Inertial navigation system
An inertial navigation system is a navigation device that uses a computer, motion sensors and rotation sensors to continuously calculate by dead reckoning the position, the orientation, the velocity of a moving object without the need for external references. The inertial sensors are supplemented by a barometric altimeter and by magnetic sensors and/or speed measuring devices. INSs are used on vehicles such as ships, submarines, guided missiles, spacecraft. Other terms used to refer to inertial navigation systems or related devices include inertial guidance system, inertial instrument, inertial measurement unit and many other variations. Older INS systems used an inertial platform as their mounting point to the vehicle and the terms are sometimes considered synonymous. Inertial navigation is a self-contained navigation technique in which measurements provided by accelerometers and gyroscopes are used to track the position and orientation of an object relative to a known starting point and velocity.
Inertial measurement units contain three orthogonal rate-gyroscopes and three orthogonal accelerometers, measuring angular velocity and linear acceleration respectively. By processing signals from these devices it is possible to track the position and orientation of a device. Inertial navigation is used in a wide range of applications including the navigation of aircraft and strategic missiles, spacecraft and ships. Recent advances in the construction of microelectromechanical systems have made it possible to manufacture small and light inertial navigation systems; these advances have widened the range of possible applications to include areas such as human and animal motion capture. An inertial navigation system includes at least a computer and a platform or module containing accelerometers, gyroscopes, or other motion-sensing devices; the INS is provided with its position and velocity from another source accompanied with the initial orientation and thereafter computes its own updated position and velocity by integrating information received from the motion sensors.
The advantage of an INS is that it requires no external references in order to determine its position, orientation, or velocity once it has been initialized. An INS can detect a change in its geographic position, a change in its velocity and a change in its orientation, it does this by measuring the linear angular velocity applied to the system. Since it requires no external reference, it is immune to deception. Inertial navigation systems are used in many different moving objects. However, their cost and complexity place constraints on the environments in which they are practical for use. Gyroscopes measure the angular velocity of the sensor frame with respect to the inertial reference frame. By using the original orientation of the system in the inertial reference frame as the initial condition and integrating the angular velocity, the system's current orientation is known at all times; this can be thought of as the ability of a blindfolded passenger in a car to feel the car turn left and right or tilt up and down as the car ascends or descends hills.
Based on this information alone, the passenger knows what direction the car is facing but not how fast or slow it is moving, or whether it is sliding sideways. Accelerometers measure the linear acceleration of the moving vehicle in the sensor or body frame, but in directions that can only be measured relative to the moving system; this can be thought of as the ability of a blindfolded passenger in a car to feel himself pressed back into his seat as the vehicle accelerates forward or pulled forward as it slows down. Based on this information alone, he knows how the vehicle is accelerating relative to itself, that is, whether it is accelerating forward, left, right, up, or down measured relative to the car, but not the direction relative to the Earth, since he did not know what direction the car was facing relative to the Earth when they felt the accelerations. However, by tracking both the current angular velocity of the system and the current linear acceleration of the system measured relative to the moving system, it is possible to determine the linear acceleration of the system in the inertial reference frame.
Performing integration on the inertial accelerations using the correct kinematic equations yields the inertial velocities of the system and integration again yields the inertial position. In our example, if the blindfolded passenger knew how the car was pointed and what its velocity was before he was blindfolded and if he is able to keep track of both how the car has turned and how it has accelerated and decelerated since he can know the current orientation and velocity of the car at any time. All inertial navigation systems suffer from integration drift: small errors in the measurement of acceleration and angular velocity are integrated into progressively larger errors in velocity, which are compounded into still greater errors in position. Since the new position is calculated
Production Corporation Polyot
Production Association Polyot is a Russian aerospace engineering company best known for being the manufacturer of GLONASS satellites and the Kosmos-3M space launch vehicle. The company is based in the Russian Federation. In 2007, the company was integrated into the Khrunichev enterprise, its full name is "Polyot" Manufacturing Corporation – A Branch of The Federal State Unitary Enterprise "Khrunichev State Research and Production Space Center". The Kosmos-3M launch vehicle, produced at the company since 1969, has established a reputation as one of the most reliable rockets in its class with a reliability coefficient of 0.97. Polyot develops navigation satellites, such as Nadezhda, Parus, GLONASS and GLONASS-M. In the aviation sector, the company's products include the AN-3T light multi-purpose aircraft, AN-70 transport aircraft and the AN-74 multi-purpose aircraft. PC Polyot is slated to produce the upcoming URM-1 first stage of the Angara, a part of Khrunichev's new Angara rocket family; the Angara is projected to become Russia's primary unmanned launch vehicle in the near future.
