Editing Space Race (section)

==ICBM capability, satellites, lunar probes (1955–1960)==
The period from 1955 to 1960 saw the first artificial satellites put into earth orbit by both the USSR and the US, the first animals sent into orbit, and the first robotic probes to impact and flyby the Moon by the Soviets.

===Artificial satellite development===
In 1955, with both the United States and the Soviet Union building ballistic missiles that could be used to launch objects into space, the stage was set for nationalistic competition.{{sfn|Schefter|1999|pp=3–5}} On July 29, 1955, [[James C. Hagerty]], President [[Dwight D. Eisenhower]]'s press secretary, announced that the United States intended to launch "small Earth circling satellites" between July 1, 1957, and December 31, 1958, as part of the US contribution to the [[International Geophysical Year]] (IGY).{{sfn|Schefter|1999|pp=3–5}} On August 2, at the [[International Astronautical Federation|Sixth Congress of the International Astronautical Federation]] in Copenhagen, scientist [[Leonid I. Sedov]] told international reporters at the Soviet embassy of his country's intention to launch a satellite as well, in the "near future".{{sfn|Schefter|1999|pp=3–5}}

==== Soviet secrecy and obfuscation ====
{{Further|Soviet space program}}On August 30, 1955, [[Sergei Korolev]] succeeded in convincing the [[Soviet Academy of Sciences]] to establish a commission dedicated to achieving the goal of launching a satellite into Earth orbit before the United States,{{sfn|Schefter|1999|pp=3–5}} this can be viewed as the ''de facto'' start date of the space race. The [[Council of Ministers of the Soviet Union]] began a policy of treating development of its space program as top-secret. When the Sputnik project was first approved, one of the immediate courses of action the [[Politburo]] took was to consider what to announce to the world regarding their event. The [[Telegraph Agency of the Soviet Union]] (TASS) established precedents for all official announcements on the Soviet space program. The information eventually released did not offer details on who built and launched the satellite or why it was launched.<ref name="books.google.com">{{cite book|url=https://books.google.com/books?id=W7oRuOZbb8IC|title=Into the Cosmos: Space Exploration and Soviet Culture|isbn=978-0-8229-7746-9|access-date=2016-01-19|last1=Andrews|first1=James T.|last2=Siddiqi|first2=Asif A.|year=2011|publisher=University of Pittsburgh Pre }}</ref>

The Soviet space program's use of secrecy served as both a tool to prevent the leaking of [[classified information]] between countries, and to avoid revealing specifics to the Soviet populace in regards to their short and long term goals; the program's nature embodied ambiguous messages concerning its goals, successes, and values. Launches were not announced until they took place, [[cosmonaut]] names were not released until they flew, and outside observers did not know the size or shape of their rockets or cabins of most of their spaceships, except for the first Sputniks, lunar probes, and Venus probe.<ref name="ebooks.ohiolink.edu">{{cite web|url=http://ebooks.ohiolink.edu/xtf-ebc/view?docId=tei/sv2/9781461430520/9781461430520.xml&query=&brand=default|title=OhioLINK Institution Selection |website=Ebooks.ohiolink.edu|access-date=2016-01-19}}</ref>

The Soviet military maintained control over the space program; Korolev's [[OKB-1]] design bureau was subordinated under the [[Ministry of General Machine Building]],<ref name="books.google.com"/> tasked with the development of intercontinental ballistic missiles, and continued to give its assets random identifiers into the 1960s.<ref name="books.google.com"/> Information about failures was systematically withheld, historian James Andrews notes that Soviet media coverage of the space program, particularly human space missions, rarely reported any failures or difficulties, creating the impression of a flawless operation:<blockquote>"With almost no exceptions, coverage of Soviet space exploits, especially in the case of human space missions, omitted reports of failure or trouble".<ref name="books.google.com" /></blockquote>Dominic Phelan noted in the book ''Cold War Space Sleuths'' (Springer-Praxis 2013): "The [[USSR]] was famously described by [[Winston Churchill]] as '''a riddle, wrapped in a mystery, inside an enigma''<nowiki/>' and nothing signified this more than the search for the truth behind its space program during the Cold War. Although the Space Race was literally played out above our heads, it was often obscured by a figurative 'space curtain' that took much effort to see through".<ref name="ebooks.ohiolink.edu" />

