According to Soviet data, the world's first man to fly into outer space, Yuri Gagarin, withstood an overload of about 4 g during the launch. American researchers report that cosmonaut Glenn withstood an increasing overload of up to 6.7 g from the moment of launch until the moment of separation of the first stage of the rocket, that is, for 2 minutes and 10 seconds. After separation of the first stage, the acceleration increased from 1.4 to 7.7 g in 2 minutes and 52 seconds.
Since under these conditions the acceleration, and with it the g-forces, build up gradually and do not last long, the strong, trained organism of the cosmonauts endures them without any harm.
JET SLED
There is another type of installation for studying the reaction of the human body to overloads. This is a jet sleigh, which is a cabin moving along a rail track of considerable length (up to 30 kilometers). Cabin speed on skids reaches 3500 km/h. On this stand, it is more convenient to study the reactions of the body to overloads, since they can create not only positive, but also negative accelerations. After a powerful jet engine informs the sledge a speed of the order of 900 m / s (that is, the speed of a rifle bullet) a few seconds after the start, the acceleration can reach 100 g. At hard braking, also with the help of jet engines, negative acceleration can reach even up to 150 g.
Jet sled tests are suitable mainly for aviation, not astronautics, and, in addition, this installation costs much more than a centrifuge.
CATAPULTS
On the same principle as jet sleighs, catapults operate with inclined guides along which the seat with the pilot moves. Catapults are especially suitable for aviation. They test the reactions of the body of pilots, who may in the future have to eject in the event of an aircraft accident in order to save their lives. In this case, the cockpit, together with the pilot, is fired from the crashed jet aircraft and with the help of a parachute we descend to the ground. Catapults are capable of reporting an acceleration of no more than 15 g.
"IRON SIREN"
Looking for a way to prevent harmful effect overload on the human body, scientists have found that great benefit brings a person immersed in a liquid medium, the density of which approximately corresponds to the average density of the human body.
Pools were built filled with a liquid suspension of appropriate density, with a breathing device; experimental animals (mice and rats) were placed in the pools, after which centrifugation was carried out. It turned out that the resistance of mice and rats to overload increased tenfold.
In one of the American scientific institutes pools were built, allowing you to put a person in them; (the pilots subsequently nicknamed these pools "iron sirens"). The pilot was placed in a bath filled with a liquid of the appropriate density, and centrifugation was performed. The results exceeded all expectations - in one case, the overloads were brought up to 32 g. The person sustained such an overload for five seconds.
True, the "iron siren" is not perfect from a technical point of view and, in particular, there are objections from the point of view of convenience for the astronaut. However, one should not judge too hastily. Perhaps in the near future, scientists will find a way to improve test conditions at such a facility.
It should be added that resistance to overloads largely depends on the position of the cosmonaut's body during the flight. Based on many tests, scientists have found that a person is easier to tolerate overload in a reclining position, since this position is more convenient for blood circulation.
HOW TO ACHIEVE INCREASED LONGEVITY
We have already mentioned that in the conducted space flights, the overloads were relatively small and lasted only a few minutes. But this is only the beginning of the space age, when people fly into space in orbits relatively close to the Earth.
Now we are on the verge of flights to the Moon, and during the life of the next generation - to Mars and Venus. It may then be necessary to experience much greater accelerations, and the astronauts will be subjected to much greater overloads.
There is also the problem of astronauts' resistance to small, but long-term, constant overloads, lasting throughout the entire interplanetary journey. Preliminary data show that the constant acceleration of the order of shares, "g" is tolerated by a person without any difficulty. Projects have already been developed for such rockets, the engines of which will operate with constant acceleration. Despite the fact that during the experiment itself, people had to endure various unpleasant phenomena, the experiments did not bring them any harm.
It is possible that in the future it will be possible to increase the resistance of the human body to overloads in another way. Interesting experiences were set by scientists at the University of Cambridge in the United States. They subjected pregnant mice to a constant acceleration on the order of 2 g until mice appeared, which were kept on a centrifuge for their entire life until their death. Mice born under such conditions thrived under the influence of a constant overload of 2 g, and their behavior was no different from the behavior of their counterparts living in normal conditions.
