A photo from open sources
Throughout the twentieth century, science fiction writers wrote a lot and talented about space exploration. The heroes of “Hiusa” gave mankind wealth Uranium Golconda pilot Pirks worked as captain of space bulk carriers, container carrier leaders walked through the solar system and bulk carrier trumps, and I’m not talking about all the mysticism of traveling to mysterious monoliths.
However, the 21st century did not live up to expectations. Humanity is timidly standing in hallway of Cosmos, not permanently selected beyond the earthly orbits. Why it happened and what to hope for those who would like read the news about increasing the yield of Martian apple trees?
Violinist is not needed
The first paradox we encountered is that man is not the most suitable subject for space exploration. Science fiction writers who invented space expeditions could only rely on the historical experience of the pioneers of the Earth – mariners, polar explorers, the first aviators. Indeed, than, seemingly, will the conquest of Mars differ from the conquest of the South Pole?
Both here and there unsuitable for life without prior preparation environment, you need to bring supplies with you, and outside the ship or at home you cannot go out without putting on special equipment. But science fiction and futurologists could not predict the development of electronics and robotics, and research robots are usually described in anecdotal vein:
“I had to break away from the letter for half an hour and listen lamentations of my neighbor, cybernetist Shcherbakov. You probably you know that north of the rocket race there is a grand underground plant for the processing of uranium and transuranides. People work in six shifts. Robots – round the clock; wonderful machines, the last word of practical cybernetics. But as they say Japanese, a monkey also falls from a tree. Now come to me Shcherbakov, angry as hell, and said that the gang of these mechanical idiots (his own words) tonight pulled one of large ore depots, taking it, obviously, as unusually rich field. Robot programs were different, so by morning part of the warehouse was in the rocket launcher’s warehouses, part – at the entrance to geological management, and part of it is generally unknown where. Search going on. ”
But none of the well-known authors guessed that the robot is in development space has many advantages over humans:
Unlike humans, a robot only needs power and ensuring heat balance. No need to carry tens of tons greenhouses, food, water, oxygen, clothing and hygiene products, medicines and other things. The robot can be sent in one direction, without returning. The robot is able to work for years. Experience of “Voyagers”, rovers or “Cassini” says that now it’s more correct to talk not about years, and decades. The robot is able to work for years in conditions which are deadly to humans. Galileo probe received a dose of 25 times exceeding mortal for a person and after that he worked for orbit 8 years.
As a result, it turned out that only robots weighing several tons fit into the technical capabilities of mankind send them to other planets for reasonable money and began the only way to satisfy the scientific curiosity and getting beautiful photos.
We live in a logistic curve
The second mistake of the science fiction was that they predicted linear or even exponential development of astronautics. Although still in 1838 such a phenomenon as a logistic curve was discovered. What is this terrible beast? For example, take the history of aviation:
1900s The first clumsy whatnots, the first records – flying to several kilometers with one passenger. 1910s The first scouts fighters, bombers, postal and passenger aircraft. 1920-1930s Flight mastering at night, the first transcontinental flights. 1940s Aviation is a serious military and transport force. 1950s Jet engines give a new impetus to the development of aviation – new speeds, ranges and heights, even more passengers. 1960-70s. The first supersonic and widebody passenger airplanes, aviation are qualitatively more accessible. 1980-90s. Braking. Development is becoming more expensive, development companies are combined into giant company. And airplanes are more and more alike. 2000s Limit. Two giants Boeing and Airbus make outwardly identical cars, supersonic passenger planes generally died out.
If you translate these achievements into numbers, you get this picture:
A photo from open sources
In space, the situation is exactly the same:
A photo from open sources
For clarity, the graph of the S-curve can be superimposed expenses to achieve this level:
A photo from open sources
And the sadness of our “today” is that in space existing technologies, we are close to the level of saturation. Technically can fly in a manned version to the moon and even Mars, but somehow sorry for the money.
