Vostok 1 (, ) was the first spaceflight of the Vostok programme and the first human orbital spaceflight in history. The Vostok 3KA space capsule was launched from Baikonur Cosmodrome on 12 April 1961, with Soviet cosmonaut Yuri Gagarin aboard, making him the first human to reach orbital velocity around the Earth and to complete a full orbit around the Earth.
The orbital spaceflight consisted of a single orbit around the Earth that reached a maximum altitude of 327 kilometers (203 miles; 177 nautical miles) and a minimum of 181 kilometers (112 miles; 98 nautical miles). The flight took 108 minutes from launch to landing. Gagarin parachuted to the ground separately from his capsule after ejecting at altitude.
Background
The Space Race between the Soviet Union and the United States, the two Cold War superpowers, began just before the Soviet Union launched the world's first artificial satellite, Sputnik 1, in 1957. Both countries wanted to develop spaceflight technology quickly, particularly by launching the first successful human spaceflight. The Soviet Union secretly pursued the Vostok programme in competition with the United States' Project Mercury. Vostok launched several precursor uncrewed missions between May 1960 and March 1961, to test and develop the Vostok rocket family and space capsule. These missions had varied degrees of success, but the final two—Korabl-Sputnik 4 and Korabl-Sputnik 5—were complete successes, allowing the first crewed flight.
Pilot
The Vostok 1 capsule was designed to carry a single cosmonaut. Yuri Gagarin was chosen as the prime pilot of Vostok 1, with Gherman Titov and Grigori Nelyubov as backups. These assignments were formally made on April 8, four days before the mission, but Gagarin had been a favourite among the cosmonaut candidates for at least several months.
The final decision of who would fly the mission relied heavily on the opinion of the head of cosmonaut training, Nikolai Kamanin. In an April 5 diary entry, Kamanin wrote that he was still undecided between Gagarin and Titov.Burgess and Hall, p.140 "The only thing that keeps me from picking [Titov] is the need to have the stronger person for the one day flight."Quoted in Burgess and Hall, p.140-141 Kamanin was referring to the second mission, Vostok 2, compared to the relatively short single-orbit mission of Vostok 1. When Gagarin and Titov were informed of the decision during a meeting on April 9, Gagarin was very happy, and Titov was disappointed.Burgess and Hall, p.141. The press said that Titov was so happy for Gagarin that he almost kissed him, but Titov denies this – Burgess and Hall, p.145. On 10 April, this meeting was reenacted in front of television cameras, so there would be official footage of the event. This included an acceptance speech by Gagarin.Burgess and Hall, p.142 As an indication of the level of secrecy involved, one of the other cosmonaut candidates, Alexei Leonov, later recalled that he did not know who was chosen for the mission until after the spaceflight had begun.Burgess and Hall, p.151
Backup
Reserve
Preparations
Unlike later Vostok missions, there were no dedicated tracking ships available to receive signals from the spacecraft. Instead they relied on the network of ground stations, also called Command Points, to communicate with the spacecraft; all of these Command Points were located within the Soviet Union.Hall and Shayler, p.148-149
Because of weight constraints, there was no backup retrorocket engine. The spacecraft carried 13 days of provisions to allow for survival and natural orbital decay in the event the retrorockets failed. The provisions included food for Gagarin. As focus was made on food that would not form crumbs, Gagarin was provided with liver meat puree and chocolate sauce, packed in metal toothpaste-style tubes.
The letters "СССР" were hand-painted onto Gagarin's helmet by engineer Gherman Lebedev during transfer to the launch site. As it had been less than a year since U-2 pilot Francis Gary Powers was shot down, Lebedev reasoned that without some country identification, there was a small chance the cosmonaut might be mistaken for a spy on landing.
Automatic control
The entire mission would be controlled by either automatic systems or by ground control. This was because medical staff and spacecraft engineers were unsure how a human might react to weightlessness, and therefore it was decided to lock the pilot's manual controls. In an unusual move, a code to unlock the controls was placed in an onboard envelope, for Gagarin's use in case of emergency. Prior to the flight, Kamanin and others told Gagarin the code (1-2-5) anyway.Burgess and Hall, p.156
11 April 1961
At Baikonur Cosmodrome on the morning of 11 April 1961, the Vostok-K rocket, together with the attached Vostok 3KA space capsule, were transported several kilometers to the launch pad, in a horizontal position. Once they arrived at the launch pad, a quick examination of the booster was conducted by technicians to make sure everything was in order. When no visible problems were found, the booster was erected on LC-1.Burgess and Hall, p.150 At 10:00 (Moscow Time), Gagarin and Titov were given a final review of the flight plan. They were informed that launch was scheduled to occur the following day, at 09:07 Moscow Time. This time was chosen so that when the capsule started to fly over Africa, which was when the retrorockets would need to fire for reentry, the solar illumination would be ideal for the orientation system's sensors.
