amazing secret weapon of Nazi Germany public.
According to Life magazine, Nazi Germany’s solar cannon is an unprecedented giant weapon and the largest artificial object ever designed by human beings. In order to focus enough sunlight and cause devastating killing effect, this weapon will be suspended in a space orbit with a height of 8,200 kilometers, with a reflector area of over 9 square kilometers and a weight of one million tons. Once completed, it will be more than 100,000 times more powerful than Archimedes’ mirror, and it can easily destroy any big city, which can be called killing people and killing Buddha!
According to the idea of Nazi scientists, the work of building a space station began with the launch of an unmanned rocket. When the rocket enters the 8200-kilometer-high orbit, it will unfold six long metal cables, which are only about 0.5-1.5 inches in diameter, and will be deployed in place by themselves under the rotation of the rocket as the starting skeleton of the solar cannon project.
Next, the subsequent rocket will transport a pair of sunglasses components from the earth to space. These sunglasses components are essentially hollow metal frames made of sodium. On the earth, high-purity metallic sodium will be rapidly oxidized and lose its luster. However, there is no such problem in space. Sodium metal has good reflection effect and low density, and it is an ideal raw material for sunglasses in the eyes of Germans. Along the skeleton, the sunglasses components are pieced together one by one, and the installation angles are slightly different from each other. Finally, a huge concave mirror can be assembled, and the solar cannon is finished.
After the solar cannon is completed, this huge mirror will leave a round hole with a diameter of 30 feet wide as a connecting channel. The cargo rocket launched from the earth will be inserted into this round hole in a seamless way to transport building materials and supplies for the solar cannon. In fact, as long as we compare the modern space station, we can find that the German design was too complicated. As long as the operation is a little careless, the launch vehicle is likely to cause irreparable damage to the docking channel, which will directly affect the safety of the solar cannon. However, in the 1940s, it was not easy for German scientists to have such a design.
The solar cannon is actually a giant space station, which needs to accommodate a large number of people for daily maintenance. To this end, German scientists deliberately launched various designs.
First of all, the energy problem of solar cannons should be solved. In this space station with an area of 9 square kilometers and a weight of millions of tons, the operation of any equipment needs the promotion of energy. Where does the energy come from? The reader’s first reaction may be to directly convert sunlight into electric energy. However, in the 1940s, the technology of solar cells was still far from mature, so the Germans chose the principle of steam turbine-placing a transparent totally enclosed water tank on the outside of sunglasses, using sunlight to heat water, generating high-temperature and high-pressure steam, driving the turbine to drive the generator, and then transporting the cooled water back to the water tank, thus generating a steady stream of electric energy.
Secondly, in the 8200-kilometer-high orbit, the interior of the space station is almost weightless. In order to make workers move relatively freely, scientists have designed special "space shoes", with magnets installed on the soles, which can be stably adsorbed on the metal floor to create an environment similar to the ground.
However, the next question is quite important. Living in space, where does the oxygen that workers breathe come from? How to get food?
The German solution made future generations feel incredible-pumpkin!
From the perspective of Nazi scientists, pumpkins can effectively consume carbon dioxide exhaled by workers and provide sufficient oxygen, and more importantly, pumpkins are nutritious and healthy food. As for eating pumpkins all day, will it lead to a decline in staff morale? Germans don’t seem to think too much. Maybe in their view, this is a problem that can be solved by preparing more spices. As a result, thousands of hydroponic farms were placed inside the space station, all of which were used to grow pumpkins. It is worth mentioning that these pumpkins can’t be directly exposed to sunlight, because there is a lack of air in outer space, which can’t filter out some cosmic rays that are unfavorable to plant growth. Therefore, some of the electric energy output by the generator of the space station is used for fluorescent lamps instead of sunlight to illuminate pumpkins and help them carry out photosynthesis.
After providing a suitable living environment, the next step is the control of the solar cannon. How to aim at a target and focus sunlight on a point is a very challenging job. Behind the mirror with an area of 9 square kilometers, there are many miniature rocket engines. By adjusting the thrust of the engine, the staff can push the solar cannon to rotate slowly. What needs to be explained here is that even with the back to the sun, the other side of the mirror is polished to minimize the solar radiation.
In addition to marveling at the huge amount of work, Life magazine thinks that the height of solar cannons is low, and the best deployment position should be geosynchronous orbit 36,000 kilometers away from the earth. Here, the solar cannon can keep relatively static with the earth, and the staff have enough time to adjust the angle of the mirror and aim at the target on the earth. In addition, American calculations show that the diameter of the spot reflected by the solar cannon to the earth may be 40 miles, which means that the focusing effect is not enough to produce any destructive power.
