Editing Sputnik 1 (section)

== Before the launch ==
=== Satellite construction project ===
On 17 December 1954, chief Soviet rocket scientist [[Sergei Korolev]] proposed a developmental plan for an artificial satellite to the Minister of the Defense Industry, [[Dimitri Ustinov]]. Korolev forwarded a report by [[Mikhail Klavdievich Tikhonravov|Mikhail Tikhonravov]], with an overview of similar projects abroad.<ref>{{cite web |url=http://rgantd.ru/vzal/korolev/pics/015_025.jpg |title=On the possibility of Earth's artificial satellite development |language=ru |first=Sergei |last=Korolev |date=26 May 1954 |access-date=26 March 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080408193139/http://rgantd.ru/vzal/korolev/pics/015_025.jpg |archive-date=8 April 2008}}</ref> Tikhonravov had emphasized that the launch of an orbital satellite was an inevitable stage in the development of rocket technology.<ref name="ZE">[http://www.buran.ru/htm/gud%2017.htm Создание первых искусственных спутников Земли. Начало изучения Луны. Спутники "Зенит" и "Электрон"], book: Гудилин В.Е., Слабкий Л.И.([[:ru:Слабкий Леонид Ильич|Слабкий Л.И.]])(Gudilin V., Slabkiy L.)"Ракетно-космические системы (История. Развитие. Перспективы)", М., 1996 {{Webarchive|url=https://web.archive.org/web/20070314133238/http://www.buran.ru/htm/gud%2017.htm |date=14 March 2007}} (in Russian)</ref>

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.<ref>{{cite web |url=http://www.hq.nasa.gov/office/pao/History/monograph10/korspace.html |title=Korolev and Freedom of Space: 14 February 1990 – 4 October 1957 |publisher=[[NASA]] |access-date=18 February 2007 |archive-url=https://web.archive.org/web/20061007175859/http://www.hq.nasa.gov/office/pao/History/monograph10/korspace.html |archive-date=7 October 2006 |url-status=live}}</ref> Four days later, [[Leonid Sedov]], a leading Soviet physicist, announced that they too would launch an artificial satellite. On 8 August, the [[Politburo of the Communist Party of the Soviet Union]] approved the proposal to create an artificial satellite.<ref>{{cite web |url=http://rgantd.ru/vzal/korolev/pics/015_001.jpg |title=On the creation of the Earth's artificial satellite |author=The Presidium of the Central Committee of the CPSU |language=ru |date=8 August 1955 |access-date=26 March 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080408193149/http://rgantd.ru/vzal/korolev/pics/015_001.jpg |archive-date=8 April 2008}}</ref> On 30 August, Vasily Ryabikov—the head of the State Commission on the [[R-7 Semyorka|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.<ref>{{cite web |url=http://epizodsspace.testpilot.ru/bibl/vetrov/korolev-delo/06-01.html |title=G. S. Vetrov, Korolev And His Job. Appendix 2 |language=ru |access-date=26 March 2008 |archive-url=https://web.archive.org/web/20080307111932/http://epizodsspace.testpilot.ru/bibl/vetrov/korolev-delo/06-01.html <!-- Bot retrieved archive --> |archive-date=7 March 2008}}</ref>

[[File:Sputnik 1 Arming Key.jpg|right|thumb|Last remaining piece of Sputnik 1: metal arming key which prevented contact between batteries and transmitter prior to launch; on display at the [[Smithsonian Institution|Smithsonian]] [[National Air and Space Museum]]<ref>{{cite web|url=https://airandspace.si.edu/multimedia-gallery/2007-13215hjpg|title=Sputnik Arming Key in Space Race|date=28 January 2018 |publisher=Smithsonian National Air and Space Museum|access-date=13 July 2019}}</ref>]]
On 30 January 1956, the [[Council of Ministers (Soviet Union)|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 {{convert|1000|to|1400|kg|lb|abbr=on}} and would carry {{convert|200|to|300|kg|lb|abbr=on}} of scientific instruments.<ref>{{cite web |url=http://nauka.relis.ru/05/9710/05710002.htm |title=The Beginning |language=ru |access-date=26 March 2008 |archive-url=https://web.archive.org/web/20070927205937/http://nauka.relis.ru/05/9710/05710002.htm <!-- Bot retrieved archive --> |archive-date=27 September 2007}}</ref> The first test launch of "Object D" was scheduled for 1957.<ref name="ZE" /> Work on the satellite was to be divided among institutions as follows:<ref name="NL">{{cite web |url=http://www.lidorenko.ru/ns1.htm |title=On the Launch of the First Earth's artificial satellite in the USSR |first=Nikolai |last=Lidorenko |language=ru |access-date=26 March 2008 |archive-url=https://web.archive.org/web/20080402041653/http://www.lidorenko.ru/ns1.htm |archive-date=2 April 2008 |url-status=live}}</ref>