At 18:00, once various physiological readings had been taken, the doctors instructed the cosmonauts not to discuss the upcoming missions. That evening Gagarin and Titov relaxed by listening to music, playing pool, and chatting about their childhoods. At 21:50, both men were offered sleeping pills, to ensure a good night's sleep, but they both declined.Burgess and Hall, p.151. During a post-flight press conference on April 15, Alexander Nesmeyanov claimed that Gagarin took a sleeping pill. Also, Siddiqi, p.273, claims that they were both asleep at 21:30 when Korolev came to visit them, but Burgess and Hall, p.151, says Korolev spoke with them at this time. Physicians had attached sensors to the cosmonauts, to monitor their condition throughout the night, and they believed that both had slept well.Siddiqi, p.273; In a post-flight press conference, Gagarin also stated that he slept well. Gagarin's biographers Doran and Bizony say that neither Gagarin nor Titov slept that night.Burgess and Hall, p.153. Chief Designer Sergei Korolev did not sleep that night, due to anxiety caused by the imminent spaceflight.
Gagarin statement before the mission Before the mission, Gagarin made a statement to the press, addressed to the Soviet Union and to the whole world:
In his autobiography, Gagarin recalled that, looking at the spacecraft before start, he was "seized with an unprecedented rise of all mental strength [...] some extraordinary words were born that I had never used before in everyday speech." This is disputed by historian Asif Siddiqi, who claims the speech "was taped much earlier, in Moscow" and Gagarin "was essentially forced to utter a stream of banalities prepared by anonymous speechwriters" .
Flight
At 05:30 Moscow time, on the morning of 12 April 1961, both Gagarin and his backup Titov were woken.Burgess and Hall, p.153 They were given breakfast, assisted into their spacesuits, and then were transported to the launch pad. Gagarin entered the Vostok 1 spacecraft, and at 07:10 local time (04:10 UTC), the radio communication system was turned on. Once Gagarin was in the spacecraft, his picture appeared on television screens in the launch control room from an onboard camera. Launch would not occur for another two hours, and during the time Gagarin chatted with the mission's main CapCom, as well as Chief Designer Sergei Korolev, Nikolai Kamanin, and a few others, periodically joking and singing songs. Following a series of tests and checks, about forty minutes after Gagarin entered the spacecraft, its hatch was closed. Gagarin, however, reported that the hatch was not sealed properly, and technicians spent about 15 minutes removing all the screws and sealing the hatch again. According to a 2014 obituary, Vostok's chief designer, Oleg Ivanovsky, personally helped rebolt the hatch.Obituary, Aviation Week and Space Technology, September 29, 2014, p.11- There is some disagreement over whether the hatch was in fact not sealed correctly, as a more recent account stated the indication was false.
During this time Gagarin requested some music to be played over the radio.Siddiqi, p.276; neither Siddiqi, nor Hall and Shayler claim that music was actually played after this request. Korolev was reportedly suffering from chest pains and anxiety, as up to this point the Soviet space launch rate was 50% (12 out of 24 launches had failed). Two Vostoks had failed to reach orbit due to launch vehicle malfunctions and another two malfunctioned in orbit. Korolev was given a pill to calm him down.Siddiqi describes it as a "tranquilizer pill", while Hall and Shayler describe it as a "cardiac pill". Gagarin, on the other hand, was described as calm; about half an hour before launch his pulse was recorded at 64 beats per minute.
Launch
06:07 UTC Launch occurred from the Baikonur Cosmodrome Site No.1. Korolev radioed, "Preliminary stage..... intermediate..... main..... lift off! We wish you a good flight. Everything is all right." Gagarin replied, "Let's go! (Poyekhali!)."Hall and Shayler, p.150 06:09 (T+ 119 s) The four strap-on boosters of the Vostok rocket used up the last of their propellant and dropped away from the core vehicle. 06:10 (T+ 156 s) The payload shroud covering Vostok 1 was released, uncovering a window at Gagarin's feet, with an optical orientation device (lit. "look" or "glance"). 06:12 (T+ 300 s) The rocket core stage used up its propellant and fell away from the capsule and final rocket stage. The final rocket stage ignited. 06:13 Gagarin reported, "...the flight is continuing well. I can see the Earth. The visibility is good.... I almost see everything. There's a certain amount of space under cumulus cloud cover. I continue the flight, everything is good." 06:14 Vostok 1 passed over central Russia. Gagarin reported, "Everything is working very well. All systems are working. Let's keep going!" 06:15 Three minutes into the burn of the final rocket stage, Gagarin radioed, ", I can't hear you very well. I feel fine. I'm in good spirits. I'm continuing the flight..." Vostok 1 started to move out of radio range of the Baikonur ground station. 06:17 The rocket final stage shut down and Vostok 1 reached orbit. Gagarin exclaimed "Kosberg has worked! (Kosberg Srabotal!)", Kosberg being the chief designer of the final rocket stage's engine. Ten seconds later the rocket separated from the capsule.
Time in orbit
06:18 UTC (T+ 676 s) Gagarin reported, "The craft is operating normally. I can see Earth in the view port of the . Everything is proceeding as planned". Vostok 1 moved on over Siberia as it passed over the Soviet Union. 06:21 Vostok 1 passed over the Kamchatka Peninsula and out over the North Pacific Ocean. Gagarin radioed, "...the lights are on on the descent mode monitor. I'm feeling fine, and I'm in good spirits. Cockpit parameters: pressure 1; humidity 65; temperature 20; pressure in the compartment 1; first automatic 155; second automatic 155; pressure in the retro-rocket system 320 atmospheres...."