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Description
World's first manned spacecraft, it was developed into the later Voskhod, and numerous versions of recoverable unmanned satellites for reconnaissance (Zenit), materials, and biological research (Bion). These remained in service into the 21st Century. Launched 1961 - 1963.
AKA: 1K;1K, 1KP;1KP;3KA;Korabl-Sputnik. Status: Operational 1960. First Launch: 1960-05-15. Last Launch: 2014-07-18. Number: 14 . Thrust: 15.83 kN (3,558 lbf). Gross mass: 4,730 kg (10,420 lb). Unfuelled mass: 4,455 kg (9,821 lb). Specific impulse: 266 s. Height: 4.40 m (14.40 ft).
Overview
The Vostok crew accommodation was for one cosmonaut, in a spacesuit, equipped with an ejection seat for launch aborts and for landing on the earth. The spacecraft had two windows: one above the cosmonaut's head in the entry hatch, one at his feet, equipped with the Vzor optical device for orientation of the spacecraft. Attitude control was by cold gas thrusters for on-orbit orientation; passive control for the capsule during re-entry. A single parachute allowed recovery of the capsule. There was no soft-landing system; the pilot ejected for a separate landing under his own parachute.
The Vostok and Voskhod spacecraft, like the U.S. Mercury, could not perform orbital maneuvers - they could only be translated around their axes. The main engine was used only at the end of the mission for the re-entry braking maneuver. However Korolev, before being authorized to proceed with development of the Soyuz, did study the Vostok Zh. This would have been a maneuverable Vostok that would have made repetitive dockings with propulsion modules - a method of achieving a circumlunar mission using only the Soyuz booster. Later on maneuverable versions of the Vostok were developed as Zenit reconnaissance satellites.
The Vostok could not be used for circumlunar missions or earth missions with non-astronaut qualified crew due to the 'Sharik' reentry vehicle design. The spherical design itself was ingenious - it had no maneuvering engines to orient it, since it was like a ball with the heavy weight concentrated at one end. If you throw such a weighted ball in the air (or re-enter the atmosphere with it) it will automatically swing around with the heavy end downward. The only problem was that it was only capable of a purely ballistic re-entry, which means 8 G's for the occupant from earth orbit and 20 G's from the moon. Mercury was ballistic, but Gemini, Apollo, and Soyuz all had the center of gravity offset, so they could produce lift, lower the G forces, and maneuver somewhat to vary the landing point. This reduced G's to 3 G for earth orbit returns and 8 G's for lunar returns.
Instrumentation on the Vostoks was rudimentary in the extreme. There were no gyros and no eight-ball for maneuvering as on Mercury or Gemini. The automatic system could only align the spacecraft's axis with the sun. This meant it could only be used for reentry twice a day, when the solar orientation matched the point on the orbit in space and time that would allow a landing in the recovery zone on Soviet territory. Emergency reentry at any other time would depend on the cosmonaut first using the Vzor device for orientation. To decide when to re-enter, the cosmonaut had a little clockwork globe that showed current position over the earth. By pushing a button to the right of the globe, it would be advanced to the landing position assuming a standard re-entry at that moment. This was sufficient for an emergency landing somewhere on a continental land mass.
Development
In the spring of 1957 Tikhonravov began study of a manned orbital spacecraft. The April 1958 preliminary design indicated a mass of 5.0 to 5.5 metric tons, 8 to 9 G re-entry, spherical capsule, 2500 to 3500 deg C re-entry temperatures. The heat shield would weigh 1300 to 1500 kg, and the landing accuracy would be 100 to 170 km. Operating altitude was 250 km. The astronaut would eject from the spacecraft at an altitude of 8 to 10 km.
In the spring of 1957 Korolev organized project section 9, with Tikhonravov at its chief, to design new spacecraft. Simultaneous with this they were building the first earth satellites - the PS-1, PS-2 and Object D (which would be Sputniks 1, 2, and 3). By April they had completed a research plan to build a piloted spacecraft and an unmanned lunar probe, using the R-7 as the basis for the launch vehicle. Studies indicated that the R-7 with a third stage could lift 5 metric tons into low earth orbit.