The company will take over the production of the Briz-KM upper stage, used on the Rockot launch vehicle, this module will function as the second stage of the Angara 1.2 launch vehicle. By 2015, 60 URM stages are expected to be produced at the company annually for Angara-3.2 and Angara 1.2 rockets. The company has entered a partnership with the German company OHB-System, providing the Kosmos-3M launch vehicle as well as designing and producing satellite platforms for OHB-System's ORBCOMM project. Six such satellites were launched on 19 June 2008 with the Kosmos-3M rocket: one ORBCOMM CDS weighing 80 kg, five ORBCOMM Quick Launches weighing 115 kg each. On November 9, 2009 ORBCOMM filed a report to the United States Securities and Exchange Commission stating that since launch, communications capability for three of the quick-launch satellites and the CDS has been lost; the failed satellites experienced attitude control system anomalies as well as anomalies with its power systems, which resulted in the satellites losing their proper orientation toward the sun and in reduced power generation.
The company has filed a $50 million claim with its insurers covering the loss of all six satellites and received $44.5 million in compensation. In 2009, ORBCOMM turned to another satellite manufacturer to build 18 satellites for its second-generation constellation, it produced. United Rocket and Space Corporation Company website
The PGM-19 Jupiter was the first nuclear tipped, medium-range ballistic missile of the United States Air Force. It was a liquid-propellant rocket using RP-1 fuel and LOX oxidizer, with a single Rocketdyne LR70-NA rocket engine producing 667 kN of thrust, it was armed with the 1.44 megaton W49 nuclear warhead. The prime contractor was the Chrysler Corporation; the Jupiter was designed by the US Army, looking for a accurate missile designed to strike high-value targets like bridges, railway yards, troop concentrations and the like. The Navy expressed an interest in the design as an SLBM, but left the collaboration to work on their Polaris. Jupiter retained the squat shape intended to fit in naval submarines; the U. S. Army set accuracy goals so high that some expressed skepticism they could be met, but the Redstone Arsenal team designed a system with a circular error probable of 0.5 miles more accurate than designs like the US Air Force's Thor ICBM. A presidential report suggested this made it the most valuable missile being developed.
This led to continual inter-service fighting between the Army and Air Force, to Charles Erwin Wilson's decision to give the Jupiter missiles to the U. S. Air Force; the Air Force were never interested in supporting Jupiter. Production went ahead and the nuclear tipped missiles were deployed in both Italy and Turkey in 1961 due to NATO's Cold War deterrence against the Soviet Union. All were later removed by the United States as part of a secret agreement with the Soviet Union during the Cuban Missile Crisis, they were considered to be outdated. It was used as the basis for a satellite launcher known as Juno II, but had a short and unsuccessful career in this role, it is unclear as to what happened to the missiles in Italy. In the aftermath of World War II, a number of German rocket scientists and engineers were moved to the United States as part of Operation Paperclip. Rocketry was at that time considered to be a sort of long-range artillery, fell to the Army to explore; the group was settled at Fort Bliss, Texas – where they aided General Electric's Project Hermes efforts to build and test a variety of V-2-derived designs at the nearby White Sands Proving Ground.