We are far from the idea of setting up similar experiments with people, but still we believe that the phenomenon of such an adaptability of the organism to overloads can solve a number of problems facing biologists.
It is also possible that scientists will find a way to neutralize the forces of acceleration, and a person equipped with appropriate equipment will easily endure all the phenomena that accompany overloads. More big hopes associated with the freezing method, when a person's sensitivity drops sharply (we write about this below).
Progress in the field of increasing the resistance of the human body to overload is very large and continues to develop. Great success has already been achieved in increasing resistance by giving the human body right position during the flight, the use of a soft seat lined with spongy plastic and specially designed spacesuits. Maybe soon will bring even greater success in this area.
WHEN EVERYTHING IS VIBRATING
Of the many dangers that lie in wait for an astronaut during a flight, one more must be pointed out, connected with the aerodynamic features of flight and the operation of jet engines. This danger, although fortunately not very great, is brought with it by vibration.
Work during start powerful engines, and the whole structure of the rocket is subjected to strong vibration. The vibration is transmitted to the astronaut's body and can lead to very unpleasant consequences for him.
The harmful effect of vibration on the human body has been known for a long time. Indeed, workers who use a pneumatic hammer or drill for a more or less long time fall ill with the so-called vibration disease, which is manifested not only by severe pains in the muscles and joints of the upper limbs, but also by pains in the abdomen, heart, and head. Shortness of breath appears and breathing becomes difficult. The sensitivity of the body largely depends on which of the internal organs is most exposed to vibration. Respond differently to vibration internal organs digestion, lungs, upper and lower limbs, eyes, brain, throat, bronchi, etc.
It has been found that the vibration spaceship it has a harmful effect on all tissues and organs of the human body - and vibration of a high frequency is the worst tolerated, that is, one that is difficult to notice without precise instruments. During experiments with animals and people, it was found that, under the influence of vibration, their heartbeat first increases, blood pressure increases, then changes appear in the composition of the blood: the number of red blood cells decreases, the number of white ones increases. The general metabolism is disturbed, the level of vitamins in the tissues decreases, changes in the bones appear. Interestingly, body temperature is largely dependent on the frequency of vibration. With an increase in the frequency of oscillations, the body temperature rises, with a decrease in the frequency, the temperature decreases.
People throughout history have been obsessed with speed and have always sought to "squeeze" the maximum out of their vehicles. Once upon a time, racehorses were bred and specially trained, and today they create super-fast cars and other vehicles. In our review, the fastest of the cars, helicopters, boats and other vehicles that exist today.
1. Wheel train
In April 2007, the French TGV POS train set a new world speed record for travel on conventional rails. Between Meuse and Champagne-Ardenne stations, the train reached a speed of 574.8 km/h (357.2 mph).
2. Streamliner motorcycle
Having reached the officially registered top speed at 634.217 km/h (394.084 mph), TOP 1 Ack Attack (a purpose-built faired motorcycle equipped with two Suzuki engines Hayabusa boasts the title of the world's fastest motorcycle.
3. Snowmobile
The world record for the fastest snowmobile is currently held by a vehicle known as the G-Force-1. The record-breaking snowmobile, which was produced by the Canadian company G-Force Division, in 2013 managed to accelerate through the salt marsh to a maximum speed of 211.5 miles per hour (340.38 km / h). Now the team plans to break their record in 2016, reaching a speed of 400 km/h.
4. Serial superfast car
In 2010 Bugatti Veyron Super Sport, sport car developed by German Volkswagen Group and built by Bugatti in France, reached a speed of 267.857 miles per hour (431.074 km / h), breaking the world speed record for mass-produced cars.
5. Maglev train
Designed and built by the Central Japan Railway Company, the L0 series high-speed maglev train set a new world record for rail vehicles when it reached 603 km/h (375 mph) in April 2015.
6. Unmanned rocket sled
In April 2003, the rocket-powered Super Roadrunner sled became the fastest land sled. vehicle. At the Holloman Air Force Base in New Mexico, they were able to accelerate them to a speed of 8.5 times the speed of sound - 6,416 miles per hour (10,326 km / h).