==== US concerns and strategy ====
{{Further|Space policy of the United States}}
[[File:1957-10-07 New Moon.ogv|thumb|One of the first reports of Sputnik 1 by Universal Newsreel on October 7, 1957]]
Initially, President Eisenhower was worried that a satellite passing above a nation at over {{convert|100|km|mi|sp=us}} might be seen as violating that nation's airspace.{{sfn|Schefter|1999|p=8}} He was concerned that the Soviet Union would accuse the Americans of an illegal overflight, thereby scoring a propaganda victory at his expense.{{sfn|Schefter|1999|p=6}} Eisenhower and his advisors were of the opinion that a nation's airspace sovereignty did not extend past the [[Kármán line]], and they used the 1957–58 International Geophysical Year launches to establish this principle in international law.{{sfn|Schefter|1999|p=8}} Eisenhower also feared that he might cause an international incident and be called a "warmonger" if he were to use military missiles as launchers. Therefore, he selected the untried [[Naval Research Laboratory]]'s [[Vanguard rocket]], which was a research-only rocket.{{sfn|Schefter|1999|pp=15–18}} This meant that von Braun's team was not allowed to put a satellite into orbit with their Jupiter-C rocket, because of its intended use as a future military vehicle.{{sfn|Schefter|1999|pp=15–18}} On September 20, 1956, von Braun and his team did launch a Jupiter-C that was capable of putting a satellite into orbit, but the launch was used only as a suborbital test of reentry vehicle technology.{{sfn|Schefter|1999|pp=15–18}}

=== Sputnik ===
[[File:Sputnik-stamp-ussr.jpg|thumb|upright=0.8|Soviet stamp commemorating Sputnik 1, 1957]]
Korolev received word about von Braun's 1956 Jupiter-C test and, mistakenly thinking it was a satellite mission that failed, expedited plans to get his own satellite in orbit. Since the R-7 was substantially more powerful than any of the US [[launch vehicle]]s, he made sure to take full advantage of this capability by designing [[Sputnik 3|Object D]] as his primary satellite.{{sfn|Cadbury|2006|pp=154–57}} It was given the designation 'D', to distinguish it from other R-7 payload designations 'A', 'B', 'V', and 'G' which were nuclear weapon payloads.{{sfn|Siddiqi|2003a|p=151}} Object D dwarfed the proposed US satellites, having a weight of {{convert|1400|kg|lb|sp=us}}, of which {{convert|300|kg|lb|sp=us}} would be composed of scientific instruments that would photograph the Earth, take readings on radiation levels, and check on the planet's magnetic field.{{sfn|Siddiqi|2003a|p=151}} However, things were not going along well with the design and manufacturing of the satellite, so in February 1957, Korolev sought and received permission from the Council of Ministers to build a ''Prosteishy Sputnik'' (PS-1), or simple satellite.{{sfn|Cadbury|2006|pp=154–57}} The council also decreed that Object D be postponed until April 1958.{{sfn|Siddiqi|2003a|p=155}} The new ''Sputnik'' was a metallic sphere that would be a much lighter craft, weighing {{convert|83.8|kg|lb|sp=us}} and having a {{convert|58|cm|in|adj=on|sp=us}} diameter.<ref>{{cite web| url = https://history.nasa.gov/sputnik/| title = Sputnik and The Dawn of the Space Age| first = Steve| last = Garber| date = October 10, 2007| work = Sputnik 50th Anniversary| publisher = [[National Aeronautic and Space Administration|NASA History Website]]| location = Washington
}}</ref> The satellite would not contain the complex instrumentation that Object D had, but had two radio transmitters operating on different [[short wave radio]] frequencies, the ability to detect if a meteoroid were to penetrate its pressure hull, and the ability to detect the density of the Earth's [[thermosphere]].{{sfn|Hardesty|Eisman|2007|pp=72–73}}

