Editing Space Race (section)

=== Both programs recover ===

[[File:ZOND.jpg|thumb|Soyuz 7K-L1 Zond spacecraft, artist view]]

The United States recovered from the Apollo 1 fire, fixing the fatal flaws in an improved version of the [[Apollo Command and Service Module#Major differences between Block I and Block II|Block II command module]]. The US proceeded with unpiloted test launches of the Saturn V launch vehicle ([[Apollo 4]] and [[Apollo 6]]) and the Lunar Module ([[Apollo 5]]) during the latter half of 1967 and early 1968.{{sfn|Cadbury|2006|pp=310–12, 314–16}} The first Saturn V flight was an unqualified success, and although the second suffered some non-catastrophic engine failures, it was considered a partial success and the launcher achieved human rating qualification. Apollo 1's mission to check out the Apollo Command and Service Module in Earth orbit was accomplished by Grissom's backup crew on [[Apollo 7]], launched on October 11, 1968.<ref>Burrows (1999), p. 417</ref> The eleven-day mission was a total success, as the spacecraft performed a virtually flawless mission, paving the way for the United States to continue with its lunar mission schedule.{{sfn|Murray|Cox|1990|pp=323–24}}

The Soviet Union also fixed the parachute and control problems with Soyuz, and the next piloted mission [[Soyuz 3]] was launched on October 26, 1968.{{sfn|Hall|Shayler|2003|pp=144-47}} The goal was to complete Komarov's rendezvous and docking mission with the un-piloted Soyuz 2.{{sfn|Hall|Shayler|2003|pp=144-47}} Ground controllers brought the two craft to within {{convert|200|m|ft|sp=us}} of each other, then cosmonaut [[Georgy Beregovoy]] took control.{{sfn|Hall|Shayler|2003|pp=144-47}} He got within {{convert|40|m|ft|sp=us}} of his target, but was unable to dock before expending 90 percent of his maneuvering fuel, due to a piloting error that put his spacecraft into the wrong orientation and forced Soyuz 2 to automatically turn away from his approaching craft.{{sfn|Hall|Shayler|2003|pp=144-47}} The first docking of Soviet spacecraft was finally realized in January 1969 by the [[Soyuz 4]] and [[Soyuz 5]] missions. It was the first-ever docking of two crewed spacecraft, and the first transfer of crew from one space vehicle to another.<ref>{{cite web |title=Soyuz 4 & 5: The First Crew Exchange in Space |url=https://www.drewexmachina.com/2019/01/17/soyuz-4-5-the-first-crew-exchange-in-space/ |website=drewexmachina |date=January 17, 2019 |access-date=24 July 2022}}</ref>

[[File:NASA-Apollo8-Dec24-Earthrise.jpg|alt=A small blue-white semicircle of Earth, almost glowing with color in the blackness of space, rising over the limb of the desolate, cratered surface of the Moon|thumb|left|''[[Earthrise]]'', as seen from Apollo&nbsp;8, December 24, 1968 (photograph by astronaut [[William Anders]])]]

The Soviet [[Soyuz 7K-L1|Zond spacecraft]] was not yet ready for piloted [[circumlunar]] missions in 1968, after six unsuccessful automated test launches: [[Kosmos 146]] on March 10, 1967; [[Kosmos 154]] on April 8, 1967; [[Zond 1967A]] on September 28, 1967; [[Zond 1967B]] on November 22, 1967; [[Zond 1968A]] on April 23, 1968; and [[Zond 1968B]] in July 1968.<ref name="tent">{{cite web |url=http://nssdc.gsfc.nasa.gov/planetary/tent_launch.html |title=Tentatively Identified Missions and Launch Failures|publisher=NASA NSSDC|first=David R.|last=Williams|access-date=July 30, 2010|date=January 6, 2005}}</ref> [[Zond 4]] was launched on March 2, 1968, and successfully made a circumlunar flight,{{sfn|Siddiqi|2003b|pp=616-618}} but encountered problems with its Earth reentry on March 9, and was ordered destroyed by an explosive charge {{convert|15000|m|ft|sp=us}} over the [[Gulf of Guinea]].{{sfn|Hall|Shayler|2003|p=25}} The Soviet official announcement said that Zond 4 was an automated test flight which ended with its intentional destruction, due to its recovery trajectory positioning it over the Atlantic Ocean instead of over the USSR.{{sfn|Siddiqi|2003b|pp=616-618}}