7 Manned Rocket Sleigh
US Air Force officer John Stepp, known as "the fastest man on earth", dispersed rocket sled Sonic Wind No. 1 to 1,017 km/h (632 mph) in December 1954.
8. Vehicle driven by muscle power
In September 2013, Dutch cyclist B. Bovier reached 133.78 km/h (83.13 mph) on a custom faired VeloX3 bike. He set the record on a 200-meter section of road in Battle Mountain, Nevada, having previously accelerated on an 8-kilometer road.
9. Rocket car
Thrust Supersonic Car (better known as Thrust SCC) - British jet car, which reached speeds of 1,228 km/h (763 mph) in 1997.
10. Vehicle with an electric motor
American pilot Roger Schröer Schröer drove a student-built electric car to 308 mph (495 km/h) in August 2010.
11. Serial tank
The lightly armored reconnaissance tank Scorpion Peacekeeper, developed by Repaircraft PLC (UK), reached a speed of 82.23 kilometers per hour (51.10 mph) on a test track in Chertsey, UK on March 26, 2002.
12. Helicopter
An experimental high-speed helicopter, the Eurocopter X3, reached 255 knots (472 km/h; 293 mph) on 7 June 2013, setting an unofficial helicopter speed record.
13. Unmanned aircraft
Developed by the DARPA Falcon Project, the Hypersonic Technology Vehicle 2 (or HTV-2) experimental rocket airframe reached speeds of 13,201 miles per hour (21,245 km/h) during a test flight. According to the creators, the goal of this project is to create a vehicle that will allow you to reach any point on the planet from the United States within one hour.
Wooden powerboat Spirit of Australia with jet engine- the fastest vehicle that has ever touched water. In 1978, Australian speedboat racer Ken Warby reached 317.596 mph (511.11 km/h) on this boat.
Another car from Australia - Sunswift IV (IVy) - entered the Guinness Book of Records as the most fast car on solar energy. At the Royal Australian Navy Air Station in 2007 unusual car reached a top speed of 88.5 kilometers per hour (55 mph).
If speed limits at 100-120 kilometers per hour seems too cruel for you, you should definitely visit the Holloman Air Force Base located in New Mexico, USA. Operated by the US Department of Defense, Holloman Base has one of the longest and fastest test tracks in the world. Its length is 15.47 kilometers, and it is here that the highest observed speed limit in the world. No kidding, there really is a sign at the entrance to the track indicating a speed limit of 10 MAX, which is equal to ten times the speed of sound (the speed of sound is 1193 km / h). Thus, here you are allowed to accelerate at speeds up to 11,930 kilometers per hour, and this is probably the only limiting sign for breaking the limit of which you will be applauded, and not issued a fine. However, to date, no one has managed to overcome this limitation. The closest record at this location was in April 2003, when a test rider hit Mach 8.5.
Base Holloman is located in New Mexico, in the Tularoso Basin, between the Sacramento and San Andres mountain ranges, about 16 kilometers west of the city of Alamogordo. It is predominantly a desert plain, located at an altitude of 1280 meters above sea level, surrounded by mountain slopes. In summer, the local temperatures can reach 43 degrees Celsius, and in winter they can drop to -18 degrees, but in general, temperatures here are quite acceptable.
The high-speed test track at Holloman Base is not the usual track that is used for. It is a so-called rocket sled - a test platform that slides along a special rail track with the help of a rocket engine. This route is used by the US Department of Defense and its departments to perform various kinds of tests for high speed. Last year, tests conducted at the site resulted in new experimental ejection seats, parachutes, nuclear missiles and seat belts.
Initially, when it was only laid down in 1949, the test track was just over a kilometer long. The first test carried out on it was the Northrop N-25 Snark rocket launch in 1950. This was followed by tests on the human body, the researchers had to find out what would happen to the pilot's body under conditions of extreme acceleration and deceleration.