{{Listen
| filename     = Sputnik beep.ogg
| title        = ''Beep ... beep ... beep''
| alt          =
| description  = The signals of ''Sputnik 1'' continued for 22 days
}}

Korolev was buoyed by the first successful launches of the R-7 rocket in August and September, which paved the way for the launch of ''Sputnik''.{{sfn|Siddiqi|2003a|pp=163–68}} Word came that the US was planning to announce a major breakthrough at an International Geophysical Year conference at the [[United States National Academy of Sciences|National Academy of Sciences]] in Washington D.C., with a paper titled "Satellite Over the Planet", on October 6, 1957.{{sfn|Cadbury|2006|p=163}} Korolev anticipated that von Braun might launch a Jupiter-C with a satellite payload on or around October 4 or 5, in conjunction with the paper.{{sfn|Cadbury|2006|p=163}} He hastened the launch, moving it to October 4.{{sfn|Cadbury|2006|p=163}} The launch vehicle for PS-1 was a modified R-7 – vehicle 8K71PS number M1-PS – without much of the test equipment and radio gear that was present in the previous launches.{{sfn|Siddiqi|2003a|pp=163–68}} It arrived at the Soviet missile base [[Baikonur Cosmodrome|Tyura-Tam]] in September and was prepared for its mission at [[Gagarin's Start|launch site number one]].{{sfn|Siddiqi|2003a|pp=163–68}}

The first launch took place on Friday, October 4, 1957, at exactly 10:28:34&nbsp;pm Moscow time, with the R-7 and the now named Sputnik 1 satellite lifting off the launch pad and placing the artificial "moon" into an orbit a few minutes later.{{sfn|Hardesty|Eisman|2007|p=74}} This "fellow traveler", as the name is translated in English, was a small, beeping ball, less than two feet in diameter and weighing less than 200 pounds. But the celebrations were muted at the launch control center until the down-range far east tracking station at [[Yelizovo|Kamchatka]] received the first distinctive beep&nbsp;... beep&nbsp;... beep sounds from ''Sputnik 1''{{'}}s radio transmitters, indicating that it was on its way to completing its first orbit.{{sfn|Hardesty|Eisman|2007|p=74}} About 95 minutes after launch, the satellite flew over its launch site, and its radio signals were picked up by the engineers and military personnel at Tyura-Tam: that's when Korolev and his team celebrated the first successful artificial satellite placed into Earth-orbit.{{sfn|Cadbury|2006|pp=164–65}}

The next satellite sent by the Soviets after Sputnik 1 was [[Sputnik 2]], launched on November 3, 1957, just a month later. This would put the first animal into orbit.<ref name=":7">{{Cite web |title=Sputnik 2 |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1957-002A |website=nssdc.gsfc.nasa.gov}}</ref><ref>{{Cite web |date=2017-11-06 |title=60 years ago: The First Animal in Orbit - NASA |url=https://www.nasa.gov/history/60-years-ago-the-first-animal-in-orbit/ |access-date=2024-12-09 |language=en-US}}</ref>