The manned spacecraft work led them into new fields of research in re-entry, thermal protection, and hypersonic aerodynamics. The initial study material was reviewed by mathematicians at the Academy of Science. It was found that a maximum of 10 G's would result in a ballistic re-entry from earth obit. From September 1957 to January 1958 Tikhonravov's section examined heating conditions, surface temperatures, heat shield materials, and obtainable maximum payloads for a wide range of aerodynamic forms with hypersonic lift to drag ratios ranging from zero to a few points. Parametric trajectory calculations were made using successive approximations on the BESM-1 electromechanical computer.
It was found that the equilibrium temperatures for winged spacecraft with the highest L/D ratios exceeded the capability of available heat resistant alloy construction methods. These designs also had the lowest net payloads. The final conclusion was:
L/D ratio should be greater than zero, between 0.0 to 0.5 G's, in order to provide body lift and reduce the G forces a pure ballistic re-entry would inflict on the human passenger
The spacecraft form should be a cone with a rounded nose and spherical base, with a maximum diameter of 2.0 m - the 'headlight' shape later used for the Soyuz capsule.
The pilot would eject at a few kilometers altitude after re-entry and land by parachute. The capsule would not be recovered.
The necessity to refine and qualify the lifting design seemed a major impediment to meeting a quick program schedule. Then in April 1958 aviation medicine research using human subjects in a centrifuge showed that pilots could endure up to 10 G's without ill effects. This allowed a pure ballistic design, removing a major stumbling block, and allowing the study to move quickly to the advanced project stage. Detailed design of the spacecraft layout, structures, equipment, and materials were all done in parallel. This required everything to be redesigned 2 to 3 times, but resulted in a quick final design. The advance project was completed by the middle of August 1958. Konstantin Feoktistov was one of the leading enthusiasts in this effort.
After selection of the ballistic concept, the shape of the re-entry vehicle had to be symmetrical. A sphere was the simplest such form, having the same aerodynamic characteristics at all angles of attack and all velocities. By putting the center of mass aft of the center of the sphere, the re-entry vehicle would naturally assume the correct orientation for re-entry.
Redundancy of all systems became a new strategic design principle for this first manned spacecraft. The final report 'Material on the research question of a manned Sputnik' (OD-2) gave the following flight characteristics:
Mass 4,500 - 5,500 kg, launched by a three stage version of the R-7 into a circular orbit with a minimum altitude of 250 km
Payload of a single human, life support supplies, and scientific equipment
Spherical ballistic re-entry capsule, with a 2500 to 3500 deg C surface temperature on re-entry, 8 to 9 G's maximum load, with a resulting heat shield mass of 1300 to 1500 kg
65,000 to 85,000 kgf-sec re-entry burn
Minus 2 degree re-entry angle at 100 km altitude
Landing accuracy plus 175 km / minus 100 km from aim point
Pilot to eject from capsule at 8 to 10 km altitude
Insulation to keep acoustic and vibration levels within cabin to tolerable levels
Assumption that pilot would not control spacecraft in first flight
Orientation control system using cold gas jets and flywheels
Limited avionics: orientation control system, guidance command processor, redundant voice radio
Orbital flight equipment and deorbit braking rocket contained in a separate module from re-entry vehicle
Development program:
Test stands in the factory
Ejection seat test from aircraft and R-2, R-5, or R-7 core launch vehicles
Sub-scale heat shield tests
Instrumented full size prototype flights
Two flights with mannequins
Redundancy features for manned flight included:
Functional redundancy in capsule systems
Life support system and separate space suit system. The suit could operate four hours independently in case of cabin depressurization or failure of the main life support system.
Orientation by infrared vertical sensors and manual orientation by the pilot
Parachute ejection by both inertial and barometric sensors
Re-entry by command timer, heat sensors, or radio command
Unfortunately the TDU deorbit braking engine could not be made redundant within the available mass budget.
In June 1958 the principal findings were already in and Korolev took personal management of the project. A section devoted to the spacecraft was formed on 15 August 1958. A last look at the headlight-shaped lifting capsule was made. It had the potential of cutting the mass of the heat shield in half, but there was simply no time to do the research on the flight characteristics of such a design. The final project was signed by Korolev on 15 September 1958. This allowed for full production drawing release to the fabrication shops and the beginning of tests of the spacecraft systems.
