The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
Pioneer 5 was a spin-stabilized space probe in the NASA Pioneer program used to investigate interplanetary space between the orbits of Earth and Venus. It was launched on March 11, 1960 from Cape Canaveral Air Force Station Launch Complex 17A at 13:00:00 UTC with an on-orbit dry mass of 43 kg, it was a 0.66 m diameter sphere with 1.4 m span across its four solar panels and achieved a solar orbit of 0.806 × 0.995 AU. Data was received until April 30, 1960. Among other accomplishments, the probe confirmed the existence of interplanetary magnetic fields. Pioneer 5 was the most successful probe in the Pioneer/Able series; the original mission plan was for a launch in November 1959 where Pioneer 5 would conduct a flyby of Venus, but technical issues prevented the launch from occurring until early 1960 by which time the Venus window for the year had closed. Since it was not possible to send the probe to Venus, it would instead investigate interplanetary space and an actual mission to the planet would have to wait another three years.
The spacecraft was a 0.66 m diameter sphere with four solar panels. It was equipped with four scientific instruments: A triple coincidence omnidirectional proportional counter telescope to detect solar particles and observe terrestrial trapped radiation, it could detect photons with E > 75 MeV and electrons with E > 13 MeV. A rotating search coil magnetometer to measure the magnetic field in the distant field of the Earth, near the geomagnetic boundary, in interplanetary space, it was capable of measuring fields from 1 microgauss to 12 milligauss. It consisted of a single search coil, mounted on the spacecraft in such a way that it measured the magnetic field perpendicular to the spin axis of the spacecraft, it could output its measurements in a digital format. A Neher-type integrating ionization chamber and an Anton 302 Geiger-Müller tube to measure cosmic radiation, it was mounted normal to the spin axis of the spacecraft. A micrometeorite momentum spectrometer that consisted of two microphone combinations.
It was used to measure the momentum of these particles. Booster performance during launch was overall excellent considering the numerous earlier difficulties with the Thor-Able vehicle. There were some minor anomalies with the second stage flight control system that resulted in unplanned pitch and roll motions, however they were not enough to endanger the mission; the spacecraft returned data collected by the magnetometer on the magnetic field and it measured that the median undisturbed interplanetary field was 5 γ ± 0.5 γ in magnitude. The spacecraft measured solar flare particles, cosmic radiation in the interplanetary region; the micrometeorite counter failed to operate as the data system saturated and failed to operate properly. The recorded digital data were transmitted at 1, 8, 64 bit/s, depending on the distance of the spacecraft from Earth and the size of the receiving antenna. Weight limitations on the solar cells prevented continuous operation of the telemetry transmitters. About four operations of 25 min duration were scheduled per day with occasional increases during times of special interest.
A total of 138.9 h of operation was completed, over three megabits of data were received. The major portion of the data was received by the Lovell radio telescope at Jodrell Bank Observatory and the Hawaii Tracking Station because their antennas provided grid reception. Data was received until April 30, 1960, after which telemetry noise and weak signal strength made data reception impossible; the spacecraft's signal was detected by Jodrell Bank from a record distance of 36.2 million km on June 26, 1960, although it was much too weak by to acquire data. In common with Explorer 6, Pioneer 5 used the earliest known digital telemetry system used on spacecraft, codenamed "Telebit". Which was a tenfold improvement in channel efficiency on previous generation "Microlock" analog systems in use since Explorer 1 and the biggest single improvement in signal encoding on western spacecraft; the spacecraft received the uplink carrier at 401.8 MHz and converted it to a 378.2 MHz signal using a 16/17 coherent oscillator circuit.
