Rockets and spacecraft. How a rocket takes off: astronautics in simple words
This article will introduce the reader to such an interesting topic as a space rocket, a launch vehicle and all the useful experience that this invention has brought to mankind. It will also be told about payloads delivered into outer space. Space exploration began not so long ago. In the USSR, it was the middle of the third five-year plan, when World War II ended. The space rocket was developed in many countries, but even the United States failed to overtake us at that stage.
First
The first in a successful launch to leave the USSR was a space launch vehicle with an artificial satellite on board on October 4, 1957. The PS-1 satellite was successfully launched into low Earth orbit. It should be noted that for this it took six generations, and only the seventh generation of Russian space rockets were able to develop the speed necessary for reaching near-Earth space - eight kilometers per second. Otherwise, it is impossible to overcome the attraction of the Earth.
This became possible in the process of developing long-range ballistic weapons, where engine boosting was used. Not to be confused: a space rocket and a spaceship are two different things. A rocket is a delivery vehicle, and a ship is attached to it. Anything can be there instead - a space rocket can carry a satellite, equipment, and a nuclear warhead, which has always served and still serves as a deterrent for nuclear powers and an incentive to preserve peace.
Story
The first to theoretically substantiate the launch of a space rocket were the Russian scientists Meshchersky and Tsiolkovsky, who already in 1897 described the theory of its flight. Much later this idea was picked up by Oberth and von Braun from Germany and Goddard from the USA. It was in these three countries that work began on the problems of jet propulsion, the creation of solid-fuel and liquid-propellant jet engines. Best of all, these issues were resolved in Russia, at least solid-fuel engines were already widely used in World War II ("Katyusha"). Liquid-propellant jet engines turned out better in Germany, which created the first ballistic missile - the V-2.
After the war, the team of Wernher von Braun, having taken drawings and developments, found shelter in the USA, and the USSR was forced to be content with a small number of individual rocket assemblies without any accompanying documentation. The rest they invented themselves. Rocket technology developed rapidly, increasing the range and mass of the load carried more and more. In 1954, work began on the project, thanks to which the USSR was the first to carry out the flight of a space rocket. It was an intercontinental two-stage ballistic missile R-7, which was soon upgraded for space. It turned out to be a success - exceptionally reliable, providing many records in space exploration. In a modernized form, it is still used today.
"Sputnik" and "Moon"
In 1957, the first space rocket - that same R-7 - launched the artificial Sputnik-1 into orbit. The United States later decided to repeat such a launch. However, in the first attempt, their space rocket did not go into space, it exploded at the start - even live. "Vanguard" was designed by a purely American team, and he did not live up to expectations. Then Wernher von Braun took over the project, and in February 1958 the launch of the space rocket was a success. Meanwhile, in the USSR, the R-7 was modernized - a third stage was added to it. As a result, the speed of the space rocket became completely different - the second space rocket was reached, thanks to which it became possible to leave the Earth's orbit. A few more years, the R-7 series was modernized and improved. The engines of space rockets were changed, they experimented a lot with the third stage. The next attempts were successful. The speed of the space rocket made it possible not only to leave the Earth's orbit, but also to think about studying other planets of the solar system.
But first, the attention of mankind was almost completely riveted to the natural satellite of the Earth - the Moon. In 1959, the Soviet space station Luna-1 flew to it, which was supposed to make a hard landing on the lunar surface. However, due to insufficiently accurate calculations, the device passed somewhat by (six thousand kilometers) and rushed towards the Sun, where it settled into orbit. So our luminary got his first own artificial satellite - a random gift. But our natural satellite was not alone for long, and in the same 1959, Luna-2 flew to it, having completed its task absolutely correctly. A month later, "Luna-3" delivered us photographs of the reverse side of our night luminary. And in 1966, Luna 9 softly landed right in the Ocean of Storms, and we got panoramic views of the lunar surface. The lunar program continued for a long time, until the time when the American astronauts landed on it.
Yuri Gagarin
April 12 has become one of the most significant days in our country. It is impossible to convey the power of national jubilation, pride, truly happiness when the world's first manned flight into space was announced. Yuri Gagarin became not only a national hero, he was applauded by the whole world. And therefore, April 12, 1961, a day that triumphantly went down in history, became Cosmonautics Day. The Americans urgently tried to respond to this unprecedented step in order to share space glory with us. A month later, Alan Shepard took off, but the ship did not go into orbit, it was a suborbital flight in an arc, and the US orbital only turned out in 1962.
