Botched Vostok launch tests emergency landing
On December 22, 1960, just three weeks after the previous flight, the USSR fired its fifth prototype of the Vostok spacecraft on a mission to prepare for the human conquest of space. However, the spacecraft never made it into orbit and got no mention in the official press. Yet, behind the scene, the dramatic emergency landing and a subsequent rescue operation provided irreplaceable experience for Vostok's developers.
Vostok-1 (1K No. 6) mission at a glance:
Preparing the launch
The failure to return the fourth prototype of the Vostok spacecraft in early December 1960 derailed a bold plan of the Soviet space program to put a man in space by the end of 1960. However, the Vostok project still continued at an incredible pace, even if not as fast as it had been projected in government documents in November 1960.
By December 3, 1960, the 8K72 rocket No. L1-13A arrived at the launch site in Tyuratam with the assignment of delivering the Vostok 1K No. 6 spacecraft into orbit. The rocket's third stage, known as Block E, was upgraded for the first time with the RO-7 (RD-0109) engine, providing a thrust of 54.5 kilonewtons and replacing the RO-5 engine with a thrust of 49 kilonewtons. (537)
As in the three previous missions, the Descent Module of the Vostok-1K spacecraft carried the pressurized animal container GKZh. The two canine passengers were named Kometa (Comet) and Shutka (Joke). (463) According to another source, the female dogs on that flight were named Zhemchuznaya (Pearly) and Zhulka (Little thief). (537)
During the preparation of the spacecraft at the processing area in Tyuratam, the PS-6415-59 parachute system had to be temporarily removed from the Descent Module in order to conduct calibration of the P-3 long-range radio-beacon of the Peleng system, which was designed for search and rescue operations and whose antenna was imbedded in the lines of the main parachute. (537)
Fifth Vostok fails at launch
The Vostok rocket carrying the fifth unpiloted Vostok spacecraft lifted off on December 22, 1960, at 10:45:19 Moscow Time (10:30 Moscow Time, according to one source).
The telemetry on the ground confirmed that the first stage of the rocket separated as planned at T+119.3 seconds, followed by the jettisoning of the payload fairing at 151.35 seconds in flight. As the core (second) stage of the rocket continued firing, the RU radio-control system issued a command at T+304.13 seconds to pressurize the propulsion system of the third stage getting it ready for a scheduled ignition in flight. However, the so-called "main command" (GK), expected between 308th and 309th second in flight, was not registered in the telemetry, possibly, the first sign of trouble aboard the rocket. Then, the GK command triggered by the RU radio-control system was recorded at T+321.38 seconds, marking the ignition of the engine on the third stage. The third stage seemingly fired normally until T+432.02 seconds in flight, when the telemetry indicated a premature engine cutoff. According to the flight program, the third stage had to operate until T+676.61 seconds in flight. (537)
Despite reaching an altitude of 214 kilometers, the vehicle was far short of orbital velocity and was doomed to an immediate plunge back into the atmosphere. The telemetry showed that the flight control system issued a command for the separation of the spacecraft from the Block E booster, probably as it was supposed to do after the engine cutoff. In turn, temperature sensors aboard the spacecraft had to trigger the separation of the Descent Module from the Service Module and activate the landing sequence upon detecting the heat of atmospheric reentry.
According to the flight sequence, at an altitude of 6.5 kilometers from the ground, the capsule had a descent speed of 210 meters per second. The hatch of the parachute compartment was jettisoned at an altitude of four kilometers and a descent speed of 180 meters per second. Along with it, came out a small pullout parachute with an area just 1.5 square meters, which in turn released a much larger 18-square-meter braking parachute. It helped to slow down the capsule to a speed of 70 meters per second at an altitude of two kilometers, when the main huge parachute with an area 574 square meters was released. Along with it, was unfurled the P-3 antenna of the Peleng system, whose 10.003-megahertz signals were picked up by super-sensitive radio receivers of the Air Force's Krug system in Tashkent, Moscow and Krasnodar. They confirmed that the Descent Module had survived the reentry, opened the parachute and was descending somewhere in Siberia, around 3,000 kilometers downrange from the launch site.
Ironically, the presumed landing site was apparently narrowed down to an area only a few hundred kilometers north from the infamous Tunguska impact 52 years earlier.
As the main parachute fully inflated and slowed the capsule's descent to just 10 or 12 meters per second, the P-5 transmitter was also released from the parachute container and dropped on a string below the descending capsule.
As soon as the general circumstances of the launch failure became apparent, Sergei Korolev, Head of OKB-1 design bureau that developed Vostok, called an engineer ironically named Fedor Vostokov, who worked at Factory No. 918, the supplier of the GKZh cabin and other life-support equipment for the project. Vostokov had previously served as a liaison between OKB-1 and Factory 918, so he knew Korolev quite well. "You will fly alone," Korolev told Vostokov, essentially assigning him to be a scout for a recovery team to follow. Vostokov's main task was to extract the GKZh cabin from the capsule.
Vostokov was instructed to head to Novosibirsk first and then change planes to Krasnoyarsk, where Korolev promised to give Vostokov directions for further travel, as the specialists scrambled to narrow down the coordinates of the landing site. In case of questions during his trip, Vostokov was instructed to say that he was going to help with an accident at the Krasnoyarsk hydroelectric power station. Vostokov immediately gathered his warmest cloth and was quickly driven to the airport.