On December 10, 1954, Lieutenant Colonel John Stapp became "the most fast man on Earth,” after riding a rocket sled at 1,017 kilometers per hour and experiencing an overload 40 times greater than Earth’s gravity. Unfortunately, during the testing process, he received a lot of damage, such as broken ribs and temporary retinal detachment. He determined that a pilot flying at an altitude of 10.6 kilometers at a speed exceeding the speed of sound twice, is able to withstand gusts of wind during an emergency ejection.
In October 1982, an unmanned sled launched an unmanned cargo weighing 11.3 kilograms, dispersing it to a speed of 9847 kilometers per hour, this record lasted the next 20 years, after which the 87-kg cargo was dispersed to a speed of 10385 kilometers per hour. The next record of 8.5 Mach was achieved in April 2003 during the Hypersonic Upgrade Program. The program improved the track in many ways, including its ability to withstand tests carried out at supersonic speeds, which made it possible to test the behavior of loads from a real aircraft to real speeds flights. At the moment, they are updating the magnetic suspension of the sled to eliminate vibrations that occur on steel rails. The system was first launched in 2012 and continues to function successfully.
View of the Holloman Base High Speed Test Track from south to north
Satellite view of Holloman Base's high-speed test track
Rocket sled capable of Mach 8.5
Lieutenant Colonel John P. Stapp travels down the track on a Sonic Wind Rocket Sled 1 at 1017 kilometers per hour, for which he was awarded the title of "the fastest man on Earth." This experiment was the last on this track involving a human.
On February 25, 1959, a preliminary sleigh ride was made to check the vibration level of the new equipment.
Left: The nose of an F-22 on a MASE sled at Holloman Base. Right: N-25 Snark at Holloman.
From Wikipedia, the free encyclopedia
rocket sled- a test platform sliding on a special rail track with the help of a rocket engine. As the name implies, this platform does not have wheels, and instead of them, special skids are used that follow the contour of the rails and prevent the platform from flying off.
It is the rocket sled that holds the land speed record, which is Mach 8.5. (10430 km/h)
Application
The first mention of the use of rocket sleds dates back to March 16, 1945, when in Germany at the end of World War II they were used to launch A4b rockets (German. A4b
) from underground mines.
Rocket sleds were actively used in the United States at the beginning of the Cold War, as they made it possible to provide testing on the ground various systems security for new high-speed aircraft (including supersonic). To obtain high accelerations and speeds, the sled was accelerated along specially built straight long rail tracks, and the tested devices and devices were equipped with sensors.
The most famous are the tracks at Edwards and Holloman airbases. Holloman Air Force Base ), where, in addition to testing equipment, tests were also carried out with people in order to find out the effect on the human body of high accelerations during acceleration and braking. At the same time, ejection systems were also tested at transonic speeds. Subsequently, at the first of the bases, the path was dismantled in order to lengthen the path to the second. It is noteworthy that among the engineers who were involved in the rocket sleigh was Edward Murphy (Eng. Edward Murphy ), the author of the law of the same name.
The rocket sled still holds the land speed record. It was installed on April 30, 2003 at Holloman Air Force Base and amounted to 10,325 km / h or 2868 m / s (according to other sources, 10,430 km / h), which is Mach 8.5. The speed record for a manned rocket sled was set on December 10, 1954, also at Holloman Air Force Base, when Lieutenant Colonel John Paul Stapp (Eng. John Stapp ) accelerated them to a speed of 1017 km / h, which at that time was a record for ground controlled vehicles.
After John Stapp (John Stapp) until 2003, 2 more records were set on the rocket sled - 4972 km / h (3089.45 mph) in New Mexico (USA) in 1959 and 9845 km / h (6117.39 mph) h) also on a rocket sled at Holloman Air Force Base (USA) in October 1982.
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Notes
Literature
- Skorenko T.// Popular mechanics: magazine. - M ., 2013. - No. 4.
An excerpt characterizing the Rocket Sleigh
- Well, tell me ... but how did you get your food? he asked. And Terenty began a story about the ruin of Moscow, about the late count, and stood for a long time with his dress, telling, and sometimes listening to Pierre's stories, and, with a pleasant consciousness of the master's closeness to himself and friendliness to him, went into the hall.The doctor who treated Pierre and visited him every day, despite the fact that, according to the duty of doctors, considered it his duty to look like a person, every minute of which is precious for suffering humanity, spent hours with Pierre, telling his favorite stories and observations on the mores of patients in general. and especially ladies.