For this, oberth did not agree. "This beam is really not hotter than the sun on the equator, but if the diameter of the mirror is doubled, the irradiation intensity will be four times, and the temperature of the beam irradiated on the ground will be as high as 200 degrees. This beam may not be able to directly burn the city or blow up the battleship, but it can definitely cook the humans on the ground! "
When the war ended, oberth devoted himself to the study of UFO phenomenon, and firmly believed that human beings would one day be able to build the solar reflector he envisioned and put it into peaceful use. On December 28th, 1989, when the Iron Curtain of the Cold War was about to fall, oberth died quietly. At this time, his dream-the goal of making a sun mirror in earth orbit-has still not been realized.
What oberth didn’t know was that after the war, at the other end of the Iron Curtain, a Soviet rocket scientist was trying to realize his ideal.
In the late 1980s, Vladimir Sergevich Syromyatnikov (hereinafter referred to as Tennikov), a famous Soviet space scientist and inventor of the docking mechanism of Soviet/International Space Station spacecraft, came up with a solar reflector scheme to solve the lighting problem in the polar regions of the Soviet Union at midnight. Although the solar reflector he designed was not as crazy as the Nazi German solar cannon, it was enough to provide a full moon-like lighting effect for the area 5 kilometers above Fiona Fang. According to Tennikov’s idea, this design can completely ensure night lighting, making street lamps and flashlights a decoration.
Soon after, the powerful red empire collapsed, but Tennikov’s solar mirror plan was unexpectedly unaffected. On October 27th, 1992, the cargo ship "Progress M-15" was successfully launched with the solar reflector "Flag 2" designed by Tennikov. After completing the replenishment mission for the Mir space station, Progress M-15 left the Mir space station on February 4, 1993, and then launched a 20-meter-wide "Flag 2" solar reflector in orbit near the space station to carry out preliminary theoretical experiments. This experiment was quite successful. The "Flag 2" solar reflector successfully illuminated a 5-kilometer-wide area, and the brightness was almost comparable to that of the full moon! In the end, this solar mirror followed the "Progress M-15" into the atmosphere and burned out.
Tennikov was greatly encouraged and designed "Flag 2.5" again. According to his prediction, this 25-meter-wide improved solar reflector can produce brightness equal to 5-10 full moons when it is started, illuminating a circular area with a diameter of 7 kilometers. Unfortunately, after the launch, an accident occurred during the deployment of the "Flag 2.5" solar reflector. At that time, a lens was caught in the communication antenna of Mir space station, and the strong communication antenna quickly tore the lens, causing the sunglasses to lose control. In the end, this attempt failed, and this solar mirror, together with the cargo ship "Progress", was burned when it re-entered the atmosphere. Tennikov’s solar mirror plan was cancelled by the Russian Space Agency, which had poor financial resources, because of its high cost.
However, Tennikov didn’t give up easily. He went around trying to find new investors, hoping to carry on his solar mirror plan. In order to raise funds, Tennikov almost devoted his efforts to this project. Unfortunately, until his death in 2006, Tennikov had not raised enough funds to continue his "Flag" project.
Throughout the development of solar cannons, we can see that there are three obvious shortcomings that limit the development of this equipment.
First of all, the cost of building a solar cannon is amazing! According to oberth’s original idea, his solar cannon would cost $3 billion-an astronomical sum at that time. Even the Manhattan Project of the United States to develop nuclear weapons at the same time cost only $2 billion! Compared with the atomic bomb that can instantly destroy a big city, oberth’s solar cannons cost a lot, but even people on the ground are hard to kill, which is obviously not worth it.
At the same time, to build a huge solar cannon in space orbit, its engineering quantity and assembly difficulty are very amazing. Although oberth once imagined that this million-ton solar cannon could be built in 15-20 years. But until today, the most Ushizo object assembled by human beings in Earth orbit is only the "International Space Station" with a total weight of 500 tons-this is the result of the cooperation of dozens of countries, including the United States and Russia, in 20 years! Moreover, compared with the international space station built by docking module, the engineering complexity of the solar cannon is several times more difficult: because each mirror must be accurately installed in place, the workers responsible for assembling the solar cannon must wear heavy spacesuits and manipulate wrench tools to install the mirrors one by one, which is difficult for ordinary people to imagine. Even by the time standard of building the International Space Station, it takes at least a dozen generations of efforts and hundreds of years to complete a solar cannon with a weight of one million tons!
