Above: Gagarin's descent module and key features of its interior, minus the ejection seat, as seen via the ejection hatch. Severe damage to the thermal protection layer visible at the top of the capsule was likely caused by the wind drag after the touchdown and before the parachute could deflate, not by the heat during the reentry.
Previous chapter: Preparing Gagarin's mission
1961 April 12: Launch!
At 5:00 in the morning, communications tests between the various ground control stations took place. Gagarin and Titov were awaken at 5:30. They had "space food" for breakfast, which was followed by routine medical checkups, which both cosmonauts passed with flying colors.
At 6:00, the car of the medical service arrived to the launch pad, delivering food to be loaded into the spacecraft. (229) In the meantime, the two cosmonauts arrived in the spacesuit processing room of the vehicle assembly building at Site 2. Contrary to popular descriptions, Gagarin put on his space suit after Titov to reduce chances of overheating and discomfort. One of the onlookers in the dressing room semi-jokingly suggested that upon landing in his futuristic outfit Gagarin could be mistaken for the pilot of an American spy plane like the one that had been shot down over USSR in the previous year. The idea was taken seriously and officials made the urgent decision to paint C C C P (USSR) on the front of Gagarin's helmet in big red letters. A number of photos showing Gagarin in his helmet before and after the letters were painted confirm the aucenticity of the story. One life-support engineer known for his calligraphic writing quickly accomplished the improvised task. Gagarin reportedly pleaded with the "artist" to be careful not to drop red paint on his nose.
From this point on, a major source of information on the historic mission is Gagarin's own report which he delivered to the State Commission some 24 hours after his landing. The document would not be fully published for decades. (230)
Upon suiting up, Gagarin spent a few minutes in the special test seat, as technicians were checking ventilation and other systems. Then, accompanied by Titov, Nelyubov, Nikolaev and life-support engineers, Gagarin boarded a specially equipped bus for the short ride from Site 2 to the launch pad. Gagarin's companions on this historic trip later disputed popular and persistent stories that midway to the destination, the bus made a stop, letting the cosmonaut to get out and relieve himself onto a tire.
At the so-called zero-point of the launch pad Gagarin bid farewell to Korolev and other officials and in the company of leading engineer Oleg Ivanovsky climbed the legendary stairway toward the elevator which then carried him to the top of the launch vehicle and to the hatch of his spacecraft. After the initial closure of the hatch, one of the lights in the launch control bunker refused to confirm a proper seal. The hatch had to be re-opened, one of the sensors adjusted and the hatch closed again. This time everything was ready to go. Via the announcement system, the launch personnel was ordered to clear the pad and Gagarin was left alone at the top of the fueled rocket to face History.
Gagarin's launch vehicle blasted off into the cloudless blue sky almost as scheduled, just a fraction of a second before 09:07 Moscow Time. Several thousands of military officers, soldiers, technicians and engineers spread over various facilities of the top-secret test range later known as Baikonur witnessed the roaring vehicle rising over the steppe and heading eastward.
A number of photos of this historic event have been published, however film footage, traditionally associated with Gagarin's liftoff, was actually recorded during the ill-fated launch of the unmanned Vostok prototype on July 28, 1960. (Just seconds after those dramatic images of the rocket's shadow moving across the giant flame duct of the launch complex had been captured, the vehicle exploded killing two dogs onboard.)
Fortunately for Gagarin, his liftoff and the ride to orbit went smoothly. Inside the spacecraft, Gagarin felt how the heavy pressure of g-loads pressed him into the seat, stiffening his legs, arms and face and making it difficult to talk. One minute after launch the acceleration had reached 3-4 g and Gagarin's pulse rose from a regular 64 to 150. (469) Suddenly, it let go with the first stage separation but then started piling up again, as the second stage kept accelerating. (465) Witnesses in Tyuratam could still see how the four rocket boosters of the first stage separated simultaneously two minutes after liftoff. (51)
Two and a half minutes after launch, the payload fairing, covering the spacecraft split in two petals with a powerful jolt and fell away, revealing to the pilot a breath-taking view in the lower window. "Beautiful," Gagarin exclaimed, after seeing one of the petals of the nose cone slowly tumbling away from the rocket backdropped by the magnificent surface of the Earth.