Gagarin flew into space on the Vostok spacecraft. This is a special machine in which Korolev created an exceptionally successful space platform that solves many different practical problems. At the same time, at the very beginning of the sixties, not only a manned version of space flight was being developed, but a photo reconnaissance project was also completed. "Vostok" generally had many modifications - more than forty. And today satellites from the Bion series are in operation - these are direct descendants of the ship on which the first manned flight into space was made. In the same 1961, German Titov had a much more difficult expedition, who spent the whole day in space. The United States was able to repeat this achievement only in 1963.
"East"
An ejection seat was provided for cosmonauts on all Vostok spacecraft. This was a wise decision, since a single device performed tasks both at the start (emergency rescue of the crew) and a soft landing of the descent vehicle. Designers have focused their efforts on the development of one device, not two. This reduced the technical risk; in aviation, the catapult system was already well developed at that time. On the other hand, a huge gain in time than if you design a fundamentally new device. After all, the space race continued, and the USSR won it by a fairly large margin.
Titov landed in the same way. He was lucky to parachute down near the railway, on which the train was traveling, and journalists immediately photographed him. The landing system, which has become the most reliable and soft, was developed in 1965, it uses a gamma altimeter. She still serves today. The US did not have this technology, which is why all their descent vehicles, even the new Dragon SpaceX, do not land, but splash down. Only shuttles are an exception. And in 1962, the USSR had already begun group flights on the Vostok-3 and Vostok-4 spacecraft. In 1963, the detachment of Soviet cosmonauts was replenished with the first woman - Valentina Tereshkova went into space, becoming the first in the world. At the same time, Valery Bykovsky set the record for the duration of a solo flight, which has not been beaten so far - he spent five days in space. In 1964, the Voskhod multi-seat ship appeared, and the United States lagged behind by a whole year. And in 1965, Alexei Leonov went into outer space!
"Venus"
In 1966, the USSR began interplanetary flights. The spacecraft "Venera-3" made a hard landing on a neighboring planet and delivered there the globe of the Earth and the pennant of the USSR. In 1975, Venera 9 managed to make a soft landing and transmit an image of the planet's surface. And Venera-13 made color panoramic pictures and sound recordings. The AMS series (automatic interplanetary stations) for the study of Venus, as well as the surrounding outer space, continues to be improved even now. On Venus, the conditions are harsh, and there was practically no reliable information about them, the developers did not know anything about the pressure or temperature on the surface of the planet, all this, of course, complicated the study.
The first series of descent vehicles even knew how to swim - just in case. Nevertheless, at first the flights were not successful, but later the USSR succeeded so much in Venusian wanderings that this planet was called Russian. Venera-1 is the first spacecraft in the history of mankind, designed to fly to other planets and explore them. It was launched in 1961, communication was lost a week later due to overheating of the sensor. The station became uncontrollable and was only able to make the world's first flyby near Venus (at a distance of about one hundred thousand kilometers).
In the footsteps
"Venus-4" helped us to know that on this planet two hundred and seventy-one degrees in the shade (the night side of Venus), the pressure is up to twenty atmospheres, and the atmosphere itself is ninety percent carbon dioxide. This spacecraft also discovered the hydrogen corona. "Venera-5" and "Venera-6" told us a lot about the solar wind (plasma flows) and its structure near the planet. "Venera-7" specified data on temperature and pressure in the atmosphere. Everything turned out to be even more complicated: the temperature closer to the surface was 475 ± 20°C, and the pressure was an order of magnitude higher. Literally everything was redone on the next spacecraft, and after one hundred and seventeen days, Venera-8 softly landed on the day side of the planet. This station had a photometer and many additional instruments. The main thing was the connection.
It turned out that the lighting on the nearest neighbor is almost no different from the earth - like ours on a cloudy day. Yes, it’s not just cloudy there, the weather cleared up for real. Pictures seen by the equipment simply stunned earthlings. In addition, the soil and the amount of ammonia in the atmosphere were studied, and the wind speed was measured. And "Venus-9" and "Venus-10" were able to show us the "neighbor" on TV. These are the world's first recordings transmitted from another planet. And these stations themselves are now artificial satellites of Venus. Venera-15 and Venera-16 were the last to fly to this planet, which also became satellites, having previously provided mankind with absolutely new and necessary knowledge. In 1985, the program was continued by Vega-1 and Vega-2, which studied not only Venus, but also Halley's comet. The next flight is planned for 2024.
Something about space rocket
Since the parameters and technical characteristics of all rockets differ from each other, let's consider a new generation launch vehicle, for example, Soyuz-2.1A. It is a three-stage medium-class rocket, a modified version of the Soyuz-U, which has been in operation with great success since 1973.
This launch vehicle is designed to ensure the launch of spacecraft. The latter may have military, economic and social purposes. This rocket can put them into different types of orbits - geostationary, geotransitional, sun-synchronous, highly elliptical, medium, low.