* The [[USSR Academy of Sciences]] was responsible for the general scientific leadership and the supply of research instruments.
* The Ministry of the Defense Industry and its primary design bureau, [[OKB-1]], were assigned the task of building the satellite.
* The Ministry of the Radio technical Industry would develop the control system, radio/technical instruments, and the [[telemetry]] system.
* The Ministry of the Ship Building Industry would develop [[gyroscope]] devices.
* The Ministry of the Machine Building would develop ground launching, refueling, and transportation means.
* The Ministry of Defense was responsible for conducting launches.

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]], [[magnetic field]]s, and [[cosmic ray]]s. 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.<ref>{{cite web |url=http://epizodsspace.testpilot.ru/bibl/nk/1997/16/16-1997.html |title=40 Years of Space Era |language=ru |access-date=26 March 2008 |archive-url=https://web.archive.org/web/20080229190257/http://epizodsspace.testpilot.ru/bibl/nk/1997/16/16-1997.html <!-- Bot retrieved archive --> |archive-date=29 February 2008}}</ref>

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&nbsp;seconds instead of the planned 309 to 310&nbsp;seconds). Consequently, the government rescheduled the launch for April 1958.<ref name="ZE" /> Object D would later fly as [[Sputnik 3]].<ref>Lanius, ''et al'', p. 38.</ref>

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 ({{convert|100|kg|lb|abbr=on|disp=or}}), 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', PS meaning ''"prosteishiy sputnik",'' or "elementary satellite".<ref name="1957sat">{{cite web|url=http://claudelafleur.qc.ca/Spacecrafts-1957.html|title=Spacecrafts &#91;sic&#93; launched in 1957|last=Lafleur|first=Claude|date=2004|website=ClaudeLafleur.qc.ca|archive-url=https://web.archive.org/web/20110827232818/http://claudelafleur.qc.ca/Spacecrafts-1957.html|archive-date=27 August 2011|url-status=live|access-date=26 March 2008}}</ref> This version allowed the satellite to be tracked visually by Earth-based observers, and it could transmit tracking signals to ground-based receiving stations.<ref name="1957sat" /> 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.<ref name="1957sat" />

