Sputnik 1 ( or ; "Satellite-1", or "PS-1", Простейший Спутник-1 or Prosteyshiy Sputnik-1, "Elementary Satellite 1")Siddiqi, p. 155. was the first Satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957, orbiting for three weeks before its batteries died, then silently for two more months before falling back into the atmosphere. It was a 58 cm (23 in) diameter polished metal sphere, with four external radio antennas to broadcast radio pulses. Its radio signal was easily detectable even by amateur radio, and the 65° inclination and duration of its orbit made its flight path cover virtually the entire inhabited Earth. This surprise success precipitated the American Sputnik crisis and triggered the Space Race, a part of the Cold War. The launch was the beginning of a new era of political, military, technological, and scientific developments.Swenson, et al, p. 71.
Tracking and studying Sputnik 1 from Earth provided scientists with valuable information. The density of the upper atmosphere could be deduced from its aerodynamic drag on the orbit, and the propagation of its radio signals gave data about the ionosphere.
Sputnik 1 was launched during the International Geophysical Year from Site No.1/5, at the 5th Tyuratam range, in Kazakh SSR (now known as the Baikonur Cosmodrome). The satellite travelled at about , taking 96.2 minutes to complete each orbit. It transmitted on 20.005 and 40.002 MHz, which were monitored by radio operators throughout the world. The signals continued for 21 days until the transmitter batteries ran out on 26 October 1957. Sputnik burned up on 4 January 1958 while reentering Earth's atmosphere, after three months, 1440 completed orbits of the Earth, and a distance travelled of about .
On 29 July 1955, U.S. President Dwight D. Eisenhower announced through his press secretary that, during the International Geophysical Year (IGY), the United States would launch an artificial satellite. A week later, on 8 August, the Politburo of the Communist Party of the Soviet Union approved the proposal to create an artificial satellite. On 30 August Vasily Ryabikov – the head of the State Commission on the R-7 rocket test launches – held a meeting where Korolev presented calculation data for a spaceflight trajectory to the Moon. They decided to develop a three-stage version of the R-7 rocket for satellite launches.
On 30 January 1956 the Council of Ministers approved practical work on an artificial Earth-orbiting satellite. This satellite, named Object D, was planned to be completed in 1957–58; it would have a mass of and would carry of scientific instruments. The first test launch of "Object D" was scheduled for 1957. Work on the satellite was to be divided among institutions as follows:
Preliminary design work was completed in July 1956 and the scientific tasks to be carried out by the satellite were defined. These included measuring the density of the atmosphere and its ion composition, the solar wind, , and . These data would be valuable in the creation of future artificial satellites. A system of ground stations was to be developed to collect data transmitted by the satellite, observe the satellite's orbit, and transmit commands to the satellite. Because of the limited time frame, observations were planned for only 7 to 10 days and orbit calculations were not expected to be extremely accurate.
By the end of 1956 it became clear that the complexity of the ambitious design meant that 'Object D' could not be launched in time because of difficulties creating scientific instruments and the low specific impulse produced by the completed R-7 engines (304 sec instead of the planned 309 to 310 sec). Consequently, the government rescheduled the launch for April 1958. Object D would later fly as Sputnik 3.Lanius, et al, p. 38.
Fearing the U.S. would launch a satellite before the USSR, OKB-1 suggested the creation and launch of a satellite in April–May 1957, before the IGY began in July 1957. The new satellite would be simple, light (), and easy to construct, forgoing the complex, heavy scientific equipment in favour of a simple radio transmitter. On 15 February 1957 the Council of Ministers of the USSR approved this simple satellite, designated 'Object PS'. This version allowed the satellite to be tracked visually by Earth-based observers, and it could transmit tracking signals to ground-based receiving stations. The launch of two satellites, PS-1 and PS-2, with two R-7 rockets (8K71) was approved, provided that the R-7 completed at least two successful test flights.
The first launch of an R-7 rocket (8K71 No.5L) occurred on 15 May 1957. A fire began in the Blok D strap-on almost immediately at liftoff, but the booster continued flying until 98 seconds after launch when the strap-on broke away and the vehicle crashed some 400 km downrange. Three attempts to launch the second rocket (8K71 No.6) were made on 10–11 June, but an assembly defect prevented launch. The unsuccessful launch of the third R-7 rocket (8K71 No.7) took place on 12 July. An electrical short caused the to put the missile into an uncontrolled roll which resulted in all of the strap-ons separating 33 seconds into the launch. The R-7 crashed about 7 km from the pad.