Thanks to the optical navigation tool, called Vzor (Look) mounted on the bottom window near his feet, Gagarin could now watch the changing landscapes of the Earth below. He reported seeing growing cloud formations, mountains, rivers and islands. Even more importantly, by watching the horizon in the special ring reflector of Vzor, Gagarin was now aware of his vehicle's position in space. He later reported that the rocket had been climbing at a very low angle, however by the end of the second-stage burn its trajectory leveled out almost parallel to the horizon, and then, even deepened somewhat. (It is typical for the launch vehicle to start a slight descent by the end of acceleration.)
Five minutes after launch, the main engine of the core stage shut down, while four small vernier nozzles continued firing for a few more seconds fine-tuning the enormous speed of the rocket to a needed 5.5 kilometers per second. (51) For Gagarin, the heavy loads of acceleration and powerful rumble sharply turned into 10-15 seconds of weightlessness.
Then the third stage fired with a bang and moments later, the spent second stage separated. It was the job of the third stage to accelerate spacecraft to the almost eight kilometers per second needed to reach orbit some 10 minutes after the liftoff.
G-loads were growing and the vehicle was climbing again, when suddenly another bang marked for Gagarin the shutdown of the third stage. Some 10 seconds later, he felt the slight jolt of separation from the third stage and slow tumbling of his now free-floating spacecraft (465) at all three axis. Gagarin pushed himself from the seat as much as his safety straps allowed and "hanged" on them. (469) The world's first space traveler watched in amazement the kaleidoscope of the Earth surface, curved horizon, stars and pitch-black sky behind his window, as the spacecraft was going through its slow spin. The blinding sunlight burst into the cabin, forcing Gagarin to cover his eyes. (465)
According to Korolev around 13 minutes after launch, he had confirmation that the first man from Earth had reached the Earth's orbit. (469) The question remained what kind of orbit it was!
For decades, countless books repeated each other, claiming that Gagarin's launch was flawless. Only by the end of the 20th century, did the truth start to emerge. Later calculations showed that Gagarin's orbit was 327 kilometers above the Earth's surface in its highest point (apogee), instead of the planned 230 kilometers. (464)
Overshooting its apogee by almost 100 kilometers posed multiple and potentially deadly problems. Since Vostok had no backup braking engine, its planned orbit was calculated to be low enough to allow the rarified air at that altitude to slow down the spacecraft so that it could reenter the atmosphere and land 5-7 days after launch without any additional thrust. Vostok carried enough air, food and other vital consumables onboard for a 10-day flight. However, Gagarin's actual orbit would need more than two weeks (30 days according to one source) to decay and allow the return to Earth. Therefore, if the first cosmonaut's braking engine failed, he would be doomed to a slow death in orbit. (466, 231)
Even if everything went as planned, the higher-than-normal orbit could still affect the flight. Immediately after the separation from the third stage of the launch vehicle, a special timer called PVU Granit was activated onboard Vostok, counting down toward the firing of the braking engine. Probably as a result of the higher, (and consequently longer) orbit, the timer was now programmed to start the deorbiting maneuver slightly ahead of the correct point. In turn, the premature reentry would shift Gagarin's touchdown point forward, short of its target.
The Vostok 3A No. 3 launch timeline:
*or 09:18:07 (464)
Next chapter: Gagarin in orbit
Page author: Anatoly Zak; Last update: September 30, 2011
Page editor: Alain Chabot; Last edit: April 8, 2011
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Yuri Gagarin on his way to the launch pad. Click to enlarge. Credit: RKK Energia
Launch of the Vostok spacecraft. Click to enlarge. Anatoly Zak's archive
The business end of the core stage of the R-7 rocket with RD-108 four nozzle engine and four small vernier thrusters. Less than half a second of overwork by this powerful machine was enough to send Gagarin's spacecraft almost 100 kilometers beyond the safe altitude. Copyright © 2011 Anatoly Zak
The caprcious third stage of the Vostok rocket apparently performed flawlessly in Gagarin's launch. Copyright © 2011 Anatoly Zak