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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Space Race | 13/18 | https://en.wikipedia.org/wiki/Space_Race | reference | science, encyclopedia | 2026-05-05T13:12:13.188868+00:00 | kb-cron |
The Soviet 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. Zond 4 was launched on March 2, 1968, and successfully made a circumlunar flight, but encountered problems with its Earth reentry on March 9, and was ordered destroyed by an explosive charge 15,000 meters (49,000 ft) over the Gulf of Guinea. 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. 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. This mission was in part motivated by intelligence rumors the Soviet Union might be ready for a piloted Zond flight in late 1968. 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. 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. 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 16 kilometers (9.9 mi) from where it had been launched six days earlier. It turned out there was no chance of a piloted Soviet circumlunar flight during 1968, due to the unreliability of the Zonds. On December 21, 1968, Frank Borman, 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. They made ten orbits in twenty hours, and transmitted one of the most watched TV broadcasts in history, with their Christmas Eve program from lunar orbit, which concluded with a reading from the biblical Book of Genesis. 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. Apollo 8 safely landed in the Pacific Ocean on December 27, in NASA's first dawn splashdown and recovery. 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 47,400 feet (14.4 km) above the surface, the point where the powered descent to the surface would begin. 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. After two successive launch failures of the N1 rocket in 1969, Soviet plans for a piloted landing suffered delay. The launch pad explosion of the N-1 on July 3, 1969, was a significant setback. The rocket hit the pad after an engine shutdown, destroying itself and the launch facility. 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.
== Men on the Moon, space stations, space shuttles (1969–1991) == The latter period of the space race began with the United States landing the first men on the Moon, and was followed by the Soviets operating the first space stations and putting the first robotic landers on Venus and Mars, the US space shuttles marking the first significant reusable space vehicles, and a cooling down of tensions with the first docking between a Soviet and American vessel.
=== First humans on the Moon ===
Apollo 11 was prepared with the goal of a July landing in the Sea of Tranquility, just half a year after the first crewed flight to the Moon. The crew, selected in January 1969, consisted of commander (CDR) Neil Armstrong, Command Module Pilot (CMP) Michael Collins, and Lunar Module Pilot (LMP) Edwin "Buzz" Aldrin. They trained for the mission until just before the launch day. On July 16, 1969, at 9:32 am EDT, the Saturn V rocket, AS-506, lifted off from Kennedy Space Center Launch Complex 39 in Florida. The trip to the Moon took just over three days. After achieving orbit, Armstrong and Aldrin transferred into the Lunar Module named Eagle, leaving Collins in the Command and Service Module Columbia, and began their descent. Despite the interruption of alarms from an overloaded computer caused by an antenna switch left in the wrong position, Armstrong took over manual flight control at about 180 meters (590 ft) to correct a slight downrange guidance error, and set the Eagle down on a safe landing spot at 20:18:04 UTC, July 20, 1969 (3:17:04 pm CDT). Six hours later, at 02:56 UTC, July 21 (9:56 pm CDT July 20), Armstrong left the Eagle to become the first human to set foot on the Moon.