Luggage KTs – get a gravitsapu
The next sad aspect that slows down the jerk into space is not yet found something very valuable, for which it’s worth spending money on space exploration beyond the earth’s orbit. Please note that on Near-Earth orbit is now a mass of commercial satellites – communications, TV and the Internet, meteorological, cartographic. And u all of them have tangible benefits expressed in money. And what the benefits of a manned moon flight program? Here is the official US $ lunar program results list for approximately $ 170 billion (in 2005 prices):
The moon is not the primary object, it is a planet of the earth group, with its evolution and internal structure similar to Earth. The moon is ancient and preserves the history of the first billions of years of evolution of the terrestrial planets. The youngest moon rocks are about the same age as the ancient earthly. Traces of the earliest processes and events that, possibly influenced the moon and the earth, can only be found now on the moon. Moon and Earth are genetically related and formed from various proportions of the general set of materials. The moon is lifeless and not contains living organisms or local organic matter origin. Lunar rocks descended from high temperature processes without the participation of water. They are divided into three types: basalts, anorthosites and breccias.
A very long time ago the moon was melted to a great depth and formed an ocean of magma. Lunar mountains contain the remains of early rocks low density that floated on the surface of this ocean. The ocean of magma was formed by a series of strokes of huge asteroids, which formed pools filled with lava flows.
The moon is somewhat asymmetric, possibly due to the influence of the Earth. The surface of the moon is covered with pieces of rock and dust. It is called lunar regolith and contains a unique radiation history of the Sun, which is important for understanding climate change on Earth.
This is all very interesting (no jokes), but all this knowledge they have an irreparable flaw – they cannot be spread on bread, pour into a gas tank or build a house out of them. If in the vast space would have been discovered a certain “elerium”, “Tiberium” or another shishdostanium, which could be used as:
Cost effective source of energy.
An integral element of the production of something valuable and necessary.
Food / medicine / vitamin of a fundamentally new quality.
A luxury item or a source of pleasure.
If he also grew only on Mars or in the asteroid belt (and not reproduced on Earth) and could only be mined by man (so that cunning humanity does not send cheaper and unpretentious robots), then it would be precisely manned development space would receive an invaluable stimulus. And in the absence of him in pessimistic scenario in the 2020s, humanity can lose permanent presence even in Earth orbit – on background of politically battered pots of international cooperation taxpayers may ask: “Why do we need a new station after ISS? ”
Curse of the Tsiolkovsky formula
Here it is, Nemesis of Cosmonautics:
A photo from open sources
Here:
V is the final velocity of the rocket. I – specific impulse of the engine (how many seconds an engine per 1 kilogram of fuel can create thrust 1 Newton) M1 – the initial mass of the rocket. M2 – final mass rockets.
V for the case of full tanks is the characteristic reserve speed, i.e., the margin of speed that we can accelerate / decelerate if necessary. It is also called by delta-V stock (delta means change, i.e. this is stock speed changes).
What is the problem here? Take a map of the required speed changes for the solar system:
A photo from open sources
Imagine now that we want to fly to Mars and back. it will be:
9400 m / s – start from the Earth. 3210 m / s – departure from the Earth’s orbit. 1060 m / s – the interception of Mars. 0 m / s – access to the low orbit of Mars (white triangle means the possibility of braking about the atmosphere). 0 m / s – landing on Mars (brake on the atmosphere). 3800 m / s – start from Mars. 1440 m / s – acceleration from Mars orbit. 1060 m / s – interception of the Earth. 0 m / s – access to the Earth’s low orbit (retardation of the atmosphere). 0 m / s – landing on Earth (we brake about the atmosphere).
The result is a beautiful figure 19970 m / s, which we round to 20,000 m / s. May our rocket be perfect, and fuel volume does not affect its mass in any way (tanks, pipelines do not weigh anything). Let’s try to calculate the dependence of the initial mass rockets from the final mass and specific impulse. Transforming the formula Tsiolkovsky, we get:
M1 = eV / I * M2
We will use the free mathematical package Scilab. Ultimate we take the mass in the range of 10-1000 tons, the specific impulse will be vary from 2000 m / s (chemical engines on hydrazine) to 200 000 m / s (theoretical estimate of the maximum impulse of electric propulsion for today). I must say right away that for maximum mass and minimum momentum will be very important (22 million tons), so the scale The display will be logarithmic.
[m2 I] = meshgrid (10: 50: 1000,2000: 5000: 200000); m1 = log (exp (20000 * I. ^ – 1). * m2); surf (m2, I, m1)
A photo from open sources
This beautiful graph, in fact, is a visual chemical sentence engines. This is not news – on chemical engines like this practice shows perfectly, you can normally run small probes, but even to the moon to fly with the crew already several difficult.
