Sun delays Vostok-5 launch

On June 4, at 10 a.m., the State Commission started a meeting that formally approved Bykovsky and Tereshkova to fly Vostok-5 and Vostok-6 respectively. Volynov, Ponomareva and Solovyova were confirmed as backups. (466)

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Photo-mosaic of the State Commission meeting on June 4, 1963: Primary and backup candidates for the Vostok-5 and Vostok-6 missions are sitting in the front row flanked by the head of the NIIP-5 test range in Tyuratam Aleksandr Zakharov on the left and General Nikolai Kamanin on the right. Georgy Tyulin (right) chairs the meeting. Key officials from the cosmonaut training center Mikhail Odintsov and Evgeny Karpov are in the second row.

Launch delays

According to some reports, Tereshkova had two backups "due to the peculiarity of the female organism." It is tempting to speculate that not having a period by the time of the launch was a factor in the very late decision to name the pilot of Vostok-6. At the same time, a rumored synchronization of menstrual cycles among all female pilots, as a result of a very similar lifestyle, would leave officials without much choice beyond postponing the launch.

In any case, by June 4, the weather forecast showed the possibility of wind gusts reaching 15-20 meters per second near the ground, crossing the 15-meter-per-second safety limit for both the rollout and the liftoff scheduled for June 7.

At 6 p.m. in the evening, the State Commission gathered again for a ceremonial meeting complete with prepared speeches by Bykovsky and Tereshkova before a few cameras of the Soviet "media" sanctioned to access the launch site. It was announced that a male pilot would fly for eight days and a female for three.

On June 5, as the rollout of the rocket to the launch pad and the launch itself had to be put off for 24 hours by strong winds, the cosmonauts listened to last instructions from engineers and Air Force superiors. Kamanin insisted cosmonauts used coded messages in open communications with ground control, when it came to the status of their health or their spacecraft. "All cosmonauts... unanimously supported this idea," Kamanin wrote, "everything is great" -- meant the mission can continue, "everything is good" -- meant some doubts or problems and "everything is satisfactory" -- meant a call to abort the mission. Kamanin did not elaborate, how cosmonauts would describe their problems to ground control beyond these generalities.

It was cloudy and very windy in Baikonur with temperatures staying 25 degrees C during the day and falling to 15 degrees at night.

On June 6, at 7:00, the rollout of the rocket was prepared again, however this time it was delayed due to a failure of the command radio channel, KRL. The problem required three or four days to be fixed.

On the evening of June 8, the State Commission reviewed the issue with KRL. Another "problem" that was suddenly brought up before the commission was whether to publicly announce Tereshkova as an Air Force officer. Opinions split and after the meeting Kamanin "escalated" the issue to the Central Committee in Moscow.

Finally, the commission agreed to launch the second Vostok two days after the first. However officials still considered the option of flying Vostok-5 for five days, then launching Vostok-6 and landing them simultaneously three days later.

In the meantime, Tereshkova had a chance to sit inside her flight-ready capsule.

June 9: Finally on the pad

The rocket with Vostok-5 was finally rolled out to the launch pad on the morning of June 9, with liftoff planned on June 11. From 11 a.m. to 1 p.m., Korolev supervised integrated tests of the vehicle on the launch pad.

At noon on June 10, Bykovsky made the traditional trip to the launch pad to meet the personnel preparing his rocket. After the meeting, Korolev took an elevator to the entrance to Vostok along with Marshall Krylov. He then took a second ride to the top of the rocket, this time with Bykovsky, and let the cosmonaut sit in the capsule. (574)

By the end of June 10, everything was "go" for launch, however late that evening, Keldysh called from Moscow and asked the launch to be postponed due to the danger of an increased solar radiation. Korolev immediately summoned Bushuev and Chertok to his cottage at Site 2 and ordered them to fly to Moscow in the morning and discuss the situation with Keldysh.