The launch of the fourth rocket (8K71 No.8), on 21 August at 15:25 Moscow Time, was successful. The rocket's core boosted the dummy warhead to the target altitude and velocity, reentered the atmosphere, and broke apart at a height of after traveling 6,000 km. On 27 August, the TASS issued a statement on the successful launch of a long-distance multistage ICBM. The launch of the fifth R-7 rocket (8K71 No.9), on 7 September, was also successful, but the dummy was also destroyed on atmospheric re-entry, and hence needed a redesign to completely fulfill its military purpose. The rocket, however, was deemed suitable for satellite launches, and Korolev was able to convince the State Commission to allow the use of the next R-7 to launch PS-1,Harford, p. 127. allowing the delay in the rocket's military exploitation to launch the PS-1 and PS-2 satellites.
On 22 September a modified R-7 rocket, named Sputnik and indexed as 8K71PS,Siddiqi, p. 163. arrived at the proving ground and preparations for the launch of PS-1 began. 45th Anniversary of the First Start of Native ICBM R-7 at Ukrainian Aerospace Portal Compared to the military R-7 test vehicles, the mass of 8K71PS was reduced from 280 tonnes to 272 tonnes; its length with PS-1 was and the thrust at liftoff was .
A second, nationwide observation complex was established to track the satellite after its separation from the rocket. Called the Command-Measurement Complex, it consisted of the coordination center in NII-4 and seven distant stations situated along the line of the satellite's ground track.Siddiqi, p. 162. These tracking stations were located at Tyuratam, Sary-Shagan, Yeniseysk, Klyuchi, Yelizovo, Makat in Atyrau Province, and Ishkup in Krasnoyarsk Krai. Stations were equipped with radar, optical instruments, and communications systems. Data from stations were transmitted by into NII-4 where ballistics specialists calculated orbital parameters.
The observatories used a trajectory measurement system called "Tral", developed by OKB (Moscow Energy Institute), by which they received and monitored data from mounted on the R-7 rocket's core stage. Wonderful "Seven" and First Satellites at the website of OKB MEI The data was useful even after the satellite's separation from the second stage of the rocket; Sputnik's location was calculated from the data on the second stage's location which followed Sputnik at a known distance. Yu.A.Mozzhorin Memories at the website of Russian state archive for scientific-technical documentation Tracking of the booster during launch had to be accomplished through purely passive means such as visual coverage and radar detection. R-7 test launches demonstrated that the tracking cameras were only good up to an altitude of , but radar could track it for almost .
Outside the Soviet Union, the satellite was tracked by amateur radio operators in many countries.Lovell, p. 196. The booster rocket was located and tracked by the British using the Lovell Telescope at the Jodrell Bank Observatory, the only telescope in the world able to do so by radar. Canada's Newbrook Observatory was the first facility in North America to photograph Sputnik 1.
The power supply, with a mass of , was in the shape of an octagonal nut with the radio transmitter in its hole. It consisted of three silver-zinc batteries, developed at the All-Union Research Institute of Power Sources (VNIIT) under the leadership of Nikolai S. Lidorenko. Two of these batteries powered the radio transmitter and one powered the temperature regulation system. The batteries had an expected lifetime of two weeks, and operated for 22 days. The power supply was turned on automatically at the moment of the satellite's separation from the second stage of the rocket.
The satellite had a one-watt, radio transmitting unit inside, developed by Vyacheslav I. Lappo from NII-885, the Moscow Electronics Research Institute, that worked on two frequencies, 20.005 and 40.002 MHz. Signals on the first frequency were transmitted in 0.3 sec pulses (under normal temperature and pressure conditions onboard), with pauses of the same duration filled by pulses on the second frequency. Form of Signals of the First Earth's Artificial Satellite – a document at the website of Russian state archive for scientific-technical documentation Analysis of the radio signals was used to gather information about the electron density of the ionosphere. Temperature and pressure were encoded in the duration of radio beeps. A temperature regulation system contained a fan, a dual thermal cutoff, and a control thermal switch. If the temperature inside the satellite exceeded , the fan was turned on; when it fell below , the fan was turned off by the dual thermal switch. If the temperature exceeded or fell below , another control thermal switch was activated, changing the duration of the radio signal pulses. Sputnik 1 was filled with dry nitrogen, pressurized to 1.3 atm. The satellite had a barometric switch, activated if the pressure inside the satellite fell below 130 kPa, which would have indicated failure of the pressure vessel or puncture by a meteor, and would have changed the duration of radio signal impulse.