The telemetry system phase modulated a 512 Hz subcarrier, in turn amplitude modulated at 64, 8, or 1bit/s. The spacecraft was unable to aim its antennas, so had no high-gain dish antenna common on spacecraft. Instead, the system could introduce a 150W amplifier into its 5W transmitter circuit, it was powered by a battery of 28 F-size NiCd cells recharged by the solar paddles, allowing up to eight minutes of high power communications before risking damage to the batteries. Each hour of 5W communications or five minutes of 150W communications required ten hours of recharging the batteries. Unlike interplanetary spacecraft, this spacecraft did not use the Deep Space Network, not yet available, but a somewhat ad hoc Space Network called SPAN consisting of the 76m Lovell Telescope, a 26-meter radio telescope in Hawaii, a small helical array in Singapore. Pioneer program Timeline of artificial satellites and space probes Mariner 2 Pioneer 5 Profile by NASA's Solar System Exploration Space Technology Laboratories Documents Archive
Apollo 11 was the spaceflight that landed the first two people on the Moon. Commander Neil Armstrong and lunar module pilot Buzz Aldrin, both American, landed the Apollo Lunar Module Eagle on July 20, 1969, at 20:17 UTC. Armstrong became the first person to step onto the lunar surface six hours on July 21 at 02:56:15 UTC, they spent about two and a quarter hours together outside the spacecraft, collected 47.5 pounds of lunar material to bring back to Earth. Command module pilot Michael Collins flew the command module Columbia alone in lunar orbit while they were on the Moon's surface. Armstrong and Aldrin spent 21.5 hours on the lunar surface before rejoining Columbia in lunar orbit. Apollo 11 was launched by a Saturn V rocket from Kennedy Space Center on Merritt Island, Florida, on July 16 at 13:32 UTC, was the fifth crewed mission of NASA's Apollo program; the Apollo spacecraft had three parts: a command module with a cabin for the three astronauts, the only part that returned to Earth. After being sent to the Moon by the Saturn V's third stage, the astronauts separated the spacecraft from it and traveled for three days until they entered lunar orbit.
Armstrong and Aldrin moved into Eagle and landed in the Sea of Tranquillity. The astronauts used Eagle's ascent stage to lift off from the lunar surface and rejoin Collins in the command module, they jettisoned Eagle before they performed the maneuvers that blasted them out of lunar orbit on a trajectory back to Earth. They returned to Earth and splashed down in the Pacific Ocean on July 24 after more than eight days in space. Armstrong's first step onto the lunar surface was broadcast on live TV to a worldwide audience, he described the event as "one small step for man, one giant leap for mankind." Apollo 11 ended the Space Race and fulfilled a national goal proposed in 1961 by President John F. Kennedy: "before this decade is out, of landing a man on the Moon and returning him safely to the Earth." In the late 1950s and early 1960s, the United States was engaged in the Cold War, a geopolitical rivalry with the Soviet Union. On October 4, 1957, the Soviet Union launched the first artificial satellite.
This surprise success fired imaginations around the world. It demonstrated that the Soviet Union had the capability to deliver nuclear weapons over intercontinental distances, challenged American claims of military and technological superiority; this precipitated the Sputnik crisis, triggered the Space Race. President Dwight D. Eisenhower responded to the Sputnik challenge by creating the National Aeronautics and Space Administration, initiating Project Mercury, which aimed to launch a man into Earth orbit, but on April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first person in space, the first to orbit the Earth. It was another body blow to American pride. Nearly a month on May 5, 1961, Alan Shepard became the first American in space, completing a 15-minute suborbital journey. After being recovered from the Atlantic Ocean, he received a congratulatory telephone call from Eisenhower's successor, John F. Kennedy. Kennedy believed that it was in the national interest of the United States to be superior to other nations, that the perception of American power was at least as important as the actuality.
It was therefore intolerable that the Soviet Union was more advanced in the field of space exploration. He was determined that the United States should compete, sought a challenge that maximized its chances of winning. Since the Soviet Union had better booster rockets, he required a challenge, beyond the capacity of the existing generation of rocketry, one where the US and Soviet Union would be starting from a position of equality. Something spectacular if it could not be justified on military, economic or scientific grounds. After consulting with his experts and advisors, he chose such a project. On May 25, 1961, he addressed the United States Congress on "Urgent National Needs" and declared:I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space. We propose to accelerate the development of the appropriate lunar space craft.