=== US reaction to Sputnik ===
{{Main|Sputnik crisis}}

==== CIA assessment ====
At the latest, the successful start of [[Sputnik 2]] with the satellite weighing more than 500&nbsp;kg proved that the USSR had achieved a leading advantage in rocket technology. The CIA, initially astonished, estimated the launch weight of the rocket at 500 metric tons, requiring an initial thrust exceeding 1,000 tons, and assumed the use of a three-stage rocket. In a classified report, the agency described the event as a "stupendous scientific achievement" and concluded that the USSR had likely perfected an intercontinental ballistic missile (ICBM) capable of accurately targeting any location.<ref>{{cite web |url=https://www.cia.gov/readingroom/docs/DOC_0000124270.pdf |title=Analysis of Soviet Earth Satellite and Launching Device |access-date=2022-12-01 |date=1957-11-09 }}</ref> In reality, the launch weight of the Soviet rocket was 267 metric tons with an initial thrust of 410 tons with one and a half stages. The CIA's misjudgement was caused by extrapolating the parameters of the US [[SM-65 Atlas|Atlas]] rocket developed at the same time (launch weight 82 tons, initial thrust 135 tones, maximum payload of 70&nbsp;kg for [[low Earth orbit]]).<ref>{{cite encyclopedia |author=Mark Wade |url=http://www.astronautix.com/a/atlasa.html |title=Atlas A |encyclopedia=Encyclopedia Astronautica |access-date=2022-11-01}}</ref> In part, the favourable data of the Soviet launcher was based on concepts proposed by the German rocket scientists headed by [[Helmut Gröttrup]] on [[Gorodomlya Island]], such as, among other things, the rigorous weight saving, the control of the residual fuel quantities and a reduced thrust to weight relation of 1.4 instead of usual factor 2.<ref>{{Cite book |last=Gröttrup |first=Helmut |title=Aus den Arbeiten des deutschen Raketen-Kollektivs in der Sowjet-Union. |date=April 1958 |publisher=Deutsche Gesellschaft für Raketentechnik und Raumfahrt |series=Raketentechnik und Raumfahrtforschung |pages=58–62 |language=de |trans-title=About the work of the German rocketry collective in the Soviet Union |quote=Towards the end of the war the general opinion was that a starting acceleration of 2 g was optimal. We have carried out detailed studies on this point, taking into account the increase in engine weights and the weights of the components used to transmit thrust. It turned out that a starting acceleration of a considerably smaller value can be optimal. One of our projects was designed for a starting acceleration of 1.4 g.}}</ref> The CIA had heard about such details already in January 1954 when it interrogated Göttrup after his return from the USSR but did not take him seriously.<ref>{{Cite web |url=https://archive.org/details/CIA-RDP80-00810A003300530005-2 |title=Development of guided missiles at Bleicherode and Institut 88 |work=[[Central Intelligence Agency|CIA Historical Collections]] |date=1954-01-22 |access-date=2022-09-30 |quote=It was generally held up to now that the ratio thrust/take-off weights should be approximately two. [Gröttrup] discovered … that values as low as 1.2 for this ratio could give optimum results under certain conditions.}} Remark: The designations R-12 und R-14 are related to the internal project names (also known as G-2 und G-4), not to the rockets installed during the Cuban Missile Crisis</ref>

==== US reactions ====
The Soviet success raised a great deal of concern in the United States. For example, economist Bernard Baruch wrote in an open letter titled "The Lessons of Defeat" to the ''[[New York Herald Tribune]]'': "While we devote our industrial and technological power to producing new model automobiles and more gadgets, the Soviet Union is conquering space. ... It is Russia, not the United States, who has had the imagination to hitch its wagon to the stars and the skill to reach for the moon and all but grasp it. America is worried. It should be."<ref>{{cite book|last1=Crompton|first1=Samuel|title=Sputnik/Explorer I: The Race to Conquer Space|year= 2007|publisher=Chelsea House Publications|location=New York City|isbn=978-0-7910-9357-3|page=4}}</ref>