While attached to the rocket, Sputnik 1 was protected by a cone-shaped payload fairing, with a height of . The fairing separated from both Sputnik and the spent R-7 second stage at the same time as the satellite was ejected. Tests of the satellite were conducted at OKB-1 under the leadership of Oleg Ivanovsky.
The Sputnik rocket was launched on 4 October 1957 at 19:28:34 UTC (5 October at the launch site) from Site No.1 at NIIP-5. Telemetry indicated that the strap-ons separated 116 seconds into the flight and the core stage engine shutdown 295.4 seconds into the flight. At shutdown, the 7.5-tonne core stage (with PS-1 attached) had attained an altitude of above sea level, a velocity of , and a velocity vector inclination to the local horizon of 0 degrees 24 minutes. This resulted in an initial orbit of by , with an apogee approximately lower than intended, and an inclination of 65.1 degrees and a period of 96.2 minutes.
A fuel regulator in the booster also failed around 16 seconds into launch, which resulted in excessive RP-1 consumption for most of the powered flight and the engine thrust being 4% above nominal. Core stage cutoff was intended for T+296 seconds, but the premature propellant depletion caused thrust termination to occur one second earlier when a sensor detected overspeed of the empty RP-1 turbopump. There were of liquid oxygen remaining at cutoff.
At 19.9 seconds after engine cut-off, PS-1 separated from the second stage and the satellite's transmitter was activated. These signals were detected at the IP-1 station by Junior Engineer-Lieutenant V.G. Borisov, where reception of Sputnik 1's "beep-beep-beep" tones confirmed the satellite's successful deployment. Reception lasted for two minutes, until PS-1 fell below the horizon. How the First Sputnik Was Launched at Zemlya i Vselennaya magazine, No.5, 2002 The Tral telemetry system on the R-7 core stage continued to transmit and was detected on its second orbit.
The designers, engineers and technicians who developed the rocket and satellite watched the launch from the range. After the launch they drove to the mobile radio station to listen for signals from the satellite. They waited about 90 minutes to ensure that the satellite had made one orbit and was transmitting before Korolev called Soviet premier Nikita Khrushchev.Brzezinski, pp. 158–159.
On the first orbit the Telegraph Agency of the Soviet Union (TASS) transmitted: "As result of great, intense work of scientific institutes and design bureaus the first artificial Earth satellite has been built." The R-7 core stage, with a mass of 7.5 tonnes and a length of 26 meters, also reached Earth orbit. It was a first magnitude object following behind the satellite and visible at night. Deployable reflective panels were placed on the booster in order to increase its visibility for tracking. A small highly polished sphere, the satellite was barely visible at sixth magnitude, and thus harder to follow optically. The batteries ran out on 26 October 1957, after the satellite completed 326 orbits.
News reports at the time pointed out that "anyone possessing a short wave receiver can hear the new Russian earth satellite as it hurtles over this area of the globe."
The Soviet Union agreed transmit on frequencies that worked with the United States' existing infrastructure, but later announced the lower frequencies. Asserting that the launch "did not come as a surprise", the White House refused to comment on any military aspects. On 5 October the Naval Research Laboratory captured recordings of Sputnik 1 during four crossings over the United States. The USAF Cambridge Research Center collaborated with Bendix Aviation, Westinghouse Broadcasting Co., and the Smithsonian Astrophysical Observatory to obtain a video of Sputnik's rocket body crossing the pre-dawn sky of Baltimore, broadcast on 12 October by WBZ-TV in Boston.Ted Molczan, "Motion Picture of Sputnik 1 Rocket from Baltimore on October 12, 1957" , 30 June 2013.