Due to a bitter fight with the military over the nature and priority of the manned spacecraft and photo-reconnaissance space programs, the final decree for the Vostok was not issued until 22 May 1959. This authorized production of a single design that could be used either as a manned spacecraft or as a military reconnaissance satellite.
Altogether 123 organizations and 36 factories participated in the project. The leading members of the industrial team that built the Vostok included:
OKB-1 - Korolev - prime contractor; spacecraft integrator; responsible as well for the orientation system, the guidance system of the braking engine section, the thermoregulation system, emergency systems, ground support and development test equipment.
OKB-2 - Isayev - TDU retrofire rocket engine system
NII-88 - G A Tyulin - Mir-2 automated system
TsKB-598 - N A Vinogradov - Vzor optical orientation system and Grif photoelectric sensors of the solar orientation system
Factory 918 - S M Alekseyev - space suit with its associated air circulator and oxygen supply, helmet, emergency provisions, ejection system, mannequin for unmanned flight tests.
LII - N S Stroev - Guidance unit
OKB-124 - G I Voronin - Oxygen regeneration system
NII-137 - V A Kostrov - Emergency destruct system (used only in the unpiloted spacecraft)
NII-695 - A I Gusev - Zarya radio telemetry system
NII-668 - A S Mnatsakanian - Command radio system
VNIIIT - N S Lidovenko - Electric storage batteries
OKB MEI - A F Bogomolov - Tral-P1 radio telemetry system
NII-380 - I A Rosselevich - Rubin radio control system and Topaz television system
GNIIA and SKTB Biofizpribor - A V Pokrovksiy - Life signs monitoring, medical dosimetry systems
NIEI PDS - F D Tkachev - parachute system of the SA re-entry capsule
KGB - K V Bulyakov and Red Mechanical Device Factory - N M Yegorov - movie camera
On 10 December 1959 a decree setting forth the work on the first manned spacecraft was issued. In April 1960 the draft project was completed. This defined the various versions of the spacecraft to be produced:
Vostok-1 (1K) prototype spacecraft to test basic systems and prove the concept
Vostok-2 (2K) photo-reconnaissance spacecraft, designed for lower resolution route surveys and signals intelligence. This was later redesignated the Zenit-2.
Vostok-3 (3K) manned spacecraft
By 4 June 1960 the first decree with a manned flight date was issued. This called for:
May 1960 - completion of two 1KP prototype spacecraft (no heat shield or life support systems)
August 1960 - Three 1K systems completed for test of photo-reconnaissance and radio reconnaissance systems
September - December 1960 - Three 3K systems for manned flights.
11 October 1960 to December 1960 - Manned flights.
1960 was a year of intense testing. In test rigs the hatch seal was tested 50 times, spacecraft separation from the last rocket stage 15 times, SA/PO separation 5 times, and separation of the retaining straps form the SA 16 times. The SA capsule was dropped from an An-12 aircraft at 9 to 12 km to test the parachute and ejection seat systems. The life support system was tested at altitude in a Tu-104 aircraft and in thermal chambers. The ejection seat was tested from 4 km to the altitude of cut-off of the first stage of the Vostok rocket, simulating cosmonaut escape during launch vehicle aborts. Seven spacecraft were built for flight tests. Korolev personally hand-picked the equipment to be used on these spacecraft.
From the end of 1960 to the beginning of 1961 the 3K unpiloted version of the spacecraft was built and tested. To guarantee their reliability Korolev prohibited introduction of changes not only in the technical documentation but also in the technician staff that prepared them for flight. The military developed the recovery forces and techniques, including appropriate aircraft, helicopters, and handling equipment. At that time it was felt that there was a 60% chance on each launch of an abort requiring rescue operations for the cosmonaut.
From the end of 1960 six unmanned Vostok variants were launched, followed by six crewed missions. The official draft project for the 3KA manned spacecraft was not completed until the end of July 1961, long after the first flight of the actual spacecraft.
Technical Description
Both the 1K and 3K versions would have a 2.4 metric ton SA re-entry capsule, and 2.3 metric ton PO service module, and a 1600 kgf TDU braking engine.