During the summer of 1968, the Apollo program hit another snag: the first pilot-rated Lunar Module (LM) was not ready for orbital tests in time for a December 1968 launch. NASA planners overcame this challenge by changing the mission flight order, delaying the first LM flight until March 1969, and sending [[Apollo 8]] into lunar orbit without the LM in December.{{sfn|Kraft|2001|pp=284–97}} This mission was in part motivated by intelligence rumors the Soviet Union might be ready for a piloted Zond flight in late 1968.{{sfn|Chaikin|1994|pp=57–58}} In September 1968, [[Zond 5]] made a circumlunar flight with [[tortoises]] on board and returned safely to Earth, accomplishing the first successful water landing of the Soviet space program in the Indian Ocean.{{sfn|Siddiqi|2003b|pp=654–56}} It also scared NASA planners, as it took them several days to figure out that it was only an automated flight, not piloted, because voice recordings were transmitted from the craft en route to the Moon.{{sfn|Turnhill|2004|p=134}} On November 10, 1968, another automated test flight, [[Zond 6]], was launched. It encountered difficulties in Earth reentry, and depressurized and deployed its parachute too early, causing it to crash-land only {{convert|16|km|mi|sp=us}} from where it had been launched six days earlier.{{sfn|Siddiqi|2003b|pp=663–66}} It turned out there was no chance of a piloted Soviet circumlunar flight during 1968, due to the unreliability of the Zonds.{{sfn|Cadbury|2006|pp=318–19}}

On December 21, 1968, [[Frank Borman]], [[Jim Lovell|James Lovell]], and [[William Anders]] became the first humans to ride the Saturn V rocket into space, on Apollo 8. They also became the first to leave low-Earth orbit and go to another celestial body, entering lunar orbit on December 24.{{sfn|Poole|2008|pp=19–34}} They made ten orbits in twenty hours, and transmitted one of the most watched TV broadcasts in history, with their [[Apollo 8 Genesis reading|Christmas Eve program]] from lunar orbit, which concluded with a reading from the biblical [[Book of Genesis]].{{sfn|Poole|2008|pp=19–34}} Two and a half hours after the broadcast, they fired their engine to perform the first [[trans-Earth injection]] to leave lunar orbit and return to the Earth.{{sfn|Poole|2008|pp=19–34}} Apollo 8 safely landed in the Pacific Ocean on December 27, in NASA's first dawn splashdown and recovery.{{sfn|Poole|2008|pp=19–34}}

The American Lunar Module was finally ready for a successful piloted test flight in low Earth orbit on [[Apollo 9]] in March 1969. The next mission, [[Apollo 10]], conducted a "dress rehearsal" for the first landing in May 1969, flying the LM in lunar orbit as close as {{convert|47400|ft|km}} above the surface, the point where the powered descent to the surface would begin.<ref name="chariots12-7">{{cite book |last1=Brooks |first1=Courtney G. |last2=Grimwood |first2=James M. |last3=Swenson |first3=Loyd S. Jr. |others=Foreword by [[Samuel C. Phillips]] |title=Chariots for Apollo: A History of Manned Lunar Spacecraft |url=http://www.hq.nasa.gov/office/pao/History/SP-4205/cover.html |access-date=January 29, 2008 |series=NASA History Series |year=1979 |publisher=Scientific and Technical Information Branch, NASA |location=Washington, D.C. |isbn=978-0-486-46756-6 |oclc=4664449 |lccn=79001042 |id=NASA SP-4205 |chapter=''Apollo 10:'' The Dress Rehearsal |chapter-url=http://www.hq.nasa.gov/office/pao/History/SP-4205/ch12-7.html |archive-date=October 20, 2015 |archive-url=https://web.archive.org/web/20151020095653/http://www.hq.nasa.gov/office/pao/History/SP-4205/cover.html }}</ref> With the LM proven to work well, the next step was to attempt the landing.

Unknown to the Americans, the Soviet Moon program was in deep trouble.{{sfn|Cadbury|2006|pp=318–19}} After two successive launch failures of the N1 rocket in 1969, Soviet plans for a piloted landing suffered delay.{{sfn|Siddiqi|2003b|pp=665, 832–34}} The launch pad explosion of the N-1 on July 3, 1969, was a significant setback.{{sfn|Siddiqi|2003b|pp=690–93}} The rocket hit the pad after an engine shutdown, destroying itself and the launch facility.{{sfn|Siddiqi|2003b|pp=690–93}} Without the N-1 rocket, the USSR could not send a large enough payload to the Moon to land a human and return him safely.{{sfn|Parry|2009|pp=178–79}}