Eisenhower ordered project Vanguard to move up its timetable and launch its satellite much sooner than originally planned.{{sfn|Brzezinski|2007|pp=254–67}} The December 6, 1957 [[Vanguard TV3|Project Vanguard launch failure]] occurred at [[Cape Canaveral Air Force Station]] in Florida. It was a monumental failure, exploding a few seconds after launch, and it became an international joke. The satellite appeared in newspapers under the names Flopnik, Stayputnik, Kaputnik,<ref name="O'Neill, Terry 2002">O'Neill, Terry. The Nuclear Age. San Diego: Greenhaven, Inc., 2002.(146)</ref> and Dudnik.<ref>Knapp, Brian. Journey into Space. Danbury: Grolier, 2004.(17)</ref> In the United Nations, the Soviet delegate offered the US representative aid "under the Soviet program of technical assistance to backwards nations."<ref name="O'Neill, Terry 2002"/> Only in the wake of this very public failure did von Braun's Redstone team get the go-ahead to launch their Jupiter-C rocket as soon as they could. In Britain, the US's Western Cold War ally, the reaction was mixed: some celebrated the fact that the Soviets had reached space first, while others feared the destructive potential that military uses of spacecraft might bring.<ref>Barnett, Nicholas. '"Russia Wins Space Race": The British Press and the Sputnik Moment', ''Media History'', (2013) 19:2, 182–95.</ref> The ''[[Daily Express]]'' predicted that the US would catch up to and pass the USSR in space; "never doubt for a moment that America would be successful".<ref name="time19571014">{{Cite web |date=1957-10-14 |title=THE NATION: Red Moon Over the U.S. |url=http://www.time.com/time/magazine/article/0,9171,862748,00.html |archive-url=https://web.archive.org/web/20090506101411/http://www.time.com:80/time/magazine/article/0,9171,862748,00.html |archive-date=2009-05-06 |access-date=2016-02-24 |publisher=TIME}}</ref>

=== Explorer ===
[[File:Explorer1 people.jpg|thumb|upright|[[William Hayward Pickering]], [[James Van Allen]], and von Braun display a model of ''Explorer 1'' at a news conference after confirmation the satellite was in orbit.]]

On January 31, 1958, nearly four months after the launch of ''Sputnik 1'', von Braun and the United States successfully launched its first satellite on a four-stage [[Juno I]] rocket derived from the US Army's Redstone missile, at Cape Canaveral.<ref name = nicogossian1993>{{cite book|last=Nicogossian|first=Arnauld E.|title=Space Biology and Medicine: Space and Its Exploration |year=1993|publisher=American Institute of Aeronautics|location=Washington, DC.|page=285}}</ref> The satellite ''[[Explorer 1]]'' was {{convert|30.66|lb|kg}} in mass.<ref name = nicogossian1993/> The payload of Explorer 1 weighed {{convert|18.35|lb|kg}}. It carried a micrometeorite gauge and a [[Geiger-Müller tube]]. It passed in and out of the Earth-encompassing radiation belt with its {{convert|360|by|2534|km|nmi|adj=on|order=flip|sp=us}} orbit, therefore saturating the tube's capacity and proving what Dr. [[James Van Allen]], a space scientist at the [[University of Iowa]], had theorized.<ref name = nicogossian1993/> The belt, named the [[Van Allen radiation belt]], is a doughnut-shaped zone of high-level radiation intensity around the Earth above the magnetic equator.<ref name="Ref-1">{{cite book|last=Angelo|first=Joseph, A.|title=Encyclopedia of Space Astronomy|url=https://archive.org/details/encyclopediaofsp0000ange |url-access=registration|year=2006|publisher= Facts on Files, Inc.|location=New York|page=[https://archive.org/details/encyclopediaofsp0000ange/page/634 634]|isbn=978-0-8160-5330-8}}</ref> Van Allen was also the man who designed and built the satellite instrumentation of ''Explorer 1''. The satellite measured three phenomena: cosmic ray and radiation levels, the temperature in the spacecraft, and the frequency of collisions with micrometeorites. The satellite had no [[computer memory|memory]] for data storage, therefore it had to transmit continuously.<ref>{{cite book|last=Angelo |first= Joseph, A.|title=Encyclopedia of Space Astronomy|url= https://archive.org/details/encyclopediaofsp0000ange |url-access=registration|year=2006|publisher=Facts on Files, Inc.|location=New York|page=[https://archive.org/details/encyclopediaofsp0000ange/page/225 225]|isbn= 978-0-8160-5330-8}}</ref> The next successful mission was [[Explorer 3]], launched later that month (March 26, 1958), which carried similar scientific instruments and successfully recorded cosmic ray data.<ref>{{Cite web |title=Explorer 2 - Earth Missions - NASA Jet Propulsion Laboratory |url=https://www.jpl.nasa.gov/missions/explorer-2/ |access-date=2024-12-09 |website=NASA Jet Propulsion Laboratory (JPL) |language=en-US}}</ref><ref>{{Cite web |title=Explorer 3 |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1958-003A |website=nssdc.gsfc.nasa.gov}}</ref><ref>{{Cite web |title=Explorer 3 - Earth Missions - NASA Jet Propulsion Laboratory |url=https://www.jpl.nasa.gov/missions/explorer-3/ |access-date=2024-12-09 |website=NASA Jet Propulsion Laboratory (JPL) |language=en-US}}</ref>