The detailed mass breakdown of the 3KA manned flight version was as follows:
Structure - 20%
Heat shield - 17.7%
Systems - 21.5%
Cables - 8.6%
Electrical system - 12.5%
TDU braking engine - 8.4%
Landing systems - 3.2%
Ejection seat and cosmonaut - 7.1%
Gases for orientation system and environmental control system - 1.0%
The most crucial on-board system was the guidance system. A May 1959 report covering ballistic computations of variances in landing from orbit showed that the biggest danger was incorrect orientation for retrofire. B E Chertok was in charge of the orientation system. It consisted of two redundant systems: an automatic/solar orientation system and a manual/visual orientation system. Either system could operate two redundant cold nitrogen gas thruster systems, each with 10 kg of gas.
The automatic solar orientation system consisted of solar sensors, DUS-L2 angle of flight sensors, and an SRB analogue computer unit. The TDU would only fire if the sun sensors - consisting of a slit arranged over three photocells - indicated correct orientation. The DUS-L2 angle of flight sensor utilized two-step double gyroscopes with mechanically opposed directions. The SRB used these inputs and generated impulses to carry out the burn at the time along the orbit set by ground control.
The cosmonaut (or on unmanned flights, ground control via television) could take manual control of the spacecraft and manually re-enter. This was done by using the ingenious Vzor periscope device mounted on the floor of the cabin. This had a central view and eight ports arranged in a circle around the center. When the spacecraft was perfectly centered in respect to the horizon, all eight of the ports would be lit up. Alignment along the orbit was judged by getting lines on the main scope to be aligned with the landscape flowing by below. In this way, the spacecraft could be oriented correctly for the re-entry maneuver. This Vzor system would obviously only be used during daylight portions of the orbit. At night the dark mass of the earth could not have been lined up with the optical Vzor device. The reentry burn after orientation would be commanded by ground control. If the cosmonaut was out of contact, he could manually initiate the burn using a time calculation radioed earlier to him br ground control, or using the Globus device to ensure he would land somewhere on a continent.
Ten minutes after the retrofire burn the service module separated from the capsule. This was accomplished by squibs separating four metal bands holding the capsule to the service module. On some missions these did not separate all the bands, leaving the two components to whirl about one another until the heat of reentry melted the recalcitrant band and allowed the capsule to continue reentry in its designed manner.
Crew Size: 1. Orbital Storage: 30 days. Spacecraft delta v: 155 m/s (508 ft/sec).

Description
World's first manned spacecraft, it was developed into the later Voskhod, and numerous versions of recoverable unmanned satellites for reconnaissance (Zenit), materials, and biological research (Bion). These remained in service into the 21st Century. Launched 1961 - 1963.
AKA: 1K;1K, 1KP;1KP;3KA;Korabl-Sputnik. Status: Operational 1960. First Launch: 1960-05-15. Last Launch: 2014-07-18. Number: 14 . Thrust: 15.83 kN (3,558 lbf). Gross mass: 4,730 kg (10,420 lb). Unfuelled mass: 4,455 kg (9,821 lb). Specific impulse: 266 s. Height: 4.40 m (14.40 ft).
Overview
The Vostok crew accommodation was for one cosmonaut, in a spacesuit, equipped with an ejection seat for launch aborts and for landing on the earth. The spacecraft had two windows: one above the cosmonaut's head in the entry hatch, one at his feet, equipped with the Vzor optical device for orientation of the spacecraft. Attitude control was by cold gas thrusters for on-orbit orientation; passive control for the capsule during re-entry. A single parachute allowed recovery of the capsule. There was no soft-landing system; the pilot ejected for a separate landing under his own parachute.
The Vostok and Voskhod spacecraft, like the U.S. Mercury, could not perform orbital maneuvers - they could only be translated around their axes. The main engine was used only at the end of the mission for the re-entry braking maneuver. However Korolev, before being authorized to proceed with development of the Soyuz, did study the Vostok Zh. This would have been a maneuverable Vostok that would have made repetitive dockings with propulsion modules - a method of achieving a circumlunar mission using only the Soyuz booster. Later on maneuverable versions of the Vostok were developed as Zenit reconnaissance satellites.
The Vostok could not be used for circumlunar missions or earth missions with non-astronaut qualified crew due to the 'Sharik' reentry vehicle design. The spherical design itself was ingenious - it had no maneuvering engines to orient it, since it was like a ball with the heavy weight concentrated at one end. If you throw such a weighted ball in the air (or re-enter the atmosphere with it) it will automatically swing around with the heavy end downward. The only problem was that it was only capable of a purely ballistic re-entry, which means 8 G's for the occupant from earth orbit and 20 G's from the moon. Mercury was ballistic, but Gemini, Apollo, and Soyuz all had the center of gravity offset, so they could produce lift, lower the G forces, and maneuver somewhat to vary the landing point. This reduced G's to 3 G for earth orbit returns and 8 G's for lunar returns.