We propose to develop alternate liquid and solid fuel boosters, much larger than any now being developed, until certain, superior. We propose additional funds for other engine development and for unmanned explorations-explorations which are important for one purpose which this nation will never overlook: the survival of the man who first makes this daring flight, but in a real sense, it will not be one man going to the Moon-if we make this judgment affirmatively, it will be an entire nation. For all of us must work to put him there; the effort to land a man on the Moon had a name: Project Apollo. An early and crucial decision was choosing lunar orbit rendezvous over both direct ascent and Earth orbit rendezvous. A space rendezvous is an orbital maneuver in which two spacecraft navigate through space and meet up. On July 11, 1962, James Webb announced the decision to use lunar orbit rendezvous; this resulted in a much smaller launch vehicle, in the Apollo spacecraft being composed of three major parts: a command module with a cabin for the three astr
Pioneer 4 was an American spin-stabilized unmanned spacecraft launched as part of the Pioneer program on a lunar flyby trajectory and into a heliocentric orbit making it the first probe of the United States to escape from the Earth's gravity. It carried a payload similar to Pioneer 3: a lunar radiation environment experiment using a Geiger–Müller tube detector and a lunar photography experiment, it passed within 58,983 km of the Moon's surface. However, Pioneer 4 did not come close enough to trigger its photoelectric sensor; the spacecraft was still in solar orbit as of 1969. It was the only successful lunar probe launched by the U. S. in 12 attempts between 1958–63. After the Soviet Luna 1 probe conducted the first successful flyby of the Moon on January 3, 1959, the pressure felt by the US to succeed with a lunar mission was enormous since American mission failures were public while the Soviet failures were kept a secret. Pioneer 4 was 23 cm in diameter at its base; the cone was composed of a thin fiberglass shell coated with a gold wash to make it electrically conducting and painted with white stripes to maintain the temperature between 10 and 50 degrees Celsius.
At the tip of the cone was a small probe which combined with the cone itself to act as an antenna. At the base of the cone a ring of mercury batteries provided power. A photoelectric sensor protruded from the center of the ring; the sensor was designed with two photocells which would be triggered by the light of the Moon when the probe was within about 30,000 km of the Moon. At the center of the cone was a voltage supply tube and two Geiger–Müller tubes; the Laboratory's Microlock system, used for communicating with earlier Explorer satellites, did not have sufficient range to perform this mission. Therefore a new radio system called TRAC Communication was designed. TRAC was an integral part of the Goldstone Deep Space Communications Complex. A transmitter with a mass of 0.5 kilograms delivered a phase modulated signal of 0.1 W at a frequency of 960.05 MHz. The modulated carrier power was 0.08 W and the total effective radiated power 0.18 W. A despin mechanism consisted of two 7 gram weights which spooled out to the end of two 150 cm wires when triggered by a hydraulic timer 10 hours after launch.
The weights were designed to slow the spacecraft spin from 400 rpm to 6 rpm, weights and wires were released. Pioneer 4 received a few small modifications over its predecessor, namely added lead shielding around the Geiger tubes and modifications to the telemetry system to improve its reliability and signal strength; the probe had S/N #4, with probe #3 recalled from launch due to technical issues. Pioneer 4 was launched with a Juno II launch vehicle, which launched Pioneer 3. Juno II resembled the Juno I vehicle that launched Explorer 1, its first stage was a 19.51 m elongated Jupiter IRBM missile, used by the U. S. Army. On top of the Jupiter propulsion section was a guidance and control compartment that supported a rotating tub containing the rocket stages 2, 3 and 4. Pioneer 4 was mounted on top of stage 4. At 12:10 AM EST on the night of March 2-3 of 1959, Pioneer 4 lifted from LC-5; this time, the booster performed perfectly so that Pioneer 4 achieved its primary objective, returned radiation data and provided a valuable tracking exercise.
A longer than nominal second stage burn however was enough to induce small trajectory and velocity errors, so that the probe passed within 60,000 km of the Moon's surface on 4 March 1959 at 22:25 UT at a speed of 7,230 km/h. The distance was not close enough to trigger the photoelectric sensor; the probe continued transmitting radiation data for 82.5 hours, to a distance of 409,000 miles, reached perihelion on 18 March 1959 at 01:00 UT. The cylindrical fourth stage casing went into orbit with the probe; the communication system had worked well, it was estimated that signals could have been received out to 680,000 miles had there been enough battery power. Luna 1 – a similar Soviet space program mission launched January 2, 1959, several weeks before Pioneer 4. NASA JPL Pioneer 3 and 4 NSSDC Master Catalog: Spacecraft Pioneer 4
Vanguard 1 is an American satellite, the fourth artificial Earth orbital satellite to be launched. Vanguard 1 was the first satellite to have solar electric power. Although communication with the satellite was lost in 1964, it remains the oldest man-made object still in orbit, together with the upper stage of its launch vehicle, it was designed to test the launch capabilities of a three-stage launch vehicle as a part of Project Vanguard, the effects of the space environment on a satellite and its systems in Earth orbit. It was used to obtain geodetic measurements through orbit analysis. Vanguard 1 was described by the Soviet Premier, Nikita Khrushchev, as "the grapefruit satellite"; the spacecraft is a 1.47 kg aluminum sphere 16.5 cm in diameter. It contains a 10 mW, 108 MHz transmitter powered by a mercury battery and a 5 mW, 108.03 MHz transmitter, powered by six solar cells mounted on the body of the satellite. Six short antennas protrude from the sphere; the transmitters were used for engineering and tracking data, but were used to determine the total electron content between the satellite and the ground stations.
