Flight scenario for Soyuz-2 and -3 (original) (raw)

Flight scenario for Soyuz-2 and -3

The planned Soyuz-3 mission got a very ambitious "front-loaded" flight scenario, involving a fast-track rendezvous and docking with a target spacecraft immediately after launch on the night side of the Earth and out of range of ground control stations. After completion of the main task, both ships would remain in orbit for 3-4 days for a series of tests.

Previous chapter: Preparations for the Soyuz-2 and -3 mission

Georgy Beregovoi was expected to dock with Soyuz-2 in the darkness of night relying on navigation lights. He would then change the orientation of the joint stack, all under manual control.

The Soyuz dual mission was scheduled to begin with the launch of the 6,550-kilogram Vehicle No. 11 at 12:00 Moscow Time. Following its orbital insertion and reappearance over the Soviet ground stations, the spacecraft would be commanded to conduct its first orbit correction using infra-red, IKV, and ion-sensors, IO, attitude control systems during the fifth orbit of the mission. The maneuver was expected to deliver 0.6 meters in velocity change (delta V).

At the end of the ship's first day in orbit, a second orbit correction was planned during Orbit 14 using IO sensors for attitude control. That maneuver, delivering 10 meters per second in delta V, would put the "passive" ship into an ideal position for a rendezvous with the intercepting "active" Vehicle No. 10.

The 6,575-kilogram active ship, (Vehicle No. 10) piloted by Georgy Beregovoi and carrying a slightly larger propellant cache, would be launched and conduct automated rendezvous during the 17th and 18th orbit for the first ("passive") spacecraft. For Vehicle No. 10 it would be its first orbit.

At a distance of 200 meters between the two spacecraft, the pilot of the active ship was to turn off the Igla rendezvous system and initiate manual rendezvous and berthing on the night side of the Earth. The "passive" segment of the Igla system would continue to function pointing the docking port of the automated spacecraft toward the approaching "active" spacecraft. By the time they would reach the range of the western-most Soviet ground station, the docking was expected to be completed. (774)

According to Boris Chertok, the docking during the first orbit was intended to demonstrate the capability to destroy enemy satellites.

However, the most critical operations of manual rendezvous and berthing would be conducted on the night side of the Earth and beyond the range of ground control stations. That fact was pointed out by a ballistic expert Zoya Degtyarenko during one of the meetings, where the flight program was being discussed. Mishin's deputy Konstantin Bushuev questioned the wisdom of that timeline, proposing to shift the launch time to ensure docking in daylight.

However, the flight planners explained to Bushuev that the launch time was chosen to guarantee a daytime touchdown of the spacecraft during the short fall days in primary landing zones. Feoktistov chimed in, saying that docking in darkness using navigation lights could be even easier than in daylight, when sun could blind the cosmonaut's optical periscope, VSK, used as the sole navigation tool for manual alignment of the active spacecraft with its target. (466)

Second docking

Right after docking, during the 18th orbit (for the first ship), the pilot was scheduled to conduct an attitude control maneuver of the joint spacecraft and during the 20th orbit, the stack was supposed to enter spin stabilization, slowly rotating around a common center.

After a nearly day-long joint flight, the undocking of the two spacecraft was scheduled during the 33rd orbit. Upon reaching a separation distance of between 70 and 90 meters, the pilot of the active ship would initiate his second manual rendezvous exercise during the 34th orbit, followed by another manual docking attempt. This time, the ships were expected to remain docked for about an hour and separate for the last time during the 35th orbit.

During the 36th and 37th orbit, the "passive" vehicle would be commanded by mission control into a spin stabilization mode, while, the "active" ship would do the same under manual control of the pilot.

Preparations for landing would begin for the "passive" spacecraft during its 47th orbit (after nearly three days in orbit), placing it in the correct attitude with IKV and IO sensors. The descent mode would be activated during the 48th orbit, culminating with the braking engine firing near the Equator.

In the meantime, the active vehicle would remain in orbit for two more days, conducting a manual attitude control exercise during the 51st orbit of the dual mission, followed with the IKV/IO orientation and the main engine firing during the 52nd orbit. The ship would then enter spin stabilization under manual commands, which would continue until the 66th and 67th orbit. At that point, the pilot would conduct another engine firing, testing the AO orientation mode, followed by another prolonged passive flight in spin stabilization mode under the pilot's control.

After four days in orbit, the return operations would begin during the 80th orbit with a manual orientation, followed by a switch to the IKV/IO orientation mode and the initiation of the descent sequence. (774)

Planned orbital parameters of the dual mission:

Orbital insertion timeline for Soyuz-3 and Soyuz-2 missions:

Next chapter: Soyuz-2 lifts off

The article and illustrations by Anatoly Zak; Last update:October 28, 2018

Page editor: Alain Chabot; Last edit: October 26, 2018

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