Instrumentation on the Vostoks was rudimentary in the extreme. There were no gyros and no eight-ball for maneuvering as on Mercury or Gemini. The automatic system could only align the spacecraft's axis with the sun. This meant it could only be used for reentry twice a day, when the solar orientation matched the point on the orbit in space and time that would allow a landing in the recovery zone on Soviet territory. Emergency reentry at any other time would depend on the cosmonaut first using the Vzor device for orientation. To decide when to re-enter, the cosmonaut had a little clockwork globe that showed current position over the earth. By pushing a button to the right of the globe, it would be advanced to the landing position assuming a standard re-entry at that moment. This was sufficient for an emergency landing somewhere on a continental land mass.
Development
In the spring of 1957 Tikhonravov began study of a manned orbital spacecraft. The April 1958 preliminary design indicated a mass of 5.0 to 5.5 metric tons, 8 to 9 G re-entry, spherical capsule, 2500 to 3500 deg C re-entry temperatures. The heat shield would weigh 1300 to 1500 kg, and the landing accuracy would be 100 to 170 km. Operating altitude was 250 km. The astronaut would eject from the spacecraft at an altitude of 8 to 10 km.
In the spring of 1957 Korolev organized project section 9, with Tikhonravov at its chief, to design new spacecraft. Simultaneous with this they were building the first earth satellites - the PS-1, PS-2 and Object D (which would be Sputniks 1, 2, and 3). By April they had completed a research plan to build a piloted spacecraft and an unmanned lunar probe, using the R-7 as the basis for the launch vehicle. Studies indicated that the R-7 with a third stage could lift 5 metric tons into low earth orbit.
The manned spacecraft work led them into new fields of research in re-entry, thermal protection, and hypersonic aerodynamics. The initial study material was reviewed by mathematicians at the Academy of Science. It was found that a maximum of 10 G's would result in a ballistic re-entry from earth obit. From September 1957 to January 1958 Tikhonravov's section examined heating conditions, surface temperatures, heat shield materials, and obtainable maximum payloads for a wide range of aerodynamic forms with hypersonic lift to drag ratios ranging from zero to a few points. Parametric trajectory calculations were made using successive approximations on the BESM-1 electromechanical computer.
It was found that the equilibrium temperatures for winged spacecraft with the highest L/D ratios exceeded the capability of available heat resistant alloy construction methods. These designs also had the lowest net payloads. The final conclusion was:
L/D ratio should be greater than zero, between 0.0 to 0.5 G's, in order to provide body lift and reduce the G forces a pure ballistic re-entry would inflict on the human passenger
The spacecraft form should be a cone with a rounded nose and spherical base, with a maximum diameter of 2.0 m - the 'headlight' shape later used for the Soyuz capsule.
The pilot would eject at a few kilometers altitude after re-entry and land by parachute. The capsule would not be recovered.
The necessity to refine and qualify the lifting design seemed a major impediment to meeting a quick program schedule. Then in April 1958 aviation medicine research using human subjects in a centrifuge showed that pilots could endure up to 10 G's without ill effects. This allowed a pure ballistic design, removing a major stumbling block, and allowing the study to move quickly to the advanced project stage. Detailed design of the spacecraft layout, structures, equipment, and materials were all done in parallel. This required everything to be redesigned 2 to 3 times, but resulted in a quick final design. The advance project was completed by the middle of August 1958. Konstantin Feoktistov was one of the leading enthusiasts in this effort.
After selection of the ballistic concept, the shape of the re-entry vehicle had to be symmetrical. A sphere was the simplest such form, having the same aerodynamic characteristics at all angles of attack and all velocities. By putting the center of mass aft of the center of the sphere, the re-entry vehicle would naturally assume the correct orientation for re-entry.