Vanguard carries two thermistors which measured the interior temperature over sixteen days in order to record the effectiveness of the thermal protection. A backup version of Vanguard 1 is on display at the Smithsonian National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Virginia. On March 17, 1958, the three-stage launch vehicle placed Vanguard into a 654-by-3,969-kilometer, 134.2 minute elliptical orbit inclined at 34.25 degrees. Original estimates had the orbit lasting for 2,000 years, but it was discovered that solar radiation pressure and atmospheric drag during high levels of solar activity produced significant perturbations in the perigee height of the satellite, which caused a significant decrease in its expected lifetime to only about 240 years. Vanguard 1 transmitted its signals for nearly seven years. A 10 mW transmitter, powered by a mercury battery, on the 108 MHz band used for International Geophysical Year scientific satellites, a 5 mW, 108.03 MHz transmitter powered by six solar cells were used as part of a radio phase-comparison angle-tracking system.
The tracking data were used to show that the shape of the Earth has a slight north-south asymmetry described as "pear-shaped" with the stem at the North Pole. These radio signals were used to determine the total electron content between the satellite and selected ground-receiving stations; the battery-powered transmitter provided internal package temperature for about sixteen days and sent tracking signals for twenty days. The transmitter powered by solar cells transmitted for more than six years, its signal weakened and was last received at Quito, Ecuador, in May 1964. Since the spacecraft has been tracked optically from Earth, via telescope; because of its symmetrical shape, Vanguard 1 was used by experimenters for determining upper atmospheric densities as a function of altitude, latitude and solar activity. As the satellite continuously orbited, it would deviate from its predicted positions accumulating greater and greater shift due to drag of the residual atmosphere. By measuring the rate and timing of orbital shifts, together with the body's drag properties, the relevant atmosphere's parameters could be back-calculated.
It was determined that atmospheric pressures, thus drag and orbital decay, were higher than anticipated, since Earth's upper atmosphere does taper off into space gradually. This experiment was planned extensively prior to launch. Initial Naval Research Laboratory proposals for the project included conical satellite bodies. Radio tracking would establish a position. Early in the program, optical tracking was added. A panel of scientists proposed changing the design to spheres, at least twenty inches in diameter and thirty. A sphere would have a constant optical reflection, constant coefficient of drag, based on size alone, while a cone would have properties that varied with its orientation. James Van Allen of the University of Iowa proposed a cylindrical satellite based on his work with rockoons, which became Explorer 1, the first American satellite; the Naval Research Laboratory accepted a sphere with a 6.4-inch diameter as a "test vehicle", with a diameter of twenty inches set for the follow-on satellites.
The weight savings, from reduced size as well as decreased instrumentation in the early satellites, was considered to be acceptable. Since three of the Vanguard satellites are still orbiting 8 April 2019 with their drag properties unchanged, they form a baseline data set on the atmosphere of Earth, over 50 years old and continuing. After its scientific mission ended in 1964, Vanguard 1 became a derelict object—just like the upper stage of the rocket used to launch the satellite had after it finished the delta-v maneuver to place Vanguard 1 in orbit in 1958; as of April 2018, both objects remain in orbit. The Vanguard 1 satellite and upper launch stage hold the record for being in space longer than any other man-made object. A small group of former NRL and NASA workers had been in communication with one another, a number of government agencies were asked to commemorate the event; the Naval Research Laboratory commemorated the event with a day-long meeting at NRL on March 17, 2008. The meeting concluded with a simulation of the satellite's track as it passed into the orbita
Luna 3, or E-2A No.1 was a Soviet spacecraft launched in 1959 as part of the Luna programme. It was the first-ever mission to photograph the far side of the Moon and the third Soviet space probe to be sent to the neighborhood of the Moon. Though it returned rather poor pictures by standards, the historic, never-before-seen views of the far side of the Moon caused excitement and interest when they were published around the world, a tentative Atlas of the Far Side of the Moon was created after image processing improved the pictures; these views showed mountainous terrain different from the near side, only two dark, low-lying regions which were named Mare Moscoviense and Mare Desiderii. Mare Desiderii was found to be composed of a smaller mare, Mare Ingenii, several other dark craters; the reason for this difference between the two sides of the Moon is still not understood, but it seems that most of the dark lavas that flowed out to produce the maria formed under the Earth-facing half. Luna 3 was followed by the United States with Ranger 7, Ranger 8, Ranger 9.