“Yes, it’s nice to talk with such a person, not like we have in the provinces,” he said.
Several captured French officers lived in Orel, and the doctor brought one of them, a young Italian officer.
This officer began to go to Pierre, and the princess laughed at those tender feelings that the Italian expressed to Pierre.
The Italian, apparently, was happy only when he could come to Pierre and talk and tell him about his past, about his home life, about his love and pour out his indignation at the French, and especially at Napoleon.
- If all Russians are at least a little like you, - he told Pierre, - c "est un sacrilege que de faire la guerre a un peuple comme le votre. [It's blasphemy to fight with people like you.] You who have suffered so much from the French, you don't even have a grudge against them.
And Pierre now deserved the passionate love of the Italian only by what he evoked in him. the best sides his souls and admired them.
During the last time Pierre was in Orel, his old acquaintance, the Mason, Count of Villarsky, came to him, the same one who introduced him to the lodge in 1807. Villarsky was married to a wealthy Russian who had large estates in the Oryol province, and occupied a temporary position in the city in the food department.
Learning that Bezukhov was in Orel, Villarsky, although he never knew him briefly, came to him with those declarations of friendship and intimacy that people usually express to each other when they meet in the desert. Villarsky was bored in Orel and was happy to meet a man of the same circle with himself and with the same, as he believed, interests.
But, to his surprise, Villarsky soon noticed that Pierre was very behind the real life and fell, as he himself defined Pierre, into apathy and egoism.
- Vous vous encroutez, mon cher, [You start, my dear.] - he told him. Despite the fact that Villarsky was now more pleasant with Pierre than before, and he visited him every day. Pierre, looking at Villarsky and listening to him now, it was strange and incredible to think that he himself had very recently been the same.
Villarsky was married, a family man, busy with the affairs of his wife's estate, and service, and family. He believed that all these activities are a hindrance in life and that they are all contemptible, because they are aimed at the personal benefit of him and his family. Military, administrative, political, Masonic considerations constantly absorbed his attention. And Pierre, without trying to change his look, without condemning him, with his now constantly quiet, joyful mockery, admired this strange phenomenon, so familiar to him.
If we exclude spacecraft designed to enter orbit, then the fastest moving vehicle in the earth's atmosphere can be called the strategic reconnaissance aircraft Lockheed SR-71 Blackbird, which once accelerated to 3530 km / h. But, oddly enough, there is even more fast transport. Indeed, very specific...
Sled, just a sled The first rocket sled in history was designed in 1928 by German engineer Max Vallier - they were intended for testing rocket engines and were manned. Valier came to the conclusion that at high speeds it is necessary to minimize the number of moving parts - and developed the concept of a sled. By 1929, the Valier Rak Bob1 sled was built; they were set in motion by four rows of 50-mm powder rockets of the Zander system - a total of 56 pieces. In January-February, Vallière held a series of demonstrations of his systems on the ice of Lake Starnbergersee - without any rails and guides! In the last races on the improved Valier Rak Bob2, he reached a speed of 400 km / h. Vallière subsequently worked with rocket cars.
Tim Skorenko
It all started in Germany. The famous "V-2", aka A-4, had a number of modifications designed to improve the flight and lethal properties of the rocket. One of these versions was the A-4b missile, which later changed its index to A-9. The main task of the A-4b was to cover a considerable distance, that is, in fact, to turn into an intercontinental missile (into the "American missile" A-9, as the prototype was presented to Hitler). Destabilizers of a characteristic shape were installed on the rocket, designed to improve its longitudinal controllability, and the flight range actually increased relative to the A-4. True, America was far away. Moreover, the first two test launches at the end of 1944 and at the beginning of 1945 turned into failures. But there was a third launch, which, according to written sources, took place in March 1945. A specific launcher was designed for it: rails were led from an underground mine to the surface of the earth, on which stood ... sledges. The rocket rested on the latter. Thus, the initial stability of the flight was ensured - movement along the guides excluded wobbling or blockage on the side. True, disputes about whether the launch took place are still ongoing. Documents contain technical data original system, but no direct evidence of such a launch has been found.