=== Launch vehicle preparation and launch site selection ===
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[[File:1967 CPA 3496.jpg|right|thumb|upright|[[Ruble|30 kopek]] USSR [[Postage stamps and postal history of Russia|stamp]] depicting Sputnik 1 orbiting the Earth, the Earth orbiting the Sun and the Sun orbiting the centre of the Milky Way galaxy]]
[[File:1957-10-07 New Moon.ogv|thumb|One of the first reports of Sputnik 1 by Universal Newsreel on 7 October 1957]]
{{Main|Sputnik (rocket)|R-7 Semyorka}}
The R-7 rocket was initially designed as an [[intercontinental ballistic missile]] (ICBM) by OKB-1. The decision to build it was made by the [[Central Committee of the Communist Party of the Soviet Union]] and the Council of Ministers of the USSR on 20 May 1954.<ref>{{cite web |url=http://www.arms.ru/nuclear/R7.htm |publisher=Arms.ru |language=ru |access-date=10 January 2013 |title=Межконтинентальная баллистическая ракета Р-7 |archive-url=https://web.archive.org/web/20120307172826/http://www.arms.ru/nuclear/R7.htm |archive-date=7 March 2012 |url-status=live|trans-title=Intercontinental ballistic missile R-7}}</ref> The rocket was the most powerful in the world; it was designed with excess thrust since they were unsure how heavy the hydrogen bomb payload would be.<ref>{{cite web|url=https://usatoday30.usatoday.com/money/topstories/2007-09-30-3949485139_x.htm|title=Sputnik at 50: An improvised triumph|last1=Isachenkov|first1=Vladimir|agency=Associated Press|work=USA Today|date=30 September 2007|access-date=13 July 2019}}</ref> The R-7 was also known by its GRAU (later GURVO, the Russian abbreviation for "Chief Directorate of the Rocket Forces") designation 8K71.<ref>Zaloga, p. 232.</ref> At the time, the R-7 was known to NATO sources as the T-3 or M-104,<ref name="CoxStoiko69">Cox & Stoiko, p. 69.</ref> and Type A.<ref>Bilstein, p. 387.</ref>

Several modifications were made to the R-7 rocket to adapt it to 'Object D', including upgrades to the main engines, the removal of a {{cvt|300|kg|lb|adj=on}} radio package on the booster, and a new payload fairing that made the booster almost four meters shorter than its ICBM version.<ref>{{cite web |last1=Zak |first1=Anatoly |title=Sputnik-3 |url=http://www.russianspaceweb.com/sputnik3.html |archive-url=https://web.archive.org/web/20071005112056/https://www.russianspaceweb.com/sputnik3.html |archive-date=5 October 2007 |publisher=RussianSpaceWeb.com}}</ref><ref name=":23">{{Cite web |last=Siddiqi |first=Asif A. |date=2023-03-29 |title=Korolev, Sputnik, and The International Geophysical Year |url=https://history.nasa.gov/sputnik/siddiqi.html |website=NASA History Division: Sputnik and the Dawn of the Space Age |publisher=National Aeronautics and Space Administration}}</ref> Object D would later be launched as [[Sputnik 3]] after the much lighter 'Object PS' (Sputnik 1) was launched first.<ref>Lanius, et al, p. 38</ref> The trajectory of the launch vehicle and the satellite were initially calculated using [[arithmometer]]s and six-digit trigonometric tables. More complex calculations were carried out on a newly-installed computer at the [[Academy of Sciences of the Soviet Union|Academy of Sciences]].<ref name=":23"/>

A special [[reconnaissance]] commission selected Tyuratam for the construction of a rocket [[proving ground]], the 5th Tyuratam range, usually referred to as "NIIP-5", or "GIK-5" in the post-Soviet time. The selection was approved on 12 February 1955 by the Council of Ministers of the USSR, but the site would not be completed until 1958. Actual work on the construction of the site began on 20 July by military building units.<ref>{{cite web |url=http://www.russianspaceweb.com/baikonur_origin.html |title=Origin of the test range in Tyuratam |year=2015 |first1=Anatoly|last1=Zak |publisher=RussianSpaceWeb.com |access-date=27 December 2015 |archive-url=https://web.archive.org/web/20151123203845/http://www.russianspaceweb.com/baikonur_origin.html |archive-date=23 November 2015 |url-status=live}}</ref>

