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Vostok-1K No. 5

Vostok-1K No. 5

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Vostok-1K No. 6


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Vostok-3A No. 2


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Belka and Strelka pioneer two-way trip to orbit

In August 1960, two dogs completed a day-long orbital flight aboard a Soviet spacecraft and returned to Earth alive and well, reversing the sad fate of their three predecessors who died in previous orbital launches, as well as many others lost in failed suborbital rocket flights and ground experiments. Introduced to the world as Belka and Strelka, the pair of formerly stray dogs became an instant sensation around the world and delivered the USSR another major propaganda coup.

Previous chapter: Vostok-1K No. 1 mission

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The Vostok ejection seat fitted with the Pressurized Animal Cabin, GKZh-2, which returned Belka and Strelka back to Earth. A taxidermist portrayal of Strelka is in the background. Notable are indentations on the aft bulkhead of the ejection seat.

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Vostok-1 (1K No. 2) mission at a glance:

Spacecraft designation Korabl-Sputnik-2, Vostok-1 (No. 3), 1K No. 2
Launch vehicle 8K72K No. L1-12 (Vostok)
Spacecraft mass 4.6 tons
Launch Site Tyuratam, Site 1
Launch date and time 1960 August 19, 08:44:06.8 Moscow Time
Orbital altitude 306 x 339 kilometers
Orbital inclination 64.57 degrees
Orbital period 90.6 minutes
Flight duration Planned: 2-3 days; Actual: 1 day 2 hours 23 minutes (17-18 orbits)
Landing 1960 August 20, 11:07 Moscow Time
Crew No


Second attempt

After the July 28, 1960, launch accident that took the lives of two dogs and destroyed a test version of the Vostok spacecraft, the launch campaign resumed almost immediately at the Tyuratam test range to prepare another Vostok prototype for flight, despite a severe heat wave in Kazakhstan. The fresh vehicle was almost identical to its lost predecessor in configuration and payload. The two dogs and a multitude of biological objects, including a pair of white rats, 40 black and white mice and insects were placed in separate compartments inside a pressurized container, GKZh-2, which was integrated with the ejection seat and fitted inside Vostok's Descent Module.

In addition to live animals, the GKZh container also carried a large botanical set with various plants, fungi and several kinds of cereals, including corn seeds. The latter were apparently intended to please the Soviet leader Nikita Khrushchev, who, during his recent trip to the US, famously bought into the idea of the miraculous properties of corn and its ability to revolutionize the lagging Soviet agriculture. The experiment probably meant to test the influence of space radiation on the reproductive properties of corn and other grains.

There were also payloads onboard for micro-biological, genetic, immunology and other life-science experiments.

Continuing the scientific program of the first experimental satellites, Vostok also carried a "space weather" experiment developed by a team of physicists led by Sergei Vernov. The payload's special photo-sensitive plates were designed to capture particles of space rays and then process the resulting images onboard. There were also experiments to measure UV and X-ray radiation from the Sun. (466)

The Signal telemetry system aboard Vostok was configured to downlink telemetry with information about the systems of the spacecraft as well as scientific data on the condition of the animals. It was also expected to test the quality of tonal modulation transmissions from orbit, which would be used for voice communications with pilots aboard Vostok. For that purpose, a special sound generator built into the Signal instrument was designed to simulate radio-telephone communications. (463)


However, as in the previous attempt, the main goal of the mission was to perform a safe return of the Descent Module after two or three days in orbit. (509) Following reentry, the capsule was expected to deploy its PS-6415-59 parachute system at an altitude of around eight kilometers. Upon descent to five kilometers, the cover of the Descent Module would be jettisoned and the container with the animals would be ejected to land under its own parachute.

Space dogs

The Soviet effort to fly dogs in support of the Vostok project started in December 1959. It followed a similar program from the early 1950s which supplied dogs for sub-orbital flights on research rockets and for the infamous mission of the second Soviet satellite in November 1957.

A veteran of the program Lyudmila Radkevich, who worked at the Aviation Medicine Institute, later remembered how, armed with a ruler, she crisscrossed Moscow suburbs in a car driven by a conscript soldier, looking for stray dogs. Around 60 dogs aged between 1.5 and three years and having a mass of around five or six kilograms each were picked at the start of the program, but only about a dozen were actually trained for orbital flights. Only female dogs were selected this time, because they required a much simpler design of the waste-disposal system, which was absent on short-duration ballistic flights.

