Vostok 3 and 4

Vostok 3 / Vostok 4

Vostok 3KA capsule
Mission type	Low Earth orbital
Operator	Soviet space program
Harvard designation	Vostok 3: 1962 Alpha Mu 1 Vostok 4: 1962 Alpha Nu 1
SATCATno.	Vostok 3: 365 Vostok 4: 367
Mission duration	Vostok 3: 3 days, 22 hours, 28 minutes Vostok 4: 2 days, 22 hours, 56 minutes
Orbits completed	Vostok 3: 64 Vostok 4: 48
Spacecraft properties
Spacecraft	Vostok 3:3KANo.5 Vostok 4: 3KA No. 6
Manufacturer	Experimental Design BureauOKB-1
Launch mass	Vostok 3: 4,722 kilograms (10,410 lb) Vostok 4: 4,728 kilograms (10,423 lb)
Crew
Crew size	1
Members	Vostok 3:Andriyan Nikolayev Vostok 4:Pavel Popovich
Callsign	Vostok 3:Сокол(Sokol– "Falcon" ) Vostok 4:Беркут(Berkut- "Golden Eagle" )
Start of mission
Launch date	Vostok 3: August 11, 1962, 08:24(1962-08-11UTC08:24Z)UTC Vostok 4: August 12, 1962, 08:02:33(1962-08-12UTC08:02:33Z)UTC
Rocket	Vostok-K8K72K
Launch site	Baikonur1/5
End of mission
Landing date	Vostok 3: August 15, 1962, 06:52(1962-08-15UTC06:53Z)UTC Vostok 4: August 15, 1962, 06:59(1962-08-15UTC07:00Z)UTC
Landing site	Vostok 3:42°2′N75°45′E Vostok 4:48°9′N71°51′E
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Perigee altitude	Vostok 3: 166 kilometres (103 mi) Vostok 4: 169 kilometres (105 mi)
Apogee altitude	Vostok 3: 218 kilometres (135 mi) Vostok 4: 222 kilometres (138 mi)
Inclination	65.0 degrees
Period	88.5 minutes
Epoch	Vostok 3: 11 August 1962, 04:24:00 UTC Vostok 4: 12 August 1962, 07:55:00 UTC
Andryan G Nikolaiev / Pavel Popovich Vostok program

Model of the Vostok capsule with its carrier rocket's upper stage

Vostok 3(Russian:Восток-3,lit. 'Orient3' or 'East 3') andVostok 4(Восток-4,'Orient4' or 'East 4') wereSoviet space programflights in August 1962, intended to determine theability of the human body to functionin conditions ofweightlessness,test the ground control capability to launch and manage two separate, concurrent flights, and test the endurance of theVostok 3KAspacecraft over longer flights. CosmonautAndriyan Nikolayevorbited the Earth 64 times in Vostok 3 over nearly four days in space, August 11–15, 1962, a feat which would not be matched byNASAuntil theGemini program(1965–1966).Pavel Popovichwas launched on Vostok 4 on August 12, and made 48 Earth orbits. The two capsules were launched on trajectories that brought the spacecraft within approximately 6.5 km (4.0 mi) of each another.

They also communicated with each other via radio, the first ship-to-ship communications in space.These missions marked the first time that more than one crewed spacecraft was in orbit at the same time, givingSovietmission controllers the opportunity to learn to manage this scenario.

Although the two spacecraft were placed in very similar orbits (within 3-4 kilometers altitude), the Vostok did not possess the capability to achieverendezvous.At one point they came within visual range of each other, and Popovich later reported at a news conference that he saw the other craft from orbit. Popovich is quoted as saying, "I saw it at once," referring to seeing Vostok 3 in orbit. "It looked like a very small moon in the distance."

Vostok 4 went largely as planned, despite a malfunction with the Vostok's life-support systems that caused cabin temperature to drop to 10 °C (50 °F). The flight was terminated early after a misunderstanding by ground control, who believed that Popovich had given them a codeword asking to be brought back ahead of schedule.

The two spacecraft landed seven minutes and about 200 km apart, south ofKaraganda,Kazakhstan.

Vostok 3

Position	Crew
Pilot	Andrian G. Nikolayev First spaceflight

Backup

Position	Crew
Pilot	Boris Volynov

Reserve

Position	Crew
Pilot	Valery Bykovsky

Vostok 4

Position	Crew
Pilot	Pavel Popovich First spaceflight

Backup

Position	Crew
Pilot	Vladimir M. Komarov

Reserve

Position	Crew
Pilot	Boris Volynov

Mission parameters

• Mass:4,722 kg (10,410 lb)
• Perigee:166 km (103 mi)
• Apogee:218 km (135 mi)
• Inclination:65.0°
• Period:88.5 minutes

Background

Gherman Titovhad sufferedspace sicknessduring his record-breaking one-day mission aboardVostok 2.This condition was unknown at the time, leading Soviet scientists to devote efforts to study theeffect of spaceflight on the human body.

In 1961, Soviet rocket engineerSergei Korolevpushed for a three-day spaceflight as a follow-up to Vostok 2. Such a mission was opposed by the head of cosmonaut trainingNikolai Kamaninand the cosmonauts themselves, who were concerned about unforeseen health effects that might result from extending space flights too quickly. Plans for a three-day mission only went forward when the approval of Soviet PremierNikita Khrushchevwas obtained; in the end, Vostok 3 would last nearly four days.