Around the same time, North American Aviation won the contract to build a long-range cruise missile that became the SM-64 Navaho. This needed to be boosted up to operational speed by a rocket, their Propulsion Division was given two V-2 engines to work with to meet this requirement, along with a wealth of research papers from the original V-2 engine team. The NAA team discovered that a major upgrade to the V-2's original Model 39 engine was planned through the use of a new fuel injector design, but the Germans were not able to cure lingering combustion problems. Attacking this task, NAA solved the problems and began using this new injector; this became the XLR-41 Phase III engine, which provided 75,000 pounds-force of thrust, one third greater than the Model 39, was lighter and smaller than the German design. The outbreak of the Korean War in June 1950 led to calls for the rapid deployment of new missiles, the Army responded by developing a requirement for a ballistic missile with 500 miles range while carrying a 500 pounds warhead that could be operational as as possible.
The fastest solution was to provide the German team with anything they needed to achieve this goal by adapting the V-2 design. The team, under the leadership of Wernher von Braun, began work on the problem at Fort Bliss. In 1951 they moved to the Redstone Arsenal in Huntsville, home to the Army's Ordnance commands. Known as the Ordnance Guided Missile Center the Guided Missile Development Division, in 1956 they became the Army Ballistic Missile Agency, or ABMA. Taking the XLR-41, renamed as the NA-75-110 in Army use, they wrapped it in the largest airframe it could lift, increasing fuel load and extending the range; the result was a larger version of the V-2. As tensions of the Cold War mounted, the Army changed the requirement to be able to carry smallest nuclear warheads in the inventory – with a warhead weight of 6,900 pounds, range was reduced to only 175 miles. Design work was complete in 1952 and on 8 April it became known as the SSM-G-14 Redstone; the first ABMA-built prototype flew in August 1953, the first production-line model from Chrysler in July 1956, the Redstone entered service in 1958.
While the "Redstone" program continued, NAA was receiving a continual stream of orders from the Air Force to extend the range and payload of their Navaho design. This required a much larger missile, a much larger booster to launch it; as a result, NAA was continually introducing new versions of their engines. By the mid-1950s, NAA had a version known as the XLR-43 running at 120,000 pounds-force thrust, while further reducing weight at the same time. Much of this was due to the introduction of the tubular wall combustion chamber, much lighter than the cast-steel designs of the V-2, while offering much better cooling which allowed the combustion rate, thus thrust, to be increased. While the Navajo program dragged on, NAA split the team into three groups, Rocketdyne handled engines, Autonetics developed inertial navigation systems and the Missile Division retained the Navaho itself. With this breakup of duties, both Rocketdyne and Autonetics were soon asked to provide solutions for ot
Kapustin Yar is a Russian rocket launch and development site in Astrakhan Oblast, between Volgograd and Astrakhan. It was established by the Soviet Union on 13 May 1946 and in the beginning used technology and scientific support from defeated Germany. Numerous launches of test rockets for the Russian military were carried out at the site, as well as satellite and sounding rocket launches; the town of Znamensk and Kapustin Yar was built nearby to serve the missile test range. The 4th Missile Test Range "Kapustin Yar" was established by a decree of the Soviet Government "On Questions of Jet Propelled Weapons" on 13 May 1946; the test range was created under the supervision of General-lieutenant Vasily Voznyuk in the desert north end of the Astrakhan region. The first rocket was launched from the site on 18 October 1947; the State R&D Test Range No 8 was established at Kapustin Yar in June 1951. Five atmospheric nuclear tests of small power were performed over the site in 1957-1961; as of 1959 Kapustin Yar was the only publicly known Soviet missile test range.
Non-Soviet observers believed at first that 2 launched from the site. With the further growth and development, Kapustin Yar became a cosmodrome, serving in this function since 1966; the rate of space launches was low 1-2 a year and during the Soviet era, it hosted only the two smallest launch vehicles, the R-12 and R-14 derived Kosmos boosters. There were no space launches at all from 1988-1998; the town of Znamensk was established to support the scientists working on the facilities, their families and supporting personnel. This was a secret city, not shown on maps and requiring official permission to visit. Evidence of the importance of Kapustin Yar was obtained by Western intelligence through debriefing of returning German scientists and spy flights; the first such flight took place in mid-1953 using a high flying Canberra aircraft of the RAF. The UK Government has never admitted such a flight took place nor have any of the supposed participants provided direct evidenceDue to its role as a development site for new technology, Kapustin Yar is the site of numerous Soviet-era UFO sightings and has been called "Russia's Roswell".