The first launch of an R-7 rocket (8K71 No.5L) occurred on 15 May 1957. A fire began in the Blok D [[Booster (rocketry)#Strap-on|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 {{convert|400|km|mi|abbr=on}} downrange.<ref name="AR7">{{cite web|url=http://www.astronautix.com/lvs/r7.htm |title=R-7|archive-url=https://web.archive.org/web/20110629074344/http://www.astronautix.com/lvs/r7.htm |archive-date=29 June 2011|url-status=dead|publisher=Encyclopedia Astronautica|last1=Wade|first1=Mark}}</ref> Three attempts to launch the second rocket (8K71 No.6) were made on 10–11 June, but an assembly defect prevented launch.<ref>{{cite web|url=http://www.energia.ru/english/energia/launchers/rocket-r7.html|title=S.P.Korolev RSC Energia – Launchers|website=www.energia.ru|access-date=4 October 2007|archive-url=https://web.archive.org/web/20170109062006/http://www.energia.ru/english/energia/launchers/rocket-r7.html|archive-date=9 January 2017|url-status=live}}</ref> The unsuccessful launch of the third R-7 rocket (8K71 No.7) took place on 12 July.<ref name="AR7" /> An [[electrical short]] caused the [[vernier engine]]s 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 {{convert|7|km|mi|abbr=on}} from the pad.<ref name="RR7">{{cite web|url=http://www.russianspaceweb.com/r7.html|title=R-7 family of launchers and ICBMs|archive-url=https://web.archive.org/web/20071004091253/https://www.russianspaceweb.com/r7.html |archive-date=4 October 2007|publisher=RussianSpaceWeb.com|first1=Anatoly|last1=Zak}}</ref>

The launch of the fourth rocket (8K71 No.8), on 21 August at 15:25 [[Moscow Time]],<ref name="AR7" /> 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 {{convert|10|km|mi|abbr=on}} after traveling {{convert|6000|km|mi|abbr=on}}. On 27 August, the [[Telegraph Agency of the Soviet Union|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,<ref name="AR7" /> was also successful, but the dummy was also destroyed on atmospheric re-entry,<ref name="RR7" /> 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,<ref>Harford, p. 127.</ref> allowing the delay in the rocket's military exploitation to launch the PS-1 and PS-2 satellites.<ref name="NKA" /><ref>{{cite web |url=http://www.novosti-kosmonavtiki.ru/content/numbers/237/36.shtml |trans-title=Creation and Launch of the First Earth's Satellite |author=V.Poroshkov |publisher=Novosti Kosmonavtiki |script-title=ru:Создание и запуск Первого спутника Земли |archive-url=https://web.archive.org/web/20110606033433/http://www.novosti-kosmonavtiki.ru/content/numbers/237/36.shtml |archive-date=6 June 2011 |language=ru |access-date=10 January 2013}}</ref>

On 22 September a modified R-7 rocket, named [[Sputnik (rocket)|Sputnik]] and indexed as 8K71PS,<ref name="Siddiqi, p. 163">Siddiqi, p. 163.</ref> arrived at the proving ground and preparations for the launch of PS-1 began.<ref>[http://www.nkau.gov.ua/gateway/news.nsf/NewsALLR/BC8D1101C20C9643C3256BB90039079F!open 45th Anniversary of the First Start of Native ICBM R-7] {{Webarchive|url=https://web.archive.org/web/20090108023258/http://www.nkau.gov.ua/gateway/news.nsf/NewsALLR/BC8D1101C20C9643C3256BB90039079F!open |date=8 January 2009}} at Ukrainian Aerospace Portal {{in lang|ru}}</ref> Compared to the military R-7 test vehicles, the mass of 8K71PS was reduced from {{convert|280|to|272|t|lb}}, its length with PS-1 was {{convert|29.167|m|ftin}} and the [[thrust]] at liftoff was {{convert|3.90|MN|abbr=on|lk=on}}.<ref name="rswsputniklv">{{cite web|url=http://www.russianspaceweb.com/sputnik_lv.html|title=Sputnik launch vehicle 8K71PS (M1-1PS)|publisher=RussianSpaceWeb.com|access-date=4 October 2007|archive-url=https://web.archive.org/web/20151211204512/http://www.russianspaceweb.com/sputnik_lv.html|archive-date=11 December 2015|url-status=live|first1=Anatoly|last1=Zak}}</ref>