==== Creation of NASA ====
{{Main|Creation of NASA}}

On April 2, 1958, President Eisenhower reacted to the Soviet space lead in launching the first satellite by recommending to the US Congress that a civilian agency be established to direct nonmilitary space activities. Congress, led by [[Party Leaders of the United States Senate|Senate Majority Leader]] [[Lyndon B. Johnson]], responded by passing the [[National Aeronautics and Space Act]], which Eisenhower signed into law on July 29, 1958. This law turned the [[National Advisory Committee on Aeronautics]] into the [[NASA|National Aeronautics and Space Administration]] (NASA). It also created a Civilian-Military Liaison Committee, appointed by the President, responsible for coordinating the nation's civilian and military space programs.<ref>{{cite web |url=https://history.nasa.gov/SP-4201/ch4-6.htm |title=Birth of NASA |website=history.nasa.gov |access-date=February 12, 2020}}</ref>

On October 21, 1959, Eisenhower approved the transfer of the Army's remaining space-related activities to NASA. On July 1, 1960, the Redstone Arsenal became NASA's [[Marshall Space Flight Center|George C. Marshall Space Flight Center]], with von Braun as its first director. Development of the [[Saturn (rocket family)|Saturn rocket family]], which when mature gave the US parity with the Soviets in terms of lifting capability, was thus transferred to NASA.<ref>{{cite book |last1=Bilstein |first1=Roger E. |title=Stages to Saturn |publisher=NASA |location=Washington D.C. |page=39 |url=https://history.nasa.gov/SP-4206/ch2.htm |access-date=March 19, 2021 |chapter=2. Aerospace Alphabet: ABMA, ARPA, MSFC}}</ref>

=== First mammals in space ===

[[File:Posta Romana - 1959 - Laika 120 B.jpg|thumb|right|[[Laika]] on a Romanian post stamp]]

The US and the USSR sent animals into space to determine the safety of the environment before sending the first humans. The USSR used [[space dogs|dogs]] for this purpose, and the US used [[monkeys and apes in space|monkeys and apes]]. The first mammal in space was [[Albert II (monkey)|Albert II]], a rhesus monkey launched by the US on a sub-orbital flight on June 14, 1949, who died on landing due to a parachute malfunction.<ref name="albert2">{{cite web |title=The Beginnings of Research in Space Biology at the Air Force Missile Development Center, 1946-1952 |url=https://history.nasa.gov/afspbio/part1.htm |publisher=NASA |access-date=26 June 2021 |date=January 1958}}</ref>