June 3, 1947 Resolution of the Council of Ministers of the USSR and the Central Committee of the CPSU No. 2642–817 Kapustin Yar was designated as the location of the new rocket test site, Major General V. I. Voznyuk, the chief of staff of the GPC, a colonel A. G. Karas; the first officers arrived at the future training ground on August 20, 1947. In September 1947, a special brigade of the Reserve of the Supreme Main Command, Major General of Artillery, arrived from Germany A. F. Tveretsky two special trains with equipment taken from Germany. By the beginning of October 1947, in addition to the concrete test stand and bunker, at the 1st site, a launch site with a bunker, a temporary technical position, an installation building were built. Housing construction at the site was not conducted until 1948, builders and testers lived in tent x, dugout x, temporary buildings, lived in peasant izba x village Kapustin Yar. Guide landfill lived in special train. By October 1, 1947, VV Voznyuk reported to the leadership about the readiness of the launch site for launching rockets, on October 14, 1947, the first batch of missiles V-2 arrived at the test site.
On October 18, 1947 at 10:47 Moscow time, the first launch of ballistic missile in the USSR was made. In the period from October 18 to November 13, 1947, 11 V-2 rockets were launched, of which 9 reached the target and 2 crashed. From 1947 to 1957, Kapustin Yar was the only place to test Soviet ballistic missiles. On the test site were tested missiles R-2, R-5, R-12, R-14, etc.. On September 2, 1959, a missile, for the first time in the world, was launched from a missile silo. In 1957-1959, intercontinental cruise missile "Burya" started at the Kapustin Yar proving ground. On May 20, 1960, the Training Center of the Rocket Forces of the Ground Forces was established on the territory of the State Landfill, whose task was to create combat coherence of missile Parts created and retrain rocket specialists, create regulatory documents for all-round missile combat activities parts of the Ground Forces. On March 16, 1962, Kapustin Yar became cosmodrome: Cosmos-1 satellite was launched ”. Subsequently, small research satellites were launched from the Kapustin Yar cosmodrome, to launch which were used launch vehicle of the light class of the series Cosmos ”.
In subsequent years, a large number of various short- and medium-range missiles, cruise missiles and air defense missiles were tested and tested at the test site. According to open data, since the 1950s, at least 11 have been conducted at the Kapustin Yar test site nuclear explosions, the total capacity of, 65 atomic bombs, dropped on Hiroshima. In addition to nuclear tests, 24 thousand guided missiles were blown up in Kapustin Yar, 177 samples of military equipment were tested, 619 missiles were destroyed RSD-10. In 1994, the 4 GPC Russian Ministry of Defense entered the test site Air Defense Forces. In October 1998, the 4th State Central Polygon was transformed into the 4th State Central Interspecific Polygon. In 1998, the “Sary-Shagan” test site
The UGM-27 Polaris missile was a two-stage solid-fueled nuclear-armed submarine-launched ballistic missile. The United States Navy's first SLBM, it served from 1961 to 1996; the Polaris project was created to replace the solid-fueled Jupiter S project, approved in 1956 to replace the liquid-fueled SM-78 and PGM-19 Jupiter missiles. In December 1956, the United States Navy awarded Polaris development contracts to Lockheed Corporation and Aerojet Rocketdyne; the Polaris missile was designed to be used for second strike countervalue as part of the Navy's contribution to the United States arsenal of nuclear weapons, replacing the Regulus cruise missile. Known as a Fleet Ballistic Missile, the Polaris was first launched from the Cape Canaveral, missile test base on January 7, 1960. Following the Polaris Sales Agreement in 1963, Polaris missiles were carried on British Royal Navy submarines between 1968 and the mid-1990s. Plans to equip the Italian Navy with the missile ended in the mid-60s, after several successful test launches carried out onboard the Italian cruiser Giuseppe Garibaldi.