=== Observation complex ===
PS-1 was not designed to be controlled; it could only be observed. Initial data at the launch site would be collected at six separate observatories and telegraphed to [[NII-4]].<ref name="NKA">{{cite web|url=http://www.novosti-kosmonavtiki.ru/content/numbers/237/36.shtml|trans-title=Creation and Launch of the First Earth's Satellite|author=V.Poroshkov|publisher=Novosti Kosmonavtiki|script-title=ru:Создание и запуск Первого спутника Земли|language=ru|archive-url=https://web.archive.org/web/20110606033433/http://www.novosti-kosmonavtiki.ru/content/numbers/237/36.shtml|archive-date=6 June 2011}}</ref> Located back in Moscow (at [[Yubileyny, Moscow Oblast|Bolshevo]]), NII-4 was a scientific research arm of the [[Ministry of Defence (Soviet Union)|Ministry of Defence]] that was dedicated to missile development.<ref>Siddiqi, p. 39.</ref> The six observatories were clustered around the launch site, with the closest situated {{convert|1|km|abbr=on}} from the launch pad.<ref name="NKA" />

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]].<ref name="Siddiqi162">Siddiqi, p. 162.</ref> These tracking stations were located at [[Tyuratam]], [[Sary-Shagan]], [[Yeniseysk]], [[Klyuchi, Kamchatka Krai|Klyuchi]], [[Yelizovo]], [[Makat]] in [[Atyrau Province|Guryev Oblast]], and [[Ishkup]] in [[Krasnoyarsk Krai]].<ref name="NKA" /><ref name="Siddiqi162" /> Stations were equipped with [[radar]], optical instruments, and communications systems. Data from stations were transmitted by [[telegraph]]s into NII-4 where [[ballistics]] specialists calculated orbital parameters.<ref>{{cite web|url=http://nauka.relis.ru/26/0507/26507086.htm|script-title=ru:ИСТОРИЯ ЦУПА: ТРУД, РАДОСТИ, МЫТАРСТВА|trans-title=History of Decoration: Labor, Joy, Treatment|publisher=НАУКА и ЖИЗНЬ|archive-url=https://web.archive.org/web/20080618204538/http://nauka.relis.ru/26/0507/26507086.htm |archive-date=18 June 2008|language=ru}}</ref>

The observatories used a trajectory measurement system called "Tral", developed by [[OKB|OKB MEI]] (Moscow Energy Institute), by which they received and monitored data from [[transponder]]s mounted on the R-7 rocket's core stage.<ref>[http://www.okbmei.ru/upage.html?id=30 Wonderful "Seven" and First Satellites] at the website of OKB MEI {{webarchive |url=https://web.archive.org/web/20070903073846/http://www.okbmei.ru/upage.html?id=30 |date=3 September 2007}}</ref> The data were useful even after the satellite's separation from the second stage of the rocket; Sputnik's location was calculated from data on the location of the second stage, which followed Sputnik at a known distance.<ref>[http://rgantd.ru/book_2.php?link=mozjorin Yu.A.Mozzhorin Memories] {{webarchive|url=https://web.archive.org/web/20071018165625/http://rgantd.ru/book_2.php?link=mozjorin |date=18 October 2007}} at the website of Russian state archive for scientific-technical documentation{{in lang|ru}}</ref> 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 {{convert|200|km|mi|abbr=on}}, but radar could track it for almost {{convert|500|km|mi|abbr=on}}.<ref name="rswsputniklv" />

[[File:Bahnspur sputnik 1.jpg|thumb|First ground track of Sputnik 1 on 13 October 1957 4:51 from [[Rodewisch]]|220x175px]]
Outside the Soviet Union, the satellite was tracked by [[amateur radio]] operators in many countries.<ref name="Lovell196">Lovell, p. 196.</ref> 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.<ref name="Lovell196" /> Canada's [[Newbrook Observatory]] was the first facility in North America to photograph Sputnik 1.<ref>{{Cite web |url=http://www.historicplaces.ca/en/rep-reg/place-lieu.aspx?id=8809&pid=0 |title=Newbrook Observatory |author=Canadian Register of Historic Places |year=2015 |publisher=Canada's Historic Places |work=Historicplaces.ca |access-date=29 December 2015 |archive-url=https://web.archive.org/web/20121030164908/http://www.historicplaces.ca/en/rep-reg/place-lieu.aspx?id=8809&pid=0 |archive-date=30 October 2012 |url-status=live}}</ref>