Per Korolev instructions, aboard the Il-18 passenger aircraft, Vostokov met an explosive expert from Leningrad heading to the same destination.
Vostokov was well aware that below the catapult, the Descent Module had an explosive charge of the APO system designed to blow up the craft in case of landing outside the USSR. Korolev explained that his colleague's task was to unscrew the plugs of the powerful self-destruct mechanism inside the Descent Module. Since the module transmitted signals at landing, it was clearly in one piece, which obviously meant that the APO system had not worked, but its status after the touchdown was impossible to ascertain.
Korolev promised Vostokov that by the time the pair disarmed the mechanism, they would be supported by a whole team of engineers led by Korolev's deputy Arvid Pallo.
According to the recollections of the E.F. Atachkin from the NII-4 military institute, which at the time was responsible for the flight control of the mission, the closest available search team to the unexpected landing site was in the city of Krasnoyarsk. The group was led by Captain M.A. Chernovsky. (463)
After Vostokov's arrival at Krasnoyarsk, he was directed to Tura, the district capital of the Evenk Region. There, on December 23, both specialists boarded a World War II-era Li-2 transport plane, which departed for a survey of the expected landing area. However, by that time the pilots could not home in on any signal from the spacecraft and their search on December 23 proved fruitless.
They started another overflight the next morning (December 24) and around 10:00 spotted the parachute stuck in the trees and, next to it, the capsule half-buried in the meter-thick snow on a relatively flat but tilted plateau around 500 meters above sea level. The 18-square-meter braking parachute was strewn between 300 and 400 meters away.
The landing site was some 60 kilometers from Tura, near the Nizhniya Tunguska River. (537) According to Arvid Pallo, the landing site was between rivers Ognekte and Yuteken.
Upon returning to Tura, the searchers called their superiors with the news. Both specialists then boarded a helicopter and headed back to the capsule.
They landed seemingly close to the Descent Module, just 20 or 30 meters away, but getting to the spacecraft in chest-deep snow required a major effort. Despite the severe cold, with temperatures between -35 and -40C degrees, Vostokov and his colleague dropped their bulky jackets and began trekking to the spacecraft, digging through the snow. When they finally approached the ball-shaped vehicle, they discovered that the GKZh cabin was still inside, but its ejection mechanism was missing. They had some ropes with them, which they wrapped around the GKZh cabin and pulled it off its catapult. Fortunately, the cabin easily slid off its guide rails. The explosive specialist immediately dove inside the cabin and quickly disconnected the cables of the APO mechanism, finally eliminating the danger of an explosion.
Vostokov then inspected the guide rails of the catapult the best he could but found only minor deformations which did not explain why the ejection engine had seemingly flown away without the GKZh cabin. The capsule itself also showed little damage. Vostokov speculated that g-loads during the descent had prevented the ejection.
On the evening of the same day (according to one source around 12:00 on December 24), Arvid Pallo and his group finally arrived at the site and began proper recovery operations. They were able to open the GKZh container and extract the shivering but still live dogs... (463) Other biological organisms aboard the capsule, such as mice, were apparently not that lucky, succumbing to the severe cold.
The inspection of the spacecraft quickly revealed that a multi-line umbilical that carried multiple cables from the Service Module to the Descent Module failed to separate from the capsule as planned. Instead, the heat of reentry melted and severed the umbilical, baking and fusing together various cables and likely throwing off the normal landing sequence. As a result, the command to eject the GKZh container from the Descent Module could not go through. For the same reason, the self-destruct mechanism aboard the capsule failed to activate four hours after landing. Obviously, both failures turned out to be a blessing for the dogs who had survived for two days in the Siberian winter, protected by the insulated walls of the Descent Module.
In the meantime, the short winter day was drawing to a close and search specialists had to hurry. (463) Their next challenge was to evacuate the capsule from the frozen tundra. A Mi-4 helicopter had to operate at the brink of its capabilities to airlift the 2-ton ball. (537) The helicopter first delivered the module to the nearest airfield in Tura, however the runway there could not receive the heavy An-12 transport plane capable of taking the spacecraft onboard for a trip back to OKB-1 near Moscow. Instead, the helicopter had to carry the capsule on an external tether for nearly 600 kilometers to the city of Turukhansk, where the plane sent by Korolev could finally pick it up. (463)
Outcome of the flight
Despite the botched launch, the mission of Vostok-1K No. 6 provided invaluable lessons to developers. As it transpired, the gas generator in the main engine of the third stage disintegrated 425 seconds (seven minutes) into the flight, leading to the failure. (52)
However, the resulting emergency situation demonstrated that the Descent Module and its parachute system could provide a safe landing, even though a considerable effort still continued to develop an ejection seat for the pilot to bail out from the Vostok during its nominal landing or in case of a failed liftoff.
In addition, the incident tested the emergency landing operations in case of a rocket failure during the final phase of ascent to orbit, which would never have been tried otherwise before the first attempt to launch a man in space would be made in 1961.
Photos attributed to dogs Kometa (top) and Shutka.
A mockup of the Descent Module of the Vostok spacecraft and the top section of its Service Module. Click to enlarge. Copyright © 2011 Anatoly Zak
The umbilical mast of the Vostok-1K spacecraft, whose failure probably saved lives of dogs aboard Vehicle No. 6. Click to enlarge. Copyright © 2011 Anatoly Zak
Landing sequence of the Vostok-1K No. 6 spacecraft on December 22, 1960.