Redundancy of all systems became a new strategic design principle for this first manned spacecraft. The final report 'Material on the research question of a manned Sputnik' (OD-2) gave the following flight characteristics:
Mass 4,500 - 5,500 kg, launched by a three stage version of the R-7 into a circular orbit with a minimum altitude of 250 km
Payload of a single human, life support supplies, and scientific equipment
Spherical ballistic re-entry capsule, with a 2500 to 3500 deg C surface temperature on re-entry, 8 to 9 G's maximum load, with a resulting heat shield mass of 1300 to 1500 kg
65,000 to 85,000 kgf-sec re-entry burn
Minus 2 degree re-entry angle at 100 km altitude
Landing accuracy plus 175 km / minus 100 km from aim point
Pilot to eject from capsule at 8 to 10 km altitude
Insulation to keep acoustic and vibration levels within cabin to tolerable levels
Assumption that pilot would not control spacecraft in first flight
Orientation control system using cold gas jets and flywheels
Limited avionics: orientation control system, guidance command processor, redundant voice radio
Orbital flight equipment and deorbit braking rocket contained in a separate module from re-entry vehicle
Development program:
Test stands in the factory
Ejection seat test from aircraft and R-2, R-5, or R-7 core launch vehicles
Sub-scale heat shield tests
Instrumented full size prototype flights
Two flights with mannequins
Redundancy features for manned flight included:
Functional redundancy in capsule systems
Life support system and separate space suit system. The suit could operate four hours independently in case of cabin depressurization or failure of the main life support system.
Orientation by infrared vertical sensors and manual orientation by the pilot
Parachute ejection by both inertial and barometric sensors
Re-entry by command timer, heat sensors, or radio command
Unfortunately the TDU deorbit braking engine could not be made redundant within the available mass budget.
In June 1958 the principal findings were already in and Korolev took personal management of the project. A section devoted to the spacecraft was formed on 15 August 1958. A last look at the headlight-shaped lifting capsule was made. It had the potential of cutting the mass of the heat shield in half, but there was simply no time to do the research on the flight characteristics of such a design. The final project was signed by Korolev on 15 September 1958. This allowed for full production drawing release to the fabrication shops and the beginning of tests of the spacecraft systems.
Due to a bitter fight with the military over the nature and priority of the manned spacecraft and photo-reconnaissance space programs, the final decree for the Vostok was not issued until 22 May 1959. This authorized production of a single design that could be used either as a manned spacecraft or as a military reconnaissance satellite.
Altogether 123 organizations and 36 factories participated in the project. The leading members of the industrial team that built the Vostok included:
OKB-1 - Korolev - prime contractor; spacecraft integrator; responsible as well for the orientation system, the guidance system of the braking engine section, the thermoregulation system, emergency systems, ground support and development test equipment.
OKB-2 - Isayev - TDU retrofire rocket engine system
NII-88 - G A Tyulin - Mir-2 automated system
TsKB-598 - N A Vinogradov - Vzor optical orientation system and Grif photoelectric sensors of the solar orientation system
Factory 918 - S M Alekseyev - space suit with its associated air circulator and oxygen supply, helmet, emergency provisions, ejection system, mannequin for unmanned flight tests.
LII - N S Stroev - Guidance unit
OKB-124 - G I Voronin - Oxygen regeneration system
NII-137 - V A Kostrov - Emergency destruct system (used only in the unpiloted spacecraft)
NII-695 - A I Gusev - Zarya radio telemetry system
NII-668 - A S Mnatsakanian - Command radio system
VNIIIT - N S Lidovenko - Electric storage batteries
OKB MEI - A F Bogomolov - Tral-P1 radio telemetry system
NII-380 - I A Rosselevich - Rubin radio control system and Topaz television system
GNIIA and SKTB Biofizpribor - A V Pokrovksiy - Life signs monitoring, medical dosimetry systems
NIEI PDS - F D Tkachev - parachute system of the SA re-entry capsule
KGB - K V Bulyakov and Red Mechanical Device Factory - N M Yegorov - movie camera
On 10 December 1959 a decree setting forth the work on the first manned spacecraft was issued. In April 1960 the draft project was completed. This defined the various versions of the spacecraft to be produced:
Vostok-1 (1K) prototype spacecraft to test basic systems and prove the concept
Vostok-2 (2K) photo-reconnaissance spacecraft, designed for lower resolution route surveys and signals intelligence. This was later redesignated the Zenit-2.