One objective of the missions of Vostok 3 and Vostok 4 was the study of how the reactions of Nikolayev andPavel Popovichmight differ during a series of tests under similar circumstances. The close orbits of the two spacecraft would keep the number of variables to a minimum, allowing the measurement of individual differences in adaptation to spaceflight. TheVostok spacecraftwere upgraded to increase the volume of information collected about the flight conditions and the crew.

Training was expanded to condition cosmonauts against space sickness and select those candidate spacefarers deemed least susceptible.Informed by Titov's experience in Vostok 2, Nikolayev and Popovich thoroughly rehearsed their spacecraft maneuvers and other planned activities in a simulator.

The Vostok 3/4 flights were originally scheduled for November 1961, which would have had the propaganda value of the Soviet program having flown four men in space along with a dual mission in the same calendar year when the United States had yet to orbit a single man, but Korolev's plans were frustrated by theZenitphoto reconnaissance satellite program which needed to use the R-7 pads at Baikonur. He then suggested launching at the end of December or the start of January, but Chief of Cosmonaut TrainingNikolai Kamaninand the State Planning Commission opposed launching in the wintertime due to harsh weather conditions and instead suggested waiting until March.

The first Zenit launch took place on 11 December, but the Blok E stage malfunctioned and the satellite was destroyed. Since this was the same model of booster used by the Vostok (8K72K), it was a concern for the program. While engineers attempted to resolve the problem, Vostok 3/4's mission was pushed back a month to April. However, further delays happened when the second Zenit satellite (Kosmos 4) experienced problems with its orientation system, necessitating another test and further delays.

On 1 June, an attempted launch of aZenitphoto reconnaissance satellite ended with the booster crashing near the pad. One of the strap-ons had also fallen back onto LC-1 and burned, resulting in extensive damage that took over a month to repair.By mid-July, the pad had been restored to use, but another delay occurred when the United States carried out ahigh-altitude nuclear teston 9 July known asStarfish Prime.The test had unexpected consequences in that it released high levels of radiation into the upper atmosphere and space, knocking out several satellites and making any crewed space launch unsafe for at least a month. By the second week of August, radiation levels had diminished enough that the Vostok 3/4 mission could go ahead.

The Zenit launch accident had occurred in a new, uprated version of the R-7 launch vehicle (the 8A92) while the Vostok used the older 8K72K booster, so it was not a direct concern for the program. However, just to be cautious, it was decided to fly an additional Zenit satellite to verify the reliability of the R-7. In addition, since the Zenit satellite was essentially a modified Vostok, the flight doubled as an engineering test of certain Vostok components. This was done successfully on July 28, after which preparations at LC-1 began for Vostok 3.

Mission highlights

Vostok 3 lifted off fromGagarin's StartatBaikonur Cosmodromeon August 11, 1962 at 08:24 UTC atop aVostok 8K72Krocket.During his first day in orbit, Nikolayev unstrapped himself from his seat and became the first spacefarer to float freely in conditions ofmicrogravityin space.

Nikolayev's orbital companion Popovich was launched the next day aboardVostok 4.The former adjusted his spacecraft's orientation to watch the launch, but failed to see anything despite reporting considerable details on the ground as he had passed overTurkey.Data on the two spacecraft's orbital parameters that were released periodically by Soviet news agencyTASSseemed to indicate a change in Vostok 3's orbital trajectory within ten hours of Vostok 4's launch, leading to speculation that the former spacecraft modified its orbit to bring it closer to that of the latter.The Vostok spacecraft is not believed to have had the ability to modify its orbit.Plans were for the spacecraft to approach to 5 km (3.1 mi), but the closest distance achieved was 6.5 km (4.0 mi). At the start of Vostok 3's thirty-third orbit, this distance had diverged to 850 km (530 mi), and to 2,850 km (1,770 mi) at the start of the 64th.

Nikolayev and Popovich made contact with one another viashortwave radiosoon after their spacecraft approached one another; they would maintain regular ship-to-ship communications over the course of their mission in addition to their contact with the ground. Nikolayev reported sighting the Vostok 4 capsule after it entered orbit near him.

The mission led Western observers to speculate that the Soviets must already have spacecraft capable of in-orbit maneuvering. Official press releases naturally made no mention that the Vostok spacecraft lacked this ability or that the two Vostoks were able to attain such close approach due to their extremely precise launches.

Both Nikolayev and Popovich spent time out of their seats each day, conducting a series of tests to determine their ability to maneuver and work in conditions of weightlessness. Each test was said to last "about one hour." The physical and mental state of the cosmonauts were monitored: biometric sensors relayed the cosmonauts' vital statistics to the ground; the cosmonauts' behavior and coordination was observed via a cabin-mounted video camera; and the cosmonauts' ability to perform various operations in coordination with ground controllers was considered. The cosmonauts' speech was monitored both by controllers on the ground and one another. The results of the tests were deemed positive, evidence of the ability of humans to function and work over longer periods in microgravity.Nikolayev also spoke with Soviet PremierNikita Khrushchevover the radio, but interference was so bad that he couldn't hear most of the conversation.

Attention was paid to the cosmonauts' ability to sleep, and their vital signs were monitored during their sleep periods. Nikolayev reported that he slept well, but always woke after only six hours of his scheduled eight-hour sleep period, feeling "refreshed".

Nikolayev fired hisretrorocketpack and returned to Earth on August 15, 1962, landing at 06:52 UTC at42°2′N75°45′E,nearKaraganda.As with Titov on Vostok 2—but unlike Gagarin onVostok 1—Nikolayev would admit to reporters that he ejected and parachuted to Earth separately from his spacecraft.

Spacecraft location

The re-entry capsule is now on display at theNPO Zvezda MuseuminMoscow,but it has been modified to represent theVoskhod 2capsule.