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Vostok lifts off!

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. For decades, countless books repeated each other, claiming that Gagarin's ascent to space was flawless. Only by the end of the 20th century, did the truth start to emerge. As it transpired, the main engine of the second stage burned around half a second longer than scheduled, hurtling Gagarin's capsule dangerously high.

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Vostok lifts off on April 12, 1961.


April 12: Beginning of the historic day

At 05:00 in the morning, communications tests between the various ground control stations took place. Gagarin and Titov were awaken at 05:30. They had "space food" for breakfast, which was followed by routine medical checkups. Both cosmonauts passed them with flying colors.

At 06:00, 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. The suiting up operations started with attaching of nine silver medical sensors to cosmonauts' bodies. Next, they put on thin white silk underwear with small slits to route wires for sensors. Next came the soft layer of the spacesuit, which included ventilation system, and grayish thermal layer. Finally, an orange exterior layer was put on top. Shoes were fixed to the spacesuit, but gloves with their metallic seals were only left strapped to the sleeves on strings to be put on inside the spacecraft.

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 authenticity 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 walked out of the assembly building and boarded a specially equipped bus for a 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 in the middle of the steppe, letting the cosmonaut to get out and relieve himself onto a tire. However all agree, that the atmosphere on a bus was very joyful, confirmed by a film footage where a fellow cosmonaut puts a candy into Gagarin's mouth.

Upon arrival at the pad around two hours before launch, the cosmonauts' training instructor Yevgeny Karpov was first off the bus to help Gagarin and Titov to disembark.

Gagarin was met by General Kerim Kerimov and the head of the State Commission Konstantin Rudnev among others, to whom he made an official report about his readiness for the flight.

pad

At the so-called zero-point of the launch pad, Gagarin bid farewell to Korolev and other officials, which included hugs and kisses from Korolev and Rudnev. Andriyan Nikolaev also tried to have a kiss but, according to his own recollections, instead got a considerable blow on his forehead from Gagarin's bulky helmet. (463)

In the company of leading engineer Oleg Ivanovsky, who just came down from the service gantry, Gagarin climbed around a dozen steps of a legendary stairway toward the elevator which then went up along the arm of the transporter erector to the top of the rocket. Along with Ivanovsky and life-support engineer Fyodor Vostokov, Gagarin emerged from the elevator at the top of the launch vehicle. He was met by technicians Vladimir Morozov and Viktor Skoptsov. Gagarin waved another goodbye from the top of the gantry and walked to the capsule. Two junior officers from the missile forces and a movie cameraman were also on hand. Held by Ivanovsky and Vostokov on two sides, Gagarin got into the cabin.

Once onboard, Gagarin flipped a few switches and established communications with the launch control room with Pavel Popovich on the other end of the radio link. The Ozon-SM data recorder was first activated at 07:20 providing information on Gagarin's condition during pre-launch operations until 08:45.

Ivanovsky by the hatch could hear exchanges between Gagarin and Popovich through a speaker in Vostok's cabin, until Gagarin switched the audio to his headphones. Ivanovsky then called Korolev and told him that they were ready to close the hatch and got green light. Ivanovsky, Morozov and Skoptsov lifted a nearly 100-kilogram cover, put into the position and tightened 30 bolts first by hands and then by special keys in a symmetrical fashion to ensure an even seal.

Despite practicing this operation many times, this time, one of three lights confirming the arming of the hatch jettisoning mechanism for the ejection would not light up in the launch control bunker.

Korolev called Ivanovsky and asked to re-open and close the hatch again. "C'mon guys, let's open the hatch," Ivanovsky told his technicians, who looked at him in total bewilderment.

After they re-opened the hatch, Ivanovsky checked the contacts, which looked fine, but he still adjusted the problematic one slightly with a screwdriver. As they were re-installing the hatch, Ivanovsky got a glimpse of Gagarin's face reflecting in his spacesuit sleeve mirror, as he held up his left hand to see what was going on. Shortly after they re-installed the hatch, their intercom called again. From downstairs, Korolev said that everything was in order for pressurization checks. Technicians fitted a special device on top of the hatch to check for leaks.

This time, everything worked fine and 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.

The Tral P-1-1 telemetry unit was activated at 09:02 Moscow Time. (463)

First human lifts off into space

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!

Launch problems

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) However, the situation apparently would not become clear until after the mission.

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.

At least one source, attributes the unplanned descent trajectory to the wrong orbital altitude. (463)

Interior

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.

 

The Vostok 3A No. 3 launch timeline:

Event
Time (planned)
Time (actual)
Launch
09:07
09:06:59.7
Stage I separation (T+119 seconds (51))
09:09
09:09
Payload fairing separation (T+154 seconds (51) T+150 seconds (465))
-
09:10
Stage II separation (T+299 seconds (51))
09:12:12
09:12
Spacecraft separation from Stage III
09:18
09:18:28* (463)

*or 09:18:07 (464)

 

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Page author: Anatoly Zak; Last update: April 12, 2016

Page editor: Alain Chabot; Last edit: April 8, 2011

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Gagarin

"Chief Designer's or Korolev's house" at Baikonur Cosmodrome's Site 2, where Yuri Gagarin spent his last night before the historic flight in April 1961. Copyright © 2001 Anatoly Zak


suitup

Gagarin during suiting up operations on the morning of April 12, 1961.


Gagarin

Yuri Gagarin on his way to the launch pad. Click to enlarge. Credit: RKK Energia


pad

Yuri Gagarin walks toward the launch vehicle on the pad. Korolev is on the right.


ivanovsky

Ivanovsky shakes hands with Gagarin before climbing to the spacecraft.


stairs

Gagarin climbs the stairs of the access gantry on the way to the elevator with Ivanovsky on his left.


gantry

Gagarin at the top of the access gantry is preparing to board Vostok, with Ivanovsky on his left.


Gagarin

Gagarin

Gagarin

launch

thrust

Launch of the Vostok spacecraft. Click to enlarge. Anatoly Zak's archive


R-7 core

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


Block E

The capricious third stage of the Vostok rocket apparently performed flawlessly in Gagarin's launch. Copyright © 2011 Anatoly Zak