Vostok-3 (3K) manned spacecraft
By 4 June 1960 the first decree with a manned flight date was issued. This called for:
May 1960 - completion of two 1KP prototype spacecraft (no heat shield or life support systems)
August 1960 - Three 1K systems completed for test of photo-reconnaissance and radio reconnaissance systems
September - December 1960 - Three 3K systems for manned flights.
11 October 1960 to December 1960 - Manned flights.
1960 was a year of intense testing. In test rigs the hatch seal was tested 50 times, spacecraft separation from the last rocket stage 15 times, SA/PO separation 5 times, and separation of the retaining straps form the SA 16 times. The SA capsule was dropped from an An-12 aircraft at 9 to 12 km to test the parachute and ejection seat systems. The life support system was tested at altitude in a Tu-104 aircraft and in thermal chambers. The ejection seat was tested from 4 km to the altitude of cut-off of the first stage of the Vostok rocket, simulating cosmonaut escape during launch vehicle aborts. Seven spacecraft were built for flight tests. Korolev personally hand-picked the equipment to be used on these spacecraft.
From the end of 1960 to the beginning of 1961 the 3K unpiloted version of the spacecraft was built and tested. To guarantee their reliability Korolev prohibited introduction of changes not only in the technical documentation but also in the technician staff that prepared them for flight. The military developed the recovery forces and techniques, including appropriate aircraft, helicopters, and handling equipment. At that time it was felt that there was a 60% chance on each launch of an abort requiring rescue operations for the cosmonaut.
From the end of 1960 six unmanned Vostok variants were launched, followed by six crewed missions. The official draft project for the 3KA manned spacecraft was not completed until the end of July 1961, long after the first flight of the actual spacecraft.
Technical Description
Both the 1K and 3K versions would have a 2.4 metric ton SA re-entry capsule, and 2.3 metric ton PO service module, and a 1600 kgf TDU braking engine.
The detailed mass breakdown of the 3KA manned flight version was as follows:
Structure - 20%
Heat shield - 17.7%
Systems - 21.5%
Cables - 8.6%
Electrical system - 12.5%
TDU braking engine - 8.4%
Landing systems - 3.2%
Ejection seat and cosmonaut - 7.1%
Gases for orientation system and environmental control system - 1.0%
The most crucial on-board system was the guidance system. A May 1959 report covering ballistic computations of variances in landing from orbit showed that the biggest danger was incorrect orientation for retrofire. B E Chertok was in charge of the orientation system. It consisted of two redundant systems: an automatic/solar orientation system and a manual/visual orientation system. Either system could operate two redundant cold nitrogen gas thruster systems, each with 10 kg of gas.
The automatic solar orientation system consisted of solar sensors, DUS-L2 angle of flight sensors, and an SRB analogue computer unit. The TDU would only fire if the sun sensors - consisting of a slit arranged over three photocells - indicated correct orientation. The DUS-L2 angle of flight sensor utilized two-step double gyroscopes with mechanically opposed directions. The SRB used these inputs and generated impulses to carry out the burn at the time along the orbit set by ground control.
The cosmonaut (or on unmanned flights, ground control via television) could take manual control of the spacecraft and manually re-enter. This was done by using the ingenious Vzor periscope device mounted on the floor of the cabin. This had a central view and eight ports arranged in a circle around the center. When the spacecraft was perfectly centered in respect to the horizon, all eight of the ports would be lit up. Alignment along the orbit was judged by getting lines on the main scope to be aligned with the landscape flowing by below. In this way, the spacecraft could be oriented correctly for the re-entry maneuver. This Vzor system would obviously only be used during daylight portions of the orbit. At night the dark mass of the earth could not have been lined up with the optical Vzor device. The reentry burn after orientation would be commanded by ground control. If the cosmonaut was out of contact, he could manually initiate the burn using a time calculation radioed earlier to him br ground control, or using the Globus device to ensure he would land somewhere on a continent.
Ten minutes after the retrofire burn the service module separated from the capsule. This was accomplished by squibs separating four metal bands holding the capsule to the service module. On some missions these did not separate all the bands, leaving the two components to whirl about one another until the heat of reentry melted the recalcitrant band and allowed the capsule to continue reentry in its designed manner.
Crew Size: 1. Orbital Storage: 30 days. Spacecraft delta v: 155 m/s (508 ft/sec).