Spheres of application of rocket skids: study of the ballistic properties of rockets, projectiles, and other objects; tests of parachutes and other braking systems; - launching small rockets to study their properties in free flight; tests of the effect of acceleration and deceleration on devices and people; aerodynamic studies; other tests (for example, ejection systems).
Man on a skid
What is a rocket sled? In principle, this device is surprising in that its entire design is fully disclosed by the name. This is really a sled on which a rocket engine is installed. Due to the fact that at high speeds (usually supersonic) it is almost impossible to organize control, the sled moves along the guide rails. Braking is most often not provided at all, with the exception of manned units.
Sleigh, just a sleigh
The first rocket sled in history was designed in 1928 by the German engineer Max Vallier - they were intended for testing rocket engines and were manned. Vallière began his experiments with wheeled carts, but quickly came to the conclusion that at high speeds it was necessary to minimize the number of moving parts - and developed the concept of a skid. By 1929, the Valier Rak Bob 1 sled was built; they were set in motion by four rows of 50-mm powder rockets of the Zander system - a total of 56 pieces. In January and February, Vallière himself held a series of demonstrations of his systems on the ice of Starnberger See - note, without any rails and guides! In the last races on the improved Valier Rak Bob 2 system, he reached a speed of 400 km / h (the record for the first sled was 130 km / h). Subsequently, Vallière abandoned sled testing and worked with rocket cars.
The main purpose of the sled is to analyze the ability of various systems and technical solutions work at high acceleration and speed. The skids function approximately like a balloon on a leash, that is, they allow, under comfortable, laboratory conditions, to check systems on which the life of a pilot piloting a supersonic aircraft may depend, or the reliability of instruments responsible for a particular indicator. Sensor-equipped devices are installed on the sledges accelerating to design speeds - their ability to withstand overloads, the influence sound barrier etc.
In the 1950s, Americans used skids to test the effects of high speeds on humans. At that time, it was believed that the lethal overload for a person is 18g, but this number was the result of a theoretical calculation accepted as an axiom in the developing aerospace industry. For real work, both on aircraft and on subsequent spacewalks, more accurate data were required. Edwards Air Force Base in California was chosen as the test base.
Interestingly, the rocket sled appeared in another German project - the famous "Silver Bird". The Silbervogel project was initiated back in the late 1930s by designer Eugen Senger and meant the creation of a partially orbital bomber designed to reach distant territories - the United States and the Soviet Trans-Urals. The project was never implemented (as subsequent calculations showed, it was not viable anyway), but in 1944, a launch scheme appeared in his drawings and sketches using rocket sleds moving along a three-kilometer section of the monorail.
The sled itself was a flat platform weighing 680 kg, on which stood a chair for the tester. Several rocket launchers with a total thrust of 4 kN served as the engine. The main problem was, of course, the brakes, since they had to be not only powerful, but also controlled: the influence of overloads was studied both during acceleration and during braking. Actually, the second part was even more important, since the most comfortable seat belt system for the pilots was created in parallel. The incorrect design of the latter could be fatal, with severe braking, squeezing the pilot, breaking his bones or suffocating him. As a result, a water jet braking system was developed: a certain number of water containers were attached to the skid, which, when activated, threw a jet against the movement. How more containers activated, the more intense the braking.
On April 30, 1947, tests of unmanned sleds were carried out, and experiments with volunteers began a year later. The studies were different, in part of the races the tester sat with his back to the oncoming flow, in part - with his face. But the real glory for this program (and for himself, perhaps) was brought by Colonel John Paul Stapp, the most courageous of the “guinea pigs”.
1950s Colonel John Paul Stapp before the start of one of the tests aimed at studying a new generation of seat belts. There is practically no protection at Steppe, since the influence of serious accelerations and decelerations on the human body is being studied in parallel.