The space probe was a wide flange near the top. The probe 120 cm at its maximum diameter at the flange. Most of the cylindric section was 95 cm in diameter; the canister was hermetically pressurized to about 0.22 atmosphere. Several solar cells were mounted on the outside of the cylinder, these provided electric power to the storage batteries inside the space probe. Shutters for thermal control were positioned along the cylinder and opened to expose a radiating surface when the internal temperature exceeded 25 °C; the upper hemisphere of the probe held the covered opening for the cameras. Four antennas protruded from the top of two from its bottom. Other scientific equipment was mounted on the outside, including micrometeoroid and cosmic ray detectors, the Yenisey-2 imaging system; the gas jets for its attitude control system were mounted on the lower end of the spacecraft. Several photoelectric cells helped maintain orientation with respect to the Moon. There were no rocket motors for course corrections.
Its interior held the cameras and the photographic film processing system, radio transmitter, storage batteries, gyroscopic units, circulating fans for temperature control. It was spin-stabilized for most of its flight, but its three-axis attitude control system was activated while taking photos. Luna 3 was radio-controlled from ground stations in the Soviet Union. After launching on a Luna 8K72 rocket over the North Pole, the Blok-E escape stage was shut down by radio control to put Luna 3 on its course to the Moon. Initial radio contact showed that the signal from the space probe was only about one-half as strong as expected, the internal temperature was rising; the spacecraft spin axis was reoriented and some equipment was shut down, resulting in a temperature drop from 40 °C to about 30 °C. At a distance of 60,000 to 70,000 km from the Moon, the orientation system was turned on and the spacecraft rotation was stopped; the lower end of the craft was pointed at the Sun, shining on the far side of the Moon.
The space probe passed within 6,200 km of the Moon near its south pole at the closest lunar approach at 14:16 UT on 6 October 1959, continued on over the far side. On 7 October, the photocell on the upper end of the space probe detected the sunlit far side of the Moon, the photography sequence was started; the first picture was taken at 03:30 UT at a distance of 63,500 km from the Moon, the last picture was taken 40 minutes from a distance of 66,700 km. A total of 29 pictures were taken. After the photography was complete the spacecraft resumed spinning, passed over the north pole of the Moon and returned towards the Earth. Attempts to transmit the pictures to the Soviet Union began on October 8 but the early attempts were unsuccessful due to the low signal strength; as Luna 3 drew closer to the Earth, a total of about 17 viewable but poor quality photographs were transmitted by 18 October. All contact with the probe was lost on 22 October 1959; the space probe was believed to have burned up in the Earth's atmosphere in March or April 1960.
Another possibility was. The gravity assist maneuver was first used in 1959 when Luna 3 photographed the far side of Earth's Moon. After launch from the Baikonur Cosmodrome, Luna 3 passed behind the Moon from south to north and headed back to Earth; the gravity of the Moon changed the spacecraft's orbit. The return orbit was calculated so that the spacecraft passed again over the Northern hemisphere where the Soviet ground stations were located; the maneuver relied on research performed under the direction of Mstislav Keldysh at the Steklov Institute of Mathematics. The purpose of this experiment was to obtain photographs of the lunar surface as the spacecraft flew by the Moon; the imaging system was designated Yenisey-2 and consisted of a dual-lens camera AFA-E1, an automatic film processing unit, a scanner. The lenses on the camera were a 200 mm focal length, f/5.6 aperture objective and a 500 mm, f/9.5 objective. The camera carried 40 frames of temperature- and radiation-resistant 35 mm isochrome film.
The 200 mm objective could image the full disk of the Moon and the 500 mm could take an image of a region on the surface. The camera was fixed in the spacecraft and pointing was achieved by rotating the craft itself. Luna 3 was the first successful three-axis stabilized spacecraft. During most of the mission, the s