Aboard the spacecraft, dogs would be fitted with cardiovascular, blood pressure, heartbeat, temperature and motion sensors with a total mass between 200 and 280 grams. The toilet interface, clothing and fixating devices took another 450 grams for each animal. Counting the actual mass of the 5.8-kilogram dog, the fully equipped animal had a mass of between 6.5 and 7 kilograms. (923) The installation of some sensors required surgery, but they would be removed if dogs survived their journey.

Final preparations

The leading aviation medicine specialist Oleg Gazenko, who was one of the pioneers of Soviet space medicine, documented the preparation for the first two launches of Vostok spacecraft with dogs aboard starting shortly before his team's arrival to the Tyuratam launch site on July 12, 1960.

Gazenko listed six dogs which were apparently trained in three pairs and could be used as backup "crews" to each other. He identified them as Lisichka and Chaika, Silva and Vilna, Marsiana and Laska.

After the loss of Lisichka and Chaika on July 28, 1960, Gazenko's notes indicated that Silva and Vilna became prime candidates for the next launch attempt. Gazenko recorded the vital signs of Silva on the morning of July 30 – temperature: 38.1 degrees, pulse: 88 beats per minute: breath - 24 times per minute. Vilna was also reported to be in good shape. Both dogs were placed into their container for a rehearsal of the flight.

On August 5, from 5 a.m. to 15 p.m., Gazenko's team tried the operation of the Seliger cameras recording the behavior of the dogs inside the capsule. As in the previous mission, two TV cameras equipped with lighting and mirrors, were installed to view Belka at a straight angle, while Strelka was monitored in profile. Along with live transmission at low resolution, the Seliger cameras also recorded higher quality video on film for the post-landing processing.

The dogs were dressed in red and green costumes, but, despite a later popular belief, they had no spacesuits.

By August 13, 1960, Vilna (whose name could be interpreted in Russian as a reference to the city of Vilnius in Lithuania and to independent Ukraine) was renamed into the politically acceptable Belka. (Gazenko's records also indicate that at one point, Vilna was called Vega and on August 15 he names her Belochka, which is a term of endearment version of Belka. Gazenko also appear to be defaulting back to the name Vilna in his subsequent notes even after the launch of the dogs.)

In the meantime, Silva, whose name also had western connotations and was deemed unacceptable as the launch date neared, was identified as Kaplya (droplet) for a short period of time around August 15, until officials settled on the name Strelka (little arrow). (923)

Vostok lifts off after a three-day delay

A launch vehicle with a Vostok spacecraft prototype is being fueled for liftoff in the Summer of 1960.

The work with the Vostok 1K No. 2 spacecraft at the processing building at Site 2 in Tyuratam lasted 12 days. On August 16, 1960, the 8K72K rocket with the spacecraft was rolled out to the launch pad at Site 1 with the liftoff planned for the next day. On the same day, Gazenko's team dressed his dogs and by 11 p.m., placed them into the container where they had to spend the night.

In the meantime, during tests of the rocket on the pad, a problem was found in the main oxygen valve and the liftoff had to be postponed. A replacement valve had to be delivered to the launch site on an aircraft from Kuibyshev (now Samara), where the R-7 rocket series were built, requiring postponing the mission until August 19.

After the replacement of the valve and multiple checks, the vehicle was ready for launch. (466)

In preparation for the second launch attempt on August 19, the GKZh container with the dogs was re-installed into the spacecraft around 5:30 a.m. local time or around eight hours before the planned liftoff. Medics were concerned about the health of the dogs on the hot launch pad, but fortunately there was some reprieve in the weather. (923)

The thermal cover was removed from the rocket between 11:45 and 12:15 local time, or 1.5 hours before launch.

Belka and Strelka lift off

The 8K72K No. L1-12 rocket carrying the 1K No. 2 spacecraft lifted off on August 19, 1960, at 11:44:06.8 Moscow Time. (51) The specialists and officials who crowded into a small room of the operational Group T (telemetry) at Site 2 in Tyuratam, waited anxiously for the confirmation from the Soviet Far East that the spacecraft had reached orbit.

Finally, the NIP-4 ground station in Yeniseisk and then another site on the Kamchatka Peninsula reported that the Vostok had separated from the upper stage and was indeed circling the Earth.