Let’s ease the conditions. First, let’s say we start already from Earth’s orbit, and instead of 20 km / s we’ll need 10. Secondly, we cut the tail of inefficient chemical engines by minimum value I 4400 m / s (UI of the hydrogen engine Space Shuttle RS-25):
[m2 I] = meshgrid (10: 50: 1000,4400: 5000: 200000); m1 = log (exp (10000 * I. ^ – 1). * m2); surf (m2, I, m1)
Logarithmic scale:
A photo from open sources
Linear scale:
A photo from open sources
We give up completely on chemical engines. Nuclear engine NERVA had a UI of 9000 seconds. Recount:
[m2 I] = meshgrid (10: 50: 1000,9000: 5000: 200000); m1 = exp (10000 * I. ^ – 1). * m2; surf (m2, I, m1)
Linear scale:
A photo from open sources
Why am I repeating these monotonous graphs? The fact is that a flat area labeled as “cause for optimism” shows that when engines with a UI of more than 50,000 m / s appear, within The solar system will be able to more or less tolerably fly without ships starting mass of millions of tons. And the ERD, which are already Now, they have UI 25000-30000 m / s (for example, SPD 2300). However, you must understand that the reason for optimism is very restrained. Firstly, these thousands of tons must be delivered to the Earth’s orbit (and this extremely difficult). Secondly, existing electric propulsion engines have little thrust, and to accelerate with a suitable acceleration, you must set multi-megawatt reactors.
Let’s build another interesting chart. Let us know the ultimate weight – 1000 tons. We construct the dependence of the initial mass on specific impulse and final speed:
[V I] = meshgrid (10000: 2000: 100000,50000: 5000: 200000); m1 = exp (V. * (I. ^ – 1)) * 1000; surf (V, I, m1)
A photo from open sources
This graph is interesting in that it is, in a sense, a look at the farther future of humanity. If we want a comfortable and fast flight through the solar system, you will have to go another higher order in the development of specific impulse – need engines with MDs of several hundred thousand meters per second.
No fish here
Humanity is distinguished by cunning and ingenuity. therefore many ideas were invented in order to facilitate access to space. One of the most important parameters characterizing that barrier, which we want to jump is the price of removing a kilogram per orbit. Now, according to various estimates (this column was removed from Wiki, here, for example, another source) for various launch vehicles, this the price is in the range of $ 4000- $ 13000 per kilogram for low Earth orbit. What they tried to come up with in order to make it easier is it easier and cheaper to get out into at least near-Earth orbit?
Reusable systems. Historically, this idea has already managed once fail in the Space Shuttle program. Now Elon is doing this Musk planning to plant the first step. I would like to wish him every success, but based on the past failure I don’t think that it will be a qualitative breakthrough. At best, the cost will fall on a few percent.
Single Stage to Orbit. Not beyond the scope of projects, despite repeated attempts. Air start. There is a successful project for small payload but does not scale under heavy goods.
Rocket-free space launch. Many projects were invented, but they all have a fatal flaw – they require astronomical investments that cannot be beaten off without complete completion project. Until the space elevator, fountain or mass driver is fully built and running, no profit from it.
What will calm my heart
How can you cheer up after these sad thoughts? At I have two arguments – one abstract and fundamental, another more specific. First, progress in general is not one S-curve, and a lot of them, which forms such an optimistic picture:
A photo from open sources
In the history of aviation, one can distinguish, for example:
A photo from open sources
And, for sure, we are at a similar point in development astronautics. Yes, now there is some stagnation, and even a rollback is possible, but humanity is in the heads of its best representatives breaks through the wall of knowledge, and somewhere, not yet seen, shoots of the new future make their way.
The second argument is news about development of a nuclear reactor for transport and energy module:
A photo from open sources
The latest news on this project was in the summer – assembled the first fuel rod. Works, albeit without regular publicity, obviously going on, and one can hope for the appearance in the coming years of a fundamentally new apparatus – a nuclear tug with ERD
P.S
These are somewhat unkempt thoughts, we will call them the first iteration. I want to get feedback – maybe I missed something or it’s wrong determined the significance of the phenomenon. Who knows, maybe after processing feedback will turn out a more slender concept or come up with something interesting?
Avor: lozga
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