Despite the successful launching tests, the plan was abandoned due to the completion of initial SSBN vessels. Nonetheless, the Italian government set out to develop an indigenous missile called Alfa; the program was successful, but was halted by Italy's ratification of the Nuclear Non-Proliferation Treaty and the failure of the NATO Multilateral Force. The Polaris missile was replaced on 31 of the 41 original SSBNs in the U. S. Navy by the MIRV-capable Poseidon missile beginning in 1972. During the 1980s, these missiles were replaced on 12 of these submarines by the Trident I missile; the 10 George Washington- and Ethan Allen-class SSBNs retained Polaris A-3 until 1980 because their missile tubes were not large enough to accommodate Poseidon. With USS Ohio beginning sea trials in 1980, these submarines were disarmed and redesignated as attack submarines to avoid exceeding the SALT II strategic arms treaty limits; the Polaris missile program's complexity led to the development of new project management techniques, including the Program Evaluation and Review Technique to replace the simpler Gantt chart methodology.
At the start of the Second World War, nearly every major world military force, involved in the war had at least developed rough ideas of a rocket program. It is important to note that at this time the distinction between rockets and missiles was this: rockets traveled over a fixed trajectory and missiles could be guided to their destination. Rockets of all shapes and sizes were being implemented in battlefields around the globe; the Soviet Union deployed rockets such as the Katyusha, which were fired from a mobile launcher in waves of up to nearly 50 small, unguided rockets, the Japanese were implementing rockets that would be used on the front lines. Rockets such as the Katyusha could fire at targets within three miles, while the first Japanese rockets were only valuable for targets less than five-hundred feet away; the initial version of the Japanese kamikaze planes were powered by rockets. These wooden suicide planes did not provide the Japanese forces with a reliable weapon, by 1945 the kamikaze gliders were being used in combat, no matter how ineffective they may have been.
British forces, had begun developments on anti-aircraft rockets of their own, which proved effective as early as 1941. Soon after the attacks on Pearl Harbor, the United States joined arms in the race for rockets borrowing much of its initial products from the British armed forces; the United States rocket program began testing both rockets and missiles, by 1945, the Army was investing $150 million a year, while the Navy was spending $1.2 billion. Despite these efforts from the major contributing forces in the war, German scientists excelled at mastering the largest and most advanced weapons. One of which, the German V-2 rocket, would become the blueprint for all of the serious global missile programs to come; as the United States Army continued to make steady advancements in its rocket and missile programs it became apparent that if the program wished to keep up with its own rapid growth, as well as with the rest of the world, it would need more space than what was available. On October 28, 1949, Alabama, was chosen based on its promising location and easy access to resources to be the new home to the American program.
By the end of 1950, the Redstone Arsenal was operational and took on the new designation as the Ordnance Guided Missile Center. The Polaris missile replaced an earlier plan to create a submarine-based missile force based on a derivative of the U. S. Army Jupiter Intermediate-range ballistic missile. Chief of Naval Operations Admiral Arleigh Burke appointed Rear Admiral W. F. "Red" Raborn as head of a Special Project Office to develop Jupiter for the Navy in late 1955. The Jupiter missile's large diameter was a product of the need to keep the length short enough to fit in a reasonably-sized submarine. At the seminal Project Nobska conference in 1956, with Admiral Burke present, nuclear physicist Edward Teller stated that a physically small one-megaton warhead could be produced for Polaris within a few years, this prompted Burke to leave the Jupiter program and concentrate on Polaris in December of that year. Polaris was spearheaded by the Special Project Office's Missile Branch under Rear Admiral Roderick Osgood Middleton, is still under the Special Project Office.
Admiral Burke was instrumental in determining the size of the Polaris submarine force, suggesting that 40-45 submarines with 16 missiles each would be sufficient. The number of Polaris submarines was fixed
Russia the Russian Federation, is a transcontinental country in Eastern Europe and North Asia. At 17,125,200 square kilometres, Russia is by far or by a considerable margin the largest country in the world by area, covering more than one-eighth of the Earth's inhabited land area, the ninth most populous, with about 146.77 million people as of 2019, including Crimea. About 77 % of the population live in the European part of the country. Russia's capital, Moscow, is one of the largest cities in the world and the second largest city in Europe. Extending across the entirety of Northern Asia and much of Eastern Europe, Russia spans eleven time zones and incorporates a wide range of environments and landforms. From northwest to southeast, Russia shares land borders with Norway, Estonia, Latvia and Poland, Ukraine, Azerbaijan, China and North Korea, it shares maritime borders with Japan by the Sea of Okhotsk and the U. S. state of Alaska across the Bering Strait. However, Russia recognises two more countries that border it, Abkhazia and South Ossetia, both of which are internationally recognized as parts of Georgia.
