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Vostok's forgotten precursor leaves lasting legacy

On July 28, 1960, the second prototype of the Vostok spacecraft lifted off with two dogs onboard to bring a human mission into orbit one step closer. However, its rocket fell apart disastrously less than half a minute after leaving the ground. The Soviet press did not say a word about this launch attempt and later histories barely mention the tragic accident, but paradoxically, the all-but-forgotten mission left future generations some of the most iconic visuals of the early Space Age.

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The Vostok ejection seat fitted with the Pressurized Animal Cabin, GKZh-2, which was first installed aboard the 1K No. 1 (a.k.a. Vostok-1) spacecraft.


Vostok-1 (1K) mission at a glance:

Spacecraft designation 1K No. 1, Vostok-1 (No. 2), (Not publicly announced)
Launch vehicle 8K72K (Vostok)
Spacecraft mass 4.5 tons
Launch Site Tyuratam, Site 1
Launch date and time 1960 July 28,* 12:31 Moscow Time (781)** (09:31 UTC)
Orbit parameters -
Flight duration 38 seconds (planned for 3-5 days)
Reentry -
Crew No

*Some sources also cite July 23 as the launch date

**12:27 Moscow Time, according to other sources

Preparations for the second Vostok launch

The original plans of the Korolev's team to launch two simplified Vostok spacecraft were apparently dropped after the first such mission flew in May 1960 and was considered to be largely successful. In the aftermath of that launch, Soviet engineers proceeded directly to the preparations of a fully equipped prototype vehicle designed to test all the necessary hardware and flight modes which would be required for piloted missions.

Like its predecessor, the prototype spacecraft was identified as Vostok-1 at the time, as opposed to the Vostok-2 variant, which was being designed as a fully automated reconnaissance satellite and the Vostok-3 version, certified to carry a cosmonaut. Unlike the first Vostok, the second prototype vehicle had the heat shield allowing the Descent Module to complete a reentry and landing. Also, engineers led by Korolev's Deputy Boris Chertok worked extensively on resolving the flight control problem which had led to the boosting of the original descent module to a higher orbit, instead of sending it back into the atmosphere. Chertok attested that the second vehicle was much thoroughly prepared than the first prototype. (62)

Obviously, after its single launch in May 1960, the Vostok was still far from being ready to carry cosmonauts, who just began their training in March 1960. Instead, the second Vostok-1 was expected to carry a pair of small dogs for the first time. The dogs and other biological organisms would be housed in a pill-shaped container officially known as GKZh-2 for Germitecheskaya Kabina Zhivotnogo, which can be translated as the "pressurized animal cabin."

The GKZh-2 container was fitted into the modified ejection seat of the pilot and, therefore, it was programmed to be ejected from the capsule during its descent to Earth and land under its own parachute, simulating the nominal landing method for future Vostok pilots.

The entire process of ejection and landing of the seat and the GKZh container during the descent of the capsule was live tested during drops of an experimental descent module from an aircraft conducted between January and April 1960. (913) However, the procedure for activating the ejection of the seat in emergency on the launch pad and during the initial ascent of the rocket was not apparently ready as of the Summer of 1960. (781) According to another source, all emergency commands, including the remote controlled activation of the ejection process, was blocked until 50 seconds in flight to ensure that the failing rocket can clear the launch facility.

By the middle of July 1960, two Vostok-1 vehicles, configured to carry dogs, were being prepared for flight with one of the ships already delivered to the launch site in Tyuratam. Its liftoff was officially planned for the end of July or early August. (509)

Flight program

For the second flight of the Vostok-1 variant, Air Force medics picked two dogs: Chaika (seagull) and the red-haired and soft-natured Lisichka (foxy), who became a favorite of Chief Designer Sergei Korolev. (62) In addition, the container was also expected to carry mice, flies and primitive micro-organisms.

On July 18, 1960, top industry officials sent a classified memo to the political leadership in Moscow outlining the upcoming mission.