Modernization
The rocket has been completely modernized, a fundamentally different digital control system has been created here, developed on a new domestic element base, with a high-speed on-board digital computer with a much larger amount of RAM. The digital control system provides the rocket with high-precision launch of payloads.
In addition, engines were installed on which the injector heads of the first and second stages were improved. Another telemetry system is in operation. Thus, the accuracy of launching the rocket, its stability and, of course, controllability have increased. The mass of the space rocket did not increase, and the useful payload increased by three hundred kilograms.
Specifications
The first and second stages of the launch vehicle are equipped with RD-107A and RD-108A liquid-propellant rocket engines from NPO Energomash named after academician Glushko, and a four-chamber RD-0110 from the Khimavtomatiki design bureau is installed on the third stage. Rocket fuel is liquid oxygen, which is an environmentally friendly oxidizer, as well as low-toxic fuel - kerosene. The length of the rocket is 46.3 meters, the mass at the start is 311.7 tons, and without the warhead - 303.2 tons. The mass of the launch vehicle structure is 24.4 tons. The fuel components weigh 278.8 tons. Flight tests of Soyuz-2.1A began in 2004 at the Plesetsk cosmodrome, and they were successful. In 2006, the launch vehicle made its first commercial flight - it launched the European meteorological spacecraft Metop into orbit.
It must be said that rockets have different payload output capabilities. Carriers are light, medium and heavy. The Rokot launch vehicle, for example, launches spacecraft into near-Earth low orbits - up to two hundred kilometers, and therefore it can carry a load of 1.95 tons. But the Proton is a heavy class, it can put 22.4 tons into low orbit, 6.15 tons into geotransitional orbit, and 3.3 tons into geostationary orbit. The launch vehicle we are considering is designed for all sites used by Roskosmos: Kuru, Baikonur, Plesetsk, Vostochny, and operates within the framework of joint Russian-European projects.
11.06.2010 00:10
The American spacecraft Dawn recently set a new speed record - 25.5 thousand km / h, ahead of its main competitor - the Deep Space 1 probe. This achievement was made possible thanks to the super-powerful ion engine installed on the device. However, according to experts NASA, this is far from the limit of its capabilities.
The speed of the American spacecraft Dawn reached a record high on June 5 - 25.5 thousand km / h. However, according to scientists, in the near future the speed of the ship will reach the mark of 100 thousand km / h.
Thus, thanks to the unique engine, Dawn surpassed its predecessor, the Deep Space 1 probe, an experimental robotic spacecraft launched on October 24, 1998 by a launch vehicle. True, Deep Space 1 still retains the title of the station whose engines have worked the longest. But to get ahead of the "competitor" in this category Dawn may already in August.
The main task of the spacecraft, launched three years ago, is to study the asteroid 4 Vesta, which the device will approach in 2011, and the dwarf planet Ceres. Scientists hope to obtain the most accurate data on the shape, size, mass, mineral and elemental composition of these objects located between the orbits of Jupiter and Mars. The total path to be overcome by the device Dawn is 4 billion 800 million kilometers.
Since there is no air in outer space, having accelerated, the ship continues to move at the gained speed. On Earth, this is not possible due to frictional deceleration. The use of ion thrusters in vacuum conditions allowed scientists to make the process of gradually increasing the speed of the Dawn spacecraft as efficient as possible.
The principle of operation of the innovative engine is to ionize the gas and accelerate it with an electrostatic field. At the same time, due to the high charge-to-mass ratio, it becomes possible to accelerate the ions to very high speeds. Thus, a very high specific impulse can be achieved in the engine, which makes it possible to significantly reduce the consumption of the reactive mass of ionized gas (compared to a chemical reaction), but requires a lot of energy.
The three engines of the Dawn are not constantly running, but are switched on briefly at certain points in the flight. To date, they have worked for a total of 620 days and have used up over 165 kilograms of xenon. Simple calculations show that the speed of the probe increased by about 100 km / h every four days. By the end of the eight-year Dawn mission (although experts do not exclude its extension), the total operating time of the engines will be 2000 days - almost 5.5 years. Such indicators promise that the speed of the spacecraft will reach 38.6 thousand km / h.
This may seem like a small amount against the background of at least the first cosmic speed at which artificial Earth satellites are launched, but for an interplanetary vehicle without any external accelerators, which does not perform special maneuvers in the gravitational field of the planets, such a result is indeed remarkable.
Here is a rocket at the cosmodrome, here it is flying, the 1st stage, the 2nd, and now the ship is launched into a near-Earth orbit with a first cosmic velocity of 8 km/s.
It seems that the formula of Tsiolkovsky quite allows.