The East Slavs emerged as a recognizable group in Europe between the 3rd and 8th centuries AD. Founded and ruled by a Varangian warrior elite and their descendants, the medieval state of Rus arose in the 9th century. In 988 it adopted Orthodox Christianity from the Byzantine Empire, beginning the synthesis of Byzantine and Slavic cultures that defined Russian culture for the next millennium. Rus' disintegrated into a number of smaller states; the Grand Duchy of Moscow reunified the surrounding Russian principalities and achieved independence from the Golden Horde. By the 18th century, the nation had expanded through conquest and exploration to become the Russian Empire, the third largest empire in history, stretching from Poland on the west to Alaska on the east. Following the Russian Revolution, the Russian Soviet Federative Socialist Republic became the largest and leading constituent of the Union of Soviet Socialist Republics, the world's first constitutionally socialist state; the Soviet Union played a decisive role in the Allied victory in World War II, emerged as a recognized superpower and rival to the United States during the Cold War.
The Soviet era saw some of the most significant technological achievements of the 20th century, including the world's first human-made satellite and the launching of the first humans in space. By the end of 1990, the Soviet Union had the world's second largest economy, largest standing military in the world and the largest stockpile of weapons of mass destruction. Following the dissolution of the Soviet Union in 1991, twelve independent republics emerged from the USSR: Russia, Belarus, Uzbekistan, Azerbaijan, Kyrgyzstan, Tajikistan and the Baltic states regained independence: Estonia, Lithuania, it is governed as a federal semi-presidential republic. Russia's economy ranks as the twelfth largest by nominal GDP and sixth largest by purchasing power parity in 2018. Russia's extensive mineral and energy resources are the largest such reserves in the world, making it one of the leading producers of oil and natural gas globally; the country is one of the five recognized nuclear weapons states and possesses the largest stockpile of weapons of mass destruction.
Russia is a great power as well as a regional power and has been characterised as a potential superpower. It is a permanent member of the United Nations Security Council and an active global partner of ASEAN, as well as a member of the Shanghai Cooperation Organisation, the G20, the Council of Europe, the Asia-Pacific Economic Cooperation, the Organization for Security and Co-operation in Europe, the World Trade Organization, as well as being the leading member of the Commonwealth of Independent States, the Collective Security Treaty Organization and one of the five members of the Eurasian Economic Union, along with Armenia, Belarus and Kyrgyzstan; the name Russia is derived from Rus', a medieval state populated by the East Slavs. However, this proper name became more prominent in the history, the country was called by its inhabitants "Русская Земля", which can be translated as "Russian Land" or "Land of Rus'". In order to distinguish this state from other states derived from it, it is denoted as Kievan Rus' by modern historiography.
The name Rus itself comes from the early medieval Rus' people, Swedish merchants and warriors who relocated from across the Baltic Sea and founded a state centered on Novgorod that became Kievan Rus. An old Latin version of the name Rus' was Ruthenia applied to the western and southern regions of Rus' that were adjacent to Catholic Europe; the current name of the country, Россия, comes from the Byzantine Greek designation of the Rus', Ρωσσία Rossía—spelled Ρωσία in Modern Greek. The standard way to refer to citizens of Russia is rossiyane in Russian. There are two Russian words which are commonly
Cuban Missile Crisis
The Cuban Missile Crisis known as the October Crisis of 1962, the Caribbean Crisis, or the Missile Scare, was a 13-day confrontation between the United States and the Soviet Union initiated by the American discovery of Soviet ballistic missile deployment in Cuba. The confrontation is considered the closest the Cold War came to escalating into a full-scale nuclear war. In response to the failed Bay of Pigs Invasion of 1961 and the presence of American Jupiter ballistic missiles in Italy and Turkey, Soviet leader Nikita Khrushchev agreed to Cuba's request to place nuclear missiles on the island to deter a future invasion. An agreement was reached during a secret meeting between Khrushchev and Fidel Castro in July 1962, construction of a number of missile launch facilities started that summer; the 1962 United States elections were under way, the White House had for months denied charges that it was ignoring dangerous Soviet missiles 90 miles from Florida. The missile preparations were confirmed when an Air Force U-2 spy plane produced clear photographic evidence of medium-range and intermediate-range ballistic missile facilities.
