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Vostok Moscow 1981
Vostok Moscow 1981 -

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Program: Vostok. Objective: Manned. Type: Spacecraft.

In the spring of 1957 Korolev organised 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 tonnes 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:

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 centre of mass aft of the centre 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:


Vostok closeupVostok closeup - Closeup view of Vostok spacecraft

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Redundancy features for manned flight included:

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 authorised production of a single design that could be used either as a manned spacecraft or as a military reconnaissance satellite.

Altogether 123 organisations and 36 factories participated in the project. The leading members of the industrial team that built the Vostok included:


Vostok spacecraftVostok spacecraft - Vostok spacecraft view 2

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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 spacecraftVostok spacecraft - Vostok spacecraft view 1

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By 4 June 1960 the first decree with a manned flight date was issued. This called for:

Both the 1K and 3K versions would have a 2.4 tonne SA re-entry capsule, and 2.3 tonne PO service module, and a 1600 kgf TDU braking engine.

The detailed mass breakdown of the 3KA manned flight version was as follows:

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. Instrumentation on the Vostoks was rudimentary in the extreme. There were no gyros and no eight-ball for manoeuvring as on Mercury or Gemini. 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.


Interior of Voskhod Interior of Voskhod - Interior of Voskhod 1

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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 utilised two-step double gyroscopes with mechanically opposed directions. The SRB used these inputs and generated impulses to carry out the burn.

The cosmonaut could also 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 manoeuvre. This manual 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 automatic system would work day or night.


Vostok variantVostok variant - Vostok variant with long boom and unidentified second spacecraft - earth orbit or circumlunar docking vehicles?

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10 minutes after TDU cut-off after the retrofire burn the PO separated from the KA.

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.

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.

The Vostok and Voskhod spacecraft, like the U.S. Mercury, could not perform orbital manoeuvres - 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 manoeuvre. However Korolev, before being authorised to proceed with development of the Soyuz, did study the Vostok Zh. This would have been a manoeuvrable Vostok that would have made repetitive dockings with propulsion modules - a method of achieving a circumlunar mission using only the Soyuz booster. Later on manoeuvrable versions of the Vostok were developed as Zenit reconnaissance satellites.


Vostok closeupVostok closeup - Closeup view of Vostok spacecraft

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The Vostok could not be used for circumlunar missions or earth missions with non-astronaut qaulified crew due to the 'Sharik' reentry vehicle design. The spherical design itself was ingenious - it has no manoeuvring engines to orient it, since it is like a ball with the heavy weight concentrated at one end - if you throw it in the air (or re-enter the atmosphere with it ) it will automatically swing around with the heavy end downward. The only problem is that it is 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 manoeuvre somewhat to vary the landing point. This reduced G's to 3 G for earth orbit returns and 8 G's for lunar returns. First manned spacecraft. Derivatives were still in use over thirty years later, for military photo-reconnaissance, earth resources, mapping, and biological missions.

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 tonnes, 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.

Construction drawings were issued beginning in the fall of 1958. The official decree to begin development was issued only on 22 May 1959. From the end of 1960 six unmanned Vostok variants were launched. 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.


Vostok Kaluga MuseumVostok Kaluga Museum

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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 US Mercury, could not perform orbital manoeuvres - they could only be translated around their axes. The main engine was not restartable and was used only at the end of the mission for the re-entry braking manoeuvre. However Korolev, before being authorised to proceed with development of the Soyuz, did study the Vostok Zh. This would have been a manoeuvrable Vostok that would have made repetitive dockings with propulsion modules - a method of achieving a circumlunar mission using only the Soyuz booster. Later on manoeuvrable versions of the Vostok were developed as Zenit reconnaissance satellites.

Instrumentation on the Vostoks was rudimentary in the extreme. There was no gyro platform and no eight-ball for manoeuvring as on Gemini. The re-entry manoeuvre was normally handled automatically by radio command. The spacecraft was oriented horizontally using infrared sensors. Alignment along the orbital axis was made using sun and star sensors.

In the event of failure of the automatic systems, the cosmonaut could take manual control of the spacecraft. 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 centre. When the spacecraft was perfectly centred 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 manoeuvre.


VostokVostok

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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 manual 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 automatic system would work day or night.

The Vostok could not be used for circumlunar missions or earth missions with non-astronaut qualified crew due to the 'Sharik' re-entry vehicle design. The spherical design itself is ingenious - it has no manoeuvring engines to orient it, since it is like a ball with the heavy weight concentrated at one end - if you throw it in the air (or re-enter the atmosphere with it ) it will automatically swing around with the heavy end downward. The only problem is that it is 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 centre of gravity offset, so they could produce lift, lower the G forces, and manoeuvre somewhat to vary the landing point. This reduced G's to 3 G for earth orbit returns and 8 G's for lunar returns. Major Events: .


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Last update 12 March 2001.
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