From the textbook: " to achieve the first space velocityυ \u003d υ 1 \u003d 7.9 10 3 m / s at u \u003d 3 10 3 m / s
(velocities of outflow of gases during fuel combustion are of the order of 2-4 km / s) the starting mass of a single-stage rocket should be approximately 14 times higher than the final mass".
Quite a reasonable figure, unless, of course, we forget that the rocket is still affected by an attractive force that is not included in the Tsiolkovsky formula.
But here is the calculation of the speed of Saturn-5 carried out by S.G. Pokrovsky: http://www.supernovum.ru/public/index.php?doc=5 (file "Get to the Moon" in the attachment) and http://supernovum .ru/public/index.php?doc=150 (old version: file "SPEED ESTIMATION" in the application). With such a speed (less than 1200 m/s), the rocket cannot reach the 1st space velocity.
From Wikipedia: "During its two and a half minutes of operation, the five F-1 engines lifted the Saturn V booster to an altitude of 42 miles (68 km) giving it a speed of 6164 miles per hour (9920 km/h)." These are the same 2750 m / s declared by the Americans.
Let's estimate the acceleration: a=v/t=2750/150=18.3 m/s ²
.
Normal threefold overload during takeoff. But on the other hand, a=2H/t ²
=2x68000/22500=6 m/s ²
. You won't get far with that speed.
How to explain the second result and the threefold difference?
For the convenience of calculations, let's take the tenth second of the flight.
Using Photoshop to measure the pixels in the picture, we get the values:
height = 4.2 km;
speed = 950 m/s;
acceleration = 94 m/s ².
At the 10th second, the acceleration was already falling, so I took the average with some error of a few percent (10% is a very good error in physical experiments).
Now let's check the above formulas:
a=2H/t²=84 m/s²;
a=v/t=95 m/s²
As you can see, the discrepancy is in those same 10%. And not at all in 300%, about which I asked the question.
Well, for those who are not in the know, let me tell you: in physics, all quality grades must be obtained by simple school formulas. Like now.
All complex formulas are needed only for precise fitting of various parts (otherwise the electron flow will pass near the target in the cyclotron).
And now let's look from the other side: average speed H/t=68000/150=450 m/s; if we assume that the speed increased uniformly from zero (as on the graph of an amateur rocket), then at an altitude of 68 km it is equal to 900 m/sec. The result is even less than the value calculated by Pokrovsky. It turns out that in any case, the engines do not allow you to gain the declared speed. You may not even be able to put a satellite into orbit.
The difficulties are confirmed by the unsuccessful tests of the Bulava rocket (since 2004): either the failure of the 1st stage, or the flight in the wrong direction, or even just a fall at launch.
Are there really no problems at spaceports?
A good example is the North Koreans, who apparently stole our blueprints, created a launch vehicle, and launched a satellite on 04/05/2009, which, as expected, fell into the Pacific Ocean.
And this is the launch of the shuttle Endeavor. As for me, this is the trajectory of falling into the Atlantic ...
And, to finish on flights with the 1st space velocity (7.76 km/s at an altitude of 500 km).
The Tsiolkovsky formula is applied to the vertical velocity component. But in order for the projectile to fly in a stationary orbit, it must have a horizontal 1st cosmic velocity, as Newton considered it, deriving his formulas:
To bring the rocket to the 1st cosmic speed, it must be accelerated not only vertically, but also horizontally. Those. in fact, the speed of the outflow of gases is one and a half times lower than the declared one, assuming that the rocket rises at an average angle of 45 ° (half of the gas works to rise upwards). That is why in the calculations of theorists everything converges - the concepts of "launching a rocket into orbit" and "raising a rocket to an orbital altitude" are equated. In order to put a rocket into orbit, it is necessary to raise it to the height of the orbit and give the 1st space velocity in the horizontal component of the movement. Those. do two work, not one (expend twice as much energy).
Alas, I still cannot say something definite - this is a very confusing matter: first there is atmospheric resistance, then not, the mass decreases, the speed increases. It is impossible to evaluate complex theoretical calculations with simple school mechanics. Let's leave the question open. He rose only for the seed - to show that not everything is as simple as it might seem at first glance.
It seemed that this question would remain suspended. What can be objected to the assertion that the shuttle in the photo entered low-Earth orbit and the downward curve is the beginning of a revolution around the Earth?
But a miracle happened: on February 24, 2011, the last launch of Discovery was filmed from a flying aircraft at an altitude of 9 km:
Filming began from the moment of launch (the report was observed on the screen in the cabin) and lasted 127 seconds.