The main official goal of the flight was testing the descent from orbit of a satellite cabin and the development of a system for recovery of necessary cargo. In parallel, the mission was said to carry out life-science experiments necessary for preparing to fly humans aboard reconnaissance satellites. In addition to the biological payload, the satellite was equipped with a suit of scientific instruments for studies of space rays and solar research. However, the reconnaissance radio and photographic equipment (which was considered to be the primary payload of the Vostok-1 variant), would not be onboard during this particular launch due to its complexity and lack of experience with spacecraft recovery, because its landing on a foreign territory could not be excluded, the document said. Perhaps it is an indication that the self-destruct system, which was considered for the previous mission and was flown on later vehicles, was still not been available to the Vostok developers in July 1960.

The document specified that the control of equipment aboard the satellite and the return of the descent module back to Earth was expected to be initiated with commands from ground stations across the Soviet Union. Also, two telemetry systems were reported to be available aboard the spacecraft to monitor the animals. Finally, it would be possible to observe the dogs in orbit with TV equipment, the document promised. (509)

Decades later, NII Televideniya, VNIIT, detailed its work on the TV-transmission system for the Vostok spacecraft. A pair of 3-kilogram Seliger cameras installed inside the Descent Module required 15 watts of power each at 27 volts to operate, producing 100-line images at a rate of 10 frames per second. The low resolution of the images was dictated primarily by the limitations of the transmitters and available telemetry channels. (916)

The mission of the 4.5-ton Vostok-1 spacecraft was expected to last from three to five days in an orbit with an altitude of 320 kilometers, before an attempt would be made to land the biological container either in Northern Kazakhstan or Western Siberia, the letter said. Fixed-wing aircraft and helicopters were equipped with radio-location hardware to assist in the search for the landing location and the fastest extraction of the live animals from the landing container, according to the document. (509)

Public announcement planned

Along with the memo detailing the first Vostok-1 mission, the officials also attached a draft of a public statement which would identify the freshly orbited vehicle as a part of the effort to prepare for human missions in space. The presence of two dogs and other animals aboard the spacecraft would also be disclosed and the statement would mention a series of life-science experiments, studies of long-duration flight and radiation research among the goals of the flight.

As was the practice with the earlier Soviet space missions, the post-launch announcement would provide the orbital parameters of the flight and outline general information about the onboard equipment and radio frequencies used by the spacecraft.

First 1K vehicle fails at liftoff

An 8K72K launch vehicle, carrying the Vostok-1 (1K No. 1) spacecraft, lifted off from Tyuratam on July 28, 1960, at 12:31 Moscow Time. The rocket cleared the launch pad and completed the vertical ascent, but as it began tilting toward its planned launch azimuth, less than half a minute after it left the ground, one of the strap-on boosters was seemingly sheered off by a powerful explosion and, moments later, the entire rocket disintegrated spectacularly. Numerous observers at the top-secret Soviet test range saw the rocket's aimlessly flying boosters and flaming debris hit the ground, but apparently far enough in the steppe not to cause any injuries. Boris Chertok remembered jumping into a prepared trench in advance of the impact. (62)

At the time of the liftoff, a young radio-control officer, Vladimir Poroshkov was on duty at the IP-1 tracking station directly overlooking the launch pad at Site 1. According to his records, the rocket lifted off at 12:31 Moscow Time, but 23.6 seconds into the flight, combustion chamber No. 1 in the 8D74 (RD-107) engine propelling the Block G booster on the first stage disintegrated and the rocket then fell apart at T+38 seconds.

Despite the violent nature of the launch accident, Poroshkov remembered the ball-shaped Descent Module of the spacecraft landing seemingly intact next to the Signal-Yupiter tracking facility at the IP-1 site. Because many rank and file conscripts at the test range rushed to the vehicle, which Poroshkov believed was laden with explosives, he immediately dispatched a patrol to secure the area around the capsule. His officers made it to the site before the professional search team. Poroshkov was not able himself to attend the vehicle because, on the orders from the unit commander, he had the duty of greeting cars with various high officials who were frantically shuttling between the vehicle assembly building at Site 2 and the IP-1 station at Site 18, in a typical post-failure commotion. However, from his associates who approached the descent module, Poroshkov learned that something was hissing and clanking inside the capsule and despite its undamaged look from a distance, the vehicle had actually cracked on impact and both dogs onboard had been killed. Poroshkov explained it by the fact that the capsule's parachute had no chance to open and inflate after the separation from the rocket earlier than 40th second from liftoff. (51)

In the aftermath of the accident

At 13:10 Moscow Time on July 28, or around 40 minutes after the failed launch, the Commander of the Soviet Strategic Missile Forces, RVSN, Marshall Mitrofan Nedelin, who apparently also witnessed the accident, sent a telegram to the Kremlin official Frol Kozlov. Nedelin reported that the vehicle had lifted off at 12:27 Moscow Time and experienced an explosion 15 seconds after launch, perhaps referring to the signs of an initial engine failure aboard the rocket. Nedelin reported that the vehicle fell within the test range but away from any habitable area and no launch facilities had suffered any damage.