In addition, the vulnerability of solar cannons is also a problem that people must consider. Although solar cannons in orbit can intercept incoming anti-satellite missiles by reflecting sunlight. However, in wartime, the enemy is likely to use a large number of missiles to launch a saturation attack on this orbital mirror. As long as one missile breaks through the interception line and hits the solar cannon, it can destroy a large number of mirrors and make this expensive special weapon a waste. Moreover, even in peacetime, solar cannons face a major threat-space junk that can be seen everywhere in space orbit. Because of its huge size, the solar cannon has become an excellent target for space junk flying at high speed. As long as space junk destroys one of the mirrors, the effect of the whole solar gun system will be greatly reduced.
Although the practical application of solar cannons has encountered many difficulties, this does not mean that no one will carry forward the concept of orbital reflector. On March 23, 1983, President Ronald Reagan announced the strategic defense plan of the United States-the famous "Star Wars" plan. In this ambitious plan, the US military also used an orbital light reflector. However, the light source of these light reflectors is no longer ordinary sunlight, but high-energy laser emitted from the ground! According to the U.S. military’s vision, this weapon can directly reflect the high-energy laser beam emitted by the ground excimer laser transmitter and destroy the enemy ballistic missiles that are on the rise. Once a nuclear war breaks out, the United States can use this weapon to quickly destroy the incoming Soviet ballistic missiles, and then launch a retaliatory nuclear strike without worrying that the nuclear bomb will fall on its own head.
Of course, such a powerful weapon still needs to pay a price. Because the laser beam must penetrate the atmosphere, and then be transmitted to the attacking satellite through the relay satellite and then refracted to the target, the laser transmitter on the ground must be very powerful to be competent for this work. In order to achieve this goal, Americans put a lot of money into the development of ground lasers. Until the "Star Wars" project was cut by President Clinton in 1993, the ground laser station for providing light source was still not developed. In the end, the orbital reflector scheme was abandoned by the US military, and the development experience related to the project was applied to other laser weapon research projects of the US military.
Although the solar cannon and its derivative products have not been successful in reality, it does not mean that it cannot be a popular weapon in various cartoons, games and movies. In the story of the classic sci-fi cartoon "mobile suit 0079", Ji Wengjun owns a solar shaped gun transformed from a colonial satellite. In the subsequent development of the plot, this solar cannon directly swept the fleet of the Union Army and destroyed one-third of the main ships of the other side. This led to a forced attack by the Union Army of the Earth, which destroyed this threatening solar shaped charge gun. However, this solar energy gathering gun provides energy through the surrounding solar panels, which is essentially different from the working principle of the solar energy gun envisioned by oberth.
Besides appearing in the mobile suit series, Sun Cannon also appeared in the Resident Evil series of games. In the plot background of the game Resident Evil: Revelation, a maritime city in the Mediterranean Sea, Tra Griga, collects sunlight through an orbiting solar reflector to provide sufficient solar energy for lighting. When the "Hound" organization launched a biochemical terrorist attack in the city, which turned the whole city into a hell full of monsters, the top management of the Federal Bioterrorism Committee decided to turn the solar reflector into a solar cannon and emit a high-energy beam to completely destroy the city. As Terra Griga was completely reduced to ashes by high-energy beams, the story of the game-Floating Island Panic came to an end.
However, the most original work of oberth’s solar cannon design is the last 007 film "Die Another Day" starring pierce brosnan. In this movie, James Bond’s enemies have a solar cannon in orbit exactly as oberth imagined. In the film, this solar cannon destroyed the rocket car driven by Bond, the huge ice sculpture building, the missiles that attacked the solar cannon, and even the transport plane that the villain was riding! Perhaps the director of the film wants to pay tribute to oberth, the visionary of the orbital solar reflector. When the villain in the film announced the existence of the solar gun, he deliberately advocated that the orbital gun was only used for "civil lighting".
Although oberth’s idea of a solar cannon, and the idea of an orbital reflector derived from it, has not yet come true. However, his solar cannon is still active in many sci-fi works and is regarded as a classic sci-fi technology setting, which makes people feel very gratified. With the continuous development of space science and technology, maybe in the near future, someone will follow oberth’s legacy, solve the technical problems that limit the development of solar cannons, and finally develop an orbital reflector for the peaceful use of solar energy for the benefit of mankind!