Let's check the official data:
We didn't get to see this moment. (I wonder what could interrupt such an interesting shooting at such an important moment?) . But we see the main thing: the height is really 50 km (compared with the height of the aircraft above the ground), the speed is around 1 km / sec.
The speed is easy to estimate by measuring the distance from a well-defined hump of smoke at an altitude of about 25 km ( his L stretch vertically up no more than 8 km). At the 79th second, the distance from its highest point is 2.78L in height and 3.24L in length (we use L , since we need to normalize different frames - Zoom changes), at the 96th second 3.47L and 5.02L , respectively. Those. in 17 seconds, the shuttle rose 0.7L and moved 1.8L. The vector is equal to 1.9L = 15 km (a little more, as it is turned slightly away from us).
Everything would be fine. Yes, only the trajectory is not at all the one shown on the flight profile. The section at 125 seconds (TTU department) is almost vertical, and we see a maximum ballistic
trajectory that should have been seen at an altitude of more than 100 km, according to both the profile and
objections of opponents on the photo
Endeavor.
Let's look at it again: the height of the lower edge of the clouds is 57 pixels, the maximum of the trajectory is 344 pixels, exactly 6 times higher. And at what height is the lower edge of the clouds? Well, not more than 8 kilometers. Those. the same ceiling of 50 kilometers.
So the shuttle really flies to its base along the ballistic trajectory shown in the photo (it is easily believed that the take-off angle below the clouds does not exceed 60 degrees), and not into space at all.
Image copyright Thinkstock
The current speed record in space has been held for 46 years. The correspondent wondered when he would be beaten.
We humans are obsessed with speed. So, only in the last few months it became known that students in Germany set a speed record for an electric car, and the US Air Force plans to improve hypersonic aircraft in such a way that they develop speeds five times the speed of sound, i.e. over 6100 km/h.
Such planes will not have a crew, but not because people cannot move at such a high speed. In fact, people have already moved at speeds that are several times faster than the speed of sound.
However, is there a limit beyond which our rapidly rushing bodies will no longer be able to withstand overloads?
The current speed record is equally held by three astronauts who participated in the Apollo 10 space mission - Tom Stafford, John Young and Eugene Cernan.
In 1969, when the astronauts flew around the moon and returned back, the capsule they were in reached a speed that on Earth would be equal to 39.897 km / h.
"I think that a hundred years ago we could hardly have imagined that a person could travel in space at a speed of almost 40,000 kilometers per hour," says Jim Bray of the aerospace concern Lockheed Martin.
Bray is the director of the habitable module project for the promising Orion spacecraft, which is being developed by the US Space Agency NASA.
As conceived by the developers, the Orion spacecraft - multi-purpose and partially reusable - should take astronauts into low Earth orbit. It may well be that with its help it will be possible to break the speed record set for a person 46 years ago.
The new super-heavy rocket, part of the Space Launch System, is scheduled to make its first manned flight in 2021. This will be a flyby of an asteroid in lunar orbit.
The average person can handle about five G's before passing out.
Then months-long expeditions to Mars should follow. Now, according to the designers, the usual maximum speed of the Orion should be approximately 32,000 km/h. However, the speed that Apollo 10 has developed can be surpassed even if the basic configuration of the Orion spacecraft is maintained.
"The Orion is designed to fly to a variety of targets throughout its lifetime," says Bray. "It could be much faster than what we currently plan."
But even "Orion" will not represent the peak of human speed potential. "Basically, there is no other limit to the speed at which we can travel other than the speed of light," says Bray.
The speed of light is one billion km/h. Is there any hope that we will be able to bridge the gap between 40,000 km/h and these values?
Surprisingly, speed as a vector quantity indicating the speed of movement and the direction of movement is not a problem for people in the physical sense, as long as it is relatively constant and directed in one direction.
Therefore, people - theoretically - can move in space only slightly slower than the "velocity limit of the universe", i.e. the speed of light.
Image copyright NASA Image caption How will a person feel in a ship flying at near-light speed?But even assuming we overcome the significant technological hurdles associated with building fast spacecraft, our fragile, mostly water bodies will face new dangers from the effects of high speed.
There could be, for now, only imaginary dangers if humans could travel faster than the speed of light through exploiting loopholes in modern physics or through discoveries that break the pattern.
How to withstand overload
However, if we intend to travel at speeds in excess of 40,000 km/h, we will have to reach it and then slow down, slowly and with patience.
Rapid acceleration and equally rapid deceleration are fraught with mortal danger to the human body. This is evidenced by the severity of bodily injuries resulting from car accidents, in which the speed drops from several tens of kilometers per hour to zero.
What is the reason for this? In that property of the Universe, which is called inertia or the ability of a physical body with mass to resist a change in its state of rest or motion in the absence or compensation of external influences.
