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Unpiloted ship lifts off in advance of the historic Soyuz-3 rendezvous mission

The Soyuz 7K-OK No. 11 spacecraft, which will be later identified as Soyuz-2, lifted off on October 25, 1968, with no crew onboard. While the official Soviet media remained completely silent for 24 hours, launch personnel in Tyuratam and mission control specialists across the USSR were scrambling to support the launch of another Soyuz, this time with a pilot onboard.

Previous chapter: Flight scenario for the Soyuz-2, -3 mission

Prior to docking, the pilot of the "active" Soyuz spacecraft had to maneuver his vehicle so that navigation lights below the target Soyuz vehicle looked perfectly aligned in the pilot's periscope. Any misalignment of the two spacecraft would shift the lights' position in the viewfinder.

The final pre-launch meeting of the State Commission opened at around 10 in the morning, local time, on October 25 and everything was declared ready for flight. The first ship in the dual flight (Vehicle No. 11) lifted off on October 25, 1968, at 12:00 Moscow Time (14:00 local). (774)

The telemetry showed that all the antennas and solar panels had been successfully deployed and that the rocket had inserted the spacecraft into orbit with a very high degree of accuracy. (466)

During the fourth orbit (before the spacecraft left the communications range), mission control uplinked commands to the spacecraft for a first orbit correction, which was to be initiated at 18:08:40 Moscow Time, during the fifth orbit. The ship's engine was programmed to deliver 8.4 meters per second in velocity change and apparently lowered its orbit. The vehicle was still guaranteed to remain in orbit for at least 49 revolutions.

Based on measurements from the Soviet ground stations throughout the day, Soyuz-2 had the following orbital parameters, which were crucial for the upcoming intercept:

(774)

The Soviet calculation centers, located at NII-4 military institute in Bolshevo, the Applied Mathematics Institute in Moscow and the TsKBEM design bureau in Podlipki, worked feverishly to determine the exact launch time for the second spacecraft, because the launch personnel in Tyuratam needed this information at least two hours before the actual liftoff of Vehicle No. 10.

The crucial communications session with Vehicle No. 11 came during its 13th orbit, at five in the morning Moscow Time on October 26. During a 10-minute communication window, mission control was able to confirm that the orbiting spacecraft was in good shape and ready for a rendezvous. By 09:00 Moscow Time, ballistic centers sent telegrams to Tyuratam with the required launch time for Vehicle No. 10: 11:34:18.1 Moscow Time (instead preliminary calculated time of 11:35 774). The launch personnel had a launch "window" which should not exceed one second, in order for the newly launched interceptor vehicle to end up no farther than 20 kilometers from its target and to initiate an immediate short-range rendezvous process.

In case the liftoff would take place beyond the super-tight launch window, a NIP-3 ground station, located downrange from Tyuratam in Sary Shagan was instructed to be on stand-by to send a command to the ship to cancel the short-range rendezvous mode. Instead, mission control would have to quickly access the resulting orbital parameters to have a chance to command a long-range rendezvous sequence via NIP-15 ground station in Ussuriisk in the Soviet Far East, before the ships disappeared beyond the horizon over the Pacific.

Specialists in Tyuratam planned to relay the exact liftoff time for Vehicle No. 10 with an accuracy of one 10th of a second to the main control center at the NIP-16 ground station in Yevpatoria, Crimea, no later than three minutes after the actual event.

In any case, personnel of the Soviet ground control network spread across multiple time zones and communications services that supported them had to work in a perfectly choreographed fashion, while top flight control officials in Crimea had only minutes, if not seconds, to relay crucial decisions to ground stations. (466)

While Vehicle No. 11 conducted a solo flight on October 25, the Soviet authorities made no announcement of the mission, even though there was apparently a debate as late as October 23, whether to give the spacecraft a Kosmos name, as had been the practice with previous Soyuz test flights. (774) However, because the second launch of the piloted Soyuz was considered imminent, the Soviet officials simply decided to wait for 24 hours and simultaneously disclose the launch of both spacecraft as Soyuz-2 and -3. (50)

Next chapter: Soyuz-3 lifts off

The article and illustrations by Anatoly Zak; Last update: October 31, 2018

Page editor: Alain Chabot; Last edit: October 28, 2018

All rights reserved

A Soyuz 7K-OK spacecraft rolls out to the launch pad.

Liftoff of the Soyuz 7K-OK spacecraft.