The USSR sent the dog [[Laika]] into orbit on [[Sputnik 2]], the second satellite launched, on November 3, 1957, for an intended ten-day flight.<ref name=":7" /> They did not yet have the technology to return Laika safely to Earth, and the government reported Laika died when the oxygen ran out,<ref name="Beischer1962">{{cite journal |author=DE Beischer and AR Fregly|title=Animals and man in space. A chronology and annotated bibliography through the year 1960. |journal=US Naval School of Aviation Medicine |volume=ONR TR ACR-64 |issue=AD0272581 |year=1962 |url=http://archive.rubicon-foundation.org/9288 |archive-url=https://archive.today/20121204154830/http://archive.rubicon-foundation.org/9288 |url-status=usurped |archive-date=December 4, 2012 |access-date=14 June 2011}}</ref> but in October 2002 her true cause of death was reported as stress and overheating on the fourth orbit<ref>{{cite news| url = http://news.bbc.co.uk/2/hi/sci/tech/2367681.stm | title = First dog in space died within hours | publisher = BBC | date=28 October 2002 | access-date=4 January 2010}}</ref> due to failure of the air conditioning system.<ref name="AT-20171103">{{cite news |last=Berger |first=Eric |title=The first creature in space was a dog. She died miserably 60 years ago |url=https://arstechnica.com/science/2017/11/sixty-years-ago-the-first-creature-went-into-space-a-stray-moscow-dog/ |date=3 November 2017 |work=[[Ars Technica]] |access-date=3 November 2017 |archive-url=https://web.archive.org/web/20171201182453/https://arstechnica.com/science/2017/11/sixty-years-ago-the-first-creature-went-into-space-a-stray-moscow-dog/ |archive-date=1 December 2017 }}</ref> At a Moscow press conference in 1998 [[Oleg Gazenko]], a senior Soviet scientist involved in the project, stated "The more time passes, the more I'm sorry about it. We did not learn enough from the mission to justify the death of the dog...".<ref>Dick Abadzis, afterword to ''Laika'', First Second, 2007, {{ISBN|1-59643-302-7}}</ref>

===Early lunar probes===
[[File:Luna_3_moon.jpg|thumb|The first photo of the far side of the Moon, taken by Luna 3]]
In 1958, Korolev upgraded the R-7 to be able to launch a {{convert|400|kg|lb|adj=on}} payload to the Moon. The [[Luna programme|Luna program]] began with three failed secret 1958 attempts to launch [[Luna E-1 No.1|Luna E-1]]-class [[Lander (spacecraft)#Impactors|impactor]] probes.{{sfn|Siddiqi|2018|p=xv}} The fourth attempt, [[Luna 1]], launched successfully on January 2, 1959, but missed the Moon. The fifth attempt on June 18 also failed at launch. The {{convert|390|kg|lb|adj=on}} [[Luna 2]] successfully impacted the Moon on September 14, 1959. The {{convert|278.5|kg|lb|adj=on}} [[Luna 3]] successfully flew by the Moon and sent back pictures of its far side on October 7, 1959.{{sfn|Siddiqi|2018|p=14}}

The US first embarked on the [[Pioneer program]] in 1958 by launching the [[Pioneer 0|first probe]], albeit ending in failure. A subsequent probe named [[Pioneer 1]] was launched with the intention of orbiting the Moon only to result in a partial mission success when it reached an apogee of 113,800&nbsp;km before falling back to Earth. The missions of [[Pioneer 2]] and [[Pioneer 3]] failed whereas [[Pioneer 4]] had one partially successful lunar flyby in March 1959.<ref>{{cite web |author1=NASA |title=Pioneer 0, 1, 2 |url=http://msl.jpl.nasa.gov/QuickLooks/pioneer0QL.html |access-date=11 July 2022 |archive-url=https://web.archive.org/web/20090131181021/http://msl.jpl.nasa.gov/QuickLooks/pioneer0QL.html |archive-date=31 January 2009}}</ref><ref>{{cite book | title = [[The Radiation Belt and Magnetosphere]] | last = Hess | first = Wilmot | author-link = Wilmot N. Hess | year = 1968}}</ref>