This idea is formulated in Newton's first law, which states: "Every body continues to be held in its state of rest or uniform and rectilinear motion, until and insofar as it is forced by applied forces to change this state."
We humans are able to endure huge G-forces without serious injury, however, only for a few moments.
"The state of rest and movement at a constant speed is normal for the human body, - explains Bray. - We should rather worry about the state of the person at the time of acceleration."
About a century ago, the development of durable aircraft that could maneuver at speed led pilots to report strange symptoms caused by changes in speed and direction of flight. These symptoms included temporary loss of vision and a feeling of either heaviness or weightlessness.
The reason is g-forces, measured in units of G, which are the ratio of linear acceleration to the acceleration of free fall on the surface of the Earth under the influence of attraction or gravity. These units reflect the effect of free fall acceleration on the mass of, for example, the human body.
An overload of 1 G is equal to the weight of a body that is in the Earth's gravity field and is attracted to the center of the planet at a speed of 9.8 m/sec (at sea level).
G-forces that a person experiences vertically from head to toe or vice versa are truly bad news for pilots and passengers.
With negative overloads, i.e. slowing down, blood rushes from the toes to the head, there is a feeling of oversaturation, as in a handstand.
Image copyright SPL Image caption In order to understand how many Gs the astronauts can withstand, they are trained in a centrifuge."Red veil" (the feeling that a person experiences when blood rushes to the head) occurs when the blood-swollen, translucent lower eyelids rise and close the pupils of the eyes.
Conversely, during acceleration or positive g-forces, blood drains from the head to the legs, the eyes and brain begin to experience a lack of oxygen, as blood accumulates in the lower extremities.
At first, vision becomes cloudy, i.e. there is a loss of color vision and rolls, as they say, a "gray veil", then a complete loss of vision or a "black veil" occurs, but the person remains conscious.
Excessive overloads lead to complete loss of consciousness. This condition is called congestion-induced syncope. Many pilots died due to the fact that a "black veil" fell over their eyes - and they crashed.
The average person can handle about five G's before passing out.
Pilots, dressed in special anti-G overalls and trained in a special way to tense and relax the muscles of the torso so that the blood does not drain from the head, are able to control the aircraft with overloads of about nine Gs.
Upon reaching a steady cruising speed of 26,000 km/h in orbit, astronauts experience no more speed than commercial airline passengers.
“For short periods of time, the human body can withstand much higher g-forces than nine Gs,” says Jeff Sventek, executive director of the Aerospace Medicine Association, located in Alexandria, Va. few".
We humans are able to endure enormous G-forces without serious injury, but only for a few moments.
The short-term endurance record was set by US Air Force Captain Eli Bieding Jr. at Holloman Air Force Base in New Mexico. In 1958, when braking on a special rocket-powered sled, after accelerating to 55 km / h in 0.1 second, he experienced an overload of 82.3 G.
This result was recorded by an accelerometer attached to his chest. Beeding's eyes were also covered with a "black veil", but he escaped with only bruises during this outstanding demonstration of the endurance of the human body. True, after the arrival, he spent three days in the hospital.
And now to space
Astronauts, depending on the vehicle, also experienced quite high g-forces - from three to five G - during takeoffs and during re-entry into the atmosphere, respectively.
These g-forces are relatively easy to bear, thanks to the clever idea of strapping space travelers into seats in a prone position facing the direction of flight.
Once they reach a steady cruising speed of 26,000 km/h in orbit, astronauts experience no more speed than passengers on commercial flights.
If overloads will not be a problem for long-term expeditions on the Orion spacecraft, then with small space rocks - micrometeorites - everything is more difficult.
Image copyright NASA Image caption Orion will need some kind of space armor to protect against micrometeoritesThese particles the size of a grain of rice can reach impressive yet destructive speeds of up to 300,000 km/h. To ensure the integrity of the ship and the safety of its crew, Orion is equipped with an external protective layer, the thickness of which varies from 18 to 30 cm.
In addition, additional shielding shields are provided, as well as ingenious placement of equipment inside the ship.
"In order not to lose the flight systems that are vital to the entire spacecraft, we must accurately calculate the angles of approach of micrometeorites," says Jim Bray.
Rest assured, micrometeorites are not the only hindrance to space missions, during which high human flight speeds in airless space will play an increasingly important role.
During the expedition to Mars, other practical tasks will also have to be solved, for example, to supply the crew with food and counteract the increased risk of cancer due to the effects of cosmic radiation on the human body.
Reducing travel time will lessen the severity of such problems, so that speed of travel will become increasingly desirable.
Next generation spaceflight
This need for speed will put new obstacles in the way of space travelers.