The US established a naval blockade on October 22 to prevent further missiles from reaching Cuba. The US announced it would not permit offensive weapons to be delivered to Cuba and demanded that the weapons in Cuba be dismantled and returned to the Soviet Union. After several days of tense negotiations, an agreement was reached between US President John F. Kennedy and Khrushchev. Publicly, the Soviets would dismantle their offensive weapons in Cuba and return them to the Soviet Union, subject to United Nations verification, in exchange for a US public declaration and agreement to avoid invading Cuba again. Secretly, the United States agreed that it would dismantle all US-built Jupiter MRBMs, deployed in Turkey against the Soviet Union; when all offensive missiles and Ilyushin Il-28 light bombers had been withdrawn from Cuba, the blockade was formally ended on November 21, 1962. The negotiations between the United States and the Soviet Union pointed out the necessity of a quick and direct communication line between Washington and Moscow.
As a result, the Moscow–Washington hotline was established. A series of agreements reduced US–Soviet tensions for several years until both parties began to build their nuclear arsenal further. With the end of World War II and the start of the Cold War, the United States had grown concerned about the expansion of communism. A Latin American country allying with the Soviet Union was regarded by the US as unacceptable, it would, for example, defy the Monroe Doctrine, a US policy limiting US involvement in European colonies and European affairs but holding that the Western Hemisphere was in the US sphere of influence. The Kennedy administration had been publicly embarrassed by the failed Bay of Pigs Invasion in May 1961, launched under President John F. Kennedy by CIA-trained forces of Cuban exiles. Afterward, former President Dwight Eisenhower told Kennedy that "the failure of the Bay of Pigs will embolden the Soviets to do something that they would otherwise not do." The half-hearted invasion left Soviet premier Nikita Khrushchev and his advisers with the impression that Kennedy was indecisive and, as one Soviet adviser wrote, "too young, not prepared well for decision making in crisis situations... too intelligent and too weak".
US covert operations against Cuba continued in 1961 with the unsuccessful Operation Mongoose. In addition, Khrushchev's impression of Kennedy's weaknesses was confirmed by the President's response during the Berlin Crisis of 1961 to the building of the Berlin Wall. Speaking to Soviet officials in the aftermath of the crisis, Khrushchev asserted, "I know for certain that Kennedy doesn't have a strong background, nor speaking, does he have the courage to stand up to a serious challenge." He told his son Sergei that on Cuba, Kennedy "would make a fuss, make more of a fuss, agree". In January 1962, US Army General Edward Lansdale described plans to overthrow the Cuban government in a top-secret report, addressed to Kennedy and officials involved with Operation Mongoose. CIA agents or "pathfinders" from the Special Activities Division were to be infiltrated into Cuba to carry out sabotage and organization, including radio broadcasts. In February 1962, the US launched an embargo against Cuba, Lansdale presented a 26-page, top-secret timetable for implementation of the overthrow of the Cuban government, mandating guerrilla operations to begin in August and September.
"Open revolt and overthrow of the Communist regime" would occur in the first two weeks of October. When Kennedy ran for president in 1960, one of his key election issues was an alleged "missile gap" with the Soviets leading; the US at that time led the Soviets by a wide margin that would only increase. In 1961, the Soviets had only four intercontinental ballistic missiles. By October 1962, they may have had a few dozen, with some intelligence estimates as high as 75; the US, on the other hand, had 170 ICBMs and was building more. It had eight George Washington- and Ethan Allen-class ballistic missile submarines, with the capability to launch 16 Polaris missiles, each with a range of 2,500 nautical miles. Khrushchev increased the perception of a missile