For several years of work in the program, Stapp received broken arms and legs, ribs, dislocations, sprains, and even partially lost his sight due to retinal detachment. But he did not give up, working until the close of the “human” tests in the mid-1950s and setting several world records, some of which have not been broken so far. In particular, Stapp suffered the largest ever impact on an unprotected person overload - 46.2g. Thanks to the program, it was found that the number 18g was indeed taken from the ceiling and a person is able to endure instantaneous overloads up to 32g without harm to health (of course, with the proper design of the chair and other systems). Under this new figure aircraft safety systems were subsequently developed (before that, belts at 20g could simply break or injure the pilot).
In addition, on December 10, 1954, Stapp became the fastest man on earth when the sled with him on board accelerated to 1017 km / h. This record for rail vehicles is still unbeaten.
1971. Minimal Envelope/Weight (MEW) evacuation system testing at China Lake Base in California. A Douglas A-4A Skyhawk is used as the base aircraft. Today, only dummies take part in such tests, but in the 70s there were enough volunteers ready for risk.
Today and tomorrow
Today, there are about 20 rocket sled tracks in the world - mostly in the USA, but also in France, Great Britain, Germany. The longest track is a 15-kilometer stretch at Holloman Air Force Base, New Mexico (Holloman High speed test Track, HHSTT). The rest of the tracks are shorter than this giant by more than two times.
In 2012, Martin-Baker, the world's largest manufacturer of ejection seats and escape systems, conducted rocket sled tests investigating the nature of high-speed ejection. The pilot was “shot” from the cockpit of a Lockheed Martin F-35 Lightning II fighter jet overclocked on the track.
But what are these test systems used for today? In general, for the same reason as half a century ago, only without people. Any device or material that must experience serious overloads is tested by overclocking on a rocket sled to avoid failure in real conditions. For example, NASA recently announced work on the Low-Density Supersonic Decelerator (LDSD) program, which is developing a landing system for other planets, in particular Mars. LDSD technology involves the creation of a three-stage scheme. The first two stages are inflatable supersonic retarders with diameters of 6 and 9 m, respectively; they will reduce the speed of the descent vehicle from Mach 3.5 to Mach 2, and then a 30-meter parachute will come into operation. Such a system as a whole will improve the landing accuracy from ±10 to ±3 km and increase maximum weight cargo from 1.5 to 3 tons.
Rocket sleds are the fastest of the land vehicles - albeit unmanned. In November 1982, an unmanned rocket sled at Holloman Base was accelerated to a speed of 9845 km / h - and on a monorail! This record was held for a long time and was broken on April 30, 2003, all in the same Holloman. The sled was built specifically for record-breaking purposes and was a complex four-stage apparatus that functioned like an orbital rocket. The steps of the sleigh were set in motion 13 separate engines, and the last two stages were equipped with rocket Super Roadrunner (SRR), again developed specifically for this race. Each SRR worked for only 1.4 seconds, but at the same time developed a crazy thrust of 1000 kN. As a result of the race, the fourth stage of the sled accelerated to 10,430 km/h, surpassing the record of 20 years ago. By the way, the record attempt was made back in 1994, but an error in the design of the track led to an accident in which, thank God, no one was hurt.
So, inflatable retarder shields are already being tested today with the help of rocket sleds in the Mojave Desert, at the China Lake Naval Base. A 9-meter shield is mounted on a skid that accelerates to about 600 km / h in a matter of seconds; the parachute is subjected to similar "bullying". In principle, since 2013, NASA has been moving to more realistic tests - in particular, to trial runs and landings. With free movement in the atmosphere, brake shields can behave completely differently than those rigidly mounted on skids.
Sometimes rocket sleds are used for a kind of crash tests. For example, in this way it can be checked how the missile warhead deforms when it collides with an obstacle and how this deformation affects the ballistic properties. A well-known series of tests of this kind were the crash tests of the F-4 Phantom aircraft, which took place in 1988 at Kirkland Air Force Base, New Mexico. The platform with a full-size model of the aircraft installed on it was dispersed to a speed of 780 km / h and forced to crash into a concrete wall to determine the force of the collision and its effect on the aircraft.
In general, rocket sleds can hardly be called a vehicle. More like a testing device. Nevertheless, the specificity of this device allows you to set world speed records on it. And it is likely that speed record Colonel Stapp is not the last.