The new NASA spacecraft that threaten to break the Apollo 10 speed record will continue to rely on time-tested rocket propulsion chemistry systems used since the first space flights. But these systems have severe speed limits due to the release of small amounts of energy per unit of fuel.
The most preferred, albeit elusive, source of energy for a fast spacecraft is antimatter, a twin and antipode of ordinary matter.
Therefore, in order to significantly increase the speed of flight for people going to Mars and beyond, scientists recognize that completely new approaches are needed.
"The systems that we have today are quite capable of getting us there," says Bray, "but we all would like to witness a revolution in engines."
Eric Davis, a senior research physicist at the Institute for Advanced Study in Austin, Texas, and a member of NASA's Breakthrough Motion Physics Program, a six-year research project that ended in 2002, identified three of the most promising tools, from a conventional physics standpoint, capable of help humanity achieve speeds reasonably sufficient for interplanetary travel.
In short, we are talking about the phenomena of energy release during the splitting of matter, thermonuclear fusion and annihilation of antimatter.
The first method is atomic fission and is used in commercial nuclear reactors.
The second, thermonuclear fusion, is the creation of heavier atoms from simpler atoms, the kind of reactions that power the sun. This is a technology that fascinates, but is not given to the hands; until it is "always 50 years away" - and always will be, as the old motto of this industry says.
"These are very advanced technologies," says Davis, "but they are based on traditional physics and have been firmly established since the dawn of the Atomic Age." According to optimistic estimates, propulsion systems based on the concepts of atomic fission and thermonuclear fusion, in theory, are capable of accelerating a ship to 10% of the speed of light, i.e. up to a very worthy 100 million km / h.
Image copyright US Air Force Image caption Flying at supersonic speeds is no longer a problem for humans. Another thing is the speed of light, or at least close to it...The most preferred, albeit elusive, source of energy for a fast spacecraft is antimatter, the twin and antipode of ordinary matter.
When two kinds of matter come into contact, they annihilate each other, resulting in the release of pure energy.
The technologies to produce and store - so far extremely small - amounts of antimatter already exist today.
At the same time, the production of antimatter in useful quantities will require new next-generation special capacities, and engineering will have to enter into a competitive race to create an appropriate spacecraft.
But, Davies says, a lot of great ideas are already on the drawing boards.
Spaceships propelled by antimatter energy will be able to accelerate for months and even years and reach greater percentages of the speed of light.
At the same time, overloads on board will remain acceptable for the inhabitants of the ships.
At the same time, such fantastic new speeds will be fraught with other dangers for the human body.
energy hail
At speeds of several hundred million kilometers per hour, any speck of dust in space, from dispersed hydrogen atoms to micrometeorites, inevitably becomes a high-energy bullet capable of piercing through a ship's hull.
"When you are moving at a very high speed, it means that the particles flying towards you are moving at the same speeds," says Arthur Edelstein.
Together with his late father, William Edelstein, professor of radiology at the Johns Hopkins University School of Medicine, he worked on a scientific paper that examined the effects of cosmic hydrogen atoms (on people and equipment) during ultrafast space travel in space.
The hydrogen will begin to decompose into subatomic particles, which will penetrate the interior of the ship and expose both crew and equipment to radiation.
The Alcubierre engine will carry you like a surfer on a wave crest Eric Davies, research physicist
At 95% the speed of light, exposure to such radiation would mean almost instantaneous death.
The starship will be heated to melting temperatures that no conceivable material can withstand, and the water contained in the bodies of the crew members will immediately boil.
"These are all extremely nasty problems," remarks Edelstein with grim humor.
He and his father estimated that in order to create some hypothetical magnetic shielding system capable of protecting the ship and its people from a deadly hydrogen rain, a starship could travel at a speed not exceeding half the speed of light. Then the people on board have a chance to survive.
Mark Millis, a translational physicist and former head of NASA's Breakthrough Motion Physics Program, warns that this potential speed limit for spaceflight remains a problem for the distant future.
“Based on the physical knowledge accumulated to date, we can say that it will be extremely difficult to develop a speed above 10% of the speed of light,” says Millis. “We are not in danger yet. A simple analogy: why worry that we can drown if We haven't even entered the water yet."
Faster than light?
If we assume that we, so to speak, have learned to swim, can we then learn to glide through space time - if we develop this analogy further - and fly at superluminal speed?
The hypothesis of an innate ability to survive in a superluminal environment, although doubtful, is not without certain glimpses of educated enlightenment in pitch darkness.
One of these intriguing modes of travel is based on technologies similar to those used in the "warp drive" or "warp drive" from Star Trek.