As it turned out, Keldysh was stuck in Moscow when he had received a warning from Andrei Severny, the director of the Crimean Observatory, forecasting a sharp increase in solar activity. Powerful solar flares had the potential to disrupt communications and bring dangerous radiation to the Earth's vicinity, scientists claimed. (466)

According to Kamanin, Severny had called Keldysh around 13:00 on June 10, and said that the Sun had shown the first signs of increased activity as early as June 8. Kamanin himself learned about the latest delay, from the Chairman of the State Commission at 22:30 local time. (574)

June 11: Burned by the Sun

In the middle of the day on June 11, Chertok and Bushuev arrived at the offices of the President of the Academy of Sciences on Leninsky Prospect to join the commission investigating the situation. They soon found out from Sergei Vernov that scientists had rather vague ideas about the exact situation, but according to observations from Severny, the level of radiation in space could increase by hundreds of times.

Korolev, obviously irritated by this unexpected obstacle, called his associates from Tyuratam and told them that the launch had been re-scheduled for June 12 and that he held Bushuev and Chertok personally responsible for "order on the Sun." He directed both engineers to stay at the Academy all day and night and get a "go" for launch from Keldysh by any means. Not expecting any new data on the Sun's activity until June 12, even less at night, both engineers went to sleep at home.

During June 11, in addition to numerous inquires from various officials and from the launch site, Keldysh also got a call on the Kremlin phone line. Frol Kozlov, (undoubtedly prompted either by Khrushchev or Korolev) was now also interested in the situation. An emotional Keldysh responded that he had no people capable of bringing the Sun to order. (466)

Ironically, back in Tyuratam, bad weather finally cleared and top space officials and cosmonauts enjoyed swimming and sunbathing on the shores of the Syr-Darya River.


Valentina Tereshkova and Andriyan Nikolaev, pilot of Vostok-3, enjoy boating on the Syr-Darya River near Tyuratam, during the unexpected break in the Vostok-5 and Vostok-6 launch campaign in June 1963.

At 17:00, the State Commission reviewed the situation. It was reported that as of 4 p.m., the Sun displayed no flares, the radiation levels in the near-Earth space seemed to be normal, however the probability of future bursts remained high and capable of subjecting cosmonauts to up to 50 roentgen of radiation. The State Commission had no choice but to postpone the launch even further. Convinced that they were stuck on the ground until at least June 14 or 15 (the last deadline for Vostok launch), Kamanin ordered the cosmonauts to leave Site 2 and move to the residential area of the center. However Korolev defiantly announced that the rocket would stay on the pad for as long as two weeks, if necessary. (574)

June 12: Finally cleared to go

"Problems" with the Sun continued during June 12. During most of the day Korolev and Tyulin were on the phone with Keldysh trying to convince him to give the green light to launch on June 13. (574) By the end of the day, most officials finally concluded that even under the worst circumstances, Vostok's metal skin and thermal layers would provide enough of a safety margin for the pilots. Deputy Healthcare Minister Avetik Burnazyan finally convinced Keldysh to give the "go" to the mission. At 10 p.m. Moscow Time (midnight at the launch site) Keldysh woke up Korolev and Tyulin and informed them that the commission was writing a permission to launch on June 14.

In response, Korolev demanded Bushuev and Chertok to sign the document, send it by telegram to the launch site and to report there themselves with the original. Korolev also asked Chertok to bring Keldysh along as a "solar hostage." However due to delays at the Moscow airport, the group would not arrive until after Bykovsky's launch. (466)

On the morning of June 13, launch preparations were finally back on track. At 7 p.m. Bykovsky and Volynov went through final medical checks. As their predecessors, they came to small cottages at Site 2 to spend their last night there before launch.

Page author: Anatoly Zak; Last update: May 17, 2020

Page editor: Alain Chabot; Last edit: June 30, 2013

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Korolev, Tereshkova and Gagarin in a cottage at Site 2 in Tyuratam during the Vostok-6 launch campaign.

A meeting of the State Commission on June 4, 1963, officially confirming Valery Bykovsky and Valentina Tereshkova as pilots of Vostok-5 and Vostok-6 spacecraft. Credit: RGANTD


On June 10, 1963, the head of Crimean Observatory Andrei Severny delivered a forecast for high solar radiation that could jeopardize Vostok missions.


Click to enlarge. Credit: Roskosmos


Cosmonauts and space officials boating on the Syr-Darya River near Tyuratam, during an unexpected break before launches of Vostok-5 and Vostok-6 spacecraft in June 1963. Click to enlarge. Credit: Roskosmos


Bykovsky and Gagarin in cottage at Site 2 on the eve of Vostok-5 launch on June 14, 1963.



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