The Soviet Union's launch of Sputnik 1 spurred the United States to create the DARPA (ARPA, later DARPA) in February 1958 to regain a technological lead. "Roads and Crossroads of Internet History" by Gregory Gromov
In Britain, the media and population initially reacted with a mixture of fear for the future, but also amazement about humankind's progress. Many newspapers and magazines heralded the arrival of the Space Age. However, when the Soviet Union launched a second craft, containing the dog Laika, the media narrative returned to one of anti-communism and many people sent protests to the Russian embassy and the RSPCA.Nicholas Barnett '"Russia Wins Space Race"': The British Press and the Sputnik Moment, 1957': Media History, 19: 2 (2013), 182–195
The launch of Sputnik 1 surprised the American public and shattered the perception, furthered by American propaganda, of the United States as the technological superpower and the Soviet Union as a backward country. The Legacy of Sputnik Editorial. (2007). The New York Times, p. 28. Privately, however, the CIA and President Eisenhower were aware of progress being made by the Soviets on Sputnik from secret spy plane imagery. Together with the Jet Propulsion Laboratory (JPL), the Army Ballistic Missile Agency built Explorer 1, and launched it on 31 January 1958. Before work was completed, however, the Soviet Union launched a second satellite, Sputnik 2, on 3 November 1957. Meanwhile, the televised failure of Vanguard TV3 on 6 December 1957 deepened American dismay over the country's position in the Space Race. The Americans took a more aggressive stance in the emerging space race,Wilson, C. (n.d.). Sputnik: a Mixed Legacy. U.S. News & World Report, 143(12), (37–38). resulting in an emphasis on science and technological research, and reforms in many areas from the military to education systems. The federal government began investing in science, engineering, and mathematics at all levels of education. An advanced research group was assembled for military purposes. These research groups developed weapons such as ICBMs and missile defense systems, as well as spy satellites for the U.S.
The U.S. soon had a number of successful satellites, including Explorer 1, Project SCORE, and Courier 1B. However, public reaction to the Sputnik crisis spurred America to action in the Space Race, leading to the creation of both the Advanced Research Projects Agency (renamed the Defense Advanced Research Projects Agency, or DARPA, in 1972),Brzezinski, p. 274. and NASA (through the National Aeronautics and Space Act),McDougall, p. 172. as well as increased U.S. government spending on scientific research and education through the National Defense Education Act.
Sputnik also contributed directly to a new emphasis on science and technology in American schools. With a sense of urgency, Congress enacted the 1958 National Defense Education Act, which provided low-interest loans for college tuition to students majoring in math and science.Zhao, p. 22.Neal, et al, pp. 3–4. After the launch of Sputnik, a poll conducted and published by the University of Michigan showed that 26% of Americans surveyed thought that Russian sciences and engineering were superior to that of the United States. (A year later, however, that figure had dropped to 10% as the U.S. began launching its own satellites into space.)Project Mercury: Main-in-Space Program of NASA, Report of the Committee on Aeronautical Sciences, United States Senate, 1 December 1959
Sputnik also inspired a generation of engineers and scientists. Harrison Storms, the North American designer who was responsible for the X-15 rocket plane, and went on to head the effort to design the Apollo Command/Service Module and Saturn V launch vehicle's second stage was moved by the launch of Sputnik to think of space as being the next step for America.Gray, p. 41. Astronauts Alan Shepard (who was the first American in space) and Deke Slayton later wrote of how the sight of Sputnik 1 passing overhead inspired them to their new careers.Shepard & Slayton, p. 43.
The launch of Sputnik 1 led to the resurgence of the suffix -nik in the English language.
The flag of the Russian city of Kaluga, which, due to its importance as Konstantin Tsiolkovsky's birthplace, is very focused on space, features a small Sputnik in the left section.
In 1959, the Soviet Union donated a replica of Sputnik to the United Nations. There are other full-size Sputnik replicas (with varying degrees of accuracy) on display in locations around the world, including the National Air and Space Museum in the US, the Science Museum in England, the Powerhouse Museum in Australia, and outside the Russian embassy in Spain.
Three one-third scale student-built replicas of Sputnik 1 were deployed from the Mir space station between 1997 and 1999. The first, named Sputnik 40 to commemorate the fortieth anniversary of the launch of Sputnik 1, was deployed in November 1997. Sputnik 41 was launched a year later, and Sputnik 99 was deployed in February 1999. A fourth replica was launched, but never deployed, and was destroyed when Mir was deorbited.