Known as the "Alcubierre Engine"* (named after the Mexican theoretical physicist Miguel Alcubierre), this propulsion system works by allowing the ship to compress the normal space-time described by Albert Einstein in front of it and expand it behind myself.
Image copyright NASA Image caption The current speed record is held by three Apollo 10 astronauts - Tom Stafford, John Young and Eugene Cernan.In essence, the ship moves in a certain volume of space-time, a kind of "curvature bubble", which moves faster than the speed of light.
Thus, the ship remains stationary in normal space-time in this "bubble" without being deformed and avoiding violations of the universal speed limit of light.
"Instead of floating through the waters of normal space-time," says Davis, "the Alcubierre engine will carry you like a surfer on a board on the crest of a wave."
There is also a certain trick here. To implement this idea, an exotic form of matter is needed, which has a negative mass in order to compress and expand space-time.
"Physics does not contain any contraindications regarding negative mass," says Davis, "but there are no examples of it, and we have never seen it in nature."
There is another trick. In a paper published in 2012, researchers at the University of Sydney speculated that the "warp bubble" would accumulate high-energy cosmic particles as it inevitably began to interact with the contents of the universe.
Some of the particles will get inside the bubble itself and pump the ship with radiation.
Stuck at sub-light speeds?
Are we really doomed to get stuck at the stage of sub-light speeds because of our delicate biology?!
It's not so much about setting a new world (galactic?) speed record for a person, but about the prospect of turning humanity into an interstellar society.
At half the speed of light - which is the limit Edelstein's research suggests our bodies can withstand - a round-trip journey to the nearest star would take more than 16 years.
(The effects of time dilation, under which the crew of a starship in its coordinate system will pass less time than for people remaining on Earth in their coordinate system, will not lead to dramatic consequences at half the speed of light).
Mark Millis is full of hope. Considering that humanity has developed anti-g suits and protection against micrometeorites, allowing people to safely travel in the great blue distance and the star-studded blackness of space, he is confident that we can find ways to survive, no matter how fast we reach in the future.
"The same technologies that can help us achieve incredible new speeds of travel," Millis muses, "will provide us with new, as yet unknown, capabilities to protect crews."
Translator's notes:
*Miguel Alcubierre came up with the idea of his "bubble" in 1994. And in 1995, Russian theoretical physicist Sergei Krasnikov proposed the concept of a device for space travel faster than the speed of light. The idea was called "Krasnikov's pipes".
This is an artificial curvature of space-time according to the principle of the so-called wormhole. Hypothetically, the ship will move in a straight line from the Earth to a given star through curved space-time, passing through other dimensions.
According to Krasnikov's theory, the space traveler will return back at the same time that he set off.
To overcome the force of gravity and put the spacecraft into Earth's orbit, the rocket must fly at a speed of at least 8 kilometers per second. This is the first space velocity. The device, which is given the first cosmic speed, after separation from the Earth, becomes an artificial satellite, that is, it moves around the planet in a circular orbit. If, however, the apparatus is informed of a speed less than the first cosmic one, then it will move along a trajectory that intersects with the surface of the globe. In other words, it will fall to Earth.
Projectiles A and B are given a speed below the first cosmic one - they will fall to the Earth;
projectile C, which was given the first cosmic velocity, will go into a circular orbit
But such a flight requires a lot of fuel. It is jet for a couple of minutes, the engine eats up an entire railway tank car, and in order to give the rocket the necessary acceleration, a huge railway composition of fuel is required.
There are no filling stations in space, so you have to take all the fuel with you.
Fuel tanks are very large and heavy. When the tanks are empty, they become extra cargo for the rocket. Scientists have come up with a way to get rid of unnecessary weight. The rocket is assembled as a constructor and consists of several levels, or steps. Each stage has its own engine and its own fuel supply.
The first step is the hardest. Here is the most powerful engine and the most fuel. She must move the rocket from its place and give it the necessary acceleration. When the first stage fuel is used up, it detaches from the rocket and falls to the ground, the rocket becomes lighter and does not need to use additional fuel to carry empty tanks.
Then the engines of the second stage, which is smaller than the first, are turned on, since it needs to spend less energy to lift the spacecraft. When the fuel tanks are empty, and this stage will “unfasten” from the rocket. Then the third, fourth...
After the end of the last stage, the spacecraft is in orbit. It can fly around the Earth for a very long time without spending a single drop of fuel.
With the help of such rockets, cosmonauts, satellites, interplanetary automatic stations are sent into flight.
Do you know...
The first cosmic velocity depends on the mass of the celestial body. For Mercury, whose mass is 20 times less than that of the Earth, it is 3.5 kilometers per second, and for Jupiter, whose mass is 318 times greater than the mass of the Earth, it is almost 42 kilometers per second!