A week later, on August 4, 1960, Nedelin and Korolev sent a more detailed account of the accident to the Central Committee of the Communist Party. This document said that the 8K72K rocket with the Vostok-1 spacecraft had lifted off at 12:31 Moscow Time and disintegrated in the 23rd second of the flight, with the resulting debris falling between 1.5 and 3 kilometers from the launch pad.

"Based on the analysis of the measurements and the inspection of the rocket debris at the impact site, it was established that the disintegration of the first combustion chamber in Block G due to high-frequency pressure oscillations was the cause of the accident," the letter said.

The officials wrote that the pressure oscillation phenomenon had been observed before and the necessary measures had already been taken to resolve the issue. As a result, engine production for serially manufactured R-7 and R-7A missiles, which served as the basis for the failed 8K78K vehicles, was being undertaken in accordance with the updated technical documentation. However, the rocket used for the launch on July 28, 1960, had some engines manufactured before the implementation of the corrective measures, the letter said.

The August 4 letter concluded that the preparation for another launch of the Vostok-1 vehicle was underway, with its liftoff planned for the second half of August 1960. (781)

According to Chertok, the accident prompted engineers at OKB-1 design bureau to speed up the work on the Emergency Escape System to bail out cosmonauts in the early stages of the flight. Chertok wrote that the exact reason for the explosive desintegration of the first-stage engine had never been established and the investigation commission characterized the high-frequency oscillations in the combustion chamber as "the most probable cause." According to Chertok, Valentin Glushko, who led the development of the propulsion system for the R-7 boosters, had not provided a clear explanation for the phenomenon and, therefore, the issue was excused by flaws in the manufacturing process. (466)

Long-lasting legacy of the forgotten launch

Needless to say, the USSR never publicly announced the July 28, 1960, launch attempt and all the details about the flight remained under wraps for most of the Cold War.

However, an initial segment of the film footage documenting the ascent of the ill-fated rocket at close range was released in 1967, following Yuri Gagarin's triumphant orbital flight in April 1961. In the usual fashion at the time, that particular footage was mixed in with other views of the actual launch of Gagarin. For decades, neither documentary makers who have used the imagery, nor a majority of viewers had any idea that the rocket dramatically rising in front of the camera explodes moments later and that the footage was taken almost a year before the launch of Gagarin, whose liftoff apparently had never been filmed from that particular angle.

The very fact of the ill-fated launch attempt on July 28, 1960, was disclosed publicly for the first time in Yaroslav Golovanov's Kosmonaut No. 1 published in 1986. (229) The footage documenting the disintegration of the rocket also came to light in the subsequent years.


Next chapter: Belka and Strelka fly aboard Vostok-1K No. 2

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

Page editor: Alain Chabot; Last edit: May 18, 2020

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insider content



The Vostok-1 (1K) vehicle likely photographed during pre-launch processing in Tyuratam.


Descent module of the Vostok 1K spacecraft with a GKZh container inside and with its main hatch open.


The Seliger TV camera similar to the one which was likely installed for the first time aboard the Vostok-1 (1K No. 1) spacecraft.


A possible photo showing dogs launched aboard the Vostok-1K No. 1.



Frames from a likely footage of the Vostok-1 (1K No. 1) launch which failed shortly after liftoff. The imagery later became associated with Gagarin's mission.






Frames from film footage apparently documenting the explosion in one of the strap-on boosters of the 8K72K rocket carrying the first Vostok-1 (1K No. 1) vehicle, following the shearing of the booster and complete disintegration of the vehicle.


An official Russian exhibit sponsored by Roskosmos and coincidently opened on the 60th anniversary of the Vostok-1K No. 1 launch still misidentified the spacecraft as Voskhod-2 (top right). Click to enlarge. Credit: Roskosmos







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