According to a secret telegram to the Central Committee of the Communist Party sent by space program officials on August 19, the spacecraft entered a near-circular orbit with an altitude of 320 kilometers. Interestingly, the document misidentified Strelka as Strela, probably in the confusion caused by the repeated re-naming of the dogs. (509)

As the night fell in Tyuratam and the spacecraft re-appeared within range of the center's antennas, Chertok and other officials jammed into the TV-receiving station. According to Gazenko, the communication window opened at 22:45 (local time) during the seventh orbit of the mission. (923)

Despite the relatively low resolution of the onboard camera, viewers on the ground saw perfectly on live TV as the dogs began barking. Ground stations also confirmed that all the equipment aboard the spacecraft was working well.

Specialists from Chertok's Group T and members of the State Commission stayed up until 2 a.m. the next morning (August 20), monitoring the situation aboard the spacecraft.

As Chertok and his colleagues were leaving the ground station in the early hours of August 20, the American Echo-1A satellite, essentially a 30-meter inflatable sphere intended for experiments with reflections of radio signals, was making an easily observable pass in the sky over Tyuratam. Still excited about the latest TV views from orbit, the Soviet engineers joked about their dogs barking at the American satellite. "Maybe they pissed on it too," Chertok remembered one of them saying laughingly.

However, during breakfast the next morning (August 20), Korolev was called to a telephone and informed that telemetry specialists suspected an anomaly in the operation of the infra-red attitude control system aboard the spacecraft, similar to the failure during the first Vostok mission.

According to Konstantin Feoktistov, chief Vostok developer, the problem with the infra-read attitude control system was discovered in telemetry records after the first couple of orbits of the mission. (196)

Chertok told Korolev that it was a good opportunity to test the operation of the backup attitude control system (that relied on the position of the Sun for reference), but in response he got a grim look on Korolev's face. The Chief Designer demanded to immediately call his deputy Konstantin Bushuev and the developer of the flight control systems Mikhail Ryazansky, who were at the NII-4 military research institute in Bolshevo, which at the time served as the main communications and calculations center for the Soviet space program. "Enough looking at (TV) pictures, let them have (their) ballistic people to prepare the descent sequence," Korolev said.

(It appears that the flight was cut short from its maximum possible duration, perhaps to minimize the probability of additional failures in the flight control system.)

The consultations with NII-4 resumed at 9:30 a.m. on August 20 and the decision was made to conduct the landing using a backup solar orientation system, instead of the infra-red sensor system. (51)

Belka and Strelka make a soft landing

On the morning of August 20, the Pravda newspaper carried an official statement from the TASS news agency identifying the ongoing mission as the Second Soviet Spacecraft-Satellite (Korabl-Sputnik). The announcement disclosed that the launch continued the program started with the mission in May 1960 and re-confirmed that the flights aimed to prepare human missions in space.

In the meantime, as the Vostok spacecraft began its final 18th orbit, the NIP-4 ground station in Yeniseisk in the Soviet Far East sent a command initiating the ship's PVU Granit programming timer with the landing sequence. NIP-6 on Kamchatka Peninsula then confirmed that Granit had activated the landing sequence and was sending time markers, as the east-bound spacecraft left the range of Soviet stations. (466) The firing of the TDU braking engine was timed to begin out of range of communications at 10:38 Moscow Time over the Gulf of Guinea near the African Coast to ensure a landing in northern Kazakhstan. (51)

At 10:50 Moscow Time, the Soviet ground stations detected the frequency of the Signal beacon, indicating that the TDU braking system had worked. The loss of signal was expected at 10:57 Moscow Time and it would confirm that the separated Descent Module had reentered the atmosphere and the searing heat of plasma surrounding the capsule had melted the antennas.

When the time came for the signal disappearance, the officials in Tyuratam had a few moments of anxiety because antennas of the Signal-Yupiter tracking system at the IP-1 station in Tyuratam were still hearing the signal, before it finally weakened and disappeared to a huge sigh of relief on the ground. (51)

Next, radio monitors were waiting for the signals from the Peleng transmitter, whose wire antennas were embedded in the parachute lines and would, therefore, confirm that the capsule had deployed its parachute system. That confirmation, known as P-3 command, came to Tyuratam over the phone at 11:04 Moscow Time. NII-4 then confirmed that the P-1, P-2 and P-3 commands had all been registered, meaning that other critical descent milestones, including the ejection of the dog container had taken place as planned. The container was confirmed ejecting at an altitude of around 7 kilometers and a speed of around 6 meters per second.

The landing of Vostok 1K No 2 spacecraft took place at 11:07 Moscow Time on August 20, 1960, after one day, two hour and 23-minute flight, marking the first return of a Soviet spacecraft from orbit and the world's first two-way trip of animals into orbit. (922)

The Soviet anti-aircraft and security services, which had been mobilized for tracking operations, then reported that the landing had taken place in the Southern Urals within a triangle formed by the towns of Orsk, Kustanai and Amangeldy with a deviation of just 10 kilometers from the projected point.

The search team led V.M. Pekin deployed at the Orsk airport then departed aboard an aircraft toward the landing zone, guided by specialists at NII-4. The aircraft soon located the capsule and a group of search specialists parachuted to the site, while the pilot called for helicopter support.

At the landing site, parachutists then radioed to the pilot of the aircraft that the Descent Module, the GKZh container and the dogs inside were all in good shape. (463) As the pilot relayed the news to mission control, cheers erupted at the ground station in Tyuratam.

Korolev and Nedelin then formed a team of specialists, including spacecraft assembly technicians and doctors, to be dispatched to the landing site, while Korolev ordered his other associates to return to Moscow as soon as possible. (466)

After search specialists unsealed the biological container at the landing site, they let their lucky dogs to run around the steppe, while technicians were busy with the hardware. When the recovery helicopter arrived, the dogs readily sprung back for the trip home.

Post-landing celebrations

Back in Moscow, the successful return of Belka and Strelka triggered a wave of public celebrations and public events. First off all, the official announcement about the landing had to be worked out.

The morning after their return from Tyuratam, the members of the State Commission gathered at Moscow mansion of its chairman Marshall Nedelin. While the members debated the text of the post-landing communique, news came that around noon, Oleg Gazenko and Lyudmila Radkevich brought Belka and Strelka to a hastily prepared press-conference at the TASS news agency building at Tsvetnoi Boulevard in Moscow. (The two dogs apparently started a fight on the way to the event). Unexpectedly, the invited press included western photographers to the consternation of the commission members, who knew that foreign publications unbound by censorship and bureaucracy, would now certainly beat Soviet newspapers with the first pictures of space dogs. Nedelin's assistants rushed to the telephones calling the Ministry of Foreign Affairs and demanding to "stop the improvisations," but to no avail. Moreover, the official TASS news agency broadcast the event over the radio. The State Commission then decided to preempt the next-morning newspapers with a TV broadcast.

During evening news at 9:30, Chertok already sitting at home, watched Colonel Gazenko, dressed in civilian dress, and Radkevich parading Belka and Strelka on TV. (466)

On August 23, the Pravda newspaper, the mouthpiece of the Communist Party, carried the triumphant TASS report on the results of the mission. (509)

However, behind the scene there were some concerns. First off all, onboard footage showed that during the fourth orbit of the mission, Belka was moving around anxiously, barked and vomited. That footage predicted the onset of motion sickness that would later be experienced by humans as well after several hours in orbit. (51) That fact prompted the chief of medical research program at the Air Force Vladimir Yazdovsky to demand that the first flight of the spacecraft with a pilot onboard would not last more than one orbit.

Also, 28 out of the 40 mice which were onboard the spacecraft died in orbit.

With their risky mission and the world-wide fame behind them, Belka and Strelka reportedly lived happily ever after at the aviation medicine institute and both had healthy puppies. Strelka had three female and two male puppies and the Soviet leader Nikita Khrushchev gave one of them, named Pushok, as a present to Jackie Kennedy. (According to Western sources, the dog was actually a female and she was called Pushinka.)

According to one Russian TV program, Belka and Strelka died of natural causes at the Moscow zoo many years after their flight.



Page author: Anatoly Zak; Last update: March 25, 2021

Page editor: Alain Chabot; Last edit: August 19, 2020

All rights reserved


insider content



Belka and Strelka inside the GKZh container.


A Seliger TV camera similar to the one which was likely installed on early Vostok spacecraft.


TV images received on the ground during the mission of Korabl-Sputnik-2, probably showing Belka.


Post-landing processing of the GKZh container.








Official photos of Belka and Strelka and their human handlers released by the Soviet press.


Colonel Oleg Gazenko shows Belka and Strelka to journalists after the flight.


Like their much less fortunate predecessor Laika, Belka and Strelka appeared in numerous Soviet visuals, including matchboxes, candy, stamps, postcards and pins. The two dogs continued to be popular in the post-Soviet Russia, becoming the subject of many books, a 3D animated feature and a musical. They also appeared on coins and even got their own monument.


Stamp dedicated to the flight of the Second Soviet "Korabl-Sputnik.









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